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Vestibular compesation in 3 patients with vestibular neuronitis was examined with static posturography (SPG) and kinetic posturography (KPG). SPG was recorded by a stabilometer during quiet standing and KPG was recorded by POLGON so that angular change of the shoulder on the frontal plane was measured during stepping in the same position. Our study showed earlier improvement of SPG than KPG. By vestibular training, the initial high levels of SPG and KPG decreased precipitously and in the case of sequela, the remarkably high level of KPG gradually decreased. The stepping test by POLGON combined with a stabilometry was useful for estimation vestibular dysfunction.

A case of multiple sclerosis with acute deafness and dizziness as initial symptoms was reported. The pure-tone audiometry showed a high-frequency sensorineural hearing loss; in the auditory evoked brain stem response (ABR), the left side had a normal peak I with an absence of subsequent peaks. In the equilibrium test, Bruns' nystagmus was present, and the caloric test demonstrated CP on the left side. MRI disclosed a high-intensity lesion in the cerebellar peduncle (T2-weighted image). With steroid therapy, the deafness and dizziness improved within 10 days, although, after 20 days, the findings of the ABR and caloric test remained unchanged.

Vestibular compensation in patients with bilateral vestibular dysfunction was examined with the use of static posturography (SPG) and kinetic posturography (KPG). SPG was recorded by a stabilometer during quiet stance and KPG was recorded by POLGON so that angular changes of the shoulder in the frontal plane were measured during stepping in the same position. In addition, we recorded movements of daily life. The subjects were 3 patients with bilateral vestibular loss. The values of SPG decreased gradually. However, abnormalities of KPG with eyes closed tended to persist, and the effect of vestibular training was transient. In regard to movements of daily life, the jumbling phenomenon during walking disappeared within 6 to 8 months, but jumbling with quick head motion persisted. Unsteadiness while standing on a sofa, or putting on socks while standing on one leg, or walking in a dark room persisted.

The course of recovery in 4 patients with Meniere's disease was examined with static posturography (SPG) and kinetic posturography (KPG). SPG was recorded by a stabilometer during quiet stance and KPG was recorded by PO LGON so that the angular change of the shoulder in the frontal plane was measured during stepping in the same position. The process of SPG improve-ment was concordant with that of KPG, and the abnormally high levels of SPG and KPG be came normal within 8 days. Those results differ from those of vestibular neuronitis. We consider that the mechanism of recovery from Meniere's attacks is different from vestibular compensation and is due to fluctuation of inner ear function.

身体障害者福祉法の定めるところにより身体障害者手帳を交付された者は, 数々の利益を受けることができる。 しかし, 同法の意義は更生医療と更生への援助であり, 同法15条指定医は正確な聴力検査に基づく等級判定を行う義務がある。 難聴を有する身体障害者が一旦手帳を手にすると, 後日障害等級の改善が確認されても手帳の返還ないし書き換えを求めることが困難となる傾向がある。 このような問題に関する実情は必ずしも解明されているとは限らない。 筆者は県から補装具装用判定の委嘱を受け, 聴力障害者の聴力を再検する機会に恵まれているので, 手帳を所有している障害者の聴力を精検し, 初回検査との関係を調べ, 問題点の解明を試みた。 結果として, 特に高齢者の聴力検査に問題点があることを強調した。

The standing body sway of normal subjects and of patients with unilateral vestibular disorders was measured. The patients were not able to stand with toes and heels together, so the upright position with toes and heels apart was applied. Visual stimulation consisted of clockwise and counter-clockwise concentrically-moving spotlights at constant velocities of 60 and 90 deg/sec. The body sway of the patients was significantly larger during contralateral stimulation by moving spotlights than during ipsilateral moving stimulation, while the sway of normal subjects was symmetrical, increasing with increasing velocity.

Vestibular evoked myogenic potentials (VEMP) occurring after click stimulation in cervical muscles are thought to be a polysynaptic response of otolith-vestibular nerve origin. In optokinetic after-nystagmus (OKAN) the direction of after-nystagmus changes and slow-phase velocity decreases with head tilt. This phenomenon may be an otolith response to the direction of gravity. We assumed that intense clicks might have some influence on OKAN via the otolith-vestibular nerve. Twelve normal subjects who showed VEMP at 75 dB normal hearing level (nHL) clicks were examined. The OKAN was recorded under four conditions: right monaural, left monaural and binaural stimulation by 75 dB nHL clicks, and absence of click stimulation. Horizontal optokinetic stimulation was applied using stepwise increasing speeds from 30 deg/s to 90 deg/s. Two seconds before the stimulus ended, clicks were sounded. The slow-phase velocity of the recorded electro-nystagmography was manually measured. There was no effect on OKAN with unilateral stimulation but binaural stimulation suppressed it. These results suggest that a velocity storage integrator is influenced by intense clicks via the otolithic area.

Patients with peripheral vestibular disorders may experience postural instability in the standing position, which means disorientation in their environment. The disturbed vestibular function in light reflects the postural instability in space. The present study investigates the relationship between the subjective vertical and the vestibular lesion. The subjects were patients with unilateral vestibular lesion, and the control subjects had no past history of vestibular lesion or any present vestibular lesion. A straight line consisting of 5 spotlights projected on a dome-shaped screen was concentrically moved like a stylus by pressing buttons. We measured the subjective vertical of the subjects using a 5-spotlight straight-line (spotlight-line) on a dome-shaped screen in front of which the subjects were placed. The result showed that the patients with unilateral peripheral disorder had a statistically significantly larger deviation to the impaired ear side, especially when the spotlight-line was moved from the impaired side, as compared with controls.

Vestibular compensation process in six patients was examined by means of static (SPG) and kinetic posturography (KPG). SPG was recorded by a stabilometer during standing and KPG was recorded by POLGON so that angular change of shoulder in the frontal plane was measured during stepping. The subjects included three cases with vestibular neuronitis, three cases with bilateral vestibular loss. In vestibular neuronitis, SPG improved earlier than KPG. As a result of vestibular training, initial high levels of SPG and KPG fall precipitously and in the case with sequela, a remarkably high level of KPG gradually decreased. In bilateral vestibular loss, abnormality of KPG tended to persist and those results would be due to the disappearance of a hip strategy. The effect of training upon the case which started from the early days was not shown. However, the case which started from 10 months after the onset showed remarkable improvement of SPG and KPG.

Using tympanometry we investigated potential changes in both middle ears developing during and after unilateral acute otitis media (AOM) in Japanese children. In 144 children with unilateral (AOM), tympanometry was performed at presentation and was repeated at the 1st, 2nd, 3rd, and 4th weeks and then every 2 weeks up to 12 weeks after entry into the study. Type B tympanograms were recorded in 81 (56%) of the affected ears and in 37 (26%) of the unaffected ears at presentation. Twelve weeks after AOM, the type B tympanogram was still observed in 21 (15%) of the affected ears and in 16 (11%) of the unaffected ears. Ears with type B changes at presentation showed a significantly slower recovery of middle ear ventilation than did those with either type A or type C1.

A polarized light goniometer (abbreviated as Polgon) and a microcomputer were applied for the calculation of the real values of changes in shoulder angulation during stepping movement in normal subjects and patients with peripheral vestibular disorders.Characteristic results were obtained from patients with Meniere's disease, showing larger means and variations as compared with those of normal subjects. The shoulder of the same side with affected ear usually showed larger values than those of another shoulder.Those patients with sudden deafness accompanying vestibular disorder presented larger means and normal standard deviations. The results obtained from two patients with vestibular neuronitis were almost normal. Five subjects with other vestibular disorders showed larger means only when stepping with the eyes closed.

The effects of horizontal and vertical optokinetic stimulation on head movement in neuro-otologically normal adults were investigated by using an optokinetic stimulator of Jung type, a cephalograph and a minicomputer. The cephalograph consisted of a lightemitting diode (LED) on the helmet and an industrial television system to pursue the movement of LED on the horizontal plane, an X-Y recorder and a data recorder. Computer analyses were performed with an off-line system.The followilg results were obtained.When the speed of optokinetic stimulation was increased the locus traced by the head movement and the total length of the locus gradually increased up to 60 deg/sec and then decreased. There was a standard two-phasic course in the position of the head movement. The ratio of the antero-posterior component to the lateral component of the head movement was below the control value with horizontal optokinetic stimulation, while with vertical stimulation it was over the control, showing a striking peak at 60 deg/sec of optokinetic stimulation. Spectral frequencies of the head movement showed two types of change. Type I showed a frequency shift to a higher division within the range below 1 Hz during optokinetic stimulation, while Type II revealed a peak at 0.2 to 0.3 Hz with 30 to 90 deg/sec of stimulation. The difference between the two types was manifest in the calculated averaged divisional frequencies of below 1 Hz.

It is most difficult to evaluate the prognosis of patients with Meniere's disease. We estimated the relationship between the activity of the disease and the caloric nystagmic response by reviewing long-term follow-up observation on these patients.Sixty-four patients aged 15 to 56 at the onset of the disease were investigated. The items for investigation were frequency of attack, spontaneous or positional nystagmus, caloric nystagmus, postrotatory nystagmus, hearing impairment, blood pressure (including the Schellong's test), treatment received and so on.The following conclusions were obtained.1. Estimation of the prognosis cannot be made at the first examination of the patient.2. The attacks occurred most frequently in the patients who tended to show DP in the caloric nystagmic response, over a long period of time.3. There were some in whom the caloric nystagmic response changed from DP to CP after a short time, or in whom there was no caloric difference between the left and right ears after a short period with caloric DP.

Ataxia and disequilibrium are clinical symptoms expressing basic conditions of body balance. The author proposed to give them clear definitions concerning the human posture. Ataxia would mean the failure in maintaining the posture during more complicated movement, while disequilibrium implys the disturbed body balance in static posture while standing or sitting. Fukuda referred the difference between disequilibrium and ataxia to the postural change, static to active, during vestibular stimulation.There are many complaints and symptoms relating to ataxia and disequilibrium. Several points in this field were raised and discussed for the future clinical purpose.1. An abnormal sensation called “Memai” in Japanese arises with ataxia or disequilibrium. It may be classified into three categories. The first category “vertigo” is a moving sensation, which is typically accompanied with vestibular dysfunction. The second, dizziness or giddiness, is a kind of unsteadiness such as staggering, blurred vision or weakness at the knees. The third contains inconstant symptoms, for example diplopia, malaise, feebleness, nausea and fainting. Those symptoms belong to a new concept of “Memai” and seem to be directly related to ataxia.2. The characteristics of labyrinthine disequilibrium were 1) laterality or past pointing, 2) easy to be compensated after onset of lesion, 3) accompanying a rotatory horizontal nystagmus, 4) no sensory disorder and 5) measurable by neurootological tests.3. Causes of ataxia were enumerated and several new diagnostic techniques were mentioned. The measurements of optokinetic nystagmus potential and correlation between head movement and movement of the center of gravity seem to be useful diagnostic tools for vertiginous and ataxic patients.

In order to evaluate the current visual scoring technique in the late vertex-evoked response audiometry (ERA), the detectability of the response, errors in judgment, consistency between scorers and test-retest reliability were studied in adults and young children in waking and sleeping states. In waking adults, ERA proved to be a quite reliable and valid method for testing hearing objectively. On the contrary, a marked inconsistency was found in the appearance of the response in children during sleep. From a clinical standpoint, ERA in waking adults and sleeping children should be regarded as two substantially different methods.

The relationship between the incipient symptoms and the long-term prognosis of Meniere's disease was investigated. Forty-five patients who had been suffering from definite Meniere's disease for more than 5 years were selected as the subjects.These patients were classified into 3 main groups on the basis of the incipient symptoms: the first group with vertigo or dizziness, the second with some cochlear symptoms and the third with symptoms related to the autonomic nervous system.There was a significant difference in the period from the incipient symptom to the active stage of the disease between the vertigo subgroup and the tinnitus subgroup, the latter showing a longer interval.There was also a significant difference in the average age at the first attack of the incipient symptom between the vertigo subgroup and the subgroup with dizziness, the latter being older in age.In the vertigo and tinnitus subgroups, more than three attacks per month occurred during the active stage.

Ten samples of the averaged spontaneous brain activity were made on a sleeping child of 5 years old. On the other hand, from a typical pattern of the averaged evoked response, 5 samples with different amplitudes were prepared. Then each of the 10 samples of the spontaneous activity and each of the 5 samples of the evoked response were composed by using an averaging computer. Two trained examiners independently made the determination of the presence or absence of the evoked response on 41 out of 50 composed samples and 10 samples without evoked response. The decision was also attempted according to an objective standard made by one of the authors. Besides, peak latencies of P2 and N2 as well as P2N2 amplitude were measured on 19 composed samples.Results obtained were summarized as follows:1. There was an individual discrepancy between the examiners as to the detectability of the response.2. False positive decision occured in about 10 to 35 per cent of the judgements.3. Almost 100 per cent detection of the response Was achieved when the amplitude of the evoked response was twice as large as the levels of the averaged background activity.4. The range of so-called “trasition zone” of the evoked response was estimated to cover the range of the stimulus intensity of 40 to 50dB or more.5. The latencies and amplitudes of the evoked response were modified considerably by the background activity.

By mean of the analog computer the evoked electroencephalngraphic responses of the vertex (Cz) during barbital sleep in normal young children to acoustic stimuli were obtained with following results:There were penta-phasic with the components of vertex-positive (P1), negative (N1), positive (P2), negative (N2) and of vertex positive (P3).The peak latencies of these components in children aged 16 days to 3 months were 60 to 80msec (P1), 160 to 210msec (N1), 250 to 340msec (P2), 470 to 690msec (N2) and 820 to 860msec (P3), while those of children aged 1 to 5 years were about 60msec (P1), 130 to 190msec (N1), 270 to 310msec (P2), 420 to 610msec (N2) and 730 to 800msec (P3) respectively.The evoked responses of the children aged 16 days to 3 months appeared at the intensity of 30 to 60dB SPL and in children aged 1 to 5 years 20 to 50dB SPL.The amplitude and the peak latencies of the evoked response varied with the stages of sleep. The major difference between the waking stage and the all stages of sleep were the appearance of P3 and the consistent increase in the peak latencies of N1, P2 and N2 during sleep.

A newly devised system was employed to measure head movement while stepping. The system consisted of three accelerometers, a multi-channel telemeter and a microcomputer.The data calculated by the computer were expressed in cm and plotted on the 3-dimensional coordinates.A total of ten normal adults and twenty-two patients with peripheral vestibular disorders were examined. The results obtained from the normal subjects were stable at the stepping speeds of 1.2 and 1.4 steps/sec. The patients with peripheral vestibular disorders, except those with benign paroxysmal positional vertigo, showed large values of head movement in all three dimensions. However, the most important clinical characteristic was confirmed to be the increased horizontal head movement with abnormal ratios of anteroposterior components to lateral components in the head movement.

We investigated galvanic body sway of ten healthy adults and eight patients by using the averaging program for measuring T1 and T2, which were latencies at the onset and at the cutoff of galvanic stimulation, respectively, and the plotting program, which adopted 1.73 sec as T1 and 0.39 sec as T2, for calculating the coordinates of the body's sway center. We estimated galvanic body sway with the difference between the coordinate of the body's sway center during stimulation and that during no stimulation. The deviation in lateral direction on the healthy subjects ranged from 0.7 or 0.9 to 2.1 cm at right- or left-side stimulation. One of the patients with peripheral disorders revealed differences between right- and left-side stimulation. The other patients did not reveal any differences. In antero-posterior direction six of the healthy subjects deviated backward at right-side stimulation and nine subjects deviated backward at left-side stimulation. The patients with peripheral disorders did not reveal any differences. The other patients revealed some differences. Waves computed by the averaging program do not always show the quantity of galvanic body sway. The deviation of the body's sway center shows the quantity of body sway consistently. The body's sway center is considered to be a suitable parameter in the galvanic body sway test for statistical analysis.