Hideki Takegoshi

Glycerol affects vestibular evoked myogenic potentials in Meniere's disease

OBJECTIVES to show that abnormal vestibular evoked myogenic potentials on the sternocleidomastoid muscle (SCM) in patients with unilateral Menieres disease are caused by endolymphatic hydrops. SUBJECTS six normal volunteers and 17 patients with unilateral Menieres disease were examined. METHODS click-evoked myogenic potentials were recorded with surface electrodes over each SCM. Responses evoked by clicks recorded after oral administration of glycerol (1.3 g/kg body weight) were compared with those recorded before administration. RESULTS the change rate of the p13-n23 amplitude was calculated. The mean+standard deviation (S.D.) of the change rate was 3.52+14.6% in normal subjects. On the unaffected side of patients the change rates were within the normal range (within the mean+/-2S.D.) in 13 patients, and three ears showed significant decrease. Only one ear showed significant increase. On the affected side, five ears showed significant increase of the amplitude while two ears showed significant decrease after oral administration of glycerol. Effects on evoked myogenic potentials were independent of those on pure tone hearing. CONCLUSION vestibular evoked myogenic potentials in some patients with unilateral Menieres disease were improved by oral administration of glycerol. This result suggests that abnormal vestibular evoked myogenic potentials in patients with unilateral Menieres disease could result from endolymphatic hydrops.

Galvanic-evoked myogenic responses in patients with an absence of click-evoked vestibulo-collic reflexes

OBJECTIVES To show that galvanic-evoked responses on the sternocleidomastoid muscle (SCM) are useful for differentiating labyrinthine lesions from retro-labyrinthine lesions in patients with an absence of click-evoked vestibulo-collic reflexes. METHODS We studied the average responses in the unrectified electromyographic (EMG) activities of the SCM to galvanic stimulation (3mA, 1ms). The cathodal electrode was on the mastoid, and the anodal electrode was on the forehead. Twenty-two healthy subjects and 28 patients with vestibular disorders were studied. All of the 28 patients showed the unilateral absence of vestibulo-collic reflexes evoked by 95dBnHL clicks on the affected side. RESULTS In healthy subjects mastoid-forehead galvanic stimulation produced a positive-negative biphasic EMG response at short latency on the SCM ipsilateral to the cathodal electrode. All patients with labyrinthine lesions showed biphasic EMG responses even in the affected side. In contrast, almost all patients with retro-labyrinthine lesions (16/18) showed no response or a decreased response on the affected side. CONCLUSIONS These results suggest that galvanic-evoked myogenic responses on the SCM may be useful in the differential diagnosis of labyrinthine lesions from retro-labyrinthine lesions in patients with an absence of vestibulo-collic reflexes evoked by clicks.

Vestibular failure in children with congenital deafness.

Congenitally deaf infants and children commonly suffer vestibular failure in both ears, and impairment of postural control, locomotion, and gait. The development of gross motor functions, such as head control, sitting, and walking is likely to be delayed, but fine motor function is usually preserved unless disorders of the central nervous system are present. These children can eventually catch up with their normal peers in terms of development and growth as a result of central vestibular compensation. The visual and somatosensory systems, pyramidal and extrapyramidal motor system (cerebellum, basal ganglia, cerebrum) and intellectual development, compensate for vestibular failure in infants and children with congenitally hypoactive or absent function of the semicircular canals and otolith organs.

Evaluation of Super-High-Dose Steroid Therapy for Sudden Sensorineural Hearing Loss

OBJECTIVE: To determine the efficacy of a high-dose steroid regimen for patients with sudden sensorineural hearing loss (SSNHL) and to evaluate the relationship between outcome and initial steroid dose. STUDY DESIGN AND SETTING: We conducted a retrospective study of 112 patients presenting to Saitama Medical Center. Patients received tapering courses of hydrocortisone (HC) with an initial dose of either 1200 mg or 600 mg. RESULTS: More than 87% of patients had recovery of hearing. When hearing stabilized, there were no significant differences between the 1200 mg and 600 mg groups in terms of hearing outcome (P > 0.05). However, at completion of treatment, the 1200 mg group exhibited significantly superior complete recovery rate and improvement rate (P < 0.05). CONCLUSION: Application of our treatment protocol of a tapered course of 1200 mg HC significantly and rapidly improves recovery outcomes in patients of SSNHL. EBM rating: C-4

Vestibular evoked myogenic potentials in patients with spinocerebellar degeneration.

To estimate vestibulo-collic reflexes in patients with spinocerebellar degeneration (SCD), vestibular evoked myogenic potentials (VEMPs) were recorded in 16 patients with SCD and in 9 normal subjects. The patients with SCD were classified into three groups: those with olivo-ponto-cerebellar ataxia (OPCA; n=10); those with cortical cerebellar atrophy (CCA; n=3); and those with Machado-Joseph disease (MJD; n=3). While all of the patients with OPCA and CCA showed biphasic responses (p13-n23), 2 of the 3 patients with MJD showed abnormal VEMPs bilaterally. Three sides in these 2 patients showed an absence of VEMPs, and one side showed a remarkably delayed p13. These two patients showed little response in caloric tests. These results suggest that the vestibulo-collic reflex as well as the vestibulo-ocular reflex could be damaged in MJD patients but preserved in OPCA and CCA patients.

Hearing Levels in Patients With Microtia: Correlation With Temporal Bone Malformation

Objective: To evaluate the relationship between hearing level and temporal bone abnormalities in patients with microtia.

Click- and Short Tone Burst-evoked Myogenic Potentials in Cerebellopontine Angle Tumors

We report results of vestibular-evoked myogenic potentials (VEMPs) in patients with cerebellopontine angle tumors and compare results obtained using clicks with those obtained using 500 Hz short tone bursts (STB). We reviewed the records of 87 patients with cerebellopontine angle tumors. Clicks (0.1 ms, 95 dB nHL) were presented to all patients and STB (500 Hz, rise/fall time 1 ms, plateau time 2 ms, 95 dB nHL) were presented to 27 patients. Click-evoked VEMPs were abnormal in 69/87 patients (79%; no response in 55 patients, decreased response in 14 patients, normal response in 18 patients). STB-evoked VEMPs were abnormal in 22/27 patients (82%; no response in 18 patients, decreased response in 4 patients, normal response in 5 patients). Click- and STB-evoked VEMPs were identical in 23/27 patients (85%). Two patients showed normal STB-evoked VEMPs and decreased click-evoked VEMPs, and 2 patients showed decreased STB-evoked VEMPs and absent click-evoked VEMPs. These results confirm our previous study in a small number of patients. Vestibular afferents seem to respond better to 500 Hz STBs than to clicks.We report results of vestibular-evoked myogenic potentials (VEMPs) in patients with cerebellopontine angle tumors and compare results obtained using clicks with those obtained using 500 Hz short tone bursts (STB). We reviewed the records of 87 patients with cerebellopontine angle tumors. Clicks (0.1 ms, 95 dB nHL) were presented to all patients and STB (500 Hz, rise/fall time 1 ms, plateau time 2 ms, 95 dB nHL) were presented to 27 patients. Click-evoked VEMPs were abnormal in 69/87 patients (79%; no response in 55 patients, decreased response in 14 patients, normal response in 18 patients). STB-evoked VEMPs were abnormal in 22/27 patients (82%; no response in 18 patients, decreased response in 4 patients, normal response in 5 patients). Click- and STB-evoked VEMPs were identical in 23/27 patients (85%). Two patients showed normal STB-evoked VEMPs and decreased click- evoked VEMPs, and 2 patients showed decreased STB-evoked VEMPs and absent click- evoked VEMPs. These results confirm our previous study in a small number of patients. Vestibular afferents seem to respond better to 500 Hz STBs than to clicks.

Facial canal anatomy in patients with mandibulofacial dysostosis: comparison with respect to the severities of microtia and middle ear deformity.

Objective: To study the difference in the facial canal anatomy in terms of the severity of microtia and deformity of the middle ear in patients with mandibulofacial dysostosis using high-resolution computed tomography. Study Design: Retrospective analyses. Setting: The study was carried out at the Department of Otorhinolaryngology, University of Tokyo, Tokyo, Japan. Patients: Thirty-six ears of 18 patients with mandibulofacial dysostosis were examined by high-resolution computed tomography. These ears were graded based on the Marx classification and Jahrsdoerfer scoring systems. Main Outcome Measures: The high-resolution computed tomography findings and age distribution of each group were compared with those of other groups by multiple comparison using Tukeys honestly significant difference test. Results: The course of the facial nerve was not significantly different in terms of the severity of microtia and deformity of the middle ear. The bony cochlea in the patients with mandibulofacial dysostosis was displaced by a mean value of 2 mm more anteriorly and a mean value of 0.7 mm shallower than that in the cases with normal auricles. Conclusion: The facial nerve of patients with mandibulofacial dysostosis is displaced more anterolaterally than that of the cases with normal auricles; however, the auricle anomaly is not severe.

Difference in Facial Canal Anatomy in Terms of Severity of Microtia and Deformity of Middle Ear in Patients With Microtia

Objective To study the difference in the facial canal anatomy in terms of the severity of microtia and deformity of the middle ear in patients with microtia using high‐resolution computed tomography (HRCT).

Mandibulofacial dysostosis: CT evaluation of the temporal bones for surgical risk assessment in patients of bilateral aural atresia.

We present the results of detailed CT investigation of nine patients with mandibulofacial dysostosis (MFD). We also graded the severity of microtia according to Marxs classification system. The results revealed a positive correlation between the severity of microtia and the severity of deformity of the external auditory canal, and attic formation. In 13 ears, the stapes was not adequately visualized to allow any comment on its form. The angle of the first genu of the facial nerve ranged from 55.0 to 123.6 degrees (mean +/-S.D.; 99.5 +/-18.5 degrees ), indicating that this angle is more obtuse in MFD patients than in normal subjects. The eustachian tube and tympanic sinus were present in all the ears examined. None of the patients had mastoid pneumatization. In four ears, the lateral semicircular canal was dysplastic. Eleven ears of six patients scored less than 5 in the grading system developed by Jahrsdoerfer for assessment of the suitability for atresia surgery. These findings indicate that most patients with mandibulofacial dysostosis are poor surgical candidates.