Otolaryngologist (ear, nose, throat), Pediatric Specialist
31 years of experience

Accepting new patients
Northwest Ohio ENT Consultants Perrysburg
1601 Brigham Dr
Ste 250
Perrysburg, OH 43551
419-873-3277
Locations and availability (7)

Education ?

Medical School
University Of Toronto Faculty Of Medicine (1979)
Foreign school

Awards & Distinctions ?

Awards  
Patients' Choice Award (2008 - 2010)
Compassionate Doctor Recognition (2012)
Associations
American College of Surgeons
American Academy of Otolaryngology: Head and Neck Surgery
American Board of Otolaryngology

Affiliations ?

Dr. Rubin is affiliated with 14 hospitals.

Hospital Affilations

Score

Rankings

  • St Luke's Hospital
    Otolaryngology
    5901 Monclova Rd, Maumee, OH 43537
    • Currently 4 of 4 crosses
    Top 25%
  • Bay Park Community Hospital
    Otolaryngology
    2801 Bay Park Dr, Oregon, OH 43616
    • Currently 4 of 4 crosses
    Top 25%
  • St Anne Mercy Hospital
    Otolaryngology
    3404 W Sylvania Ave, Toledo, OH 43623
    • Currently 4 of 4 crosses
    Top 25%
  • University of Toledo Medical Center
    Otolaryngology
    3000 Arlington Ave, Toledo, OH 43614
    • Currently 3 of 4 crosses
    Top 50%
  • Flower Hospital
    Otolaryngology
    5200 Harroun Rd, Sylvania, OH 43560
    • Currently 3 of 4 crosses
    Top 50%
  • St. Vincent Mercy Children's Hospital
    Otolaryngology
    2213 Cherry St, Toledo, OH 43608
    • Currently 3 of 4 crosses
    Top 50%
  • Toledo Hospital
    Otolaryngology
    2142 N Cove Blvd, Toledo, OH 43606
    • Currently 2 of 4 crosses
  • Wood County Hospital
    Otolaryngology
    950 W Wooster St, Bowling Green, OH 43402
    • Currently 1 of 4 crosses
  • ProMedica North Region-Bixby Campus
    Otolaryngology
    818 Riverside Ave, Adrian, MI 49221
    • Currently 1 of 4 crosses
  • Bay Park Hospital
  • Herrick Medical Center
  • Flower Memorial Hospital
  • Toledo Children's Hospital
    2142 N Cove Blvd, Toledo, OH 43606
  • ProMedica North Region-Bixby Campus
  • Publications & Research

    Dr. Rubin has contributed to 59 publications.
    Title Comparison of Gamma-aminobutyrate Receptors in the Medial Vestibular Nucleus of Control and Scn8a Mutant Mice.
    Date March 2008
    Journal Brain Research
    Excerpt

    The Purkinje cells of the cerebellum provide inhibitory input to vestibular nucleus neurons, with gamma-aminobutyrate (GABA) as neurotransmitter. Using extracellular recordings and bath application of agonists and antagonists, we compared GABA receptors in the medial vestibular nucleus of brain slices from Scn8a mutant mice of med(J) type, in which there is greatly reduced spontaneous and evoked activity of Purkinje cells, to those in slices from control mice. Muscimol, an agonist at GABA(A) receptors, produced a larger reduction of firing rate in neurons of mutant mice than in neurons of control mice, whereas there was no difference for baclofen, an agonist at GABA(B) receptors. In most cases tested, the effects of muscimol and baclofen remained similar when synaptic transmission was blocked, suggesting that the effects were predominantly directly upon GABA receptors of the neurons being recorded from. The up-regulation of GABA(A) receptors was similar in magnitude to that previously found for rats with bilateral transection of the inferior cerebellar peduncle. It may relate in both cases to reduced Purkinje cell input to medial vestibular nucleus neurons. The lack of effect on GABA(B) receptors suggests that the changes found with peduncle transection may have resulted from something more than reduced Purkinje cell activity, such as reduced concentrations of GABA, or that reduction of Purkinje cell activity in Scn8a mutant mice was insufficient to affect GABA(B) receptors. Other possible explanations of the results cannot be excluded since the Scn8a mutation affects other neuron types besides Purkinje cells.

    Title Changes of Amino Acid Concentrations in the Rat Vestibular Nuclei After Inferior Cerebellar Peduncle Transection.
    Date May 2007
    Journal Journal of Neuroscience Research
    Excerpt

    Although there is a close relationship between the vestibular nuclear complex (VNC) and the cerebellum, little is known about the contribution of cerebellar inputs to amino acid neurotransmission in the VNC. Microdissection of freeze-dried brain sections and high-performance liquid chromatography (HPLC) were combined to measure changes of amino acid concentrations within the VNC of rats following transection of the cerebellovestibular connections in the inferior cerebellar peduncle. Distributions of 12 amino acids within the VNC at 2, 4, 7, and 30 days after surgery were compared with those for control and sham-lesioned rats. Concentrations of gamma-aminobutyric acid (GABA) decreased by 2 days after unilateral peduncle transection in nearly all VNC regions on the lesioned side and to lesser extents on the unlesioned side and showed partial recovery up to 30 days postsurgery. Asymmetries between the two sides of the VNC were maintained through 30 days. Glutamate concentrations were reduced bilaterally in virtually all regions of the VNC by 2 days and showed complete recovery in most VNC regions by 30 days. Glutamine concentrations increased, starting 2 days after surgery, especially on the lesioned side, so that there was asymmetry generally opposite that of glutamate. Concentrations of taurine, aspartate, and glycine also underwent partially reversible changes after peduncle transection. The results suggest that GABA and glutamate are prominent neurotransmitters in bilateral projections from the cerebellum to the VNC and that amino acid metabolism in the VNC is strongly influenced by its cerebellar connections.

    Title An Early Favorable Outcome of Streptococcal Toxic Shock Syndrome May Require a Combination of Antimicrobial and Intravenous Gamma Globulin Therapy Together with Activated Protein C.
    Date January 2007
    Journal Scandinavian Journal of Infectious Diseases
    Excerpt

    Streptococcal toxic shock syndrome (STSS) associated with a group A beta hemolytic streptococcal infection was described 18 y ago. Since then, although the pathophysiology of the syndrome has been clarified, mortality can be as high as 80%. A middle-aged female developed STSS associated with a group A streptococcal pneumonia. Laboratory studies confirmed respiratory and renal failure as well as disseminated intravascular coagulation with a striking reduction in endogenous procoagulants. The patient, probably due to her HLA DRB1*14 haplotype was unable to generate anti-streptococcal antibodies. She was treated with appropriate antimicrobial therapy together with intravenous gamma globulin and drotrecogin or activated protein C. Her response to this combined therapy was accompanied by a rapid resolution of the multiorgan failure and correction of the accompanying disseminated intravascular coagulation. This rapid response to treatment supports the hypohesis that several host factors including the immune response and loss of procoagulants determine the development and severity of the toxic shock syndromes. Further studies with this combined approach appear warranted.

    Title Effects of Unilateral Vestibular Ganglionectomy on Glutaminase Activity in the Vestibular Nerve Root and Vestibular Nuclear Complex of the Rat.
    Date October 2004
    Journal Journal of Neuroscience Research
    Excerpt

    The metabolism of glutamate, the most likely neurotransmitter of vestibular ganglion cells, includes synthesis from glutamine by the enzyme glutaminase. We used microdissection combined with a fluorometric assay to measure glutaminase activity in the vestibular nerve root and nuclei of rats with unilateral vestibular ganglionectomy. Glutaminase activity in the lesioned-side vestibular nerve root decreased by 62% at 4 days after ganglionectomy and remained at similar values through 30 days. No change occurred in the contralateral vestibular nerve root. Glutaminase activity changes in the vestibular nuclei were lesser in magnitude and more complex, including contralateral increases as well as ipsilateral decreases. At 4 days after ganglionectomy, glutaminase activity was 10-20% lower in individual lesioned-side nuclei compared with their contralateral counterparts. By 14 and 30 days after ganglionectomy, there were no statistically significant differences between the nuclei on the two sides. This transient asymmetry of glutaminase activities in the vestibular nuclei contrasts with the sustained asymmetry in the vestibular nerve root and suggests that intrinsic, commissural, or descending pathways are involved in the recovery of chemical symmetry. This recovery resembles our previous finding for glutamate concentrations in the vestibular nuclei and may partially underlie central vestibular compensation after peripheral lesions.

    Title Remodeling of Synaptic Connections in the Deafferented Vestibular Nuclear Complex.
    Date May 2004
    Journal Journal of Vestibular Research : Equilibrium & Orientation
    Excerpt

    To determine if synaptic remodeling in the vestibular nuclear complex (VNC) may be involved in vestibular compensation, expressions of growth-associated protein-43 (GAP-43) and synaptosome-associated protein of 25 kDa (SNAP-25) were examined by immunoblotting and immunocytochemistry after unilateral vestibular ganglionectomy (UVG) in rats. GAP-43 expression increased bilaterally in the VNC after UVG, but more rapidly on the lesioned side, and remained high through 60 days. It was mainly associated with boutons at all survival times but was also present in some axonal processes and, at 7 days after UVG, in some somata. SNAP-25 expression also increased bilaterally, more rapidly on the lesioned side, but decreased bilaterally after peaking at 14 days. Its distribution in the VNC resembled that of GAP-43 but was more completely localized to boutons. Comparisons were made with auditory centers of the same rats, since the lesion also deafferented that system. Our results combined with those of previous studies suggest that degeneration of the vestibular nerve fibers is required for increased expression of GAP-43 in the VNC. The results suggest that axonal sprouting and synaptogenesis are involved in synaptic remodeling bilaterally in the rat VNC after UVG.

    Title The Impact of Osteoporosis on Patients with Maxillofacial Trauma.
    Date April 2004
    Journal Archives of Otolaryngology--head & Neck Surgery
    Excerpt

    BACKGROUND: Although maxillofacial injuries in the elderly population frequently result from falls and motor vehicle crashes, the association between osteoporosis and fractures of the maxillofacial region remains poorly defined. OBJECTIVE: To evaluate the relationship between osteoporosis and maxillofacial trauma in the elderly. DESIGN, SETTING, AND MAIN OUTCOME MEASURES: A retrospective review of 59 patients 60 years or older treated for maxillofacial fractures at a trauma center between 1989 and 2000 was performed. The severity of osteoporosis was graded by evaluating the radiographic appearance of the vertebral bodies of each trauma patient using the Saville index. The number of maxillofacial fractures and the severity of osteoporosis in each patient was assessed to determine whether an association between osteoporosis and maxillofacial trauma exists. RESULTS: Of the 59 patients evaluated, 51% were injured by falls and 46% were involved in motor vehicle crashes. Seventy-three percent of the patients had multiple facial fractures. As the severity of osteoporosis worsened, patients were more likely to sustain a greater number of maxillofacial fractures (P=.01). The mechanism of injury had no impact on the relationship between osteoporosis and the number of fractures. CONCLUSIONS: Osteoporosis is an independent risk factor for the development of maxillofacial fractures. Since more than half of these patients are injured by falls, safety measures must be instituted to prevent fall-related maxillofacial injuries in the home and the community.

    Title Plasticity of Gamma-aminobutyrate Receptors in the Medial Vestibular Nucleus of Rat After Inferior Cerebellar Peduncle Transection.
    Date June 2003
    Journal Journal of Vestibular Research : Equilibrium & Orientation
    Excerpt

    Extracellular single unit recordings were made from regularly discharging medial vestibular nucleus neurons in brain slices from control rats and from rats surviving 7 days after bilateral transection of the inferior cerebellar peduncle. Decreases in firing rate during perfusion with the gamma-aminobutyric acid (GABA) agonists, muscimol (GABA(A)) and baclofen (GABA(B)), were greater in lesioned rats than in control rats. For the grouped data, the half-maximally-effective concentrations of muscimol and baclofen were 3.2 microM, as compared with 19.6 microM for control, and 0.8 microM, as compared with 2.7 microM for control, respectively. The antagonists bicuculline (GABA(A)) and 2-OH-saclofen (GABA(B)) only minimally affected the spontaneous firing rates of neurons in lesioned rats, significantly less than in control rats. The data suggest that the decreases of endogenous GABA levels in the medial vestibular nucleus after inferior cerebellar peduncle transection are accompanied by up-regulation of GABA(A) and, to a lesser extent, GABA(B) receptors.

    Title The Assessment and Management of the Dizzy Patient.
    Date January 2003
    Journal Otolaryngologic Clinics of North America
    Excerpt

    A significant number of individuals are affected by symptoms of dizziness. It is the most common complaint among patients over 75 years of age. A large number of these patients seek counsel from their physicians. It is imperative for the evaluating physician to obtain a thorough history and perform a complete physical exam. The proper diagnostic studies must also be obtained to confirm or rule out particular diagnoses. The physician should never assume that the dizziness is the result of normal aging prior to ruling out pathologic conditions.

    Title Spontaneous Activity in Rat Vestibular Nuclei in Brain Slices and Effects of Acetylcholine Agonists and Antagonists.
    Date July 2002
    Journal Brain Research
    Excerpt

    Extracellular recording was used to investigate spontaneously active neurons in all four major nuclei of the rat vestibular nuclear complex (VNC) in brainstem slices. The density of spontaneously active neurons was highest in the medial vestibular nucleus (MVN), slightly lower in the superior (SuVN) and spinal (SpVN) nuclei, and lowest in the lateral vestibular nucleus (LVN). We compared the effects of acetylcholine agonists and antagonists on spontaneously discharging neurons in MVN, SuVN, and SpVN with those in the nearby dorsal cochlear nucleus (DCN). The proportion of neurons responding to carbachol was greatest in DCN and smallest in SpVN. Unlike in DCN, some neurons in MVN, SuVN, and SpVN showed decreased firing during carbachol or muscarine. Magnitudes of responses to carbachol and muscarine were closely correlated (P<0.01). MVN neurons possessed nicotinic as well as muscarinic receptors. Activation of either type was unaffected by blocking synaptic transmission. The IC(50) values for the muscarinic subtype-preferential antagonists were compared, and tropicamide, preferential for M(4), was the most potent. Our results suggest that: (1) the relative numbers of spontaneously active neurons in rat VNC differ among nuclei; (2) acetylcholine agonists elicit changes in mean firing rates of neurons in MVN, SuVN and SpVN, but fewer neurons respond, and responses are smaller than in DCN; (3) both muscarinic and nicotinic acetylcholine receptors are present on MVN neurons, but muscarinic receptors may be more prominent.

    Title Otolaryngologic Management of Dizziness in the Older Patient.
    Date March 1999
    Journal Clinics in Geriatric Medicine
    Excerpt

    Studies report that dizziness is the most common presenting symptom in older patients who seek primary care. To understand the causes of dizziness, which is one of the major risk factors in causing falls in the older population, basic anatomy and physiology are reviewed in this article. Age-specific histopathologic changes occur in the labyrinth of the inner ear. To display evidence of the patient's symptoms, evaluation must include a comprehensive history, neurotologic examination, and diagnostic testing. There are common disorders associated with dizziness; thus, management depends on the cause. Once a diagnosis is secured, treatment is instituted based on sound medical principles.

    Title Tinnitus: Etiology and Management.
    Date March 1999
    Journal Clinics in Geriatric Medicine
    Excerpt

    Tinnitus is the perceived sensation of sound in the absence of acoustic stimulation. Individuals who suffer from it are commonly between the ages of 40 and 80 years. Tinnitus is often classified as objective or subjective, yet the pathophysiologic cause is still unknown. Subjective tinnitus is largely identified with hearing loss. Management of tinnitus is based on an individual approach; there is no single treatment or regimen for it.

    Title Astrocyte Reaction in the Rat Vestibular Nuclei After Unilateral Removal of Scarpa's Ganglion.
    Date March 1999
    Journal The Annals of Otology, Rhinology, and Laryngology
    Excerpt

    Unilateral vestibular ganglionectomy (UVG) results in a complete degeneration of vestibular nerve fibers and terminals in the ipsilateral vestibular nuclear complex (VNC). A subsequent glial reaction may affect the activities of VNC neurons and thereby influence compensation for lesion-induced vestibular disorders. Expression of glial fibrillary acidic protein (GFAP), a specific marker for reactive astrocytes, was demonstrated immunohistochemically in the rat VNC at 7, 14, and 35 days after UVG. An increased GFAP-positive astrocytic response was evident at 7 days after lesion in all the VNC regions on the lesioned side and in some regions on the unlesioned side and remained through 35 days. The glial response included hypertrophy, which was more prominent at 7 days than at 14 days or 35 days, and proliferation, more prominent at the later times, of GFAP-positive astrocytes. Astrocytic projections around VNC neuron somata and proximal dendrites increased in number and became thicker and more elongated, especially at 14 days, in the lateral vestibular nucleus. It is suggested that UVG results in a bilateral astrocytic reaction in the VNC that would affect the subsequent compensation.

    Title Quantitative Autoradiography of 5-[3h]6-cyano-7-nitro-quinoxaline-2,3-dione and (+)-3-[3h]dizocilpine Maleate Binding in Rat Vestibular Nuclear Complex After Unilateral Deafferentation, with Comparison to Cochlear Nucleus.
    Date March 1998
    Journal Neuroscience
    Excerpt

    The distributions of non-N-methyl-D-aspartate and N-methyl-D-aspartate receptors in the rat vestibular nuclear complex were estimated by quantitative autoradiography of 5-[3H]6-cyano-7-nitro-quinoxaline-2,3-dione and (+)-3-[3H]dizocilpine maleate binding, respectively. The binding of 5-[3H]6-cyano-7-nitro-quinoxaline-2,3-dione in the vestibular nuclear complex was also compared with that in the cerebellar cortex and cochlear nucleus. Measurements were made in control rats and in rats with unilateral destruction of the inner ear and removal of the vestibular ganglion. Compared to the unlesioned side, 5-[3H]6-cyano-7-nitro-quinoxaline-2,3-dione binding in the lesioned-side vestibular nuclear complex was decreased significantly in all regions at two to four postoperative days. However, the bilateral asymmetry disappeared in most regions by 30 days. 5-[3H]6-Cyano-7-nitro-quinoxaline-2,3-dione binding increased in the molecular layer of the cerebellar cortex at 30 days after lesion, although there were no clear changes at two to seven days. 5-[3H]6-Cyano-7-nitro-quinoxaline-2,3-dione binding in the cochlear nucleus decreased on the lesioned side, compared to the unlesioned side, in regions receiving significant auditory nerve innervation, but increased in the molecular layer of the dorsal cochlear nucleus. (+)-3-[3H]Dizocilpine maleate binding in regions of the vestibular nuclear complex was reduced on the lesioned side, compared to the unlesioned side, after deafferentation, with the largest reductions usually at 30 postoperative days. It is suggested that: (i) non-N-methyl-D-aspartate receptors are involved in synaptic transmission for both vestibular and auditory nerve fibers, while the involvement of N-methyl-D-aspartate receptors is less certain; (ii) unilateral deafferentation of the vestibular nuclear complex can result in bilateral asymmetries for non-N-methyl-D-aspartate and N-methyl-D-aspartate receptors, which are most prominent at earlier and later survival times, respectively; and (iii) vestibular compensation may involve regulation of both non-N-methyl-D-aspartate and N-methyl-D-aspartate receptors in the vestibular nuclear complex and activation of non-N-methyl-D-aspartate receptor-related processes in cerebellar cortex.

    Title Monomorphic Right Ventricular Tachycardia in a Patient with Mitral Valve Prolapse.
    Date October 1996
    Journal Pacing and Clinical Electrophysiology : Pace
    Excerpt

    A patient with mitral valve prolapse and symptomatic ventricular ectopy underwent an electrophysiological study during which a sustained monomorphic ventricular tachycardia with a left bundle branch block/right axis deviation morphology was induced. This morphology was replicated by pace mapping at the right ventricular outflow tract. To the best of our knowledge, this finding has not been previously described and suggests that the association between ventricular arrhythmias and mitral valve prolapse may not necessarily be causal.

    Title Effects of Oral Propafenone on Defibrillation and Pacing Thresholds in Patients Receiving Implantable Cardioverter-defibrillators. Propafenone Defibrillation Threshold Investigators.
    Date October 1996
    Journal Journal of the American College of Cardiology
    Excerpt

    OBJECTIVES: The effects of propafenone, a predominantly class IC antiarrhythmic drug, on defibrillation and pacing thresholds were evaluated in patients undergoing cardioverter-defibrillator implantation. BACKGROUND: Previous studies have shown that the class IC agents encainide and flecainide may increase the energy requirements for pacing and defibrillation. Animal studies with propafenone have shown inconsistent results regarding its effect on defibrillation energy requirements. This report investigated the effects of propafenone on defibrillation and pacing thresholds in humans. METHODS: After cardioverter-defibrillator implantation, 47 patients were enrolled in a double-blind, three-way parallel, randomized trial of 450 mg/day (Group 1) or 675 mg/day (Group 2) of oral propafenone or placebo (Group 3) for 3 to 7 days. Predischarge defibrillation and pacing thresholds after treatment were compared with baseline thresholds obtained at implantation. RESULTS: There was no statistically significant difference between implantation and predischarge defibrillation thresholds in the three groups (Group 1: [mean +/- SE] 11.0 +/- 1.3 vs. 12.1 +/- 1.5 J; Group 2: 11.5 +/- 1.1 vs. 13.6 +/- 1.3 J; Group 3: 12.5 +/- 1.2 vs. 13.3 +/- 1.6 J), and no significant difference between treatment groups was found with a 0.86 power to detect a 5-J difference between groups. Paired pulse width pacing thresholds at 2.8 V were compared in 14 patients. A small increase of 0.02 ms was noted at predischarge testing in patients treated with propafenone and placebo. CONCLUSIONS: Short-term oral propafenone (450 and 675 mg/day) does not significantly affect defibrillation or pacing thresholds. Concomitant use of propafenone in patients with implantable cardioverter-defibrillators with recurrent ventricular or atrial tachyarrhythmias should not interfere with proper device function.

    Title Immunohistochemical Study on the Distributions of Ampa Receptor Subtypes in Rat Vestibular Nuclear Complex After Unilateral Deafferentation.
    Date August 1996
    Journal Annals of the New York Academy of Sciences
    Title Quantitative Changes of Amino Acid Distributions in the Rat Vestibular Nuclear Complex After Unilateral Vestibular Ganglionectomy.
    Date June 1996
    Journal Journal of Neurochemistry
    Excerpt

    Changes of amino acid concentrations in the vestibular nuclear complex (VNC) during lesion-induced vestibular compensation were studied in rats after unilateral vestibular ganglionectomy. Distributions of 12 amino acids within the VNC were measured at 2,4,7, and 30 days after surgery, using microdissection of freeze-dried brain sections and HPLC. Glutamate decreased on the lesioned side in nearly all VNC regions. Changes were fully developed 2 days after lesion and persisted through 30 days. In some regions, glutamate decreased also on the unlesioned side, especially at longer survival times, so that bilateral asymmetries became reduced. Aspartate changes were similar to those of glutamate on either side. Lesion-induced glutamine asymmetry was usually opposite to that of glutamate. Although GABA concentration decreased at early survival times, it recovered at later times and sometimes increased in dorsal parts of lateral and medial nuclei. Taurine changes were similar to those of GABA in most regions. Glycine change was primarily limited to a bilateral decrease in the dorsal part of the lateral vestibular nucleus. Concentrations of other amino acids were much lower, but some showed postlesion changes.

    Title Static Stabilometry, Transcranial Doppler, and Single Photon Emission Computed Tomography in Patients with Central Dizziness.
    Date March 1996
    Journal The American Journal of Otology
    Excerpt

    Previous studies have found that transcranial doppler (TCD) and single photon emission computed tomography (SPECT) are effective means of diagnosing cerebral blood flow disorders in patients with central dizziness whose etiology was unknown by standard audiologic and/or vestibular assessment techniques. Also, static stabilometry, which measures a person's standing center of pressure (COP) movements, has been used to distinguish between patients with central neurologic and peripheral vestibular disorders. The purpose of this retrospective study was to examine the relation between TCD, SPECT, and stabilometry in patients with central dizziness attributable to cerebral blood flow disorders. Stabilometry testing was conducted on 50 normal subjects and 31 subjects with dizziness, the latter group consisting of persons with cerebral dysautoregulation, migraines, and unknown etiology with negative or positive SPECT results. The results indicated that patients with cerebral dysautoregulation were not significantly different from normal subjects or the other three groups in their COP movements. The other three groups exhibited significantly higher COP movements than the normal subjects, particularly when visual inputs were compromised. Patients with negative SPECT results were significantly different in their COP movements from the other three groups of subjects with dizziness. These results suggest that the pattern of COP movements may be useful in identifying patients with postural dysfunctions whose etiology may then be detected by TCD and SPECT.

    Title Central Dizziness Associated with Cerebral Blood Flow Disorders.
    Date March 1996
    Journal The American Journal of Otology
    Excerpt

    This retrospective study describes the use of transcranial Doppler (TCD) and history for further defining and diagnosing cerebral blood flow (CBF) disorders in patients with central dizziness. Central dizziness was defined as dizziness of nonlabyrinthine, non-peripheral causes. It was believed that at least some of the causes for central dizziness are not unknown but are associated with CBF disorders. Fifty patients who presented with central dizziness were examined and subsequently tested with TCD. In 33 of 50 cases (66%) a diagnosis could be assigned after TCD; whereas, on the basis of both history and TCD a diagnosis was assigned to 38 patients (76%).

    Title Postural Stability Following Mild Head or Whiplash Injuries.
    Date March 1996
    Journal The American Journal of Otology
    Excerpt

    Studies of the sequelae of head injury suggest that cochlear and vestibular dysfunctions, comprise some of the most frequently reported delayed complications following head trauma. To date, little attention has been given to the relation between post-traumatic subjective symptoms of dizziness and the objective measures of postural stability or balance. The purpose of this study was to quantify the balance deficits in individuals who had developed symptoms of dizziness following mild head and whiplash injuries. The balance abilities of 29 patients, who developed dizziness following some type of mild head or whiplash injury, were compared to those of 51 healthy symptom-free subjects. Balance was assessed by examining the center-of-pressure movements, in the anterior-posterior and medial-lateral directions, and the total movement displacement. The isolated contributions of visual and somatosensory inputs were estimated by comparing the magnitudes of the center-of-pressure movements for the various sensory conditions. Data were collected from three 30-second trials of each combination of three visual conditions (accurate, absent, and inaccurate) and two somatosensory conditions (accurate and inaccurate), with the patient standing on a fixed-force platform. Univariate analyses of variance indicated that the group with head injury, compared to the control group, exhibited significantly greater anterior-posterior movements in four of the six sensory conditions and greater total movement displacement during the inaccurate vision/inaccurate somatosensation condition. These data suggest that patients who have sustained head or neck trauma exhibit increased reliance on accurate visual input and are unable to utilize vestibular orienting information to resolve conflicting information from the visual and somatosensory systems.

    Title Comparison of Surgeries for Removal of Primary Vestibular Inputs: a Combined Anatomical and Behavioral Study in Rats.
    Date May 1995
    Journal The Laryngoscope
    Excerpt

    Unilateral removal of Scarpa's ganglion and neurectomy of the peripheral vestibular nerve branches were compared in rats as methods to eliminate primary vestibular input. Ocular nystagmus was consistently observed after both types of lesion, but it completely disappeared within 4 to 7 days. Imbalance and rotation were more serious and prolonged after ganglionectomy than after peripheral neurectomy. Corresponding with these differences in symptoms were differences in terminal degeneration. After ganglionectomy, degenerated axons and terminals were distributed throughout all terminal regions of primary vestibular fibers on the lesioned side, while after peripheral neurectomy, the degeneration was more limited. The results of this study suggest that vestibular ganglionectomy is a more successful approach than peripheral vestibular neurectomy for removing the primary vestibular input.

    Title Sudden Hearing Loss and Unstable Angina Pectoris.
    Date May 1995
    Journal Ear, Nose, & Throat Journal
    Excerpt

    Acute sudden sensorineural hearing loss has been extensively described in the literature and is a well recognized clinical entity. The exact etiology for this entity has been difficult to ascertain. Multiple etiologies have been promoted including infectious agents, vascular abnormalities, acoustic trauma, metabolic disorders, and autoimmune syndromes. In some cases, neoplasms such as acoustic neurinoma can be identified. On occasion, ototoxic medications are present in the history. Moulonguet and Gougelot have associated mitral valve prolapse, microemboli, transient hemiparesis and sudden hearing loss. This report describes a patient who had sudden sensorineural hearing loss in conjunction with unstable angina pectoris, in whom coronary bypass surgery appeared to have resulted in acute and significant hearing improvement and stabilization.

    Title Quantitative Distribution of Amino Acids in the Rat Vestibular Nuclei.
    Date March 1995
    Journal Journal of Vestibular Research : Equilibrium & Orientation
    Excerpt

    The normal concentrations of 12 amino acids in the vestibular nuclei of rats were quantitatively measured using microdissection of freeze-dried brain sections combined with high performance liquid chromatography (HPLC) analysis. Both excitatory amino acids, aspartate and glutamate, showed only small variation across the vestibular nuclei. The distribution of glutamine tended to parallel that of glutamate. The inhibitory amino acids, gamma-aminobutyrate (GABA) and glycine, were much more concentrated in some regions than in others. GABA tended to be more concentrated than glycine in dorsal and rostral nuclei, while glycine tended to be more concentrated than GABA in ventral and caudal nuclei. The distribution of taurine was comparable to that of GABA, suggesting a close relationship with GABA function. Asparagine, serine, threonine, arginine, alanine and tyrosine had relatively low concentrations without significant differences among vestibular nuclei. Our results suggest that (1) different parts of the vestibular nuclear complex may receive similar amounts of excitatory amino acid afferents, (2) there is predominance of GABA or glycine as an inhibitory transmitter in different parts of the vestibular nuclear complex, and (3) there may be a close functional relationship between taurine and GABA within the vestibular nuclear complex. These results provide data basic to further research on the details of amino acid functions in the normal and abnormal vestibular system, as well as studies of plasticity in this system.

    Title Effect of Left Ventricular Hypertrophy and Its Regression on Ventricular Electrophysiology and Vulnerability to Inducible Arrhythmia in the Feline Heart.
    Date January 1995
    Journal Circulation
    Excerpt

    BACKGROUND: Left ventricular hypertrophy (LVH) is associated with an increased risk of death, susceptibility to ventricular arrhythmia, and multiple electrophysiological abnormalities. The purpose of the present study was to determine whether the susceptibility to arrhythmia and electrical abnormalities persists after regression of hypertrophy in an animal model of LVH. METHODS AND RESULTS: We placed constricting bands on the ascending aorta of cats (n = 9) or performed sham operations (n = 9). Serial cardiac echocardiography was performed to measure left ventricular wall thickness. After LVH had developed in the banded animals, the constricting bands were removed and serial echocardiograms were used to monitor for regression of hypertrophy. Electrophysiological studies were performed in cats that showed regression of LVH (Regress, n = 5), those that showed no change in LV wall thickness (No Regress, n = 4), and in the sham-operated animals (Sham). Cats with persistent LVH had a higher incidence of inducible polymorphic ventricular tachycardia (4 of 4) compared with Regress (1 of 5) or Sham (1 of 9) cats (P < .05) and had lower ventricular fibrillation thresholds (9 +/- 2 mA) than Regress (17 +/- 4 mA) or Sham (16 +/- 3 mA) cats (P < .05). Persistent LVH in the No Regress group was associated with prolongation of epicardial monophasic action potential duration (MAPD) in the left but not the right ventricle. Dispersion of refractoriness was greater in the No Regress group (P < .05 versus Regress or Sham). Regress cats were identical to Sham cats in having a low incidence of inducible polymorphic ventricular arrhythmia, high fibrillation threshold, and MAPD measurements (P = NS versus Sham). CONCLUSIONS: LVH produces multiple electrophysiological abnormalities and increased vulnerability to inducible polymorphic ventricular arrhythmia in this model of LVH. Cats that show regression of hyperthrophy have normal ventricular electrophysiology and have the same low vulnerability to inducible ventricular arrhythmia as Sham animals.

    Title Differentiation of Balance Deficits Through Examination of Selected Components of Static Stabilometry.
    Date February 1994
    Journal The Journal of Otolaryngology
    Excerpt

    Stabilometry, which measures the body's center of pressure (COP) movements, during relaxed standing, has been used to distinguish individuals with vestibular and neurologic dysfunctions from normal subjects. The purpose of this study was to determine whether mathematical differences in the magnitudes of the COP obtained from six somatosensory testing conditions could be used to discriminate between different types of balance deficits. Stabilometry measures, using a fixed force platform, were obtained from normal (N = 52) and dizzy (N = 149), peripheral vestibular dysfunction (PVD), post-concussion syndrome (PCS), psychogenic (PSG), and unknown/undetermined etiology (UNK). The data significantly differentiated CVD, PVD and PSG patients from normals and between some of the dizzy groups: CVD versus PVD, PCS; and PSG versus CVD, PVD, PCS and UNK. The measures of anterior-posterior COP movements provided the greatest discrimination.

    Title Electrophysiologic Testing in Patients Who Respond Acutely to Intravenous Amiodarone for Incessant Ventricular Tachyarrhythmias.
    Date June 1993
    Journal American Heart Journal
    Excerpt

    The outcome of patients who receive intravenous amiodarone for suppression of incessant ventricular tachyarrhythmia has not been studied conclusively. We conducted a prospective study in which all patients who responded acutely to intravenous amiodarone and went on to receive a subsequent oral loading dose were subjected to electrophysiologic testing before hospital discharge to determine whether additional or alternative therapy would be required. Among 18 patients (17 with ischemic heart disease) who entered the protocol, 16 had a clinical response to intravenous amiodarone alone (12 patients) or in combination with another antiarrhythmic drug (4 patients) and survived to study. Of these, 10 had monomorphic ventricular tachycardia (VT) when first seen, five had polymorphous VT or ventricular fibrillation (VF), and three had both. In seven patients sustained monomorphic VT was inducible (group 1), and in nine it was not (group 2). The only clinical factor that distinguished group 1 from group 2 was age (group 1 > group 2). Five patients in group 1 and one in group 2 received an implantable cardioverter defibrillator; one patient in group 1 had a successful endocardial resection. During a mean follow-up period of 11 months, four patients in group 1 have had appropriate implantable cardioverter defibrillator discharges, whereas only one patient in group 2 has had a clinical event (sudden death). We conclude that intravenous amiodarone is a highly effective drug used alone or in combination to suppress spontaneous incessant VT/VF. Predischarge electrophysiologic testing, even in patients who have polymorphous VT, has predictive value over and above the observed clinical response. These preliminary results favor predischarge testing and aggressive device treatment in this cohort.

    Title The Head-up Tilt Table Test and Cardiovascular Neurogenic Syncope.
    Date March 1993
    Journal American Heart Journal
    Title Head-upright Tilt-table Testing: a Useful Tool in the Evaluation and Management of Recurrent Vertigo of Unknown Origin Associated with Near-syncope or Syncope.
    Date December 1992
    Journal Otolaryngology--head and Neck Surgery : Official Journal of American Academy of Otolaryngology-head and Neck Surgery
    Excerpt

    Recurrent idiopathic vertigo associated with near-syncope and syncope is a common perplexing problem, some cases of which are considered autonomically mediated (vasovagal). Upright-tilt-table testing has emerged as a potential method to test for vasovagal episodes. This study evaluated the use of this technique in the evaluation and management of patients with recurrent idiopathic vertigo associated with near-syncope or syncope. Twenty-one patients with recurrent unexplained vertigo and syncope/near-syncope and 11 control subjects were evaluated by use of an upright-tilt-table test for 30 minutes, with or without a graded isoproterenol infusion (1 to 4 micrograms/min given intravenously), in an attempt to provoke hypotension, bradycardia, or both, which reproduced the patient's symptoms. The patients included 10 men and 11 women (mean age, 51 +/- 16 years). Eleven controls with no history of vertigo were also studied. Transcranial Doppler sonography was used to assess cerebral arteriolar blood flow during tilt. All tilt-positive patients were placed on therapy with either beta-blockers, disopyramide, or transdermal scopolamine, the effectiveness of which was determined with another tilt-table study. Symptoms occurred in seven patients (33%) during the baseline tilt and in eight patients (38%) during isoproterenol infusion (total positives, 71%). Transcranial Doppler sonography demonstrated a 225% +/- 192% increase in pulsatility index and a 70% +/- 29% increase in resistance index (indicative of cerebral arteriolar vasoconstriction) at the time of vertigo. No control subject experienced syncope during this test. Each tilt-positive patient eventually became tilt-negative with therapy, and over a mean follow-up period of 26 months, no further episodes have occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

    Title The Team Approach to Treatment of the Dizzy Patient.
    Date September 1992
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    This report describes how a rehabilitation team treats dizziness and vestibular disorders. Team members include a nurse, physician, audiologist, physical therapist, occupational therapist, and a research scientist. Although unusual, this multidisciplinary approach, involving a close-knit group of professionals, is of great benefit in the treatment of vestibular and balance disorders.

    Title Stabilometry in Balance Assessment of Dizzy and Normal Subjects.
    Date February 1992
    Journal American Journal of Otolaryngology
    Excerpt

    Normal adults and patients referred to the Dizzy Clinic at the Medical College of Ohio had their standing balance assessed during combinations of normal and altered visual and somatosensory orientation conditions using a fixed-force platform to measure center-of-pressure translations. Significant differences were identified between normal subjects and dizzy patients, depending on the particular diagnostic category, the sensory condition tested, and the particular sway component being measured. Patients with central and peripheral vestibular dysfunctions had significantly greater sway than all other categories in most test conditions, especially with eyes closed and with a visual conflict dome while standing on a foam surface. The central vestibular dysfunction and peripheral vestibular dysfunction groups could be differentiated statistically under eyes-closed and visual conflict-foam conditions. The normal and psychogenic groups could not be differentiated statistically for any test conditions except one: there was significantly greater mean anterior/posterior sway displacement in the psychogenic group compared with all other diagnostic categories for the eyes-open foam test condition. Our results indicate that static stabilometry recordings of postural sway can be used to evaluate and quantify a dizzy patient's ability to receive and process vestibular, visual, and somatosensory-proprioceptive cues for postural stability. It can also be used to monitor patients with vestibular disorders and to document their responses to rehabilitation programs.

    Title Enzymes of Transmitter and Energy Metabolism in Cat Middle Ear Muscles.
    Date February 1991
    Journal Otolaryngology--head and Neck Surgery : Official Journal of American Academy of Otolaryngology-head and Neck Surgery
    Excerpt

    Activities of the enzymes choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), which metabolize the neuromuscular transmitter acetylcholine, and malate and lactate dehydrogenase (MDH and LDH), enzymes of oxidative and glycolytic energy metabolism, respectively, were measured in the middle ear muscles of the cat. For comparison, the same enzyme activities were measured in extraocular muscle tissue and in three hindlimb muscles rich in either slow oxidative (soleus), fast glycolytic (white part of vastus lateralis), or fast oxidative glycolytic (plantaris) muscle fibers. ChAT and AChE activities were much higher in middle ear muscles than in hindlimb muscles, consistent with a denser neuromuscular innervation, as in extraocular muscles. By contrast, MDH and LDH activities were remarkably low in the middle ear muscles, lower than in any of the hindlimb muscles or the extraocular muscles. Denervation of the stapedius muscle by peripheral transection of the facial nerve resulted in decreases in all four enzyme activities without associated changes in the tensor tympani. Surgical ablation of the peripheral facial nerve supply to the stapedius muscle appears to be a feasible option for producing its denervation. The results suggest some rather specialized chemical characteristics for the middle ear muscles.

    Title Transient Cortical Blindness and Occipital Seizures with Cyclosporine Toxicity.
    Date April 1989
    Journal Transplantation
    Title Myasthenia Gravis with Thymoma and Pure Red Blood Cell Aplasia.
    Date May 1988
    Journal American Journal of Clinical Pathology
    Excerpt

    A case of myasthenia gravis with histopathologic confirmation of spindle cell thymoma and pure red blood cell aplasia is reported. This is the twelfth case in the literature in which a simultaneous occurrence of all three disorders, with documented thymic pathology, is noted. Immunologic observations in this patient include an elevated acetylcholine receptor antibody and antinuclear antibody titer, agglutination of mouse red blood cells when combined with the patient's serum, and lack of inhibition of binding of radioactive erythropoietin to mouse red cell receptors when combined with the patient's serum. Although both myasthenia with thymoma and pure red blood cell aplasia may have a common immunologic denominator, our findings in this case indicate that inhibition of erythropoiesis is unrelated to erythropoietin receptor blockade. An alternative hypothesis is offered based on defective T-cell function.

    Title Digitalized Auto-septoplasty.
    Date March 1988
    Journal The Journal of Otolaryngology
    Title Cerebral Blindness and Encephalopathy with Cyclosporin A Toxicity.
    Date June 1987
    Journal Neurology
    Excerpt

    We observed acute cerebral blindness and encephalopathy complicating cyclosporin A (CyA) toxicity in a 5-year-old transplantation patient. Serum CyA level was 1,704 ng/ml (normal, less than 300 ng/ml). Additional neurologic complications of CyA toxicity will be reviewed.

    Title Neurologic Complications of Intravenous Drug Abuse.
    Date May 1987
    Journal Hospital Practice (office Ed.)
    Title Contextual Age As a Life-position Index.
    Date April 1987
    Journal International Journal of Aging & Human Development
    Excerpt

    A contextual age construct was developed and examined as a transactional, life-position index of aging. The eighteen-item contextual age index included six interrelated dimensions: physical health, interpersonal interaction, mobility, life satisfaction, social activity, and economic security. In addition to the development of the index, associations among contextual age and sociodemographic characteristics were examined for a sample of 640 persons. Chronological age was correlated negatively with mobility and physical health, and positively with economic security, life satisfaction, and interpersonal interaction. Mobility, economic security, life satisfaction, physical health, and interpersonal interaction discriminated between chronological age groups. Interpersonal interaction, economic security, physical health, and social activity were predictors of life satisfaction. The contextual age construct raises questions concerning several negative myths about aging. The findings reflect the weak validity of chronological age as a unidimensional indicator of life-position and well-being.

    Title The Otolaryngologist's Attitude to Facial Plastic Surgery.
    Date July 1986
    Journal The Journal of Otolaryngology
    Excerpt

    Of 453 Canadian otolaryngologist, 226 responded to a questionnaire, indicating significant interest in the state of facial plastic and reconstructive surgery. The majority of these otolaryngologists practised in larger cities and one-quarter received foreign training. Half of the respondents had academic affiliations and three-quarters considered themselves general otolaryngologists. Almost all the otolaryngologists believed that cosmetic and reconstructive surgery should form a major part of their specialty, this being unanimous among current residents. A large majority felt there should be more facial plastic surgical training, this both at the residency and fellowship levels, preferably through increased surgical exposure. With respect to sub-certification, only the resident group was in favor.

    Title Mondini Dysplasia--late Complications.
    Date December 1985
    Journal The Journal of Otolaryngology
    Excerpt

    Mondini's deformity is the second most common malformation seen in congenital genetic deafness. It is characterized by bony and membranous abnormalities of the inner ear, with a wide range of morphological and functional abnormalities. The importance of the Mondini malformation is that the patient is at an increased risk of developing meningitis or bilateral total hearing loss (or both) at an early age. Six cases are presented which illustrate the various sequelae of the Mondini malformation including meningitis, vertigo, and auditory deterioration. Decompression of the endolymphatic sac was undertaken in three patients. Emphasis is placed on the danger of head trauma, even minor, in these patients. The necessity of early diagnosis with adequate patient counseling is stressed.

    Title Optokinetic Afternystagmus and Post Rotatory Nystagmus in Patients with Unilateral Labyrinthine Lesions.
    Date October 1984
    Journal The Journal of Otolaryngology
    Excerpt

    The decay times of optokinetic afternystagmus (OKAN) and the vestibuloocular reflex (VOR) were measured in six subjects with chronic unilateral labyrinthectomy and in six age-matched controls. Both OKAN and VOR decay times showed parallel reduction following unilateral labyrinthectomy when the induced nystagmus beat toward the side of the lesion. The VOR decay time for nystagmus beating toward the contralateral side was also significantly reduced. Our findings support the view that the optokinetic system increases the vestibular decay time, that separate left and right velocity storage mechanisms do exist, but that the decoupling between the two sides is far from perfect.

    Title Near-drowning, Scuba Diving: an Unusual Late Sequela of Bulbar Polio.
    Date September 1984
    Journal The Journal of Laryngology and Otology
    Excerpt

    This case report illustrates an unusual hazard of underwater sports: vagal neuropathology secondary to early poliomyelitis which resulted in residual palato-pharyngeal paresis. Gag and swallowing reflexes appeared to function adequately but in fact were not normal. When stressed, during water aspiration, they were inadequate, resulting in great risk to the underwater enthusiast. A history of early viral myelitis must be considered as a potential hazard in underwater sports.

    Title Parathyroid Gland Transplantation After Total Thyroidectomy with Pharyngolaryngoesophagectomy.
    Date December 1983
    Journal Head & Neck Surgery
    Excerpt

    Surgical treatment of extensive hypopharyngeal carcinoma often includes total thyroidectomy together with resection of the primary disease. The risk of removing or damaging the parathyroid glands is considerable; this may render the patient permanently hypoparathyroid with all the problems of management. These patients must be on lifelong supplementation and at times, due to failure to take the medication, hypocalcemic crises are precipitated. To avoid this problem, we have been identifying the parathyroid glands intraoperatively and, after pathological confirmation, have transplanted them to the forearm. Three patients who underwent this procedure are presented. All are normocalcemic without supplementation and parathyroid hormone assays on serum from the transplanted forearm show significantly elevated levels.

    Title Head and Neck Manifestations of Mycobacteria in the Absence of Pulmonary Disease.
    Date April 1983
    Journal The Journal of Otolaryngology
    Excerpt

    Mycobacterial infections, once relatively rare in North America have recently shown an upsurge with the influx of Asian and African immigrants. The infections are usually due to M. tuberculosis and present with pulmonary symptoms. However, an uncommon presentation is that of a mass in the head and neck region without any pulmonary manifestations. Although these infections are usually secondary to invasion by "atypical" mycobacteria, unusual presentations due to mycobacterium tuberculosis have been noted. Case reports depicting the very rare presentations of M. tuberculosis in the thyroglossal duct cyst, parotid, and submandibular lymph node are described. A very unusual case of atypical mycobacteria in the larynx is noted and cervical adenitis is also included. The initial subtle presentation emphasizes the importance of mycobacteria in the differential diagnosis of lesions in the head and neck region.

    Title University of Toronto Teaching Rounds. Esthetic Evaluation of the Lips and Cosmetic Reconstructions.
    Date October 1982
    Journal The Journal of Otolaryngology
    Title Limb Input to the Cat Vestibular Nuclei.
    Date March 1979
    Journal Acta Oto-laryngologica
    Excerpt

    The input from fore- and hindlimbs to the vestibular nuclear complex (VNC) was investigated in awake cats. Electrical stimulus was given to the sciatic, radial and vestibular nerves bilaterally and single unit responses were recorded in the VNC with extracellular technique. The position of the microelectrode was histologically confirmed. All four major vestibular nuclei received fore- as well as hindlimb input. Forty per cent of the neurons with limb input also received vestibular afferents. No major distinguishing features appeared between the different nuclei with regard to response characteristics. Certain differences in laterality of response, quantitative fore-hindlimb ratio and somatosensory-labyrinthine convergence were observed however. Response latencies to sciatic and radial nerve stimuli always exceeded a 3 msec and were grouped around 8 and 16 msec. A third population of vestibular neurons had latencies over 20 msec. Both excitatory and inhibitory responses were recorded, with the latter not always following an activation. The findings illustrate the complex nature of the ascending pathway to the VNC and the integrative properties of this complex.

    Title Labyrinthine and Somatosensory Convergence Upon Vestibulospinal Neurons.
    Date December 1978
    Journal Acta Oto-laryngologica
    Excerpt

    In awake cats cells forming the lateral (LVST) and medial (MVST) vestibulospinal tracts were identified by employing antidromic stimulation of the spinal cord. Neuronal responses to bilateral vestibular, forelimb, hindlimb, and neck electrical nerve stimulation were analysed. Extracellular recording in the vestibular nuclei was performed via a glass micropipette saturated with Fast Green, to aid in later histological tract identification. The number of cells projecting to cervical and lumbar regions in the dorsal and ventral division of Deiters' nucleus did not differ significantly. An unexpectedly large number of MVST units was found in the descending nucleus. Some MVST units projected to the lumbar cord but in both the medial and descending nuclei, projections to the cervical cord were in majority. Almost all spinal projecting vestibular neurons received labyrinthine input and more than half received somatosensory input. The units could be separated into several populations on basis of excitatory and inhibitory labyrinthine response latencies indicating multiple pathways. As regards labyrinthine-somatosensory integration the two tracts were found to be quite similar. The extent and complexity of labyrinthine-somatosensory convergence indicate the importance of feed-back mechanisms upon postural controls also at the level of the vestibular nuclei.

    Title Vestibulothalamic Projections in Man--a Sixth Primary Sensory Pathway.
    Date July 1978
    Journal Journal of Neurophysiology
    Excerpt

    1. Responses suggesting activation of the vestibular system, elicited by electrical stimulation of the human thalamus during 22 routine stereotaxic neurosurgical procedures, were examined in a retrospective study to determine the possible existence of vestibulothalamo-cortical projections in man. 2. Such responses were most frequently described as sensations of movement through space and were associated with two distinct vestibulothalamic projections: a) an anterior relay was situated ventral to the medial lemniscus, passing lateral to the red nucleus and dorsal to the subthalamic nucleus prior to terminating in the nucleus ventrointermedius (Vim) (comparable to VPLo in primates); b) a posterior relay associated with the auditory pathway (lateral lemniscus and brachium of the inferior colliculus) projected to the medial geniculate body. 3. The production of sensations of motion in conscious patients by stimulating areas that are similar to those reported constituting vestibulothalamic pathways in cats and primates implies a distinct primary sensory cortical projection for processing information from the vestibular receptors pertaining to the recognition of spatial movements.

    Title Labyrinthine and Somatosensory Convergence Upon Vestibulo-ocular Units.
    Date April 1978
    Journal Acta Oto-laryngologica
    Excerpt

    The vestibular nuclei were investigated in 18 adult cats. Vestibulo-oculo-motor neurons were identified by antidromic stimulation of the ascending medial longitudinal fasciculus (MLF). The neurons were subjected to various stimuli: vestibular, neck, forelimb and hindlimb nerve stimulation on both sides. The recording was extracellular with micropipettes containing Fast Green. Only the medial and the superior vestibular nuclei were found to project to the MLF. All projecting units had input from the labyrinths. Excitatory response latencies to ipsilateral labyrinth stimulation never exceeded 3 msec. Both excitatory and inhibitory response latencies could be distributed into different categories. The majority of the neurons did not receive a somatosensory input, and surprisingly few convergent units could be seen. Peripheral somatosensory information apparently plays a minor role in vestibulo-ocular relations.

    Title Vestibular and Somatosensory Interaction in the Cat Vestibular Nuclei.
    Date February 1978
    Journal Pflügers Archiv : European Journal of Physiology
    Excerpt

    The vestibular nuclei of cats were explored extracellulary with micropipettes to locate units with a resting discharge rate which responded to rotation in the horizontal plane. These units were examined for somatosensory input from neck and limbs. Fewer than half responded to somatosensory stimulation. The neck region was the body area most effective in influencing unitary activity. The response pattern most often noted was an increase and decrease in discharge frequency when the body was moved towards and away from the recording electrode respectively. Change in discharge rate was observed to be primarily dependant upon neck velocity and not upon absolute neck position. Half of the somatosensory units received input from either the forelimbs or the hindlimbs, while the remaining half responded to both.

    Title Labyrinthine Input to the Vestibular Nuclei of the Awake Cat.
    Date December 1977
    Journal Acta Oto-laryngologica
    Excerpt

    The labyrinthine input to the vestibular nuclei was investigated in 24 awake cats. Stimulus consisted of electrical shocks given through bipolar silver wire electrodes, implanted in the utricular and lateral ampullar nerves. Throughout the vestibular nuclei, single units were recorded extracellularly with glass micropipettes filled with Fast Green. The tracts of the penetrating electrodes were identified histologically. In all four nuclei units responding to both labyrinths outnumbered unilaterally responding neurones with certain differences between the individual nuclei. Excitatory as well as inhibitory responses were observed, polysynaptic being more common than mono- or disynaptic ones. No monosynaptic contralateral responses were seen. The latency distribution of contralateral responses closely mirrored that of ipsilateral responses within each nucleus. Both excitatory and inhibitory responses fell into relatively segregated populations, based upon latency distribution. This implies separate pathways for labyrinthine input to the vestibular nuclei.

    Title A Comparative Study of Vestibulocortical Projection.
    Date October 1977
    Journal International Journal of Equilibrium Research
    Title Hearing Under Stress: Ii. Effect of Hyperventilation and Hypercapnia on Speech Discrimination.
    Date February 1977
    Journal Aviation, Space, and Environmental Medicine
    Excerpt

    Changes in the ability to discriminate speech from a eucapnic state to hyperventilation and hypercapnia were investigated. Standard speech audiometric techniques were employed to determine the speech reception threshold and the speech discrimination values, while respiratory conditions were varied and measured utilizing a mixed-gas breathing method. Respiratory parameters were similar to those encountered in aircraft personnel who experience oxygen/pressure system malfunction. The results of the study suggest no significant change in the speech reception threshold while in a hyperventilated or hypercapnic state. The speech discrimination results, however, suggest a significant performance decrement while in a state of hyperventilation.

    Title Vestibulo-thalamic Projections Studied with Antidromic Technique in the Cat.
    Date January 1977
    Journal Acta Oto-laryngologica
    Excerpt

    The vestibulo-thalamic projection was investigated in anaesthetized cats. Electrical stimulation of posterolateral thalamic areas frequently changed the spontaneous firing pattern of neurons in the vestibular nuclei but only 5% were antidromically invaded. This group was further analysed with regard to types of labyrinthine and somatosensory input; thalamo-projecting neurons in the vestibular nuclei are frequently located in the lateral vestibular nucleus, they receive no monosynaptic inflow from the labyrinth and they often receive convergent vestibular and somatosensory input.

    Title Hearing Under Stress: Iv. a Speech Delivery Communication System for Utilization in High Ambient Noise Environments.
    Date September 1976
    Journal Aviation, Space, and Environmental Medicine
    Excerpt

    Many communication systems have been devised to improve the individual's ability to receive speech information in the presence of ambient noise. The purpose of this study was to determine the effectiveness of a speech delivery system which combined a high degree of ambient noise attenuation with the ear's own natural amplification phenomenon--the occlusion effect. It was demonstrated that occlusion of the auditory system at the level of the external auditory meatus, in conjuction with bone-conducted speech stimuli presented at the mastoid, was most effective in providing high speech discrimination ability with significant attenuation of ambient noise.

    Title Hearing Under Stress: Iii. The Effect of External Auditory Meatal Pressure on Speech Discrimination.
    Date June 1976
    Journal Aviation, Space, and Environmental Medicine
    Excerpt

    It has been well established that unequal air pressure across the tympanic membrane causes an increase in puretone thresholds. Very little information is available, however, concerning concommitant effects on reception and discrimination of speech material. This study was designed to determine whether or not further detrimental effects upon the communication process might occur in the form of decreased speech discrimination ability. The findings established that a high positive pressure in the external meatus can result in a deterioration of the individual's ability to discriminate speech sounds.

    Title Vestibular-neck Integration in the Vestibular Nuclei.
    Date December 1975
    Journal Brain Research
    Title Studies on the Integrative Activity of the Vestibular Nuclei Complex.
    Date October 1975
    Journal Canadian Journal of Otolaryngology. Journal Canadien D'otolaryngologie
    Excerpt

    Central mechanisms currently used in clinical vestibular tests are far more complex than generally thought. The first synaptic station, the vestibular nuclei, represents a sensory-motor centre integrating vestibular impulses with proprioceptive afferents from muscles and joints. This convergence can be found on cells with long axons projecting to the oculo-motor system, to the spinal cord and to the thalamus as well as on cells without long projecting axons. There are also vestibulo-motor cells transmitting pure vestibular information.

    Title Vestibular and Auditory Cortical Projection in the Guinea Pig (cavia Porcellus).
    Date March 1974
    Journal Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
    Title Vestibular Cortical Projection in the Rabbit.
    Date June 1973
    Journal The Journal of Comparative Neurology

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