To demonstrate the characteristic difference between "irrtative nystagmus" and "paralytic nystagmus", electronystagmographs of 72 cases of unilateral peripherel vestibular disorder were analyzed by Signal Processor 7T17 (NEC-Sanei). The patients could be divided into 3 groups i) Group(1), 24 patients with irritative nystagmus. ii) Group (Pi), 24 patients with early paralytic nyst-agmus occurring within 6 day after an attck of vertigo. iii) Group( P2), 24 patients with late paralytic nystagmus occurring 7 days or more after an attach of vertigo. 1) Irritative nystagmus, directed to the affected side, had a large amplitude, wide amplitude variation, high frequency and high velocity of the slow phase. This type of nystagmus was increased when the patients lay with the normal side down. 2) Paralytic nystagmus, directed to the normal side in the early stage the same as irritative nystagmus. However, this type of nystagmus decreased when the patient lay with the normal side down. On the other hand, late stage paralytic nystagmus showed a lower frequency and amplitude than early stage paralytic nystagmus, and the interval varied widely. 3) It was concluded that the analysis of irritative nystagmus and paralytic nystagmus is very important in monitoring the changing process of labyrinthine pathophysiology during and after attacks.
An intelligent stabilometer and a stepping test graphical analyzer were devised by the utilization of a microcomputer-powered stabilometer equipped with software for an automatic analysis of the basic stabilo-metry and of the stepping test. The instrument is able to communicate with any host computer through a telecommunication line. Thus, measured raw data can be transferred to the host, and stored in its magnetic storage devices and processed with its unique analyzing software. This means that achievement of the recommendations for stabilometry proposed by the Committee for Standardization of Equilibrium Examinations has easily come within the range of possibility. In the stepping test, measurements and recordings of stepping deviations are automatically performed with higher precision, and the time processes of step-by-step changing stepping deviations are objectively made evident. Furthermore, the possibility of measurement and analysis of body sway during stepping and of the rhythm of stepping is in view.
Precise history taking and otoneurological examination confirmed the diagnosis of Lermoyez's syndrome. A 39-year-old male had been suffering from recurrent episodes of tinnitus, hearing loss and dizziness. The course of the symptoms were of interest. First, low-grade tinnitus and hearing loss persisted for a year. At the pre-stage of vertigo, he noticed the severity of tinnitus and hearing impairment was used to increase. Then, the attacks of dizziness appeared. Meanwhile, both tinnitus and hearing impairment disappeared after the sudden onset of vertigo. These symptoms reccurred with increasing frequency and severity. On the basis of our findings and a review of the literature, we conclude that the major cause of Lermoyez' syndrome may be an abnormal flexibility of the ductus reuniens. The stages of onset might be as follows: an increase of endolymphatic pressure due to pathologic conditions similar to Meniere's disease, probably due to narrowing of the flexible ductus reuniens. This would cause tinnitus and hearing loss. The higher the pressure of the cochlear endolymph, the worse the cochlear symptoms. Further increased pressure of the endolymphatic space would cause the ductus reuniens to open suddenly with a pop (before rupture of Reissner's membrane, as noted by Lawrence and MaCabe in Meniere's disease). A sudden pressure increase in the saccule induces an abrupt change of the macula nerve action potential, lowering the threshold of nystagmus and dizziness and leading to an episode of vertigo. Simultaneosly, the tinnitus disappears and hearing is restored. Further investigation is required.
A Peculiar rotatory sensation around the right foot was complained of by a patient with left occipito-parietal subdural hematoma. A 65-year-old male had been suffering from the hypertension and arteriosclerosis for several years. He had a sudden attack of "difficulty in standing", ataxia and "black-out sensation" with headache. A left occipito-parietal subdural hematoma was removed. The patient noted peculiar rotatory sensations around the right foot, which were continuous and remained unchanged in character. We speculated that a lesion of the occipito-parietal lobe, especially around the 2 V area, caused this peculiar rotatory sensation. Though a defect of the visual field was noted, the eye tracking test and opto-kinetic pattern test were "within normal limits", probably due to sparing of the macula. We assumed that the abnormal rotatory sensation was closely related to the lesion of the 2 V area of the parietal region.
Transient ocular deviations with eyes closed during head turning were compared with those during rotation of head and trunk together. These deviations were more frequent(68.7%) and larger (26.7°±7.1°) during head turning than during trunk rotation (19.6%, 13.5°±6.8°). Moreover, eye shifts of more than 20° were seen during small degrees of head turning(10°). These results indicate that transient ocular deviation in the same direction as head turning is not cervico-ocular reflex but saccadic movement related to eye-head coordination which is elicited against VOR mainly by the input from neck proprioceptors and activation of the lateral gaze center while the eyes are closed.
In an attempt to clarify the effect of tympanoplasty on the vestibular systems, electronystagmograms (ENG) were recorded in 201 patients with chronic otitis media before and after tympanoplasty. ENG recordings were performed under four conditions : eyes closed and eyes open in darkness with or without mental calculation. Nystagmus was demonstrated in 61% of patients before tympanoplasty, a much higher incidence than in normal subjects. Both slow phase eye velocity and frequency of nystagmus were analyzed, and no significant difference was found before and 3 weeks or 6 months after tympanoplasty. These data suggest that vestibular disturbances in patients with chronic otitis media are irreversible and remain unstable even after tympanoplasty. On the other hand, it can be said that the surgical procedure which we used had no direct influence on the vestibular labyrinth.
Tests were conducted on board the training ship of the Ministry of Transportation on the Miyazaki-Amami Islands and Amami Islands-Tokyo routes. The tests consisted of questionnaires and correlations between the degree of acceleration and the severity of seasickness. The subjects were 124 students of the Merchant Marine Schools of Tokyo and Kobe. 1. A family history of susceptibility to seasickness and autonomic nervous system symptoms such as urticaria and discomfort in elavators were found to be predisposing factors in seasickness.Bad health, fear of vehicles and standing at work on the ship were considerered to be susceptibility factors of seasickness. 2. Stimulation of the Otoliths by linear acceleration was found to be the direct trigger of seasickness. The larger the acceleration, the worse was the seasickness. 3. Seasickness is thought to be due to the degree of acceleration and irritability of the vestibular labyrinths and brain stem and the degree of suppression by the cerebrum and cerebelium in addition to the various susceptibility factors.Other factors, except for the degree of acceleration, are probably related to personal predis-posing factors.
KCl and Ca2+ decreasing agents (Na2C2O4, Na-citrate, NaHCO3 and Na2EDTA) injected into the middle ear through the tympanic membrane or the facial nerve through the stylomastoid foramen provoked "Irritative Nystagmus". KCl presumably infiltrated into the perilymph and induced a slight increase of K+ concentration, resulting in decrease of the resting potential of the vestibular nerve or sensory cells in the vestibular labyrinth The solution of the Ca2+ decreasing agent might decrease Ca2+ in the perilymph and alter the excitability of the vestibular nerve or sensory cells in relation to Ca2+ stabilizing action. These effects of KCl and Ca2+ decreasing agents might be responsible for "Irrita-tive Nystagmus" due to continuous excitation of the vestibular nerve or sensory sensory cells. The relationship between these experimental results and the "Irritative Nystagmus" of Ménière's disease are dicussed in regard to K+ or Ca2+ concentration in the perilymph.
A case of bilateral transverse temporal born fracture is reported. When this patient was first sent to our clinic by a neurosurgeon, the cause of his bilateral cochleovestibular paralysis was not known. In addition to our routine otoneurological examination, the new diagnostic methods of FCR (Fuji Computed Radiography), high resolution CT, MRI (Magnetic Resonance Imaging) were applied. They led us to the final diagnosis of bilateral labyrinthine fracture. Thus, these new methods, especially MRI, are expected to be of help not only to the diagnosis of temporal bone fracture but also in that of dysequilibrium in general.
Case 1 was considered to be an acoustic tumor (AT) on the basis of a marked decrease of caloric response and a broad action potejtial (AP) on ele-ctrocochleography (ECoG) of the left ear, but showed only a C5 dip sensory hearing loss on both sides. Case 2 was considered to be an AT becoase of profound hearing loss and no response of AP with detectable cochleomicrophonics (CM), but the caloric response of the left ear was almost normal. Case 3 was presumably an AT with deafness, no caloric response and no AP response with detectable CM. In all three cases there was enlargement of the JAM on the left side. Air CT cisternography in cases 1 and 2 showed a small AT in the IAM, but no AT was detected in case 3. We conclude that the diag-nosis of early AT cannot be made with certainty without air CT cisternography.
A 65-year-old woman, who had suffered from Ramsay Hunt syndrome, had been examined several times with regular electronystagmography and long-recording portable electronystagmography. Although she had not complained of vertigo, a functional disturbance of the vestibular organs including the brain stem was suspected from the vestibular function test results and regular electronystagmography. Many varieties of nystagmus have been diagnosed by vestibular function tests and regular electronystagmography, but a few cases of nystagmus have been observed with long-recording portable electronystagmography. In this case the results of long-recor-ding portable electronystagmography seemed to be more compatible with the subjective symptoms than those of vestibular function tests and regular electronystagmography.
The relationship between smooth pursuit and fixation suppression (FS) of the caloric response was investigated in 42 patients with neurological disorders. Three results were obtained. (1) In the pattern analysis of smooth pursuit, 26 patients showed corresponding results in FS and smooth pursuit. In fifteen patients (whose cerebellum was affected), both the FS and the smooth tursuit were abnormal. Eleven patients (whose cerebellum was less affected) showed a normal FS and a normal smooth pursuit. (2) The computer analysis of smooth pursuit was abnormal in patients with cerebellar disorder and SCD, and their FS was also very abnormal. (3) FS was intact with an abnormal smooth pursuit in 15 patients. The high rate of correspondence in the two tests in (1) and (2) strongly suggests that FS and smooth pur-siut are controlled by the same mechanism in the cerebellum. Result (3) points to the existence of a cancellation system which can cancel VOR in the absence of smooth pursuit.
Endocochlear shunt operations were performed in 7 patients with intractable vertigo due to Meniere's disease and 4 patients with cochlear Meniere's disease. Of the 7 patients with intractable vertigo due to Meniere's disease, 3 were classified as B and 2 as C and D according to the criteria of the AAOO. In the 2 patients classified as D, both endolymphatic sac surgery and endocochlear shunt operation were performed without success, so that transmastoid labyrinthectomy had to ultimately be performed. The mean postoperative hearing deterioration at 5 frequencies was 24.1 dB. Aggravation of over 20 dB was seen in 4 out of 7 cases. Among the patients with cochlear Méniècre's disease, postoperative hearing deterioration was found only in one patient with severe preoperative hearing loss. Postoperative hearing fluctuation and transition to typical Menière's disease could not be prevented in these patients. Endocochlear shunt operation was thought to be indicated in patients with Meniere's disease with severe hearing loss who were either elderly or had undergone endolymphatic sac surgery without success.
To evaluate the actual condition of equilibrium and vertigo and balance disorders in children, question-naries dealing with vertigo and equilibrium tests such as standing test, stabilometry, stepping test and active rotation test were carried in 4356 pupils of onekindergarten, four primary schools, and one middle school in 1982. 1 Questionnaries 1) Rotatory vertigo, dizziness, and black-out were reported in 3.000, 4.5%, and 11.0% of the pupils respectively. 2) Children complaining of vertigo have a stronger tendency to develop motion sickness and to be slow-footed than normal children. 2 Equilibrium tests 1) The normal ranges of standing test (both foot standing, Mann's standing, and one leg standing), stabilometry, stepping test, and active rotation test were determined from the results in normal children. 2) In the equilibrium examination of children complaining of vertigo, abnormal results were found in 12.100 in the Mann's test with eyes closed, 8.0% in the stabilometry test with eyes closed, 7.0% in the stepping test, and 5.5% in the active rotation test. 3) Many children complaining of vertigo had normal results in equilibrium examinations. In health examinations of school children, careful history taking and equilibrium examinations are indispensable to detect vertiginous children. Furthermore, children found to have abnormal equilibrium must be examined carefully in a hospital.