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SEM and immunoglobulin staining of the intradural portion of the endolymphatic sac (ES) were investigated. All 15 normal subjects, from fetuses to an 80-year-old adult, showed well arranged epithelial cells. In Menière's disease (all 15 patients) the ES showed various types degeneration of the epithelial cells. Inner ear deafness experimentally produced by kanamycin injection showed a similar degeneration of the ES. IgG of the ES in Menière's disease showed moderately evident deposits compared with normal subjects. However, these findings were also found to the same degree as IgG deposits in animal deafness produced by KM injection. From the above results it can reasonably be concluded that the degenerated findings of the ES and deposits of the IgG in Menière's disease may possibly be the result of cochlear deafness.

Three patients with the chief complaints of dizziness while standing up or blackouts were diagnosed correctly as having the Shy-Drager syndrome at the Department of Otolaryngology. Both the electrocardiogram R-peak to R-peak interval and the Schellong test revealed disorders of the autonomic nervous system in each of these cases. Electronystagmography also demonstrated pathology of the oculomotor system and/or central vestibular system. Postural balance was also abnormal in one of the cases. Auditory brain-stem responses were normal in all three cases.

Eye movement during smooth pursuit examination was converted to digital values and analyzed by the fast Fourier transform (FFT). It was found that the power spectra differences between the eye and target movements at 0.3 Hz were significantly lower in the pathological pursuit patterns (saccadic and ataxic pursuit patterns). In addition, sums of the power spectra difference above 0.3 Hz were significantly greater in pathological pursuit patterns.

Direction of eye movement evoked by unilateral stimulation of the cerebellar flocculus was investigated by a video system with frame memory in ketamine-anesthetized cats. Stimulation of the Purkinje cell zone in the vertical-plane unit on the right side evoked depression of both eyes combined with intorsion of the contralateral eye and extorsion of the ipsilateral eye, and stimulation in the horizontal-plane unit evoked abduction of the ipsilateral eye and adduction of the contralateral eye.

Twenty-seven patients with hemifacial spasm underwent neurotological (auditory and equilibrium) examinations to evaluate the VIIIth cranial nerve and/or brainstem involvement. Radiological examinations were performed to evaluate the underlying abnormalities. Twenty patients had abnormal neurotological findings, with the VIIIth cranial nerve involvement being suggested in 10 and brainstem involvement in the other 10. Radiological examinations indicated that vascular abnormalities could be detected more often in the patients with brainstem involvement than in those with VIIIth cranial nerve involvement.

Electrocochleography (ECochG) of 168 ears with definite Meniere's disease was studied. The results were compared with recordings from 29 normal ears and 444 ears with other types of sensorineural hearing loss. It is shown that the SP/AP ratio is much more useful than SP amplitude for detecting endolymphatic hydrops. There was little difference in the mean values of SP/AP from those proposed by many other investigators; the mean values all being near 0.25. From 0.30 to 0.40 of SP/AP was considered adequate as the upper limit. Following intravenous administration of glycerol, a significant decrease in SP/AP was found in 21 Meniere's ears. However, there was no change of SP/AP after oral administration of glycerol and isosorbide. This difference may be due to the fact that a larger oral than intravenous administration is necessary to affect SP/AP. Although a postoperative decrease of 10% or more in SP/AP was observed in 5 patients, 10 patients followed up for 2 years or more after surgery did not show a statistically significant change of SP/AP and pure tone threshold. ECochG should be repeatedly recorded to be useful as a monitor for the presence of hydrops. It is discussed whether biochemical or mechanical changes in endolymph may cause a decrease in SP/AP after the use of dehydrating agents and endolymphatic sac surgery.

In order to investigate interaction of the vestibular and optokinetic system, a visual vestibulo-ocular reflex (V-VOR) gain in forty-five normal subjects was measured by manual and computer analysis. The test subjects sat in a newly devised, pendular rotating chair in an optokinetic drum. With this device pendular harmonic sinusoidal rotation and optokinetic stimuli could be given simultaneously. The test subjects were rotated sinusoidally at amplitudes of 120 degrees and 240 degrees and at frequencies of 0.05 Hz and 0.1 Hz (maximum velocities 18.8 degrees/s, 37.7 degrees/s, 75.4 degrees/s), and with eyes closed and open. Within these pendular stimuli, there was no response decline phenomenon nor influence of amplitude on frequency. The pure VOR gain measured in dark room with eyes open was about 0.6 and did not vary with the eyes closed as long as mental alertness was maintained. The V-VOR gain in a stationary optokinetic drum with eyes open was about 1.1. From our observations, the 0.1 Hz sinusoidal rotation with an amplitude of 240 degrees (maximum velocity, 75.4 degrees/s) is an appropriate stimulation for the V-VOR and VOR test battery in clinical practice.

In order to investigate interaction of the vestibular and optokinetic systems in patients with peripheral vestibular disorders, the visual vestibulo-ocular reflex (V-VOR) gain in 49 patients with peripheral vestibular disorders was quantitatively measured by using pendular harmonic sinusoidal rotation with optokinetic stationary stimuli. The patients were rotated sinusoidally both with eyes closed and open at an amplitude of 240 degrees and at a frequency of 0.1 Hz (peak velocity 75.4%s). Comparing the vestibulo-ocular reflex (VOR) and V-VOR gains in the patients with definite Meniere's disease (23 cases), benign paroxysmal positional vertigo (BPPV, 13 cases) and sudden deafness with vertigo or dizziness (13 cases), the VOR-DP and normal V-VOR gain were more frequently observed in patients with Meniere's disease (13 cases) and sudden deafness (7 cases) than in those with the BPPV (3 cases). In the four patients with bilateral Meniere's disease and sudden deafness, abnormally decreased VOR-gain (under 0.55) in the bilateral directions with slightly decreased V-VOR gain was measured when tested independently. However, abnormal V-VOR gain was observed in only one case of sudden deafness due to retrocochlear lesions. From our VOR and V-VOR gain observations comparing the caloric responses, we have concluded that the comparison of VOR with V-VOR gains provides additional information for evaluation of peripheral vestibular disorders as well as central nervous system disorders.

During 1986-87, 35 patients with organic mercury intoxication, who had been recognized as having Minamata disease by the Arbitration Committee in Niigata during 1968-78, were followed up neurotologically in Kido Hospital, Niigata, Japan. Characteristic follow-up features were served, as follows. 1. In 6 cases, spontaneous nystagmus had disappeared, but had newly appeared in 9 cases. However, positional nystagmus was markedly improved in 15 cases. 2. In OKN tests, especially in the vertical OKN test, relatively significant deterioration was observed at the follow-up examinations. 3. There was little significant change in the caloric nystagmus test and body-equilibrium tests. 4. In pure-tone audiometry, 16 out of 58 ears showed deterioration of hearing (28%), while 4 ears showed improvement (7%). In the neurotological findings there was much variation among the patients themselves. Therefore, these variable findings should be considered as being caused not by duration of the intoxication alone, but also by ageing factors in the patients.

There are great variations in the clinical evaluations of the effectiveness of antivertiginous drugs for Meniere's disease. In our clinical evaluation, subjective and objective signs and symptoms of 128 patients with Meniere's disease and of 98 with other peripheral vestibular disorders were analyzed in a double-blind controlled study comparing adenosine triphosphate (ATP) (300 mg) and betahistine (36 mg) each given daily for 4 weeks. The method of administration was the matched-pair-group-method for this double-blind controlled trial. The attending physicians concluded that ATP was significantly more effective than betahistine in the treatment of Meniere's disease and other peripheral vestibular disorders.

During the period from January 1973 to June 1975, 60 cases with definite Meniere's disease and 30 cases with sudden deafness were listed according to such criteria for the diagnosis of both diseases as determined by the Research Committee of Japan. A neurootological assessment for both diseases were performed in our series. In patients with definite Meniere's disease, hearing impairment was characterized by deficiency in detecting low- and middle-pitched tones and fluctuation of auditory threshold in low frequency range. In sudden deafness, highly impaired hearing loss, i.e., total deafness, was frequently observed (45%). However, recruitment occurred at the same incidence (80%) in both diseases tested. The incidence of spontaneous nystagmus was almost the same regardless of associated vertigo and the course of both diseases. Moreover, it was also recognized that a reduction of caloric responses was a better indication for assessment of the affected ear in both diseases.

In order to gain an early estimate of a prognosis for facial paralysis, the vertical eye movements associated with eyeblinks (Bell's phenomenon) in 39 patients with acute unilateral Bell's paralysis and Hunt's syndrome and of 21 normal subjects were recorded by electronystagmography. These data were then analysed with a small digital computer (PDP 11/34). The results were compared with electroneurography (ENoG) and nerve excitability test (NET) results and can be summarized as follows: 1. Difference in velocity and amplitude between left and right eye movement during eyeblink (called blink index), diminished in inverse proportion to any improvement of lagophthalmos. 2. All the 5 patients showing more than 80% in maximum blink index (MBI) proved to have a poor prognosis, whereas 18 of 19 patients having a MBI of 40% or less proved to have a good prognosis. The blink test was deemed to be of equal clinical significance to ENoG and NET for predicting facial paralysis. 3. The blink test does not require needle electrodes for electrical stimulus, nor any special equipment other than electronystagmography, and yet this test can provide a quantitative analysis of a degeneration profile in facial paralysis.

A 37-year-old woman was admitted with fever and cough. The chest roentgenogram revealed a solitary large round mass in the right lower lung field. Diagnosis was made by transbronchial lung biopsy. There was no evidence of abnormal cell-mediated immunity. The patient made an uneventful recovery and the chest X-ray showed progressive clearing without specific therapy. After 6 months, the mass lesion disappeared. This case suggests that specific therapy may not be necessary for all cases of primary pulmonary cryptococcosis.

Smooth pursuit has been determined by the examiners' visualization as 'smooth pursuit', 'saccadic pursuit', or 'ataxic pursuit' according to the shapes of the eye movements on the ENG (electronystagmography) recording paper. Even since the introduction of computers for the measurement of smooth pursuit, however, no trial to compare quantitatively between smooth pursuit, saccadic pursuit and ataxic pursuit had been made up to the present. In the present work we analysed 10 smooth (normal) pursuits, 23 saccadic pursuits and 7 ataxic pursuits quantitatively with a microcomputer and found that the phase relationship between target movements and eye movements was the most prominent factor for distinguishing smooth pursuit pattern differences.

Although slow-phase velocity of optokinetic nystagmus (OKN) increases according to the increase of stimulus velocity, it is not obvious whether both are quite equal or not. In this study, gain of slow-phase velocity in OKN response to stimulation velocity was analyzed by two methods of stimulation, constant acceleration, and constant velocity stimulation. In our observation, the gain of slow-phase velocity was not equal to 1.0 even at low-speed stimulation. On the other hand, the number of nystagmus almost corresponded to the number of stimulation stripes passing through the center of an OK-drum up to high-speed stimulation. The results of this study indicate that pursuit eye movement of slow-phase OKN should not be quite equal to that of the eye tracking test, i.e. being required to continuously look at a moving spot.

In 1980, the Research Committee of Peripheral Vestibular Disorders in Japan, which is supported by the Ministry of Health and Welfare, was founded by 24 members, from several districts in Japan. The Committee's first task was to draft the diagnostic criteria for several peripheral vestibular disorders, such as benign paroxysmal positional vertigo (BPPV), and vestibular neuronitis. For the national epidemiological survey, they then collected the data on 101 cases of BPPV out of some 783 vestibular disorder patients. In addition, data on 103 patients of BPPV out of 559 vestibular disorder patients were also collected from the Neuro-otological Clinic of the Toyama Medical and Pharmaceutical University Hospital. From these epidemiological surveys, the incidence of BPPV in Japan was estimated at 10.7 per 100,000 population, while that of BPPV in Toyama was estimated at 17.3 per 100,000 population. The ratio of BPPV was higher in female than male patients in both surveys. The age at the onset of BPPV peaked in the fourth decade in both males and females. Compared with the other epidemiological features of Meniere's disease and sudden deafness with vertigo in the same surveys, it appeared that the characteristic features of BPPV are epidemiologically similar to those of Meniere's disease, but different from those of sudden deafness.

A quantitative analysis of prediction in smooth pursuit was made in 23 normal subjects. The target wave (random sinusoidal wave), which contains a predictive portion and a nonpredictive portion, was developed by the authors, using a microcomputer. Five parameters were established quantitatively after microcomputer A/D conversion of the eye movements every 10 ms. There was no significant difference in amplitude gain, retinal error velocity, velocity gain or acceleration gain between the predictive and the non-predictive portions. However, a significant difference between the predictive portion and the nonpredictive portion was found in phase lag. We therefore concluded that the predictive function in smooth pursuit, in normal subjects, is the most important factor in the phase relationship between target wave and eye movements.

We have developed a new system to produce target movements for our particular purposes using a microcomputer and 9-bit digital-to-analog converter. A continuously changing sinusoidal wave was produced to examine the relationship between the frequencies of target movements and smooth pursuit. A random sinusoidal wave was produced to make clear the predictive function of smooth pursuit.

We have measured RR intervals on patients with equilibrium disorders to check the function of the autonomic nervous system. And we have obtained two parameters (coefficient of variation "CV%" (the static function of the autonomic nervous system] and "A-B" (the dynamic function of the autonomic nervous system). The dynamic function of the autonomic nervous system (A-B) further deteriorated in elderly patients with central nervous system disorders. We concluded that disorders in the dynamic function of the autonomic nervous system affected the autoregulation which caused the central nervous system disorders, especially in elderly patients.

Between Aril 1975 and December 1976, the second nationwide survey of Meniere's disease in Japan was made by the 17 members of the Meniere's Disease Research Committee of Japan. The epidemiological data from 520 patients with definite Meniere's disease were analyzed in comparison with those from the 126 patients in the non-Meniere vertiginous group (Control A) and the 228 patients in the rhinolaryngological group (Control B). The male:female ratio of definite cases of Meniere's disease was almost the same, and the age distribution peaked at the age group of 40--49 years for males, while the peak for females was at the age group of 30--39 years. 5.8% of the 520 patients had a close relative who also suffered from Meniere's disease. From the epidemiological features, it may appear that the occurrence of vertiginous attacks in Meniere's disease is influenced much more by individual than by environmental factors. However, this feature can be considered as another evidence of the psychosomatic disorders involved in Meniere's disease.