The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
James G Colebatch - One of the best experts on this subject based on the ideXlab platform.
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characteristics and clinical applications of vestibular evoked myogenic potentials
Neurology, 2005Co-Authors: Miriam S Welgampola, James G ColebatchAbstract:A recent technique of assessing vestibular function, the vestibular-evoked myogenic potential (VEMP), is an otolith-mediated, short-latency reflex recorded from averaged sternocleidomastoid electromyography in response to intense auditory clicks delivered via headphones. Since their first description 10 years ago, VEMPs are now being used by investigators worldwide, and characteristic changes observed with aging and in a variety of peripheral and central vestibulopathies have been described. Additional methods of evoking VEMPs, which use air- and bone-conducted short-tone bursts, forehead taps, and short-duration transmastoid direct current (DC) stimulation, have been described, and these complement the original technique. Click-evoked VEMPs are attenuated or absent in a proportion of patients with vestibular neuritis, herpes zoster oticus, late Meniere disease, and vestibular schwannomas; their amplitudes are increased and thresholds are pathologically lowered in superior semicircular canal dehiscence presenting with the Tullio Phenomenon. VEMPs evoked by clicks and DC are useful when monitoring the efficacy of intratympanic gentamicin therapy used for chemical vestibular ablation. Prolonged p13 and n23 peak latencies and decreased amplitudes have been observed in association with central vestibulopathy. VEMPs evoked by clicks are a robust, reproducible screening test of otolith function. DC stimulation enables differentiation of labyrinthine from retrolabyrinthine lesions; bone-conducted stimuli permit VEMP recording despite conductive hearing loss and deliver a relatively larger vestibular stimulus for a given level of auditory perception.
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vestibular hypersensitivity to sound Tullio Phenomenon structural and functional assessment
Neurology, 2000Co-Authors: S R D Watson, G M Halmagyi, James G ColebatchAbstract:Objectives: To establish the role of high-resolution CT imaging and tests of vestibulocollic reflexes in diagnosing and understanding the pathogenesis of the Tullio Phenomenon. Background: The Tullio Phenomenon is a syndrome in which acoustic stimulation produces symptoms and signs of vestibular activation. It has previously been associated with an abnormally low threshold for click-evoked vestibulocollic responses and also with dehiscence of the roof of the anterior (superior) semicircular canal on high-resolution CT scans of the temporal bones. Methods: High-resolution CT scans of the temporal bones and vestibulocollic responses in sternocleidomastoid to both clicks and transmastoid galvanic stimulation (3 mA/2 msec) were studied in four patients with the Tullio Phenomenon (one bilateral). Results: Click-evoked thresholds were low for all affected ears (four at 65 dB nHL, one at 55 dB nHL) and normal (>70 dB nHL) for the three unaffected ears. In contrast, galvanic-evoked vestibulocollic responses were symmetric and of normal size in all patients. The bony roof of the anterior (superior) semicircular canal was thin, possibly absent, on CT of all affected ears and also in two out of three unaffected ears. Conclusions: The normal galvanic vestibulocollic responses indicate that sound sensitivity in patients with the Tullio Phenomenon is likely to occur distal to the vestibular nerve, probably at the level of the receptors. Both click hypersensitivity and dehiscence of the anterior (superior) semicircular canal are associated with the Tullio Phenomenon but as the CT scan abnormality can occur in clinically unaffected ears, click testing is important for specific diagnosis. Abnormal sound sensitivity, as demonstrated by click responses, confirms that the radiologic abnormality is function significant.
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vestibular hypersensitivity to clicks is characteristic of the Tullio Phenomenon
Journal of Neurology Neurosurgery and Psychiatry, 1998Co-Authors: James G Colebatch, Adolfo M Bronstein, B L Day, R A Davies, M A Gresty, Linda M Luxon, J C RothwellAbstract:OBJECTIVES The frequency of pathologically reduced click thresholds for vestibular activation was explored in patients with the Tullio Phenomenon (sound induced vestibular activation). METHODS Seven patients (eight affected ears) with symptoms of oscillopsia and unsteadiness in response to loud external sounds or to the patient’s own voice were examined. In all but one patient, vestibular hypersensitivity to sound was confirmed by the fact that eye movements could be produced by pure tones of 110 dB intensity or less. Conventional diagnostic imaging was normal in all cases and three of the patients had normal middle ears at surgical exploration. Thresholds for click evoked vestibulocollic reflexes were compared with those of a group of normal subjects. Galvanic stimulation was used as a complementary method of examining the excitability of vestibular reflexes. RESULTS All the patients showed a reduced threshold for click activation of vestibulocollic reflexes arising from the affected ear. Short latency EMG responses to clicks were also present in posterior neck and leg muscles, suggesting that these muscles receive vestibular projections. Galvanic stimulation produced a normal pattern of body sway in four of the five patients tested. CONCLUSIONS A pathologically reduced threshold to click activation (⩽70 dB NHL (average normal hearing level)) seems to be a consistent feature of the Tullio Phenomenon and a useful diagnostic criterion. This in turn is most likely to be due to an increased effectiveness of the transmission of sound energy to saccular receptors. Activation of these receptors probably contributed to the vestibular symptoms experienced by the patients.
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clinical and electrophysiological findings in the Tullio Phenomenon
Acta Oto-laryngologica, 1995Co-Authors: Adolfo M Bronstein, M Faldon, J C Rothwell, Michael A Gresty, James G Colebatch, H LudmanAbstract:A 55 year old female with idiopathic Tullio Phenomenon is presented. Binocular, scleral search eye coil recordings demonstrated a predominantly torsional left-beating and vertical down-beating nystagmus in response to sound intensities over 100 dB HL to the left ear, increasing in amplitude and slow phase velocity with sound intensity and removal of visual fixation. The vertical ocular movement was conjugate, i.e. without skew deviation. Neuro-imaging, all other neuro-otological features, including ipsilateral-contralateral stapedius muscle reflexes, and surgical exploration of the middle ear, were normal. Click-evoked vestibulo-collic potentials were normal from the right ear but showed low threshold (70 dB) and increased amplitude from the left. There was no evidence that the Tullio Phenomenon in this patient arises from stapes footplate hypermobility. The findings suggest that some cases of the Tullio Phenomenon may be due to a hyperexcitability of the normal vestibular response to sound.
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click evoked vestibular activation in the Tullio Phenomenon
Journal of Neurology Neurosurgery and Psychiatry, 1994Co-Authors: James G Colebatch, J C Rothwell, A Bronstein, H LudmanAbstract:Click-evoked vestibulocollic reflexes were studied in a patient with a unilateral Tullio Phenomenon (sound induced vestibular symptoms) and the findings were compared with those of a group of normal subjects. Compared with normal subjects, the reflexes elicited from her symptomatic side were large and had an abnormally low threshold, but retained a normal waveform. The click-evoked responses in this patient show changes consistent with her symptomatology and are indicative of a pathological increase in the normal vestibular sensitivity to sound.
J C Rothwell - One of the best experts on this subject based on the ideXlab platform.
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vestibular hypersensitivity to clicks is characteristic of the Tullio Phenomenon
Journal of Neurology Neurosurgery and Psychiatry, 1998Co-Authors: James G Colebatch, Adolfo M Bronstein, B L Day, R A Davies, M A Gresty, Linda M Luxon, J C RothwellAbstract:OBJECTIVES The frequency of pathologically reduced click thresholds for vestibular activation was explored in patients with the Tullio Phenomenon (sound induced vestibular activation). METHODS Seven patients (eight affected ears) with symptoms of oscillopsia and unsteadiness in response to loud external sounds or to the patient’s own voice were examined. In all but one patient, vestibular hypersensitivity to sound was confirmed by the fact that eye movements could be produced by pure tones of 110 dB intensity or less. Conventional diagnostic imaging was normal in all cases and three of the patients had normal middle ears at surgical exploration. Thresholds for click evoked vestibulocollic reflexes were compared with those of a group of normal subjects. Galvanic stimulation was used as a complementary method of examining the excitability of vestibular reflexes. RESULTS All the patients showed a reduced threshold for click activation of vestibulocollic reflexes arising from the affected ear. Short latency EMG responses to clicks were also present in posterior neck and leg muscles, suggesting that these muscles receive vestibular projections. Galvanic stimulation produced a normal pattern of body sway in four of the five patients tested. CONCLUSIONS A pathologically reduced threshold to click activation (⩽70 dB NHL (average normal hearing level)) seems to be a consistent feature of the Tullio Phenomenon and a useful diagnostic criterion. This in turn is most likely to be due to an increased effectiveness of the transmission of sound energy to saccular receptors. Activation of these receptors probably contributed to the vestibular symptoms experienced by the patients.
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clinical and electrophysiological findings in the Tullio Phenomenon
Acta Oto-laryngologica, 1995Co-Authors: Adolfo M Bronstein, M Faldon, J C Rothwell, Michael A Gresty, James G Colebatch, H LudmanAbstract:A 55 year old female with idiopathic Tullio Phenomenon is presented. Binocular, scleral search eye coil recordings demonstrated a predominantly torsional left-beating and vertical down-beating nystagmus in response to sound intensities over 100 dB HL to the left ear, increasing in amplitude and slow phase velocity with sound intensity and removal of visual fixation. The vertical ocular movement was conjugate, i.e. without skew deviation. Neuro-imaging, all other neuro-otological features, including ipsilateral-contralateral stapedius muscle reflexes, and surgical exploration of the middle ear, were normal. Click-evoked vestibulo-collic potentials were normal from the right ear but showed low threshold (70 dB) and increased amplitude from the left. There was no evidence that the Tullio Phenomenon in this patient arises from stapes footplate hypermobility. The findings suggest that some cases of the Tullio Phenomenon may be due to a hyperexcitability of the normal vestibular response to sound.
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click evoked vestibular activation in the Tullio Phenomenon
Journal of Neurology Neurosurgery and Psychiatry, 1994Co-Authors: James G Colebatch, J C Rothwell, A Bronstein, H LudmanAbstract:Click-evoked vestibulocollic reflexes were studied in a patient with a unilateral Tullio Phenomenon (sound induced vestibular symptoms) and the findings were compared with those of a group of normal subjects. Compared with normal subjects, the reflexes elicited from her symptomatic side were large and had an abnormally low threshold, but retained a normal waveform. The click-evoked responses in this patient show changes consistent with her symptomatology and are indicative of a pathological increase in the normal vestibular sensitivity to sound.
Katherine D. Heidenreich - One of the best experts on this subject based on the ideXlab platform.
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VIDEO NEUROIMAGES Supplemental data at Neurology.org
2016Co-Authors: Gregory J. Basura, Scott J. Cronin, Katherine D. HeidenreichAbstract:Tullio Phenomenon in superior semicircular canal dehiscence syndrome Tullio Phenomenon refers to eye movements induced by sound.1 This unusual examination finding may be seen in superior semicircular canal dehiscence (SSCD) syndrome.2 This disorder is due to absent bone over the superior semicircular canal (figure). Patients complain of dizziness triggered by loud sound, aural fullness, autophony, and pulsatile tinnitus. When Tullio Phenomenon exists in SSCD syndrome, the patient develops a mixed vertical-torsional nystagmus in which the slow phase rotates up and away from the affected ear (video on the Neurology ® Web site at Neurology.org). This pattern of nystagmus aligns in the plane of the dehiscent semicircular canal and is due to excitation of its afferent nerves
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Tullio Phenomenon in superior semicircular canal dehiscence syndrome
Neurology, 2014Co-Authors: Gregory J. Basura, Scott J. Cronin, Katherine D. HeidenreichAbstract:Tullio Phenomenon refers to eye movements induced by sound.1 This unusual examination finding may be seen in superior semicircular canal dehiscence (SSCD) syndrome.2 This disorder is due to absent bone over the superior semicircular canal (figure ). Patients complain of dizziness triggered by loud sound, aural fullness, autophony, and pulsatile tinnitus. When Tullio Phenomenon exists in SSCD syndrome, the patient develops a mixed vertical-torsional nystagmus in which the slow phase rotates up and away from the affected ear (video on the Neurology ® Web site at Neurology.org). This pattern of nystagmus aligns in the plane of the dehiscent semicircular canal and is due to excitation of its afferent nerves.
Ettore Cassandro - One of the best experts on this subject based on the ideXlab platform.
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outcomes and complications in superior semicircular canal dehiscence surgery a systematic review
Laryngoscope, 2016Co-Authors: Federico Maria Gioacchini, Matteo Alicandriciufelli, Shaniko Kaleci, Alfonso Scarpa, Ettore CassandroAbstract:Objective Superior semicircular canal dehiscence (SSCD) represents a rare condition that may be associated to some particular symptoms as vertigo, autophony, and Tullio Phenomenon. In those patients who present severe symptoms surgical treatment is required. Middle fossa craniotomy and transmastoid approaches are both described. Concerning repairing techniques, plugging and/or resurfacing are typically used to close the defect. Our aim was first to analyze the overall outcomes and complications of this surgery. Our second aim was to make a comparison between the different surgical modalities to investigate the eventual advantages and disadvantages. Review Methods A search through Ovid MEDLINE was organized in January 2015 to include all eligible articles. A statistical analysis of the obtained data was performed. Results Twenty studies comprising a total of 150 procedures were included. Four modalities of canal repair were described (plugging, capping, resurfacing, plugging with resurfacing). The overall rate of success resulted in 94% (95% confidence interval: 87%-97%). No statistically significant differences were observed among the different modalities of canal repair concerning both success rate and surgical complications. Differences observed between the middle fossa approach and transmastoid approach in terms of outcome were not statistically significant. Conclusions This review showed that surgical treatment for SSCD represents a safe option for those patients with severe symptoms of this condition. Differences observed in terms of success rate or complications were analyzed between the different surgical techniques with results that were not statistically significant. Level of Evidence NA Laryngoscope, 2015
K. Kaga - One of the best experts on this subject based on the ideXlab platform.
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Vestibular-evoked myogenic potentials in three patients with large vestibular aqueduct
Hearing Research, 2004Co-Authors: K. Sheykholeslami, S. Schmerber, Habiby Kermany M., K. KagaAbstract:An enlarged vestibular aqueduct (LVA) is a common congenital inner ear anomaly responsible for some unusual vestibular and audiological symptoms. Most of the cases show bilateral early onset and progressive hearing loss in children. The gross appearance on CT scan of the inner ear is generally normal. However, precise measurements of the inner ear components reveal abnormal dimensions, which may account for the accompanying auditory and vestibular dysfunction. Despite extensive studies on hearing and the vestibular apparatus, saccular function is not studied. To our knowledge this is the first report of saccular malfunction in three patients with LVA by means of vestibular evoked myogenic potentials. Conventional audiograms revealed bilateral severe sensorineural hearing loss in two patients and mixed type hearing loss in one patient. Two of the patients complained about vertigo and dizziness but vestibular assessments of the patients showed normal results. The diagnosis had been made by high-resolution CT scans and MR images of the skull that showed LVA in the absence of other anomalies. The VEMP threshold measured from the ear with LVA in two patients with unilateral enlargement of the vestibular aqueduct was 75-80 dB nHL whereas the threshold from normal ears was 95 dB nHL. The third patient with mixed type hearing loss and bilateral LVA had VEMP responses despite a big air-bone gap in the low frequency range. The VEMP in this patient was greater in amplitude and lower in threshold in the operated ear (the patient had a tympanoplasty which did not improve her hearing). These findings and results of other patients with Tullio Phenomenon and superior semicircular canal dehiscence, who also showed lower VEMP threshold, confirmed the theory of a 'third window' that allows volume and pressure displacements, and thus larger deflection of the vestibular sensors, which would cause the vestibular organ to be more responsive to sound and pressure changes.
