The luminal surface of the human endolymphatic sac was observed by scanning electron microscope. The morphological findings of endolymphatic sac can be divided into three portions; proximal, intermediate (rugose), and distal portion. The intermediate portion is composed of three types of cells : light cell, dark, and duct cells. This portion seems to be the most active part from the point of morphological structures. The proximal portion was covered with hexagonal or pentagonal flat cells. The surface of the distal portion was also covered with flat cells, but among the flat cells, groups of dome like cells were seen here and there. These dome like cells were similar to those seen in the inter mediate portion. The dome-like cells with long microvilli seem to be light cells and those with less microvilli, dark cells.
In previous work, the muscular activity in the slow phase and fast phase of nystagmus was explicated through the range of the rise time course and the pattern of muscular contraction, the phenomena of which were elicited by electric stimulation to the horizontal ampullary and abducens nerves. The present study was undertaken to observe the responses of the lateral rectus muscle elicited by stimulations of the bilateral vestibular nerves. The cats were anesthetized with pentobarbital sodium (35mg/kg). The condition of the electric stimulation to the left horizontal ampullary nerve was a pulsetrain of 200msec or more at 100-500Hz with pulses of 0.5msec, and to the right horizontal ampullary nerve was a pulse-train of 75msec duration at a delay of 100msec from start of the left side stimulation. The responses of the right lateral rectus muscle were recorded through the mechanogram and EMG. The activities of the lateral rectus muscle elicited by stimulation of the contralateral vestibular nerve were decreased by stimulation of the ipsilateral vestibular nerve. The rates of decline ranged from 33.3-93.7%, especially, from 78.1-93.7% to the ipsilateral stimulation of high frequency at 300Hz or more, and also the spike discharges disappeared. The half decay times ranged from 15-45msec, and on the short side at the ipsilateral stimulation of high frequency. The range was similar to the half decay times in the fast decay phase of nystagmus. Following cessation of the ipsilateral stimulation, the muscular responses elicited by the contralateral stimulation showed only slight increase, the pattern of responses showed recruitment (linear increase) and resembled the slow rise phase in nystagmus. It is suggested that the formation of this recruitment pattern is influenced by the effect of inhibition.
To investigate functional correlation between the hippocampus and the oculomotor system we attempted a series of experiments in which rabbit hippocampus was successively given a certain amount of electric stimulation for 10 days and resulting changes in the activity of the oculomotor system were measured using the test for optokinetic nystagmus, the test for spontaneous nystagmus and the electroencephalograms (EEG, s). The results obtained were as follows : (1) In rabbits with a single electric stimulation of the hippocampus, optokinetic nystagmus was first inhibited after the electric stimulation and then restored to the state before the stimulation (Type 1 : from inhibitory to normal). In rabbits with repeated electric stimulation of the hippocampus, optokinetic nystagmus was first inhibited after the electric stimulation and then developed into the following 3 types : i.e., Type II (continuous inhibition), Type III (from inhibitory to excitatory) and Type IV (from inhibitory to excitatory combined with inversion of nystagmus). (2) There was a close correlation between activity of optokinetic nystagmus and that of the EEG's. That is, the inhibitory phase of optokinetic nystagmus paralled the suppressive phase of the EEG's, whereas the excitatory phase of optokinetic nystagmus paralled that of the EEG's. Furthermore, the excitatory phase of optokinetic nystagmus tended to be acompanied by the appearance of nystagmuc responses due to electric stimulation of the hippocampus. From these findings we conclude : (1) The hippocampus initially exerts an inhibitory action on the activity of the oculomotor system. (2) Continuous, abnormal excitation of the hippocampus can induce alterations in the reactivity of the oculomotor system. Such alteration is characterized by the appearance of the the two phases of the reaction : i.e., the first inhibitory and the second excitatory, with regard to development of optokinetic nystagmus.
To investigate the neural mechanism of inversion of optokinetic nystagmus we carried out a series of experiments in which normal rabbits and those given repeated electric stimulation of the hippocampus were given a small amount of adrenaline (0.005mg kg) intravenously and resulting changes in optokinetic nystagmus were measured before and 30 minutes after the injection. The results obtained were as follows : (1) In normal rabbits there was little evidence of inversion of optokinetic nystagmus. (2) In rabbits with repeated electric stimulation of the hippocampus inverted optokinetic nystagmus appeared in one third of the number animals examined. Furthermore, the inverted nystagmus thus induced was similar to that induced by electric stimulation of the hippocampus. From these findings we conclude that the neural mechanism of inversion of optokinetic nystagmus is closely correlated with excitation of adrenergic receptors in the central nervous system, particularly those involved in the neural circuits connecting the hippocampus to the oculomotor system.
Horizontal mono-ocular movements were recorded by electronystagmography. Saccades caused by alternative gazing at two targets with a 10 degree visual angle, caloric nystagmus and optokinetic nystagmus were recorded and the eye velocity recordings were measured. Eye velocity recordings showed that inward movements of the right or left eye were either faster than outward, or were equal. These phenomena were remarkable in saccadic movements of 10 degrees and in cases of caloric nystagmus, however, such were not remarkable in the case of optokinetic nystagmus.
Effects of ocular fixation on pendular rotation nystagmus were investigated in sixty-five patients. There were twenty-five with peripheral vestibular or vestibulo-cochlear disorders, seventeen with central vestibular disorders, five with congenital nystagmus, sixteen patients over sixty years old with vertigo in whom peripheral vestibular disorders were ruled out, however, the causes were unknown. Damped pendular rotation test (DPRT) was performed both under darkness and employing mental arithmetic and under ocular fixation. Patients were asked to look at a red lamp thirty-five cm from their eyes and which was fixed on the rotating chair. These findings were related to those of caloric vestibular suppression test (VST) by Takemori and those of optokinetic pattern test (OKP), eye tracking test (ETT) and spontaneous nystagmus. Thirteen out of seventeen with central vestibular disorders and five with congenital nystagmus showed loss of visual suppression during ocular fixation in DPRT, while in cases of peripheral lesions, visual suppression was observed. Loss of visual suppression during ocular fixation in DPRT was often seen in cases of brainstem and cerebellar lesions. In brainstem lesions, rotation nystagmus was evoked during ocular fixation, while no nystagmus was seen in darkness with eyes open. In cerebellar lesions, rotatory nystagmus was partly suppressed or decreased during ocular fixation. These findings coincide with findings in cases of VST in caloric nystagmus. Nystagmus enhancement during ocular fixation in DPRT may be related to an increase in slow phase velocity in caloric VST, as seen in cases of brainstem lesions. Relationships between the direction of the visual suppression during ocular fixation in DPRT and the side of the lesion were not apparent. Ocular fixation test in DPRT has a diagnostic value not only for central lesions, but for differentiating brainstem lesion from cerebellar lesion with the findings in DPRT under darkness. The findings under ocular fixation in DPRT are closely related to those of VST in cases of caloric nystagmus.
For humans to maintain an upright posture, the proprioceptive organ is most important. However, the role of the plantar pressure receptors in control of body sway is not well recognized. We prepared a special device of plates having various pressure points for stimulation of plantars, and observed variation in the body sway in response to the stimulation given to the mechanoreceptors of the plantar in normal subjects using a gravicorder. The results concerning body sway were a reduction in square area, total shifting length and velocity, all of which are attributed to an increase input of information from plantar pressure receptors. Utilizing plantar mechanoreceptor stimulation on control of body sway, the sway of patients with spinocerebellar degeneration (Olivopontocerebellar degeneration 6 cases, late onset corticocerebellar degeneration 3 cases, Marie's disease 7 cases.) were comparatively studied. A 13mm wire netting was used for the plantar stimulation. Depending on the type of disease, we found that the square area was either enlarged, the same or reduced. However, the velocity of sway or total shifting length was either slower or decreased. These phenomena were particularly obvious in late onset corticocerebellar degeneration and olivopontocerebellar degeneration groups, thus revealing the contribution of the plantar input information in the control system of body sway. This suggests that increase of information from mechanoreceptors may play a role is improvement of body sway coordination.
Our observation in two patients with recurrent vertigo will be presented in this paper on cholesterol, β-lipoprotein, triglyceride and non-esterified fatty acid (NEFA) of the blood during each attack in the same patient. Our particular interest was the level of NEFA. Case I.H.T. This 37-year old man was first seen on May 26, 1977. He complained that vertigo awaked him from his sleep. On the fourth attack he suffered from hearing impairment in the right ear. From otoneurological examination, a diagnosis of Meniere's disease associated with hyperlipoproteinemia was made. Case II.H.N. This 38-year old man was first seen on July 1, 1975. He complained of vertigo and nausea. The associated nystagmus was not labyrinthine but central, and the vertigo was attributed to disturbance of brain circulation associated with hyperlipoproteinemia. NEFA showed high levels 0.73, 1.40, 1.44 and 0.93mEq/l on the first patient and 1.12, 1.21, 0.69 and 1.16mEq/l in the second. In the absence of of vertigo, NEFA returned respectively to the normal range and cholesterol and β-lipoprotein showed no change. Triglyceride decreased in the first patient. To clarify the relationship between vertigo and the autonomic nervous system, an equilibrium test with loading of adrenaline was given. After the load, equilibrium function remained unchanged, despite an increase in NEFA. These results indicate that the increase of NEFA was not an immediate cause of attacks of vertigo. Therefore, we considered that the occurrence of vertiginous attacks was probably due to production of acetone bodies resulting from imperfect combustion related to metabolism of NEFA.
According to the literature, there seems to be symptomatologic and pathologic terminologies for Meniere's Disease. The former is based on the following conditions, i.e. 1) repeated attacks of vertigo, 2) fluctuant cochlear symptoms. 3) exclusion of central nervous system involvement, 8th cranial nerve tumor and already known cochleovestibular diseases. From the clinical point of view, this terminology has many disadvances, i.e. 1) various kinds of pathology are seen in this disease, 2) exclusion of central nervous system involvement etc. is ditticult. The latter terminology for Meniere's disease indicates the existence of idiopathic endolymphatic hydrops, yet it is difficult to prove the existence of endolymphatic hydrops. However, recent progress in clinical research such as glycerol and furosemide tests and electrocochleo-graphycal study has enabled the provision of evidence of hydrops. Since many treatments for Meniere's disease are designed to decrease endolympatic hydrops, we emphasize that idiopathic endolymphatic hydrops should be designated as a factor in Meniere's disease.
Temporal bones of patients with Meniere's disease were examined using roentgenography. Materials were obtained from 54 patients with unilateral meniere's disease and 14 patients with bilateral Meniere's disease. In cases of unilateral Meniere's disease, the pneumatization of temporal bones of the diseased ear was more extensive than that of the healthy ear. In bilateral Meniere's disease, either a sparse or a total lack of the pneumatization in each side was observed in almost all cases. Using Schuller's method, the distance from sigmoid sinus to labyrinth capsule of the temporal bone was measured in all cases. In cases of unilateral Meniere's disease, the distance in the diseased ear was shorter than that in the healthy ear. In bilateral cases distances on both sides were short. Using Stenvers method, the diameter of the internal auditory canal of cases was measured in cases of unilateral Meniere's disease. The diameter of the diseased ear and healthy ear was almost the same in most cases.
The patient was well until Feburary 1971, four months before admission when, at the age of 22, he noted abruptly the onset of dizziness, headache and diplopia. During the four months before admission, he experienced unsteadiness of gait, left sided sudden deafness, difficulty in swallowing, thick speech, urinary hesitancy, papilledema and a lack of co-ordination. Examination of the cranial nerves showed diminished left sided facial sensation including an absent left corneal reflex, left lateral rectus palsy, left facial palsy, left sided deafness, absent caloric response on the left side, left glossopharyngeal palsy and vagal palsy. At the time of the first surgery June 19, 1971, an egg-sized tumor was extirpated, (left sided cerbellarpontine angle) and the diagnosis of glioblastoma multiforme was made. Treatment with Co60 irradiation was initiated after the surgery, the patient was improving satisfactorily and was discharged on August 28, 1971. Subsequently he has been re-admitted twice. At the time of the second surgery November 2, 1972, atrophy of the left cerebellum was most evident.In the neuro-otological examinations of this patient, Bruns-Cushing type nystagmus was observed on admission June, 1971 and two months later the nystagmus changed to pendular nystagmus on leftward gaze. At the time of second surgery November 2, 1972, gaze nystagmus, like congenital nystagmus, spontaneous horizontal nystagmus to left side, and an irregular-mixed nystagmus in Frenzel glasses were observed. While the gaze nystagmus was thought to be associated with atrophy of the left cerebellum, as there were signs of tremor of eyeballs to the left gaze, spontaneous horizontal nystagmus to the left ceasing with eye closure or, in Frenzel glasses, and cerebellar findings of eye tracking and optokinetic tests, an irregullar-mixed nystagmus was probably mainly related to vestibular nuclei occurring with eyes closed or, in Frenzel glasses and from the clinical appearance. This vertical nystagmus was also thought to be related to lesions of cerebellar vermis, as the nystagmus was influenced by changes in the position of the head.
A 44-year-old woman noted sudden onset of hearing loss and tinnitus in the left ear after sneezing. This was followed several hours later by acute vertigo. Neurotological examination revealed left sided complete loss of hearing and positional nystagmus with clockwise rotatory components, when in the left lateral position. A left tympanotomy was performed after 11 days. At surgery, perilymph was found to derive from the round window in which there was a large fistula. The fistulous area was grafted with fatty tissue. After two months, the hearing in the left ear was essentially unchanged. ENG revealed no positional and spontaneous nystagmus and the vertigo gradually disappeared. In labyrinthine membrane rupture, surgical treatment is considered to be effective in alleviating vertigo, though hearing impairment remains unchanged.
A case of vertical nystagmus induced by chronic thinner inhalation was reported. An 18-year-old Japanese boy had inhaled vapor of thinner for several years and sensory disturbances of the distal parts of the extermities, and a gait disturbance became evident. The only characteristic finding in the ENG test was direction-changing opposing vertical positioning nystagmus, which was reproducible in the subsequent tests. Oculomotor function and caloric responses were within normal limits. From the neurootological findings diffuse cerebellar lesions were suspected.
A 31-year-old female complained of headache and giddiness followed later by unsteady gait. These symptoms were not definitely diagnosed with the conventional X-ray examination, however, ENG test revealed down-beat nystagmus during positioning test, impaired fixation-suppression of caloric nystagmus, and inverted optokinetic responses. From these findings described above, the central nervous system disorders, such as brainstem and/or cerebellar lesions were strongly suggested. A definite diagnosis was established with the neuroradiological examinations. Hence, neurotological examinations are considered to be one of the most reliable functional measures in the diagnosis of brainstem lensions.
Equilibrium function tests were carried out in twelve cases of Shy-Drager syndrome. Orthostatic hypotension appeared in eleven and cerebellar ataxia was found in all. The results are summarized as follows : 1) Spontaneous nystagumus was found in six cases : gaze nystagumus in three, positional nystagumus of direction changing type in three, vestibular nystagmus in two. 2) In the eye-tracking test, ETT, saccadic eye movement was provoked instead of smooth pursuit. 3) In the optokinetic nystagumus pattern (OKP) test, all patients revealed abnormal patterns of OKN. 4) In the pendular roatation test, PRT, normal rotatory nystagumus was induced in ten. However, abnormal following eye movements appeared in five patients who were asked to follow a standstill target during pendular rotation stimulation. 5) As compared with so-called spino-cerebellar degeneration, slow eye speed in the slow phase of OKN and a fewer number of total beats were usually obtained in cases of Shy-Drager syndrome rather than in cases of spino-cerebellar degeneration.
A 22-year-old woman complained of dizziness with vomiting of 6 months duration. She had a characteristic nystagmus which was the combined type of pendular and jerky waves. Nystagmus imposition in ETT and suppression of fast phase in OKP were observed. In OKN with superimposed method, inversion on slow phase was clearly demonstrated. Spontaneous nystagmus, ETT and OKP were detected in her 25yr. old brother. The incidence of congenital nystagmus in families and the usefulness of superimposed method for OKN involvements were discussed.
We carried out studies in an attempt to determine whether or not equilibrium disorders found in chronic alcoholics could be improved with long-term abstinence of alcohol. Equilibrium function was examined in Japanese male subjects diagnosed as chronic alcoholics, of whom 29 inpatients had not ingested alcohol for 3 to 8 months (alcoholic group) and 18 outpatients for 1 to 3 years (abstainer group). Spontaneous nystagmus in horizontal direction was observed in over 90% of all patients, while vertical and pendulum nystagmus were only observed in the alcoholic group. Peripheral and/or central vestibular disorders were detected in each one in the alcoholic group, however, peripheral disorders were observed in only one of the abstainer group. Thus, peripheral and/or central vestibular disorders do occur in chronic alcoholics. However, peripheral and severe central vestibular disorders do improve to some extent after an appropriate abstinence from alcohol.
From January 1974 to December 1978, in the Department of Otorhinolaryngology, Gifu University School of Medicine, there were 12 cases of vestibular ototoxicity caused by aminoglycoside antibiotics.Eight cases were due to streptomycin sulfate (SM), two cases to kanamycin (KM), one case was due to aminodeoxy kanamycin (AKM), and one to a combination of KM, AKM and dibekacin sulfate (DKB). Characteristics of the equilibrium disturbances and the prognosis were studied. The results were as follows : (1) There were many cases of equilibrium disturbances among those who injected an aminoglycoside antibiotic of 1gm. per day for over 2 weeks. (2) Equilibrium disturbances were more prominent than disturbances of hearing among those prescribed not only SM but also KM, AKM or a combination of KM, AKM and DKB. (3) The chief complaint on the first visit was not deafness but disturbances of standing and walking and disturbances in visual fixation while walking and running (jumbling phenomenon), in all cases. In 5, deafness was a subjective symptom, but not the chief complaint. (4) The characteristic complaint of jumbling phenomenon was that the outside world appeared to be moving up and down during walking and running. (5) There were 11 with a hearing loss under 30dB and one with a loss of over 30dB. In all cases, a C5 dip or C6dip was evident (audiometry). (6) In the equilibrium test, a marked or moderate disturbance of standing with eyes closed was noted in all patients.There were 11 with decrease of labyrinthine excitability and one with bilateral loss of labyrinthine excitability. (7) The galvanic test revealed that the site of damage was the vestibular neuroepithelium. (8) In those in whom labyrinthine excitability was not lost, jumbling phenomenon was also observed. (9) Five appeared to be recovering from the loss or decrease of labyrinthine excitability and jumbling phenomenon after being off the drugs for over 2 weeks. (10) There was one with an advanced depression seen in the rotatory and caloric responses where bilateral loss of labyrinthine excitability was also observed after cessation of administration of SM.
Diseases and age of the patients were investigated in 6, 523 patients who had visited the neuro-otological clinic and the laboratory of equilibrium function in Kitasato University Hospital from August, 1971 to July, 1978. Regarding those over 60 years of age, these persons numbered 6.0 per cent among the population of Sagamihara city, where 36.5 per cent of the patients in Kitasato University Hospital live, however, those over 60 years seen in the neuro-otological clinic numbered 16.8 per cent. Those with peripheral vestibular disorders, diseases of central nervous system, generalized diseases and others were 22.7%, 28.1%, 4.1%, and 45.1%, respectively. The percentage of patients over 60 years of age was 42.2 in those with diseases of central origin. However, it was 15.0 in those with peripheral vestibular diseases. An increase in the rate of diseases of central origin in those over 60 was attributed to an increase in the occurrence of cerebral vascular disease. Most patients with peripheral vestibular disease, such as Ménière's disease, sudden deafness, vestibular neuritis and positional vertigo of benign paroxysmal type were in the 3rd, 4th and 5th decades.