Dr. Yamakawa was born in Iki Island. In 1938 he published the first description in the world of the temporal bone in Menieres disease. At 35 years of age he experienced sudden hearing loss in the right ear with tinnitus, vertigo and nausea. His hearing unfortunately did not improve and he had no attacks of vertigo. His hearing was normal on the left. He died suddenly at 88 years of age of acute cardiac heart failure. A histopathological examination of the right temporal bone showed endolymphatic hydrops limited to the apical turn of the cochlea, atrophy of the stria vascularis, loss of spiral ganglion cells and absence the basal turn of the organ of Corti. The tectorial menbrane was normal throughout. The left temporal bone was normal.
Electrophysiological studies were performed on guinea pigs to elucidate the mechanism underlying the antivertigo action of eperisone, an antispastic drug. Nystagmus was observed when eperisone was introduced into the middle tympanic cavity via the external auditory meatus. The attitudes of the nystagmus induced were similar to those of nystagmus induced by lidocaine. The effect on hearing was a temporary moderate hearing loss, which almost completely disappeared in time. Eperisone was found to effectively anesthetized and suppress irritability in the inner ear. These effects are thought to be related to eperisone's antivertigo actions.
Eye movements were recorded by electronystagmography using silver plate electrodes and search coils, and they were analyzed by a microcomputer. Eye movements recorded by scleral search coils are noise-free and very stable. Especially, vertical eye movements-pursuit or saccades-are recorded precisely and are not affected by blinking. Eye movements can be recorded with visual angle of up to 30 degrees, but 20°is better for routine examinations. It is very easy to obtain DC-recording of monocular movements by search coils. The recording using search coils is not affected by EMG or by sweat. It is possible to record eye movements with search coils even in patients who have no corneoretinal potentials. However, the movements during eye closure should be carefully considered when search coils are used.
We analyzed periodic alternating nystagmus (PAN) in a 47-year-old male with spinocerebellar degeneration of three years duration. The neurological examination revealed normal mental status and higher cerebral functions, spontaneous and gaze nystagmus, neck tremor, scanning speech, ataxic gait, mild weakness of the proximal lower extremities, hypotonia, dysmetria and decomposition of limb movements, generalized hyperactive deep tendon reflexes and Babinski's sign. Neuroophthalmological examination showed gaze nystagmus on both lateral and downward gaze, hypermetria of saccadic eye movements, disturbance of pursuit eye movements, poor optokinetic response and normal caloric response with absent visual suppression. The effects of fixation, eye position and drugs on the period of oscillation and maximum slow phase velocity of nystagmus were evaluated. Eye movements were recorded by an oculotracker and DC-EOG. The slow phase velocity of PAN was calculated by a computer. The period of oscillation and maximum slow phase velocity of nystagmus did not differ in forward gaze with and without visual fixation. Maximum velocity of nystagmus tended to increase as the eyes deviate laterally. However, on upward gaze, nystagmus was suppressed. Eye position did not affect the period of oscillation of PAN. Baclofen 30 mg/day did not stop PAN, but tended to decrease the maximum velocity of PAN without changing the period of oscillation. Chlordiazepoxide 30 mg/day or baclofen 15 mg/day had no effect on PAN. We concluded that the PAN of this patient was probably related to lesions of the brain stem and cerebellum with sparing of the vestibuloocular reflex pathway and that PAN was influenced by eye position. The hypothetical model of PAN proposed by Leigh et al. resembled the findings in this case.
Miyagi's personality investigation list was used to compare vertiginous and non-vertiginous patients. (1) Vertiginous patients had less self-confidence and more introverted obsessional characteristics than non-vertiginous patients. (2) These characteristics were not related to the duration' of the disease. (3) The personality of patients with Meniere's disease was simillar to that of other vertiginous patients, but nervousness was significantly more frequent in patients with vestibular Meniere's disease.
The purpose of this study is to determine the normal range of stabilometry in children and the characteristics of upright standing posture. A group of 111 healthy children aged 4 to 15 years were tested. Each child was instructed to stand with feet close together at the center of a stabilometer with the eyes open and closed for 60 seconds, respectively. The sway of the center of gravity was sampled at 50 msec intervals by an analog-digital converter and stored in a microcomputer. From the stored data, the length of the sway, maximum diameter of forward-backward and right-left sways, area and center of the sway, probability density distribution of amplitude, velocity of sway and power spectrum were calculated with a specially designed program. 1. The length, maximum diameter, area, standard deviation of the probability density distribution of amplitude, and the velocity of the sway decreased with age. 2. The differences in the mean values of these measurements with the eyes open and with the eyes closed were large in children aged 4 to 8 years. 3. The center of sway was located further behind the center of the soles in children than in adults, and it moved forward with age. 4. The normal ranges of each parameter of stabilometry were described for each age-group.
A study was made of the children complaining of vertigo, dizziness and equilibrium disturbances who were examined at the department of otolaryngology of Gifu University from January, 1977 to April, 1985. 1. Of the 4584 patients who visited our clinic with complaints of vertigo, dizziness and equilibrium disturbance 121 (2.6%) were children under 15 years of age. Equilibrium and neurological status were evaluated in these patients. 2. Of the 121 patients, 25 (20.7%) had labyrinthine disturbances, 22 (18.2%) central nervous system disturbances, 3 (2.5%) visual disorders, 2 (1.6%) nasal vertigo, and 57 (47.1%) vertigo or dizziness due to systemic diseases. In 12 patients (9.9%) the vertigo and dizziness were of unknown etiology. 3. Among the 25 patients with labyrinthine disturbances, 7 were diagnosed as having circulatory insufficiency of the labyrinth, 3 had vertigo with sudden deafness and 3 delayed hydrops. 4. Among the 22 patients with central nervous system disturbances, 7 had epilepsy, 4 had post-traumatic disorders, 3 had brain tumors, and 2 had cerebellitis. 5. Fifty-six of the 57 patients with vertigo and dizziness due to systemic disorders had orthostatic dysregulation. 6 . Relatively uncommon cases were one patient with hyperostosis of the temporal bone and one with vertigo and congenital nystagmus, in whom multiple systemic disorders were suspected.
Thirty four patients who complained only of tinnitus and thirtry six with orthostatic hypotension were tested with the equilibrium examination. The numbers of nystagmus and of maximal slow phase velocity in OKN were comparison in different age groups. The number of nystagmus beats and the maximal slow phase velocity in OKN were similar in the yourger and older groups. However, with higher optokinetic stimuli (70, 80, 90 deg/sec) the slow phase velocity deteriorated, especially in the older groups. The reduction was significantly greater in those over 65 than in 35-54 year old group. Our clinical observations suggest that OKN disturbance in the elderly patients is due mainly to a dysfunction of the coordination mechanism which controls the optokinetic mechanism and smooth pursuit.
The influence on human equilibrium of positive and negative middle ear pressure was studied with a strain gauge platform and head position sensor system. The data obtained were digitalized and analysed by a microcomputer, Deviation of head and body sway center followed by eye closure was adopted as the parameter for the analysis. Three groups of people were examined; 1) patients with unilateral otitis media with effusion (OME), 2) normal volunteers, 3) patients with middle ear ventilation tubes on one side. Patients in group 1 were examined before and after the treatment of OME. Those in groups 2 and 3 were examined with positive or negative pressure applied on the ear randomly chosen (group 2), or on the ear with a ventilation tube inserted (group 3). The OME patients' head deviation to the affected side turned to the opposite side right after treatment. Head deviation similar to that of the untreated OME patients was observed when positive external earcanal pressure (group 2) or negative middle ear pressure was applied. The shift of the stapes' foot plate might be one of the causes of these head deviations. More studies are needed to clarify the mechanisms of disequilibrium produced by unusual middle ear pressure.
In 1983 the board of the Japan Society for Equilibrium Research presented a standard of stabilometry including both routine and precision tests. The precision test consists of measurments and analyses conducted automatically with the use of a computer. However, the items of the precision test are not specified. The purpose of this study is to describe the items of the precision test and to determine the normal range of each item in healthy adults. The subject was requested to stand on a stabilometer with the feet close together. The sway of the body center of gravity was recorded for 60 seconds with an X-Y recorder and stored in a microcomputer with a sampling rate at 20 Hz. Each examination was performed with eyes open and eyes closed. From the stored data, unit locus length, forward-backward and right-left diameters, area, standard deviation, skewness and kurtosis of amplitude probability density distribution, velocity, center of the sway and power spectrum were calculated with a program designed for this experiment. Ninety one healthy subjects aged 15 to 82 years were examined. 1 . Unit locus length, F-B and R-L diameters and sway-area were required for evaluation of the size of the sway. 2. Skewness, kurtosis, and the ratio of F-B to R-L diameter were indispensable to determine the pattern of the sway. 3. The center of the sway was useful for evaluation of the shift of the body center of gravity in the upright standing posture. 4. Vector analysis of velocity was necessary as a parameter of the characteristics of the sway and to determine the direction of the sway. 5. Power "spectrum was essential to observe the amplitude in connection with the frequency of the sway. 6. In subjects over 50-years of age, the values of each item increased with age. Therefore, the values obtained in subjects aged 20 to 49 are presented as a standard for stabilometry in healthy adults.