Human mature semicircular canals taken at autopsy and at operation were examined with scanning and transmission electron microscopes. The findings thus obtained are summarized as follows : In the semicircular canal obtained at autopsy from a 30-year-old male nonsensory ciliated cells having 5060 cilia were seen sporadically in the ampulla of the horizontal canal on its canal portion side. A labyrinthine specimen taken at operation, on the other hand, demonstrated folding of the cell membrane at the base of columnar cells lining the wall of that part of the canal portion close to the ampulla. Distal to this area, wall cells of the canal portion became progressively flattened and their intracytoplasmic organelles were less and less abundant. Outside these cells which were disposed in a layer and faced the endolymphatic space there were dense filaments and fibrocytes, with a unilayered basement membrane interposed. Being poor in capillary network, the canal portion was supposed not to be concerned with the production of endolymph but to play a role in the maintenance of the composition of endo-and perilymph.
Fifty colored rabbits were injected Nembutal intravenously, and then their cerebellar nuclei (fastigial nucleus, anterior interposed nucleus, posterior interposed nucleus, pars convexa of lateral cerebellar nucleus, pars potunda of lateral cerebelar nucleus) were broken by electric current (current 5mA DC, 5-10sec). The changes of their posture were studied, and the results were as follows. 1) Those which were braken in fastigial nucleus declined to the opposite way from those were broken in vestibular nuclei. 2) Those which were broken in anterior and posterior interposed nucleus declined to the opposite way from those were broken in vestibular nuclei. 3) Those which were broken in pars convexa and pars rotunda of lateral cerebellar did not decline at all. The above facts were discussed as to functions of fastigial nucleus, interposed nucleus and lateral cerebellar nucleus.
The head-shaking test provokes effectively a latent spontaneous vestibular nystagmus (head-shaking nystagmus). The diagnostic significance of head-shaking nystagmus for the site of lesion was studied on 191 patients who visited our otologic clinic from 1980 to 1982 with complaints of dizziness. 1. In 78.7% of the patients of unilateral lesion, the nystagmus was directed contralateral to the site of lesion, and in 21.3%, ipsilateral. 2. In 79.3% of the patients of unilateral hearing loss, the nystagmus was directed contralateral to the site of hearing loss, and in 20.7%, ipsilateral. 3. In 96.7% of the patients with caloric abnormality, the nystagmus was directed contralateral to the site of canal paresis (CP), and in 3.3%, ipsilateral.In 4 patients with directional preponderance (DP), the nystagmus had the same direction as DP. 4. The head-shaking nystagmus, which is directed contralateral to the site of lesion, the site of hearing loss, or the site of CP, is considered as the deficiency nystagmus, while the nystagmus, which is directed ipsilateral, is considered as the recovery nystagmus. The both types of nystagmus can be distinguished from their styles of beating. 5. The biphasic nystagmus was observed in 9 patients with peripheral lesions. The 1st phase was considered to be the deficiency nystagmus, and 2nd phase, recovery nystagmus.
The existence of optokinetic after-nystagmus (OKAN) has long been known, as far back as the age of Barany. The term OKAN means nystagmus appearing after first inducing optokinetic nystagmus, and then the optokinetic stimulation is removed. It is easy to appear with the eyes open in a dark place. There have been various theories about the mechanism of the onset of OKAN. Sakata et al. previously classified the types of OKAN into the following 7 types : 1) The normal type, 2) The DP-type, 3) The disinhibitory type, 4) The inversive type, 5) The inhibitory type, 6) The dysmetric type, and 7) The clonic type. In the present study, the authors performed a vestibular equilibrium function inspection, including an OKAN inspection on about 1, 300 patients who visited the Department of Neuro-Otology with complaints of vertigo and equilibrial disturbance. The results of the inspection were classified in accordance with Sakata's method, and the diagnostic contribution of the OKAN inspection was examined. The diagnostic significance of the OKAN inspection is considered as follows : 1) This inspection can detect a very small difference between the left and the right of nystagmus in the vestibular-optokinetic system, which difference cannot be detected with OKP inspection giving a rather strong stimulation or with the caloric test giving a non-physiological strong stimulation. 2) This can be a focal localization diagnostic method by the classification by type. Thus. the diagnostic contribution of OKAN inspection was examined, and the importance of OKAN inspection was recognized again as one the equilibrium function inspections. It is considered that this inspection method will spread henceforth for general use.
Congenital nystagmus has been relatively easily diagnosed by using optokinetic nystagmus test because of its characteristic reactions, such as lack of optokinetic nystagmus, so-called “inversive reactions (bilateral, unilateral, and partial)”, or ataxic reaction. These characteristic reactions have long been believed to be seen only in patients with congenital nystagmus. However, recently we experienced an ataxic pattern of optokinetic nystagmus in acquired diseases which is quite similar to the ataxic pattern of optokinetic nystagmus in congenital nystagmus. This fact has brought confusion in diagnosing congenital nystagmus, but at the same time, this might be a clue to elucidate the unknown pathophysiological mechanism of congenital nystagmus. In this paper we report 8 cases of acquired diseases which manifested ataxic reaction in optokinetic nystagmus test.
Frequency analysis of the movement of the center of gravity during standing erect was investigated in this study. One hundred cases of both the peripheral vestibular disease and the central nervous system disturbance were examined. The following results were obtained. 1. Effects of visual righting reflex. In the peripheral vestibular disturbance, increase of waves between 0.5 and 3Hz or 1 and 4Hz in both the X (right and left direction) and the Y (foreward and backward direction) and relative decrease of waves of less than 0.5Hz appeared when the patients were asked to close their eyes. However, in the cases of central disturbances in the Y such a difference between with eyes open and with eyes closed was not observed, though in the X the result was similar as one in the peripheral vestibular disease. 2. Comparison between the ataxic patients and normal controls. In the peripheral vestibular disease, increase of waves of less than 1Hz in the X, increase of waves between 0.5 and 1Hz in the Y with eyes open and increase of waves between 1 and 2Hz in the X with eyes closed were statistically confirmed. In the cases of Meniere's disease a result of increase of waves between 0.5 and 1Hz with eyes closed in the X was added. In the cases of central disturbances, the results in the X with eyes open and with eyes closed were same as the results of peripheral vestibular disease. However, lack of increase of waves between 0.5 and 1Hz in the Y with eyes open was observed. Such a characteristic frequency wave form of the movement of the center of gravity in standing posture in the cases of different diseases may have the clinical diagnostic value.
We displayed a simulation model of a body on the CRT using a minicomputer. The body sway angles were calculated in the normal subjecs and five patients with equilibrium disorders while standing on the platform of a stabilometer. The simulation program was produced with FORTRAN languages to operate PDP 11/60 minicomputer. In normal subjects, relative indexes of mean and maximum body sway angles showed larger values with eyes closed than those with eyes open. In the patients with equilibrium disorders, especially with vestibular deficiencies, lager values were obtained than those of normal subjects in both indexes. Those results suggest the usefulness of the body sway angles in the estimation of equilibrium disorders.
The statistical analysis of area and length of movement of body's of gravity, was perfoamed to find characteristics of body sway in 40 patients with peripheral vestibular disorders, and 67 patients with central nervous system disorders. The result was compaired with the result of Mann test, and following conclusions were obtained. 1) The close relationship was found between Mann test and the area of body's center of gravity of body sway. 2) In case with brain stem disorders, Mann test was negative but the area of body's center of gravity of body sway was out of normal range. 3) It seems to be possible to discriminate the central nervous system disorders, such as crebellar or brainstem disorders from the peripheral vestibular disorders by the result of the area and length of body's center of gravity of body sway.
Fifteen patients with vestibular neuronitis were followed up for the period ranging from 4 months to 5 years. These patients were examined by caloric test and galvanic body sway test (GBST). The results are as followes. 1 Twe (13.3%) of fifteen patients with canal palsy showed complete restoration of caloric response. 2 Six (50%) of twelve patients showed normal galvanic body sway response at the first examination. 3 Twe (33.3%) of six patients with abnormal galvanic body sway response restored to normal. 4 The restoration of caloric and galvanic response were found in same patients after 1 or 2 years from first examination. 5 In only one patient who showed normal galvanic response at the first examination, galvanic response reduced after nine months.
Delayed endolymphatic hydorops was already defined by H.F. Schuknecht in 1978. But, in a few cases, there are some problems to diagnose delayed endolymphatic hydorops for the following reasons : 1) in case of delayed endolymphatic hydrops, it is difficult to conjecture endolymphatic hydrops based on the electrocochleography or the glycerol test because the degree of the hearing loss is profound 2) the classification of the hearing loss slightly varies from reporter to reporter 3) it is vague what a enough interval from arising profound hearing loss to subsequent onset of episodic vertigo of the Meniere's type is. Moreover, comparing the clinical courses of six cases of delayed endolymphatic hydorops with those of nine suspect cases of Meniere's disease and seven definite cases of Meniere's disease, it seems that there are some transient cases among these three kinds of diseases. So, delayed endolymphatic hydrops must be diagnosed carefully.
Old aged persons who complain of vertigo or balance disorders are increasing with prolongation of life time. Vertigo and balance disorders of old aged persons were studied by observing the patients who visited the Neurotological Clinic, Toranomon Hospital from 1969 to 1983. Benign paroxysmal positional vertigo was the most frequently seen disease in the inner ear lesions of old aged persons over 65 year-old. Vertigo caused by brain vascular lesions and such degenerative disease as spino-cerebellar degeneration were more frequently seen in central nervous system lesions of old aged persons.
Two cases which showed sensorineural hearing loss, tinnitus and vertigo were reported. In both cases, the anterior cerebellar artery compressed the eighth nerve. In the first case, the sensorineural hearing loss recovered after displacing the nerve. Vertigo also improved after operation, and the nature of the tinnitus changed remarkably. In the second case, the sensorineural hearing loss and pulsating tinnitus seemed to occur by neurovascular compression. After operation, pulsating tinnitus reduced markedly, however the sensorineural hearing loss unchanged. From these findings, neurovascular compression must be considered as a possible cause for the sensorineural hearing loss, tinnitus and vertigo. We discuss the relationships between neurovascular compression and lesion of the eighth nerve from our two cases and other reports in the literature.
The blood pressure in the ophthalmic artery of nine dizziness patients and ten controls was measured in both lying and standing positions by means of Mikuni's ophthalmodynamometer. The nine patients' dizziness attacks often occured upon standing. In both groups, there were no persons with positive Schellong's tests. The following results were obtained. 1) The ophthalmic artery blood pressure of both groups decreased upon standing. 2) There was significantly higher decrease in dizziness patients than in the controls. 3) Statistically, it was concluded that the people with a 17% or more fall in mean ophthalmic artery blood pressures may be diagnosed as orthostatic cephalic hypotension. 4) There were three dizziness patients (33%) who had an orthostatic cephalic hypotension, but there were none in the controls. Of the three, two had no abnormalities in common equilibrium tests (ETT. OKN.…). 5) From the above results, it was infered that an ophthalmic cartery blood pressure measurement is the best way to diagnose orthostatic cephalic hypotension in dizziness patients.