Radiologists
27 years of experience
Video profile
Accepting new patients
Center City East
132 S 10th St
Philadelphia, PA 19107
215-955-2714
Locations and availability (3)

Education ?

Medical School Score Rankings
Columbia University (1983)
  • Currently 4 of 4 apples
Top 25%

Awards & Distinctions ?

Awards  
Castle Connolly's Top Doctors™ (2012 - 2013)
Appointments
Thomas Jefferson University Jefferson Medical College
Associations
American Board of Radiology

Affiliations ?

Dr. Friedman is affiliated with 4 hospitals.

Hospital Affilations

Score

Rankings

  • Thomas Jefferson University Hospital *
    111 S 11th St, Philadelphia, PA 19107
    • Currently 4 of 4 crosses
    Top 25%
  • Methodist Hospital
    2301 S Broad St, Philadelphia, PA 19148
    • Currently 3 of 4 crosses
    Top 50%
  • Long Island College Hospital
  • Methodist Hospital Division of Thomas Jefferson University Hospital
  • * This information was reported to Vitals by the doctor or doctor's office.

    Publications & Research

    Dr. Friedman has contributed to 94 publications.
    Title Experience of an Academic Neuroradiology Division Participating in a Utilization Management Program.
    Date June 2009
    Journal Journal of the American College of Radiology : Jacr
    Excerpt

    There has been a steady increase in the utilization of expensive outpatient imaging studies, with a resultant increase in health care costs. To reduce unnecessary and inappropriate studies, the authors' department has participated in a utilization management (UM) program; in this article, the authors report the experience of the division of neuroradiology.

    Title Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy for the Treatment of Nonacoustic Cranial Nerve Schwannomas.
    Date January 2009
    Journal Neurosurgery
    Excerpt

    To review outcomes after fractionated stereotactic radiotherapy (FSR) and stereotactic radiosurgery (SRS) for nonacoustic cranial nerve schwannomas.

    Title Norepinephrinergic Afferents and Cytology of the Macaque Monkey Midline, Mediodorsal, and Intralaminar Thalamic Nuclei.
    Date November 2008
    Journal Brain Structure & Function
    Excerpt

    The midline and intralaminar thalamic nuclei (MITN), locus coeruleus (LC) and cingulate cortex contain nociceptive neurons. The MITN that project to cingulate cortex have a prominent innervation by norepinephrinergic axons primarily originating from the LC. The hypothesis explored in this study is that MITN neurons that project to cingulate cortex receive a disproportionately high LC input that may modulate nociceptive afferent flow into the forebrain. Ten cynomolgus monkeys were evaluated for dopamine-beta hydroxylase (DBH) immunohistochemistry, and nuclei with moderate or high DBH activity were analyzed for intermediate neurofilament proteins, calbindin (CB), and calretinin (CR). Sections of all but DBH were thionin counterstained to assure precise localization in the mediodorsal and MITN, and cytoarchitecture was analyzed with neuron-specific nuclear binding protein. Moderate-high levels of DBH-immunoreactive (ir) axons were generally associated with high densities of CB-ir and CR-ir neurons and low levels of neurofilament proteins. The paraventricular, superior centrolateral, limitans and central nuclei had relatively high and evenly distributed DBH, the magnocellular mediodorsal and paracentral nuclei had moderate DBH-ir, and other nuclei had an even and low level of activity. Some nuclei also have heterogeneities in DBH-ir that raised questions of functional segregation. The anterior multiformis part of the mediodorsal nucleus but not middle and caudal levels had high DBH activity. The posterior parafascicular nucleus (Pf) was heterogeneous with the lateral part having little DBH activity, while its medial division had most DBH-ir axons and its multiformis part had only a small number. These findings suggest that the LC may regulate nociceptive processing in the thalamus. The well established role of cingulate cortex in premotor functions and the projections of Pf and other MITN to the limbic striatum suggests a specific role in mediating motor outflow for the LC-innervated nuclei of the MITN.

    Title The Effects of Ethanol Consumption on Vasculogenesis Potential in Nonhuman Primates.
    Date February 2008
    Journal Alcoholism, Clinical and Experimental Research
    Excerpt

    BACKGROUND: Vasculogenesis is essential to the preservation and repair of damaged or diseased vessels. Alcohol is the most commonly abused drug among young adults, but its effects on vessel growth and repair are unknown. The basis of vascular repair is endothelial progenitor cell (EPC) recruitment to assist in the formation of new vascular network (vasculogenesis). Therefore, the objective of this study was to measure the effects of ethanol consumption on the production, mobilization and vasculogenesis potential EPCs in nonhuman primates. METHODS: Four to five year-old (young adult) male rhesus monkeys consumed monkey chow and water (Control, n = 7), or chow and water + ethanol (Alcohol, 2.45 g/d, n = 7) for 12 months. Peripheral blood (PB) and bone marrow (BM) samples were collected for fluorescence-activated cell-sorting analysis of cell surface antigens (CD45, CD31, CD44, CD133, VEGF-R2 - or KDR); and for capillary formation on Matrigel-coated plates. RESULTS: There were greater numbers of nonhematopoeitic stromal cells (CD45-) and putative mesenchymal progenitor cells (CD45-/CD44+) in the PB and BM of Alcohol versus Control monkeys (p < 0.05). Additionally, there were greater numbers of EPCs (CD45-/CD133+/KDR+) in the BM and PB of Alcohol versus Control monkeys (p < 0.05). However, the EPCs of Alcohol monkeys were less likely to form capillaries on matrigel-coated plates than Control monkeys (p < 0.05). CONCLUSIONS: Ethanol consumption in monkeys markedly increased the production and mobilization of EPCs, but decreased their ability to form capillaries. The pathophysiologic consequences of such effects are unclear, but may represent an ethanol-induced chronic stress on the BM, resulting in EPC.

    Title Long-term Ethanol Self-administration by the Nonhuman Primate, Macaca Fascicularis, Decreases the Benzodiazepine Sensitivity of Amygdala Gaba(a) Receptors.
    Date August 2007
    Journal Alcoholism, Clinical and Experimental Research
    Excerpt

    BACKGROUND: Rodent models of chronic alcohol exposure are typically constrained to relatively short periods of forced ethanol due to the lifespan of these animals. Nonhuman primate models, particularly those employing long-term self-administration, are conceptually more similar to human alcoholic individuals. METHODS: We performed whole-cell patch clamp recordings on acutely dissociated amygdala neurons isolated from cynomolgus macaque coronal temporal lobe slices. Slices were prepared from control monkeys or monkeys allowed to self-administer oral ethanol for 18 months. Flunitrazepam and acute ethanol modulation of currents gated by exogenous gamma-aminobutyric acid (GABA) application was assessed in these isolated neurons. Complementary experiments were performed on amygdala total RNA using quantitative real-time reverse transcription/polymerase chain reaction to understand potential ethanol-dependent adaptations to subunit composition. RESULTS: Gamma-aminobutyric acid-gated currents from ethanol-exposed macaque amygdala neurons exhibited reduced modulation by flunitrazepam compared with control neurons. However, this was specific for benzodiazepines as the modest inhibition of GABA-gated currents by acute ethanol was not affected by the chronic ethanol consumption. We also measured mRNA expression levels for the beta, gamma, and delta subunits in total amygdala RNA isolated from control and ethanol-drinking animals. beta1 and gamma2 expression was significantly reduced in samples from ethanol-exposed amygdala. CONCLUSIONS: Our findings demonstrate that chronic ethanol self-administration reduces the benzodiazepine sensitivity of amygdala GABA(A) receptors. This reduced sensitivity may be the result of decreased expression of an amygdala gamma subunit. These findings suggest that, while rodent and nonhuman primate models of chronic ethanol exposure share many characteristics, the specific molecular adaptations associated with the amygdala GABAergic system may not be identical.

    Title Quantification of Carotid Stenosis on Ct Angiography--does Gender Matter?
    Date November 2006
    Journal Ajnr. American Journal of Neuroradiology
    Title Mr Imaging of Bk Virus Encephalitis.
    Date October 2006
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BK virus infection is most often associated with urologic disease in patients who have undergone renal or bone marrow transplantation. We report a rare case of biopsy-confirmed BK virus encephalitis in an immunocompromised patient with hemorrhagic cystitis, in whom dramatic imaging findings were present despite relatively mild clinical symptoms. MR imaging demonstrated widespread increased signal intensity on T2- and fluid-attenuated inversion recovery-weighted images, with restricted diffusion, in the cerebellum, cerebral white matter, and deep gray matter structures. The simultaneous presence of urologic abnormalities and neurologic deficits in certain immunocompromised patients should prompt consideration of BK virus encephalitis.

    Title The Native T-type Calcium Current in Relay Neurons of the Primate Thalamus.
    Date September 2006
    Journal Neuroscience
    Excerpt

    The generation of thalamic bursts depends upon calcium currents that flow through transiently open (T)-type calcium channels. In this study, we characterized the native T-type calcium current underlying thalamic burst responses in the macaque monkey. Current clamp recordings from lateral geniculate nucleus (LGN) slices showed characteristic burst responses when relay cells were depolarized from relatively hyperpolarized membrane potentials. These bursts could also be elicited by stimulation of excitatory synaptic inputs to LGN cells. Under voltage clamp conditions, the inactivation kinetics of native currents recorded from primate LGN neurons showed consistency with T-type currents recorded in other mammals and in expression systems. Real-time reverse transcriptase PCR performed on RNA isolated from the LGN (including tissues isolated from magnocellular and parvocellular laminae) detected voltage-dependent calcium channel (Ca(v)) 3.1, Ca(v) 3.2, and Ca(v) 3.3 channel transcripts. Ca(v) 3.1 occurred at relatively higher expression than other isoforms, consistent with in situ hybridization studies in rats, indicating that the molecular basis for burst firing in thalamocortical systems is an important conserved property of primate physiology. Since thalamic bursts have been observed during visual processing as well as in a number of CNS disorders, studies of the expression and modulation of these currents at multiple levels are critical for understanding their role in vision and for the discovery of new treatments for disruptions of thalamic rhythms.

    Title Chronic Ethanol Drinking Reduces Native T-type Calcium Current in the Thalamus of Nonhuman Primates.
    Date September 2006
    Journal Brain Research
    Excerpt

    BACKGROUND: Chronic ethanol use is known to disrupt normal sleep rhythms, but the cellular basis for this disruption is unknown. An important contributor to normal sleep patterns is a low-threshold calcium current mediated by T-type calcium channels. The T-type calcium current underlies burst responses in thalamic nuclei that are important to spindle propagation, and we recently observed that this current is sensitive to acute low doses of ethanol. METHODS: We used a combination of current clamp and voltage clamp recordings in an in vitro brain slice preparation of the dorsal lateral geniculate nucleus (LGN) of macaque monkeys that have chronically self-administered ethanol to determine whether chronic ethanol exposure may affect T-type currents. RESULTS: Current clamp recordings from the LGN of ethanol naive macaques showed characteristic burst responses. However, recordings from the LGN in macaques that self-administered ethanol revealed a significant attenuation of bursts across a range of voltages (n=5). Voltage clamp recordings from control LGN neurons (n=16) and neurons (n=29) from brain slices from chronically drinking macaques showed no significant differences (P>0.05) in T-type current kinetics or in the membrane resistance of the thalamic cells between the two cohorts. However, mean T-type current amplitude measured in the chronically drinking animals was reduced by 31% (P<0.01). CONCLUSIONS: We conclude that chronic ethanol self-administration reduces calcium currents in thalamic relay cells without altering underlying current kinetics, which may provide a mechanistic framework for the well-documented disruptions in sleep/wake behavior in subjects with chronic ethanol exposure.

    Title Behavioral Depression and Positron Emission Tomography-determined Serotonin 1a Receptor Binding Potential in Cynomolgus Monkeys.
    Date May 2006
    Journal Archives of General Psychiatry
    Excerpt

    CONTEXT: Current animal models of depression are inadequate to further our understanding of depression. New models that allow for analysis of cognitive function and sex differences are needed. OBJECTIVE: To characterize serotonin 1A (5-HT(1A)) receptor binding potential (BP) and its relationship with specific characteristics of behavioral depression in cynomolgus monkeys. DESIGN: A 23-month case-control study. SETTING: Small social groups in the laboratory.Subjects Seventeen adult female cynomolgus monkeys. MAIN OUTCOME MEASURES: Serotonin 1A receptor BP was examined by positron emission tomography using the radioligand 4,2"-(methoxyphenyl)-1-[2"-(N-2"-pyridinyl)-p-fluorobenzamido]ethylpiperazine in the raphe, amygdala, hippocampus, and anterior cingulate cortex in monkeys characterized by behavioral observation as depressed or not depressed. Aggression, submission, affiliation, pathologic behaviors, and activity levels were determined by behavioral observation. Heart rate and hypothalamic-pituitary-adrenal function were also determined. RESULTS: Throughout the brain areas examined, there was a reduction in 5-HT(1A) BP in depressed monkeys. The 5-HT(1A) BP in the amygdala and hippocampus was associated with aggression and submission. Friendly interaction, grooming, and locomotion were associated with 5-HT(1A) BP in the left cingulate cortex, whereas attention directed toward the environment was associated with 5-HT(1A) BP in the right cingulate cortex. The 5-HT(1A) receptor BP was inversely associated with heart rate in the raphe, left cingulate, and right amygdala. CONCLUSIONS: This is the fourth in a series of studies that suggest that depressive behavior in adult female cynomolgus monkeys is similar to that observed in humans. It has been observed in 2 large groups of monkeys randomly selected from feral populations, suggesting that the capacity for depression is inherent in the species. This animal model holds promise to further our understanding of the basic mechanisms of affective behavior, the neuropathophysiologic characteristics of depression and the cognitive dysfunction that accompanies them, genetic and environmental factors that may affect depression risk, and the role of reproductive function in the excess depression risk in women.

    Title Incidence of Vertebral Artery Thrombosis in Cervical Spine Trauma: Correlation with Severity of Spinal Cord Injury.
    Date February 2006
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BACKGROUND AND PURPOSE: The incidence of blunt traumatic vertebral artery dissection/thrombosis varies widely in published trauma series and is associated with spinal trauma. The purpose of this study was to determine the frequency of traumatic vertebral artery thrombosis (VAT) in cervically injured patients by using routine MR angiography (MRA) and MR imaging and identify associations with the severity of neurologic injury. METHODS: A retrospective review of 1283 patients with nonpenetrating cervical spine fractures with or without an associated spinal cord injury (SCI) was performed. Imaging consisted of routine cervical MR imaging and 2D time-of-flight MRA of the neck. The cervical injury level, neurologic level of injury, and American Spinal Injury Association (ASIA) grade were recorded. RESULTS: In this study, 632 patients met the inclusion criteria, 83 (13%) of whom had VAT on the admission MR imaging/MRA. Fifty-nine percent (49/83) of VAT patients had an associated SCI. VAT was significantly more common in motor-complete patients (ASIA A and B, 20%) than in neurologically intact (ASIA E, 11%) cervical spine-injured patients (P = .019). VAT incidence was not significantly different between motor-incomplete (ASIA C and D, 10%) and neurologically intact (ASIA E, 11%) cervical spine-injured patients (P = .840). CONCLUSION: The absence of neurologic symptoms in a patient with cervical spine fracture does not preclude VAT. VAT associated with cervical spinal injury occurs with similar frequency in both neurologically intact (ASIA E) and motor-incomplete patients (ASIA C and D) but is significantly more common in motor-complete SCI (ASIA A and B).

    Title Social Stress-associated Depression in Adult Female Cynomolgus Monkeys (macaca Fascicularis).
    Date August 2005
    Journal Biological Psychology
    Excerpt

    This paper describes a behavior pattern in adult female cynomolgus monkeys that has several behavioral and physiological characteristics in common with human depression including reduced body fat, low levels of activity, high heart rate, hypothalamic-pituitary-adrenal (HPA) axis disturbances, and increased mortality. Under certain circumstances, this depressive behavior appears more common in socially stressed subordinate, than dominant, females. This is the first animal model of social stress-related depression in females and the first primate model of adult depression. It is important to have a female animal model of depression because women are more likely to experience a clinically significant depression than men, and depression in women is often associated with changes in reproductive system function. This model is particularly useful because these monkeys have menstrual cycles that are similar to those of women, and those that exhibit depressive behavior have relatively low levels of ovarian steroids. These monkeys may be a useful model of reproductive system-associated mood disorders in females.

    Title Neuroimaging of Rodent and Primate Models of Alcoholism: Initial Reports from the Integrative Neuroscience Initiative on Alcoholism.
    Date July 2005
    Journal Alcoholism, Clinical and Experimental Research
    Excerpt

    Neuroimaging of animal models of alcoholism offers a unique path for translational research to the human condition. Animal models permit manipulation of variables that are uncontrollable in clinical, human investigation. This symposium, which took place at the annual meeting of the Research Society on Alcoholism in Vancouver, British Columbia, Canada, on June 29th, 2004, presented initial findings based on neuroimaging studies from the two centers of the Integrative Neuroscience Initiative on Alcoholism funded by the National Institute on Alcohol Abuse and Alcoholism. Effects of alcohol exposure were assessed with in vitro glucose metabolic imaging of rat brain, in vitro receptor imaging of monkey brain, in vivo magnetic resonance imaging of monkey brain, and in vivo magnetic resonance spectroscopic quantification of alcohol metabolism kinetics in rat brain.

    Title Isolated Cortical Venous Thrombosis Presenting As Subarachnoid Hemorrhage: a Report of Three Cases.
    Date February 2005
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    Cortical venous thrombosis (CVT) without concomitant dural sinus thrombosis is an uncommon disorder. Isolated CVT usually manifests on imaging studies as focal parenchymal hemorrhage or edema. We report three cases of isolated CVT that presented with unilateral, localized subarachnoid hemorrhage without parenchymal involvement.

    Title Long-term Ethanol Self-administration by Cynomolgus Macaques Alters the Pharmacology and Expression of Gabaa Receptors in Basolateral Amygdala.
    Date January 2005
    Journal The Journal of Pharmacology and Experimental Therapeutics
    Excerpt

    We have recently demonstrated that chronic ethanol ingestion alters the functional and pharmacological properties of GABAA receptors measured in acutely isolated rat lateral/basolateral amygdala neurons, a limbic forebrain region involved with fear-learning and innate anxiety. To understand relevance of these results in the context of primates, we have examined the effects of long-term ethanol self-administration on basolateral amygdala GABAA receptor pharmacology and expression in cynomolgus macaques (Macaca fascicularis). The impact of this 18-month-long exposure on GABAA receptor function was assessed in acutely isolated neurons from basolateral amygdala with whole-cell patch-clamp electrophysiology. Neurons from control animals expressed maximal current densities that were not significantly different from the maximal current densities of neurons from ethanol-treated animals. However, the GABA concentration-response relationships from ethanol-exposed neurons were significantly right-shifted compared with control neurons. These adaptations were associated with significant alterations in some characteristics of macroscopic current desensitization. To understand the mechanism governing these adaptations, we quantified GABAA alpha subunit mRNAs in basolateral amygdala from the same animals. mRNA levels of the alpha2 and alpha3 subunits were significantly decreased, whereas decreases in alpha1 expression only approached statistical significance. There were no changes in alpha4 mRNA levels. These findings indicate that ethanol-induced alterations in GABAA function may be regulated in part by selective changes in the expression of particular alpha subunits. We conclude that adaptations of basolateral amygdala GABAA receptors after long-term ethanol self-administration by the cynomolgus macaque are similar, but not identical, to those described in rodents after a brief forced ethanol exposure.

    Title Ethanol Modulation of Excitatory and Inhibitory Synaptic Transmission in Rat and Monkey Dentate Granule Neurons.
    Date June 2004
    Journal Alcoholism, Clinical and Experimental Research
    Excerpt

    BACKGROUND: The physiological mechanisms underlying the behavioral and cognitive effects of ethanol are not fully understood. However, there is now compelling evidence that ethanol acts, at least in part, by modulating the function of a small group of proteins that mediate excitatory and inhibitory synaptic transmission. For example, intoxicating concentrations of ethanol have been shown to enhance GABAergic synaptic inhibition and depress glutamatergic excitatory neurotransmission in a number of brain regions. Because all of these electrophysiological studies have been performed in rodent brain slice or neuronal culture preparations, direct evidence that ethanol exerts similar effects on synaptic transmission in the primate central nervous system is lacking. METHODS: We have therefore developed methods to perform patch-clamp electrophysiological recordings from neurons in acutely prepared monkey (Macaca fascicularis) hippocampal slices. We have used these methods to compare the acute effects of ethanol on excitatory and inhibitory synaptic transmission in rat and monkey dentate granule neurons. RESULTS: Under our recording conditions, ethanol significantly potentiated gamma-aminobutyric acid type A inhibitory postsynaptic currents in both rat and monkey neurons. In addition, ethanol significantly inhibited NMDA, but not AMPA, excitatory postsynaptic currents in dentate granule neurons from both species. Notably, no significant differences were observed in any of the pharmacological properties of inhibitory or excitatory synaptic responses recorded from rat and monkey neurons. CONCLUSIONS: These data suggest that the differences in the behavioral effects of ethanol that have been observed between rats and higher-order mammals, such as monkeys and humans, may not reflect differences in the sensitivity of some of the major synaptic sites of ethanol action. Moreover, our results provide empirical evidence for the use of rodent brain slice preparations in elucidating synaptic mechanisms of ethanol action in the primate central nervous system.

    Title Endovascular Interventional Neuroradiologic Procedures: Who is Performing Them, How Often, and Where? A Survey of Academic and Nonacademic Radiology Practices.
    Date January 2004
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BACKGROUND AND PURPOSE: In this report, the authors assess practice patterns at both academic and nonacademic centers regarding the treatment of aneurysms with Guglielmi detachable coils (GDCs), thrombolysis of the carotid-vertebral arteries, and stent placement with angioplasty of the carotid arteries. METHODS: A neurovascular radiology survey was sent to 102 directors of neuroradiology fellowship programs in the United States and Canada ("academic centers"). The survey was also sent to senior members of the American Society of Neuroradiology (three per state) who were not affiliated with fellowship programs ("nonacademic centers"). RESULTS: Fifty-seven surveys from academic practices and 70 surveys from nonacademic practices were returned. A total of 4361 procedures (2283 GDC; 949 thrombolysis; 1129 stent placement) were performed; 84% were performed at academic centers and 16% at nonacademic centers. Ninety percent of GDC, 71% of thrombolysis, and 82% of stent placement procedures were performed at academic centers. Seven academic and three nonacademic centers performed 48% of all GDC procedures; eight academic and four nonacademic centers performed 45% of all thrombolysis procedures; eight academic centers performed 50% of all stent placement procedures. A total of 544/4361 (12%) procedures were performed by nonradiologists. At academic centers, 14% of procedures were performed by nonradiologists; participation by nonradiologists was greatest for carotid stent placement (24% of procedures). At nonacademic centers, only 5% of procedures were performed by nonradiologists. CONCLUSION: According to this survey, most endovascular interventional neuroradiologic procedures are performed at academic centers; given the survey population, this study likely identifies the lower limit of participation by nonradiologists (12%). Performance of these procedures is concentrated in relatively few centers, and these data raise questions about the overall use of intraarterial thrombolytic therapy for acute infarction.

    Title Chronic Ethanol Exposure Alters Presynaptic Dopamine Function in the Striatum of Monkeys: a Preliminary Study.
    Date January 2004
    Journal Synapse (new York, N.y.)
    Title How Often Do Neuroradiologists Perform Sonography of the Carotid Arteries? A Survey of Academic and Nonacademic Radiology Practices, with Implications for Fellowship Training.
    Date October 2003
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BACKGROUND AND PURPOSE: Debate in the neuroradiology community surrounds the amount of formal training in sonography of the carotid arteries that should be provided to fellows. This study was designed to assess current practice patterns at both academic and nonacademic practices regarding the performance of carotid sonography. METHODS: A neurovascular radiology survey was sent to all 102 program directors of neuroradiology fellowships in the United States and Canada (academic practices). The survey was also sent to 146 randomly selected senior members of the ASNR (three per state, except one each for Alaska and Vermont) who were not affiliated with fellowship programs (nonacademic practices). RESULTS: Fifty-seven surveys from academic practices and 70 surveys from nonacademic practices were returned. Radiologists at academic practices performed approximately 42% of studies (general radiologists or sonography specialists, 36%; neuroradiologists, 5%; cardiovascular radiologists, 1%). Nonradiologists performed approximately 58% of studies (vascular surgeons, 47%; neurologists, 10%; cardiologists, 1%; neurosurgeons, <1%). Neuroradiologists performed carotid sonography at 11% (6/57) of academic practices. On average, radiologists at nonacademic practices performed approximately 62% of studies (general radiologists or sonography specialists, 38%; neuroradiologists, 15%; cardiovascular radiologists, 9%). Nonradiologists performed approximately 38% of studies (vascular surgeons, 25%; neurologists, 6%; cardiologists or internists, 6%). Neuroradiologists performed carotid sonography at 53% (37/70) of nonacademic practices. CONCLUSION: At most academic practices, neuroradiologists do not perform sonography of the carotid arteries. This may explain the reluctance of some fellowships to provide formal training in this technique. In contrast, although neuroradiologists perform carotid sonography at a majority of the nonacademic practices, the percentage of studies that they perform is small; moreover, neuroradiologists perform far fewer studies than do general radiologists or sonography specialists.

    Title Comparison of Hippocampal, Amygdala, and Perirhinal Projections to the Nucleus Accumbens: Combined Anterograde and Retrograde Tracing Study in the Macaque Brain.
    Date October 2002
    Journal The Journal of Comparative Neurology
    Excerpt

    A combination of anterograde and retrograde tracing techniques was used to study the projections to the nucleus accumbens from the amygdala, the hippocampal formation (including the entorhinal cortex), and the perirhinal cortex in two species of macaque monkey. To help identify possible subregions within the nucleus accumbens, the distribution of calbindin was examined in two additional monkeys. Although this revealed evidence of "core"- and "shell"-like regions within the accumbens, these different regions could not consistently be related to cytoarchitectonic features. The rostral amygdala sent nearly equivalent projections to both the medial and the lateral portions of nucleus accumbens, whereas projections arising from the middle and caudal amygdala terminated preferentially in the medial division of nucleus accumbens. The basal nucleus was the major source of these amygdala efferents, and there was a crude topography as parts of the basal and accessory basal nuclei terminated in different parts of nucleus accumbens. The subiculum was the major source of hippocampal projections to the nucleus accumbens, but some hippocampal efferents also originated in the parasubiculum, the prosubiculum, the adjacent portion of CA1, and the uncal portion of CA3. These hippocampal projections, which coursed through the fornix, showed a rostrocaudal gradient as more arose in the rostral hippocampus. Hippocampal efferents terminated most densely in the medial and ventral portions of nucleus accumbens, along with light label in the adjacent olfactory tubercle. The entorhinal projections were more evenly distributed between the medial nucleus accumbens and the olfactory tubercle, whereas the perirhinal projections were primarily to the olfactory tubercle. These cortical inputs were less reliant on the fornix. Amygdala and subicular (hippocampal) projections overlapped most completely in the medial division of nucleus accumbens.

    Title Metabolic Mapping of the Effects of Cocaine During the Initial Phases of Self-administration in the Nonhuman Primate.
    Date September 2002
    Journal The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
    Excerpt

    Because most human studies of the neurobiological substrates of the effects of cocaine have been performed with drug-dependent subjects, little information is available about the effects of cocaine in the initial phases of drug use before neuroadaptations to chronic exposure have developed. The purpose of the present study, therefore, was to define the substrates that mediate the initial effects of cocaine in a nonhuman primate model of cocaine self-administration using the 2-[14C]deoxyglucose method. Rhesus monkeys were trained to self-administer 0.03 mg/kg per injection (N = 4) or 0.3 mg/kg per injection (N = 4) cocaine and compared with monkeys trained to respond under an identical schedule of food reinforcement (N = 4). Monkeys received 30 reinforcers per session, and metabolic mapping was conducted at the end of the fifth self-administration session. Cocaine self-administration reduced glucose utilization in the mesolimbic system, including the ventral tegmental area, ventral striatum, and medial prefrontal cortex. In addition, metabolic activity was increased in the dorsolateral and dorsomedial prefrontal cortex, as well as in the mediodorsal nucleus of the thalamus. These latter effects are distinctly different from those seen after the noncontingent administration of cocaine, suggesting that self-administration engages circuits beyond those engaged merely by the pharmacological actions of cocaine. The involvement of cortical areas subserving working memory suggests that strong associations between cocaine and the internal and external environment are formed from the very outset of cocaine self-administration. The assessment of the effects of cocaine at a time not readily evaluated in humans provides a baseline from which the effects of chronic cocaine exposure can be investigated.

    Title Effects of Cocaine Self-administration on Striatal Dopamine Systems in Rhesus Monkeys: Initial and Chronic Exposure.
    Date August 2002
    Journal Neuropsychopharmacology : Official Publication of the American College of Neuropsychopharmacology
    Excerpt

    The purpose of this study was to examine the time course of changes in dopamine D(1)- and D(2)-like receptor densities in monkeys self-administering cocaine. Experimentally naïve adult male rhesus monkeys (n = 22) were divided into a food reinforcement group (n = 6), in which responding was maintained by food presentation, or into four cocaine self-administration groups (n = 4/group), based on dose (0.03 or 0.3 mg/kg per injection) and duration of exposure (5 or approximately 100 sessions). After the last session, monkeys were euthanized, brains were removed, frozen, and coronal sections through the striatum, rostral to the anterior commissure, were processed for D(1) ([3H]SCH23390) and D(2) ([3H]raclopride) receptor autoradiography. Compared with controls, there was no effect of 5 days of cocaine self-administration on D(1) and D(2) receptors. In monkeys with extensive cocaine histories, D(1) receptor densities were significantly increased relative to controls in some parts of the striatum, while D(2) receptor densities were significantly decreased throughout the striatum. These findings demonstrate that chronic cocaine self-administration produces neuroadaptations in dopamine systems, but that these changes do not occur in a parallel fashion.

    Title Fellowship and Practice Trends in Neuroradiology Training Programs in the United States.
    Date June 2002
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BACKGROUND AND PURPOSE: Neuroradiology has become an increasingly diverse and subspecialized discipline. We evaluated the current status and trends affecting fellowship programs and the practice of clinical neuroradiology at academic medical centers, with emphasis on invasive procedures. METHODS: All 85 program directors at Accreditation Council for Graduate Medical Education-approved fellowships in neuroradiology were sent a detailed questionnaire pertaining to various demographic aspects of their program and the performance of certain radiologic examinations of the brain and spine. RESULTS: Sixty-seven programs (79%) responded. As many as 50% of programs are 1 year in length. Twenty-five percent of 2-year fellows leave their program after 1 year of training. During the past 5 years, 36% of programs have decreased in size and 73% reported a decline in the number of applicants. The majority (55%) of programs have had applicants renege on their commitment to begin a fellowship. Twenty percent of 2-year programs do not offer training in endovascular interventional procedures. Neurosurgeons perform endovascular interventional procedures at 18% of centers. There is an 18-fold variation in the volume of neuroangiographic procedures performed each year and a 150-fold variation in the volume of myelographic procedures performed. In 29% of programs, neuroradiologists are nonparticipants in nonvascular interventional spinal procedures; in 40%, they share these procedures with musculoskeletal radiologists/nonradiologists. CONCLUSION: Interest in fellowship programs in neuroradiology is declining. An applicant's commitment to either begin a fellowship or complete 2 years of training cannot be regarded with assurance, and there is a lack of uniformity in many areas of the training experience, particularly in invasive diagnostic and therapeutic procedures.

    Title Role of Enhanced Mri in the Follow-up of Patients with Medically Refractory Trigeminal Neuralgia Undergoing Stereotactic Radiosurgery Using the Gamma Knife: Initial Experience.
    Date October 2001
    Journal Journal of Computer Assisted Tomography
    Excerpt

    PURPOSE: The purpose of this work was to evaluate the early posttreatment MR findings, and their clinical utility, in patients with trigeminal neuralgia undergoing stereotactic radiosurgery using the gamma knife. METHOD: Twenty-six patients with medically refractory trigeminal neuralgia underwent stereotactic radiosurgery. A single dose of 70-90 Gy was administered to the proximal root entry zone (n = 21) or the retrogasserian portion (n = 5) of the trigeminal nerve. Posttreatment enhanced MRI and clinical assessment were performed at 3-6 months. RESULTS: Five patients did not have radiologic follow-up. There were no changes identified in the treated trigeminal nerve or adjacent brainstem in 19 of 21 patients. Two patients with multiple sclerosis developed abnormal signal and enhancement in the brainstem and/or trigeminal nerve; neither had clinical complications. Onset of therapeutic effect ranged from 3 weeks to 3 months; 19 patients had a beneficial response. CONCLUSION: Results of enhanced MRI 3-6 months after stereotactic radiosurgical treatment of trigeminal neuralgia do not correlate with the clinical response. Because beneficial clinical responses or treatment failures are apparent by 3 months, routine posttreatment MRI in these patients is not warranted.

    Title Mr Imaging Findings After Stereotactic Radiosurgery Using the Gamma Knife.
    Date July 2001
    Journal Ajr. American Journal of Roentgenology
    Title Progression of Changes in Dopamine Transporter Binding Site Density As a Result of Cocaine Self-administration in Rhesus Monkeys.
    Date June 2001
    Journal The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
    Excerpt

    The present study examined the time course of alterations in levels of dopamine transporter (DAT) binding sites that accompany cocaine self-administration using quantitative in vitro receptor autoradiography with [(3)H]WIN 35,428. The density of dopamine transporter binding sites in the striatum of rhesus monkeys with 5 d, 3.3 months, or 1.5 years of cocaine self-administration experience was compared with DAT levels in cocaine-naive control monkeys. Animals in the long-term (1.5 years) exposure group self-administered cocaine at 0.03 mg/kg per injection, whereas the initial (5 d) and chronic (3.3 months) treatment groups were each divided into lower dose (0.03 mg/kg per injection) and higher dose (0.3 mg/kg per injection) groups. Initial cocaine exposure led to moderate decreases in [(3)H]WIN 35,428 binding sites, with significant changes in the dorsolateral caudate (-25%) and central putamen (-19%) at the lower dose. Longer exposure, in contrast, resulted in elevated levels of striatal binding sites. The increases were most pronounced in the ventral striatum at the level of the nucleus accumbens shell. At the lower dose of the chronic phase, for example, significant increases of 21-42% were measured at the caudal level of the ventral caudate, ventral putamen, olfactory tubercle, and accumbens core and shell. Systematic variation of cocaine dose and drug exposure time demonstrated the importance of these factors in determining the intensity of increased DAT levels. With self-administration of higher doses especially, increases were more intense and included dorsal portions of the striatum so that every region at the caudal level exhibited a significant increase in DAT binding sites (20-54%). The similarity of these findings to previous studies in human cocaine addicts strongly suggest that the increased density of dopamine transporters observed in studies of human drug abusers are the result of the neurobiological effects of cocaine, ruling out confounds such as polydrug abuse, preexisting differences in DAT levels, or comorbid psychiatric conditions.

    Title Chronic Cocaine-mediated Changes in Non-human Primate Nucleus Accumbens Gene Expression.
    Date May 2001
    Journal Journal of Neurochemistry
    Excerpt

    Chronic cocaine use elicits changes in the pattern of gene expression within reinforcement-related, dopaminergic regions. cDNA hybridization arrays were used to illuminate cocaine-regulated genes in the nucleus accumbens (NAcc) of non-human primates (Macaca fascicularis; cynomolgus macaque), treated daily with escalating doses of cocaine over one year. Changes seen in mRNA levels by hybridization array analysis were confirmed at the level of protein (via specific immunoblots). Significantly up-regulated genes included: protein kinase A alpha catalytic subunit (PKA(calpha)); cell adhesion tyrosine kinase beta (PYK2); mitogen activated protein kinase kinase 1 (MEK1); and beta-catenin. While some of these changes exist in previously described cocaine-responsive models, others are novel to any model of cocaine use. All of these adaptive responses coexist within a signaling scheme that could account for known inductions of genes(e.g. fos and jun proteins, and cyclic AMP response element binding protein) previously shown to be relevant to cocaine's behavioral actions. The complete data set from this experiment has been posted to the newly created Drug and Alcohol Abuse Array Data Consortium (http://www.arraydata.org) for mining by the general research community.

    Title Stereotactic Radiosurgical Pallidotomy and Thalamotomy with the Gamma Knife: Mr Imaging Findings with Clinical Correlation--preliminary Experience.
    Date July 1999
    Journal Radiology
    Excerpt

    PURPOSE: To evaluate the temporal evolution and appearance of a radiosurgical lesion at magnetic resonance (MR) imaging and the clinical response in patients undergoing stereotactic radiosurgical pallidotomy or thalamotomy with the gamma knife. MATERIALS AND METHODS: Seventeen patients with medically refractory movement disorders underwent stereotactic radiosurgical pallidotomy (n = 2) or thalamotomy (n = 15). A single dose of 120-140 Gy was administered to a target in the globus pallidus interna or ventralis intermedius thalamic nucleus. Postprocedure gadolinium-enhanced MR imaging and clinical assessment were performed at 1 month and 3 months. RESULTS: At 3 months, the radiosurgical lesion most commonly (n = 11) appeared as a ring-enhancing focus 5 mm or less in diameter surrounded by vasogenic edema that extended less than 7 mm in radius beyond the target. Five patients had ring-enhancing lesions 7 mm or more in diameter; four of these developed symptomatic perilesional edema at 3 (n = 2) or 8 (n = 2) months after the procedure. Onset of therapeutic effect began approximately 4 weeks after treatment. In the 15 patients with tremor, there was a mean decline of 2.1 on the Tremor Rating Scale. CONCLUSION: Findings in this pilot study suggest that radiosurgical thalamotomy is a promising treatment for medically refractory tremor. Three-month follow-up MR studies show a ring-enhancing lesion surrounded by a variable amount of vasogenic edema. Visualization of the radiosurgical lesion and the clinical response are delayed compared to that with radio-frequency procedures.

    Title The Relationship Between the Functional Abilities of Patients with Cervical Spinal Cord Injury and the Severity of Damage Revealed by Mr Imaging.
    Date July 1999
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BACKGROUND AND PURPOSE: The appearance of the damaged spinal cord after injury correlates with initial neurologic deficit, as determined by the American Spinal Injury Association grade and manual muscle test score, as well as with recovery, as assessed by manual muscle test scores. The purpose of this study was to determine whether the presence of spinal cord hemorrhage and the size and location of spinal cord edema on MR images is predictive of functional recovery in survivors of cervical spinal cord injury (SCI). METHODS: The degree of damage to the cervical spinal cord was measured on the MR images of 49 patients who underwent imaging within 72 hours of sustaining SCI. The effects of hemorrhage and length/location of edema on changes in the value of the motor scale of the functional independence measure (FIM) were assessed on admission to and discharge from rehabilitation. RESULTS: Patients without spinal cord hemorrhage had significant improvement in self-care and mobility scores compared with patients with hemorrhage. There was no significant effect of spinal cord hemorrhage on changes in locomotion and sphincter control scores. The rostral limit of edema positively correlated with admission and discharge self-care scores and with admission mobility and locomotion scores. Edema length had a negative correlation with all FIM scales at admission and discharge. CONCLUSION: The imaging characteristics of cervical SCI (hemorrhage and edema) are related to levels of physical recovery as determined by the FIM scale. Imaging factors that correlate with poor functional recovery are hemorrhage, long segments of edema, and high cervical locations.

    Title Neuroradiology Case of the Day. Neurosarcoidosis.
    Date January 1999
    Journal Radiographics : a Review Publication of the Radiological Society of North America, Inc
    Title Neuroradiology Case of the Day. Burkitt Lymphoma.
    Date December 1998
    Journal Radiographics : a Review Publication of the Radiological Society of North America, Inc
    Title Effect of Cocaine Self-administration on Dopamine D2 Receptors in Rhesus Monkeys.
    Date October 1998
    Journal Synapse (new York, N.y.)
    Excerpt

    The present study used autoradiography to examine the effects of chronic self-administration of cocaine on the density of dopamine D2 receptors in nonhuman primates. Three rhesus monkeys intravenously self-administered an average of 1.35 mg/kg cocaine per day for 18-22 months until they were euthanized immediately after a self-administration session. Binding site density of the D2 ligand [3H]raclopride (2 nM) was assessed in these monkeys as well as three untreated controls, using quantitative in vitro receptor autoradiography. As compared to untreated controls, D2 binding site density was significantly lower in the animals that self-administered cocaine in all regions of the striatum rostral to the anterior commissure. These regions include the anterior and central regions of the caudate nucleus, putamen, olfactory tubercle, and both the shell and core of the nucleus accumbens. Within the substantia nigra and ventral tegmental area, by contrast, no differences were found in the density of D2 binding sites. These findings suggest a pervasive effect of cocaine on the regulation of D2 receptors in the striatum. The lack of change within the ventral midbrain, however, suggests a differential regulation of D2 receptors in the striatum and ventral midbrain. This study confirms and extends our knowledge of the neurobiological changes in the mesolimbic dopamine system that result from chronic exposure to cocaine.

    Title Neuroradiology Case of the Day. Malignant Optic Glioma of Adulthood.
    Date October 1998
    Journal Radiographics : a Review Publication of the Radiological Society of North America, Inc
    Title Angiotensin-(1-7) Immunoreactivity in the Hypothalamus of the (mren-2d)27 Transgenic Rat.
    Date September 1998
    Journal Brain Research
    Excerpt

    The distribution of angiotensin-(1-7) immunoreactive neurons was compared to those of vasopressin-(VP) and oxytocin-(OT) immunoreactive (IR) neurons in the hypothalamus of adult (mRen-2d)27 transgenic hypertensive and Sprague-Dawley rats. In both strains, angiotensin (Ang)-(1-7)-IR cells were found in the supraoptic nucleus (SON), and in the anterior (ap-), medial (mp-), and lateral (lp-) parvocellular, and posterior magnocellular (pm-) subdivisions of the paraventricular (PVN) nucleus. Three-dimensional reconstructions showed that cells immunoreactive to Ang-(1-7) and VP were specifically co-distributed in the SON and in the pmPVN. Double-labeling neurons for both peptides revealed that both Ang-(1-7) and VP were colocalized in a subpopulation of neurons in the pmPVN and SON. In combination with previous studies, our results suggest that Ang-(1-7) and VP are colocalized, co-released and may have a combined action at a common target. In addition, the introduction of the mouse submandibular renin (mRen-2d) transgene into Sprague-Dawley rats does not appear to have altered the fundamental organization of hypothalamic peptide systems involved in fluid homeostasis.

    Title Neuroradiology Case of the Day. Myxopapillary Ependymoma of the Conus Medullaris or Filum Terminale Resulting in Superficial Siderosis and Dissemination of Tumor Along Csf Pathways.
    Date August 1998
    Journal Radiographics : a Review Publication of the Radiological Society of North America, Inc
    Title Neuroradiology Case of the Day. Vertebral Arteriovenous Fistula (avf).
    Date May 1998
    Journal Radiographics : a Review Publication of the Radiological Society of North America, Inc
    Title Neuroradiology Case of the Day. Unilateral Acute Hemorrhagic Leukoencephalitis (ahl) Complicated by Venous Thrombosis.
    Date March 1998
    Journal Radiographics : a Review Publication of the Radiological Society of North America, Inc
    Title Effect of Cocaine Self-administration on Striatal Dopamine D1 Receptors in Rhesus Monkeys.
    Date January 1998
    Journal Synapse (new York, N.y.)
    Excerpt

    An array of evidence indicates that long-term exposure to cocaine alters several components of the brain dopamine system. Because the release of dopamine in the nucleus accumbens (NAc) has been implicated in mediating the reinforcing effects of cocaine, changes in dopamine function can have profound effects on drug-seeking and drug-taking behavior. The present study examined the effects of the chronic self-administration of cocaine on the D1 family of dopamine receptors in the rhesus monkey. The brains of three rhesus monkeys that had intravenously self-administered an average of 1.35 mg/kg cocaine per day for 18-22 months were compared to the brains of three cocaine-naive controls. The in vitro quantitative autoradiographic technique was used to quantify binding densities of the D1 ligand [3H]SCH-23390 on cryostat-cut sections of fresh frozen tissue. In animals that self-administered cocaine, the density of D1 binding was significantly lower in the regions of the striatum at the level where the nucleus accumbens is most fully developed. The shell of the NAc showed the largest difference with significantly lower D1 binding also detected in adjacent regions of the caudate nucleus and the putamen. No differences were found in the rostral pole of the NAc or the dorsal striatum at that level. These findings suggest that chronic self-administration of cocaine can modulate the density of dopamine D1 receptors in specific portions of the primate striatum. Such changes might underlie some of the behavioral consequences, like drug dependence and craving, of long-term cocaine use.

    Title Enhanced Mr Imaging of Hypertrophic Pachymeningitis.
    Date December 1997
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    OBJECTIVE: This report illustrates the contrast enhancement characteristics on MR imaging of three patients with hypertrophic pachymeningitis and provides an explanation for the observed imaging findings. CONCLUSION: A differential pattern of enhancement, consisting of intense enhancement of the peripheral margin of the abnormal pachymeninges, was present in all cases. In two patients, much of the remaining abnormal pachymeninges did not enhance at all. On the basis of the microscopic pathology of hypertrophic pachymeningitis, the physiology of normal meningeal enhancement on MR imaging, and the described MR appearance of other pachymeningeal lesions, this differential pattern of enhancement should strongly suggest the diagnosis of hypertrophic pachymeningitis.

    Title Mr Imaging of Stereotaxic Pallidotomy and Thalamotomy.
    Date September 1997
    Journal Ajr. American Journal of Roentgenology
    Title Abnormalities of the Deep Medullary White Matter Veins: Mr Imaging Findings.
    Date April 1997
    Journal Ajr. American Journal of Roentgenology
    Title Forecasting Motor Recovery After Cervical Spinal Cord Injury: Value of Mr Imaging.
    Date December 1996
    Journal Radiology
    Excerpt

    PURPOSE: To determine whether magnetic resonance (MR) imaging quantification of cervical spinal cord damage improves the prediction of motor recovery after spinal cord injury. MATERIALS AND METHODS: The extent of cervical spinal cord injury was measured on MR images obtained in 104 patients (aged 17-70 years) within 72 hours of spinal cord injury. The effects of hemorrhage and edema length on motor outcome were examined for at least 12 months. RESULTS: Patients with spinal cord hemorrhage had significantly lower upper and lower extremity motor scores at the time of injury and at 12 months than did patients without hemorrhage (P < .001). There was little recovery of lower extremity function even in patients without hemorrhage. Upper extremity motor function improved significantly in all patients (P < .001); patients without hemorrhage showed the largest improvements. The motor recovery rates for patients without hemorrhage were 0.74 (upper extremities; range, 0-1) and 0.55 (lower extremities; range, 0-1); those for patients with hemorrhage were 0.31 (range, 0-1) and 0.091 (range, 0-1). Stepwise multiple regression analyses indicated that MR information on hemorrhage and the length of edema increases the ability to predict clinical outcome by 16%-33% over that with initial clinical scores alone. CONCLUSION: An initial MR imaging evaluation of the spinal cord after spinal cord injury provides supplemental prognostic information on the recovery of motor function in the upper and lower extremities.

    Title Symptomatic Vertebral Hemangiomas: Mr Findings.
    Date August 1996
    Journal Ajr. American Journal of Roentgenology
    Title Giant Fusiform Oncotic Aneurysm: Mr and Angiographic Findings.
    Date August 1996
    Journal Ajr. American Journal of Roentgenology
    Title Ruptured Aneurysm of the Basilar Artery Simulating Nonaneurysmal Perimesencephalic Subarachnoid Hemorrhage.
    Date July 1996
    Journal Ajr. American Journal of Roentgenology
    Title Presence of Superficial Siderosis Assists in the Diagnosis of Myxopapillary Ependymoma.
    Date June 1996
    Journal Ajr. American Journal of Roentgenology
    Title Performance of Neuroradiologic Examinations by Nonradiologists.
    Date June 1996
    Journal Radiology
    Excerpt

    PURPOSE: To determine the level of participation by nonradiologists in performing neuroradiologic examinations. MATERIALS AND METHODS: Medicare part B claims data from fiscal year 1992 were analyzed for CPT (current procedural terminology) codes related to computed tomography (CT) and magnetic resonance (MR) imaging of the brain, head and neck, and spine, as well as myelography, angiography, and diskography. Data were tabulated by place of service (hospital-based vs freestanding imaging centers) and by medical specialty. RESULTS: Among 363,224 Medicare claims for CT and MR imaging of the brain, head and neck, and spine, 91% of the examinations were performed in hospitals and 9% in offices or freestanding centers; 98% of studies were interpreted by a radiologist. The largest share of radiology billing by nonradiologists was from office-based or freestanding imaging centers (9%), versus 2% at hospital-based facilities. CONCLUSION: Radiologists perform the vast majority of neuroradiologic examinations. Most neuroradiologic examinations performed by nonradiologists are from neurologists at freestanding/office-based imaging centers.

    Title Cocaine Alters Cerebral Metabolism Within the Ventral Striatum and Limbic Cortex of Monkeys.
    Date February 1996
    Journal The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
    Excerpt

    The functional consequences of acute cocaine administration in nonhuman primates were assessed using the quantitative 2-[14C]deoxyglucose method. Local rates of cerebral metabolism were determined after an intravenous infusion of 1.0 mg/kg cocaine or vehicle in six awake cynomolgus monkeys (Macaca fascicularis) trained to sit calmly in a primate chair. Cocaine administration decreased glucose utilization in a discrete set of structures that included both cortical and subcortical portions of the limbic system. Glucose metabolism in the core and shell of the nucleus accumbens was decreased markedly, and smaller decrements were observed in the caudate and anterior putamen. In addition, cocaine administration produced significant decreases in limbic cortex. Metabolism was decreased in orbitofrontal cortex (areas 11, 12o, 13, 13a, 13b), portions of the gyrus rectus including area 25, entorhinal cortex, and parts of the hippocampal formation. The cortical regions in which functional activity was altered provide dense projections to the nucleus accumbens, and the decreased activity in these projections may be responsible in part of the large alterations in functional activity within the ventral striatum. Decreased metabolism also was evident in the anterior nuclear group of the thalamus, raphe nuclei, and locus ceruleus. The acute cerebral metabolic effects of cocaine in the conscious macaque, therefore, were contained primarily within a set of interconnected limbic regions, including ventral prefrontal cortex, medial temporal regions, the ventral striatal complex, and anterior thalamus. The decreased rates of glucose metabolism reported here resemble decrements found using positron emission tomography in humans. In the rat, by contrast, metabolic activity increased and changes were focused in subcortical regions. The present results represent an important expansion of the neural circuitry on which cocaine acts in the monkey as compared with the rat, and this in turn implies that cocaine affects a broader spectra of behaviors in primates than in rodents.

    Title Mr of Malignant Optic Glioma of Adulthood.
    Date January 1996
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    A case of malignant optic glioma of adulthood is imaged in its early and late stages with high-resolution MR. The images show the mass to arise from the right optic nerve before invasion of the optic chiasm.

    Title Mr Imaging in the Diagnosis of Intramedullary Spinal Cord Diseases That Involve Specific Neural Pathways or Vascular Territories.
    Date September 1995
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    Prior to the advent of MR imaging, the internal architecture of the spinal cord could not be directly imaged. The solution of many technical problems (e.g., respiratory motion, cardiac and CSF pulsation, inadequate spatial resolution) has provided the opportunity for an increasingly refined analysis of intramedullary lesions. This article begins with a brief review of the results of high-resolution MR imaging studies of the cadaveric spinal cord. The article then focuses on MR imaging in the diagnosis of intramedullary diseases that involve specific neural pathways or vascular territories. Lesions are categorized as degenerative, inflammatory, traumatic, or ischemic. These diseases generally have distinctive clinical findings that reflect dysfunction of particular ascending sensory tracts or descending motor tracts. The corresponding abnormalities on MR images reflect the pathologic changes that occur in the affected neural pathways. Knowledge of the appearance of these diseases on MR images allows the formation of a narrow differential diagnosis and, in many cases, the confident exclusion of neoplasm as the cause of myelopathy.

    Title What Constitutes a Routine Angiographic Examination for a Patient Presenting with Transient Ischemic Attacks or Other Less Specific Symptoms of Extracranial Cerebral Vascular Disease?
    Date August 1995
    Journal Ajr. American Journal of Roentgenology
    Title Mr Imaging in a Case of Postvaccination Myelitis.
    Date July 1995
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    We describe a case of acute transverse myelitis after the administration of the recombinant form of hepatitis B vaccine. Abnormal enhancement of MR imaging accompanied residual neurologic deficit.

    Title Mr Imaging: Quality Assessment Method and Ratings at 33 Centers.
    Date July 1995
    Journal Radiology
    Excerpt

    PURPOSE: To outline a quality assessment method with peer review for magnetic resonance (MR) imaging. MATERIALS AND METHODS: Thirty-three providers in the Philadelphia area were rated on a random sample of 132 brain, 124 cervical spine, and 113 lower extremity MR imaging examinations performed during 1990. Blinded peer review was performed by panels of three subspecialty-trained academic radiologists. Technical performance, completeness, and report appropriateness of each MR imaging examination were evaluated. Aggregated scores were calculated to rate provider performance for each of the three parameters of quality. RESULTS: Two or three panelists assessed technical performance as inadequate in 15 cases, completeness as incomplete in 58 cases, and the interpretative report as inappropriate and affecting treatment in 72 cases. Eleven providers received an unsatisfactory rating on one or more parameters of quality. The association between unsatisfactory ratings and the use of low-field-strength (< or = 0.6-T) imagers was statistically significant (P < .008). CONCLUSION: Substantial deficiencies were identified in the performance of examinations and interpretation of MR images in the Philadelphia area in 1990. These findings indicate the need for a program to monitor quality of MR imaging.

    Title Multiple Sclerosis in the Spinal Cord: Mr Appearance and Correlation with Clinical Parameters.
    Date June 1995
    Journal Radiology
    Excerpt

    PURPOSE: To determine the characteristic magnetic resonance (MR) imaging features of multiple sclerosis (MS) that affect the spinal cord. MATERIALS AND METHODS: Sixty-eight patients underwent MR imaging of the cervical and/or thoracic spine. Plaques were analyzed for lesion length, cross-sectional area and location, signal intensity, and morphology. The clinical parameters of MS type, duration of disease, sex, and age were also correlated with these MR imaging findings. RESULTS: One hundred twenty-four demyelinating plaques were found in these 68 patients; 38 had more than one plaque. The majority of plaques were two body segments in length or less and peripherally located, and occupied less than 50% of the cross-sectional area of the cord. Plaques associated with cord atrophy were more likely to occur with the relapsing-progressive form of MS. Cord swelling was found only in the relapsing-remitting form of MS. CONCLUSION: Spinal cord MS plaques are characteristically peripherally located, are less than two vertebral segments in length, and occupy less than half the cross-sectional area of the cord.

    Title Manuscript Peer Review at the Ajr: Facts, Figures, and Quality Assessment.
    Date May 1995
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    Concern by the government, funding institutions, and the public for quality assurance in all aspects of medical endeavors mandates critical examination of various professional activities. Although peer review is generally regarded as the best system for selecting and improving scientific papers for publication, the efficacy of this process has never been proved. Moreover, the administrative functions of the editorial staff are often poorly understood. The purpose of this article is to make peer review a the AJR less esoteric and more understandable by quantifying some of its activities. This information is then assessed as it relates to the quality of this important step in scientific publication.

    Title How Can I Distinguish Between Metastases and Pulsation Artifacts in Contrast-enhanced Scans of the Posterior Fossa.
    Date February 1995
    Journal Ajr. American Journal of Roentgenology
    Title New Category of Peer-review Decision: Rejection with Opportunity to Revise and Resubmit.
    Date January 1995
    Journal Ajr. American Journal of Roentgenology
    Title Hypertrophic Charcot-marie-tooth Disease: Mr Imaging Findings.
    Date October 1994
    Journal Ajr. American Journal of Roentgenology
    Title Superior Sagittal Sinus Thrombosis in the Presence of Idiopathic Bilateral Internal Jugular Vein Stenosis.
    Date April 1994
    Journal Journal of Neuroimaging : Official Journal of the American Society of Neuroimaging
    Excerpt

    Cerebral venous outflow obstruction and anomalies in cerebral venous circulation predispose to dural sinus thrombosis. This case report illustrates the magnetic resonance and angiographic findings in a patient who had superior sagittal sinus thrombosis secondary to idiopathic bilateral internal jugular vein stenosis, a previously unrecognized entity. The findings suggest that bilateral stenosis of the internal jugular veins at their junction with the innominate veins causes obstruction to cerebral venous outflow leading to dural sinus thrombosis.

    Title Vascular Neoplasms and Malformations, Ischemia, and Hemorrhage Affecting the Spinal Cord: Mr Imaging Findings.
    Date March 1994
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    This essay illustrates the imaging spectrum of vascular neoplasms and malformations, ischemia, and hemorrhage affecting the spinal cord. Most of these abnormalities occur far more frequently in the brain. The goal of this essay is to provide a sound anatomic and radiologic basis for the evaluation of these diseases. Knowledge of the unique cross-sectional anatomy, blood supply, and venous drainage of the spinal cord is essential in understanding the radiographic appearance of certain vascular lesions. The superior spatial resolution of fast spin-echo pulse sequences and improvements in MR angiography have expanded the role of MR imaging in the diagnosis of spinal cord diseases. These techniques are emphasized in this essay, and potential diagnostic pitfalls are highlighted. The diseases illustrated are grouped in the categories of enlarged vessels, ischemia, and hemorrhage.

    Title Metallic Artifacts on Mr Images of the Postoperative Spine: Reduction with Fast Spin-echo Techniques.
    Date February 1994
    Journal Radiology
    Excerpt

    PURPOSE: To determine whether the relative insensitivity of T2-weighted fast spin-echo (FSE) techniques to magnetic susceptibility can be exploited to reduce metallic artifacts on images of the postoperative spine and, thus, improve the interpretation of the postoperative study. MATERIALS AND METHODS: Three neuroradiologists retrospectively evaluated sagittal T2-weighted conventional spin-echo and FSE images obtained in 15 patients with metallic artifacts from various sources including drill particles from anterior cervical diskectomy, posterior fixation wires, fixation rods or plates, and an inferior vena cava filter. The amount of artifact present and whether these artifacts affected image interpretation were evaluated. RESULTS: Among the 45 paired evaluations, the artifact was judged to be less apparent with FSE sequences in 39. In eight of 45 evaluations (18%), the interpretation of the area of interest was possible only on the FSE images. CONCLUSION: FSE imaging, especially when performed with shorter echo spacing, increases the amount of T2-weighted information in the presence of metallic artifact because it decreases magnetic susceptibility effects.

    Title A Modality-specific Somatosensory Area Within the Insula of the Rhesus Monkey.
    Date December 1993
    Journal Brain Research
    Excerpt

    Response properties of neurons in the monkey's granular insula (Ig) were examined with somatic, auditory, visual, and gustatory stimuli. Results indicate that a major portion of Ig is a somatic processing area exclusively, with units that have large and often bilateral receptive fields, consistent with the view that this area serves as a higher-order, modality-specific link in the somatosensory-limbic pathway.

    Title Magnetic Resonance Imaging Related to Neurologic Outcome in Cervical Spinal Cord Injury.
    Date October 1993
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    The purpose of this study was to examine the relationship between the initial intramedullary hemorrhage, as seen by magnetic resonance imaging (MRI), and the neurologic deficit and eventual neurologic outcome of acute cervical spinal cord injured subjects. MRI and motor assessments were performed on 24 subjects with motor complete (Frankel A & B) and incomplete (Frankel C & D) injuries. Recovery was determined by evaluating an initial and a final motor power following spinal cord injury (SCI), as defined by the manual muscle test (grade 1-5) and motor index score (MIS). Results showed that all 15 subjects having hemorrhage had motor complete injuries (Frankel A & B). Sixteen percent of the muscles in the upper extremities and 3% of the muscles in the lower extremities in these 15 subjects improved to a grade of > or = 3/5 at the final evaluation post-SCI. In comparison, of the nine subjects not having hemorrhage, eight had motor incomplete injuries (Frankel C & D) and had 73% and 74% of muscles improving in the upper and lower extremities, respectively. In addition, a change in MIS from initial to final evaluations showed a significant difference between subjects with hemorrhage and subjects without hemorrhage (upper extremities: p = .002 and lower extremities: p = .0001). In conclusion, the initial MR image and neurologic assessment correlated with motor power recovery.

    Title Abnormalities of the Posterior Inferior Cerebellar Artery: Mr Imaging Findings.
    Date June 1993
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    The purpose of this essay is to review the normal MR appearance of the posterior inferior cerebellar artery (PICA) and to illustrate the MR findings of representative PICA abnormalities. Because of beam-hardening artifacts, the lower posterior fossa is difficult to evaluate with CT. MR imaging is not hampered by these artifacts. Moreover, the superb sensitivity of MR and its multiplanar imaging capability permit excellent diagnostic accuracy in this region. The PICA is well suited for evaluation on routine MR images, particularly because of the inherent contrast (signal void) of large arteries due to rapid flow. MR imaging has greatly improved our ability to noninvasively diagnose abnormalities of cerebral blood vessels and their resultant manifestations. Some of the diseases that affect the PICA include neoplasms, aneurysms, arteriovenous malformations, and occlusions. The MR images in this essay illustrate the normal appearance of the PICA, as well as these pathologic features. T1-weighted (e.g., 600/15 [TR/TE]), proton density-weighted (e.g., 2000/20), and T2-weighted (e.g., 2400/80) MR images were obtained in axial, sagittal, and coronal planes. The PICA can be evaluated with MR angiography also, although the relatively small size and tortuosity of the artery may preclude adequate visualization.

    Title Lesions Causing a Mass in the Medial Canthus of the Orbit: Ct and Mr Features.
    Date May 1993
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    Few detailed radiologic articles treat the medial canthus as a "compartment" of the orbit. Nasal stuffiness and epiphora (excessive tearing) are frequent clinical manifestations of diseases involving the medial canthus of the orbit. Although some lesions can be adequately evaluated by clinical examination, imaging may show unsuspected deep extensions of the abnormality. CT has traditionally been the imaging method of choice because of the inherent contrast between structures in this region and its superb depiction of bone detail (Fig. 1). MR imaging can be useful in detecting subtle marrow invasion caused by lesions extending beyond the confines of the medial canthus (e.g., frontal bone, maxilla). In this pictorial essay, we illustrate the CT and MR appearances of diseases that can manifest as a medial canthal mass and provide practical differential diagnoses. Lesions can be inflammatory, neoplastic, or developmental in origin. Moreover, these lesions can result from abnormalities in the adjacent nasolacrimal apparatus, orbit, paranasal sinuses, and nasal cavity, or they can reflect an underlying systemic illness.

    Title Amyotrophic Lateral Sclerosis: Hyperintensity of the Corticospinal Tracts on Mr Images of the Spinal Cord.
    Date March 1993
    Journal Ajr. American Journal of Roentgenology
    Title Magnetic Resonance Imaging in Acute Spinal Injury.
    Date December 1992
    Journal Seminars in Roentgenology
    Title Herpes Zoster Myelitis: Mr Appearance.
    Date November 1992
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    The author describes a 71-year-old woman in whom cutaneous cervical herpes zoster was complicated by the development of cervical myelitis. T2-weighted MR showed two focal areas of hyperintensity in the cervical cord and suggested a slight enlargement at C2-C3 and C7.

    Title Extrapineal Abnormalities of the Tectal Region: Mr Imaging Findings.
    Date October 1992
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    This essay illustrates the imaging spectrum of extrapineal lesions that involve the tectal region, with emphasis on intrinsic tectal abnormalities. The superb sensitivity of MR and its multiplanar imaging capability permit unparalleled diagnostic accuracy in this region. The sagittal and axial planes are ideal for evaluating the tectum. CT remains important in the detection of acute hemorrhage and calcification. Grouping of abnormalities on the basis of anatomic boundaries (tectum, aqueduct, and quadrigeminal plate cistern) is useful in establishing the correct diagnosis.

    Title Unusual Dissection of the Proximal Vertebral Artery: Description of Three Cases.
    Date June 1992
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    We report three cases that reveal an array of etiologic and radiologic findings associated with dissection of the proximal segment of the vertebral arteries. Regardless of etiology, the proximal segment may be the principal site of dissection in these vessels.

    Title Enhancement of Gray Matter in Anterior Spinal Infarction.
    Date June 1992
    Journal Ajnr. American Journal of Neuroradiology
    Title Intradural Schwannomas of the Spine: Mr Findings with Emphasis on Contrast-enhancement Characteristics.
    Date June 1992
    Journal Ajr. American Journal of Roentgenology
    Excerpt

    Intradural extramedullary schwannomas are nerve sheath neoplasms that consist of focal proliferations of Schwann cells involving a spinal nerve. We reviewed the MR findings in seven patients with pathologically proved intradural schwannomas. The contrast-enhancement characteristics on MR images were determined and compared with the histologic features of the tumor. Six lesions were variably hyperintense on T2-weighted images and one was uniformly hypointense compared with the signal intensity of the spinal cord. Signal on T1-weighted images ranged from hypointense to isointense. All seven tumors showed heterogeneous enhancement; in five, the enhancement involved only the periphery of the lesion. The pattern of enhancement did not correlate with the signal characteristics noted on unenhanced T1- and T2-weighted images. Pathologically, hyaline thickening of vessel walls and cyst formation were prevalent in the peripherally enhancing lesions. However, enhancement did not correlate with the relative proportion of Antoni type A and type B tissue. Recognition of the MR characteristics of intradural extramedullary schwannomas may be helpful in the differential diagnosis of spinal tumors. In particular, peripheral contrast enhancement of an intradural extramedullary tumor on MR images should suggest the diagnosis of schwannoma.

    Title Mr and Ct of Squamous Cell Carcinoma of the Middle Ear and Mastoid Complex.
    Date December 1991
    Journal Ajnr. American Journal of Neuroradiology
    Title Segmental Neurofibromatosis (nf-5): a Rare Form of Neurofibromatosis.
    Date December 1991
    Journal Ajnr. American Journal of Neuroradiology
    Title Corticocortical Connections Predict Patches of Stimulus-evoked Metabolic Activity in Monkey Somatosensory Cortex.
    Date November 1990
    Journal The Journal of Comparative Neurology
    Excerpt

    Stimulus-evoked metabolic activity in the anterior parietal cortex (areas 3a, 3b, 1, and 2) occurs in the form of column-like patches. Similar patches characterize the connections to, within, and from these fields. The relation of the patches elicited metabolically to those formed by retrograde or anterograde transport, however, is not clear. If a type of projection connecting areas 3a, 3b, 1, and 2 transmits sensory information among these cortical fields, the resultant projection pattern may directly contribute to the definition of somatosensory metabolic "columns." To test this possibility, electrophysiological recordings in areas 3b and 1 of Macaca fascicularis monkeys characterized stimuli that elicited the best neuronal response at a specific cortical site. Iontophoretic injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) were subsequently made into the identified cortical sites. Two days later, the animals were injected with 2-deoxyglucose (2DG) and received the somatic stimulus previously determined to best activate the neurons isolated at the injected cortical site. After injections of WGA-HRP into physiologically defined loci in area 3b, the patches of transported label within areas 3b and 1 were colocalized with evoked metabolic activity. Injections of WGA-HRP into area 1 produced anterogradely labeled terminals in areas 1 and 2 that also overlapped with patches of evoked metabolic activity, as did patches of retrogradely labeled cells located in area 3b. Patches of anterograde label found in area 3b after area 1 injections, however, were not coincident with the metabolically activated patches. These findings suggest that excitatory information is transmitted from area 3b to area 1 in a way that connects clusters of cells with similar response properties.

    Title Perspectives on the Medical Use of Drugs of Abuse.
    Date May 1990
    Journal Journal of Pain and Symptom Management
    Excerpt

    The treatment of severe pain requires the use of potent opioid analgesic medications. Many patients with opioid sensitive pain are being undermedicated. This results in increased morbidity and needless suffering. The most important reason for this undertreatment is the fear of addiction engendered by opioids, a fear that is greatly out of proportion to the real risk. The risk of addiction is greatly overestimated in part because many people do not understand the distinctions between drug abuse and drug addiction, on the one hand, and physical dependence and tolerance, on the other. Dependence and tolerance are virtually inevitable outcomes of long-term opioid use, but they are neither sufficient to cause addiction nor the equivalent of it. Indeed, the evidence shows that only a tiny fraction of patients treated with opioids become addicted. There is little risk of addiction for those patients receiving properly administered opioids for pain.

    Title Type I Protein Kinase C Isozyme in the Visual-information-processing Pathway of Monkey Brain.
    Date July 1989
    Journal Journal of Cellular Biochemistry
    Excerpt

    Previously using PKC isozyme-specific antibodies for immunoblot analysis, we demonstrated the heterogeneous distribution of PKC isozymes in various regions of monkey and rat brains and that type I PKC was most abundant in cerebellum, hippocampus, amygdala, and cerebral cortex (Huang et al.: J Biol Chem 262:15714-15720, 1987). Using these antibodies, we have also demonstrated that type I, II, and III PKC are products of PKC genes gamma, beta, and alpha, respectively (Huang et al.: Biochem Biophys Res Commun 149:946-952, 1987). By immunocytochemical analysis, type I PKC-specific antibody showed strong reactivity in various types of neuron in hippocampal formation, amygdala, cerebellum, and neocortex. In hippocampal formation, granule cells of dentate gyrus and pyramidal cells of hippocampus were heavily stained. By immunoblot analysis, relative levels of PKC isozymes in several areas of monkey cerebral cortex involved in the visual information processing and storage were determined. Both type II and III PKCs appeared to be evenly distributed and at moderate levels, type I PKC formed a gradient of increasing concentration rostral along the cerebral cortex of occipital to temporal and then to the limbic areas. Neurobehavioral studies have demonstrated that the neocortical and limbic areas of the anterior and medial temporal regions participate more directly than the striate, prestriate, and posterior temporal regions in the storage of visual representations and that both hippocampus and amygdala are important in the memory formation. As type I PKC is present at high levels in hippocampus, amygdala, and anterior temporal lobe, we predict that the type I protein kinase C may participate in the plastic changes important for mnemonic function.

    Title A Comparison Between the Connections of the Amygdala and Hippocampus with the Basal Forebrain in the Macaque.
    Date November 1987
    Journal Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
    Excerpt

    Autoradiographic experiments indicated that the amygdala projects to division Ch3 and Ch4 of the basal forebrain (nomenclature from Mesulam et al. 1983) and the olfactory tubercle. The heaviest of these amygdaloid outputs arose from the lateral basal, accessory basal, central, and medial amygdaloid nuclei, each with a slightly different pattern of distribution from that of the other. Injections of the retrograde tracer horseradish peroxidase (HRP) into the amygdala revealed dense reciprocal projections arising from region Ch4, especially from subdivisions Ch4al, Ch4iv, and Ch4p. The other basal forebrain regions, by contrast, provided very little input to the amygdala. Hippocampal efferents terminated densely in the medial (Ch1), lateral and dorsal septum, and in region Ch2. Hippocampal efferents terminated less densely in restricted portions of the olfactory tubercle and in Ch4. Experiments in which the fornix was transected showed that all of these hippocampal projections to the basal forebrain ran through the fornix. The hippocampal output to the septum, which was the heaviest projection of those examined, appears to have a crude topographic arrangement. Little overlap was observed between the terminal zones of the amygdaloid and hippocampal projections to the basal forebrain, indicating yet again the independence of the amygdaloid and hippocampal systems that has been demonstrated in other regions of the forebrain, such as the thalamus and cerebral cortex.

    Title Gradients of Protein Kinase C Substrate Phosphorylation in Primate Visual System Peak in Visual Memory Storage Areas.
    Date October 1987
    Journal Brain Research
    Excerpt

    Two protein kinase C (PKC) substrates of 50 and 81 kDa display topographical gradients in 32P-incorporation along the occipitotemporal visual processing pathway in rhesus monkey cerebral cortex. The 50 kDa protein appears to be homologous to protein F1 from rat (47 kDa) on the basis of isoelectric point, two-dimensional phosphopeptide maps, and kinase specificity, while the 81 kDa protein is probably the same as a previously described PKC substrate. The phosphorylation of protein F1 and 81 kDa was significantly higher in temporal regions of the occipitotemporal pathway, which have been implicated in the storage of visual representations, than in occipital regions, which appear to be less important for visual memory functions. These results suggest that the PKC phosphorylation system, which has been related previously to changes in neural plasticity, plays a progressively greater role in later stages of visual processing, and that this role may involve the storage of visual information in inferotemporal cortical areas.

    Title Physiological Evidence for Serial Processing in Somatosensory Cortex.
    Date August 1987
    Journal Science (new York, N.y.)
    Excerpt

    Removal of the representation of a specific body part in the postcentral cortex of the macaque resulted in the somatic deactivation of the corresponding body part in the second somatosensory area. In contrast, removal of the entire second somatosensory area had no grossly detectable effect on the somatic responsivity of neurons in the postcentral cortex. This direct electrophysiological evidence for serial cortical processing in somesthesia is similar to that found earlier for vision and, taken together with recent anatomical evidence, suggests that there is a common cortical plan for the processing of sensory information in the various sensory modalities.

    Title Promising Initiatives in Pain Management.
    Date May 1987
    Journal Journal of Pain and Symptom Management
    Title Cortical Connections of the Somatosensory Fields of the Lateral Sulcus of Macaques: Evidence for a Corticolimbic Pathway for Touch.
    Date February 1987
    Journal The Journal of Comparative Neurology
    Excerpt

    The ipsilateral corticocortical connections of the somatosensory fields of the lateral sulcus of macaques were examined with both anterograde and retrograde axonal transport methods. In most cases, the field of interest was identified prior to the injection of the tracer substance by recording neuronal responses to somatic stimulation. The results show that the second somatosensory area (S2) is reciprocally connected with the retroinsular area (Ri), area 7b, and the granular (Ig) and dysgranular (Id) insular fields. Ri is also reciprocally connected with Ig. Previously reported connections were confirmed between S2 and areas 3a, 3b, 1, and 2 and between area 5 and both area 7 and Ri. Moreover, the portions of Ig and Id that receive somatic inputs were shown to project to the amygdaloid complex. Id projects, in addition, to the perirhinal cortex, which supplies input to the hippocampal formation. The corticocortical projections were found to have two distinct laminar patterns of termination. One is characterized by heavy terminations in layers IV and IIIb and the other by heavy terminations in layer I, but no terminations in layers IV and IIIb. These two patterns were typically found to be reciprocally related. The results suggest that somatosensory information is processed by a series of cortical fields, including areas 3a, 3b, 1, 2, 5, 7b, S2, Ig, and Id. These fields have access to the amygdaloid complex and the hippocampal formation. Thus, a ventrally directed tactile processing pathway can be followed from S1 to the temporal lobe limbic structures via relays in S2 and the insula; this corticolimbic pathway may subserve tactile learning and memory.

    Title Thalamic Connectivity of the Second Somatosensory Area and Neighboring Somatosensory Fields of the Lateral Sulcus of the Macaque.
    Date February 1987
    Journal The Journal of Comparative Neurology
    Excerpt

    The thalamocortical relations of the somatic fields in and around the lateral sulcus of the macaque were studied following cortical injections of tritated amino acids and horseradish peroxidase (HRP). Special attention was paid to the second somatosensory area (S2), the connections of which were also studied by means of thalamic isotope injections and retrograde degeneration. S2 was shown to receive its major thalamic input from the ventroposterior inferior thalamic nucleus (VPI) and not, as previously reported, from the caudal division of the ventroposterior lateral nucleus (VPLc). Following small injections of isotope or HRP into the hand representation of S2, only VPI was labeled. Larger injections, which included the representations of more body parts, led to heavy label in VPI, with scattered label in VPLc, the central lateral nucleus (CL), and the posterior nucleus (Po). In addition, small isotope injections into VPLc did not result in label in S2 unless VPI was also involved in the injection site, and ablations of S2 led to cell loss in VPI. Comparison of injections involving different body parts in S2 suggested a somatotopic arrangement within VPI such that the trunk and lower limb representations are located posterolaterally and the hand and arm representations anteromedially. The location of the thalamic representations of the head, face, and intraoral structures that project to S2 may be in the ventroposterior medial nucleus (VPM). The granular (Ig) and dysgranular (Id) fields of the insula and the retroinsular field (Ri) each receive inputs from a variety of nuclei located at the posteroventral border of the thalamus. Ig receives its heaviest input from the suprageniculate-limitans complex (SG-Li), with additional inputs from Po, the magnocellular division of the medial geniculate n. (MGmc), VPI, and the medial pulvinar (Pulm). Id receives its heaviest input from the basal ventromedial n. (VMb), with additional inputs from VPI, Po, SG-Li, MGmc, and Pulm. Ri receives its heaviest input from Po, with additional input from SG-Li, MGmc, Pulm, and perhaps VPI. Area 7b receives its input from Pulm, the oral division of the pulvinar, the lateral posterior n., the medial dorsal n., and the caudal division of the ventrolateral n. These results indicate that the somatic cortical fields, except for those comprising the first somatosensory area, each receive inputs from an array of thalamic nuclei, rather than just one, and that individual thalamic somatosensory relay nuclei each project to more than one cortical field.

    Title Regional Distribution of [3h]naloxone Binding in the Brain of a Newborn Rhesus Monkey.
    Date April 1986
    Journal Brain Research
    Excerpt

    The distribution of opiate receptors in the brain of a newborn monkey (Macaca mulatta) was mapped by in vitro autoradiographic localization of [3H]naloxone binding to tissue sections. The autoradiographs of the newborn brain were compared to those from two adult brains. The distribution of opiate receptors appeared to be adult-like in subcortical structures (both limbic and nonlimbic) and allocortical areas. By contrast, all neocortical areas, except the primary visual cortex, lacked at birth the laminar specific patterns that characterize the adult. The results therefore suggest that, like many other aspects of neocortical maturation, such as dendritic growth, synaptogenesis, myelination and neurotransmitter concentrations, the distribution of opiate receptors continues to develop postnatally.

    Title Laminar Patterns of Termination of Cortico-cortical Afferents in the Somatosensory System.
    Date November 1983
    Journal Brain Research
    Excerpt

    Two distinct patterns of terminal labeling were seen after injections of [3H]amino acids into the second somatosensory area (S2) and the retroinsular area (Ri). The first pattern, seen both in S2 after an injection in Ri and in the granular or dysgranular insular fields after an injection in S2, is characterized by heavy labeling in layers IIIb and IV. By contrast, the second pattern, seen in the first somatosensory area and Ri after an injection in S2, is distinguished by heavy labeling of layer I and no labeling in layer IV. A reciprocal relationship between these two laminar patterns has now been seen in the somatosensory, visual and auditory systems.

    Title Projection Pattern of Functional Components of Thalamic Ventrobasal Complex on Monkey Somatosensory Cortex.
    Date December 1982
    Journal Journal of Neurophysiology
    Title Thalamic Basis of Place- and Modality-specific Columns in Monkey Somatosensory Cortex: a Correlative Anatomical and Physiological Study.
    Date December 1982
    Journal Journal of Neurophysiology
    Title Thalamic Input to Areas 3a and 2 in Monkeys.
    Date May 1981
    Journal Journal of Neurophysiology
    Title Representation Pattern in the Second Somatic Sensory Area of the Monkey Cerebral Cortex.
    Date November 1980
    Journal The Journal of Comparative Neurology
    Excerpt

    The body representation in the second somatic sensory area of macaques has been studied by tracing with anatomical techniques the projections from defined parts of the body representation in the first somatic sensory area (SI) to their terminal regions within the lateral sulcus. The second somatic sensory area (SH), as identified in terms of cytoarchitecture and its connection with the thalamic ventrobasal complex, is the only region of the lateral sulcus to receive a projection from SI. The nearby retroinsular area and area 7b receive a projection from area 5. Within SII the face and head representations lie anteriorly, occupying the dorsalmost part of the insula and portions of the front-parietal operculum. The digits, hand, and arm are represented posterior to the face and may take up the mediolateral extent of the parietal operculum in the region immediately in front of the posterior pole of the insula. The trunk representation is lateral to the arm representation, i.e., deep within the superior circular sulcus and on the dorsal insula. The hindlimb appears behind the trunk also occupying the superior circular sulcus in addition to the deepest 2--3 mm of the upper bank of lateral sulcus immediately posterior to the insula. Areas 3b, 1, and 2 each project to SII, and their projections appear to converge within the representation of a given body part. Injections of anterogradely transported tracers in SI label vertically oriented columnar arrays of a terminal ramifications in SII, resembling those previously described for other cortico-cortical projections within the sensory-motor region. In experiments which combined anterograde and retrograde labeling, cells projecting from SII to SI formed columns exactly coinciding with the columns of anterogradely labeled axons terminating in SH. The cells of origin of cortico-cortical projections emanating from SII formed two distinct laminar populations, one in the supragranular layers and the second mainly in layer VI. There is evidence for fiber terminations within the layer VI mainly underlying the column formed by the terminal ramifications in layers I and through IV.

    Title Catecholaminergic Involvement in Phasic Versus Tonic Electrocortical Arousal.
    Date September 1980
    Journal Brain Research
    Title Focal Projection of Electrophysiologically Defined Groupings of Thalamic Cells on the Monkey Somatic Sensory Cortex.
    Date August 1980
    Journal Brain Research
    Title Revisiting Anaplastic Astrocytomas I: an Expansive Growth Pattern is Associated with a Better Prognosis.
    Date
    Journal Journal of Magnetic Resonance Imaging : Jmri
    Excerpt

    PURPOSE: To study whether anaplastic astrocytomas that are nonenhancing and/or well-circumscribed (expansive) are associated with a better prognosis. MATERIALS AND METHODS: We retrospectively identified 59 patients with pathologically confirmed World Health Organizaiton (WHO) grade III anaplastic astrocytoma who underwent craniotomy at our institution from 1995 through 2006. We assessed prognostic variables including age, enhancement (EAA-34 patients) vs. nonenhancement (NEAA-25 patients), MR growth patterns (expansive [28 patients] vs. mixed/infiltrative [31 patients]), recursive partitioning analysis (RPA) class, resection extent, and addition of chemotherapy. Primary outcome measure was survival. RESULTS: Kaplan-Meier curves showed improved survival in NEAA, expansive tumors, and RPA 1 class patients. Within RPA class I patients, expansive growth pattern remained a significant advantage in survival time. Examining extent of resection also showed that patients with gross total resections (GTR) had a better prognosis. A multivariate (Cox proportional hazards) analysis showed that patient age and expansive tumor phenotype affected outcome, whereas RPA class, enhancement, and GTR did not. CONCLUSION: Circumscribed growth in histologically proven anaplastic astrocytoma, which has not been emphasized in past studies, has a considerable survival advantage.

    Title Up-regulation and Functional Effect of Cardiac Beta(3)-adrenoreceptors in Alcoholic Monkeys.
    Date
    Journal Alcoholism, Clinical and Experimental Research
    Excerpt

    Recent studies link altered cardiac beta-adrenergic receptor (AR) signaling to the pathology of alcoholic cardiomyopathy (ACM). However, the alteration and functional effect of beta(3)-AR activation in ACM are unknown. We tested the hypothesis that chronic alcohol intake causes an up-regulation of cardiac beta(3)-AR, which exacerbates myocyte dysfunction and impairs calcium regulation, thereby directly contributing to the progression of ACM.

    Title Trends in the Utilization of Ct Angiography and Mr Angiography of the Head and Neck in the Medicare Population.
    Date
    Journal Journal of the American College of Radiology : Jacr
    Excerpt

    The aim of this study was to analyze trends in the utilization of CT angiography (CTA) and MR angiography (MRA) of the head and neck in the Medicare population over a 6-year interval.


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