During the past 14 years from 1975 to 1989, two-nation-wide surveys of Meniere's disease have been carried out by the Vestibular Disorders Research Comittee of Japan, supported by the Ministry of Health and Welfare of Japan. However, an epidemiological case-control-study including normal subjects has not yet been performed by this committee. In this third survey, therefore, 148 patients with definite Meniere's disease, 138 with non-Meniere vertigo, 113 with rhinolaryngological disorders, and 165 normal control subjects were collected by the 16 mem-bers of the Research Committee from June 1990 to November 1990. The controls were selected to match as closely as possible the sex, age and location of the Meniere's disease patients. The characteristic epidemiological features of Meniere's disease in Japan were : 1) Sex-ratio : 63 males to 85 female. 2) Age-distribution : Peak at 40-49 years for males and 30-39 years for females. 3) Season and Time of Onset : Often initial vertigo attacks occurred in the afternoon or in the morning. 4) Occupational Distribution : There was a higher incidence of Meniere's disease among technicians or white-collar workers than among farmers, laborers engaged in blue-collar work, as in the 1st and 2nd surveys. However, the number of house-wives was lower in this 3rd survey. 5) Personal characteristics : In patients with Meniere's disease, precisionism and neurosis were more frequently observed than in non-Meniere's vertigo. 6) Preceding Events : Mental and physical fatigue before vertigo attacks was frequent in Meniere's disease patients. These epidemiological features reconfirm that the occurrence of vertigo attacks in Meniere's disease is influenced much more by individual factors than by environmental factors, as was found in the 1st and 2nd Nation-wide surveys. However, a marked difference in sex ratio with female preponderance was found in the 3rd survey. The incidence of bilateral Meniere's disease was 16.2% (24/148), higher than in the 1st and 2nd surveys.
Several nation-wide surveys of Meniere's disease have been carried out by the Vestibular Disorders Research Committee of Japan, supported by the Ministry of Health and Welfare of Japan. An analysis was conducted of the epidemiological and clinical features in patients reported in 2 or more surveys. The epidemiological features resembled those of previous studies, but the cynical features were different in some respects.
1. The similarity of the vestibular disorders (definite MD, suspected MD, BPPV, SD, VN, BLVF, IES) was examined and correlated with age/sex, anamnesis, initiators and triggers of vertigo attacks, and many clinical features of vestibular disorders.2. The clinico-epidemiological factors were clearly classified into three groups by the correlation analysis. 3. The similarity between definite MD and suspected MD was extremely high and a high correlation was also found between definite MD and SD in most of the factors. A correlation between definite MD and BPPV or VN was found in some of the background factors in these patients.
The relationships between stress and vertigo attacks were studied from the results of a questionnaire (Environmental Change Event Inventory reported by Kobayashi in 1977). In order to make a casecontrol study, 135 normal participants in a multiphasic health examination in Toyama Prefecture (1987) and 42 patients with Meniere's disease who visited our hospital in 1987 were sent questionnaires. This study revealed the following features: (1) Patients with Meniere's disease were more stressed than the controls. The subjective weight of a stressful impact in each change event had tended to be greater in the patients. (2) In one case the frequency of vertigo attacks decreased as the quantity of stress decreased. These data suggest that stress is closely related to vertigo attacks in patients with Meniere's disease.
Vestibular Meniere's disease was diagnosed in 18 patients in Gifu University Hospital from January 1987 to October 1989. We review here the electrocochleograms, the course of vertigo, the course of cochlear symptoms and hearing tests, and the incidence of central nervous system disease. 1 . Three patients had increased -SP. The side of increased -SP corresponded with the side of canal paresis in all cases. 2. The patients were divided into five groups according to the course of vertigo ; 1 patient had sporadic attacks. 8 patients had periodic attacks. 3 patients had frequent attacks in a short period of time. 2 patients had sporadic attacks but recently the frequency increased. In 3 patients, the outcome was unclear, because the periods of observation were short. 3. In 2 patients, fluctuating hearing loss was noted in hearing tests. The side of hearing loss was the same as the side of canal paresis. We diagnosed pre-Ménière's disease, but they were not aware of fluctuating hearing loss. Therefore, periodical hearing tests are necessary for observations of vestibular Meniere's disease. 4. In one patient, tumor of the fourth ventricle was detected. 5. Seven patients had repeated attacks of vertigo in a long time without cochlear signs and disease of the central nervous system.
Glycerol tests were used in 180 patients with Meniere's disease to evaluate frequency ranges with significant hearing changes. The tests were positive in 67 of 137 (50%). Hearing improved following glycerol administration at low and middle frequency ranges, 0.125 to 1.0 kHz, especially at middle frequency ranges, 0.5 to 1.0 kHz, with hearing improvement over 20 dB. Such definite improvement in this frequency region was common in patients with low and middle tone deafness, the type of hearing loss in Meniere's disease. Thus, glycerol-induced hearing improvement was greater at middle frequency ranges from 0.5 to 1.0 kHz than at lower frequencies. Although there is much controversy about the mechanism underlying glycerol-induced hearing improvement in Meniere's disease, our results favor the hypothesis that glycerol reduces endolymphatic hydrops and consequently the high concentration of K' in the perilymph of the scala tympani, which causes low and middle tone deafness, is washed out.
Vertigo in vestibular Ménière's disease is similar to that in Ménière's disease, but in the former there are no cochlear symptoms. A 58-year-old woman visited Gifu University Hospital on August 31, 1987, complaining of recurrent attacks of vertigo. She had no cochlear symptoms. Caloric tests indicated left canal paresis, but no abnormalities were detected on CT scan. We diagnosed vestibular Ménière's disease. She later complained of positional vertigo with severe nausea and visited our hospital again on February 15, 1990. Neurological findings : Lateral gaze directional nystagmus and down beat head shaking nystagmus were seen. In voluntary OKN, smooth pursuit was abnormal but saccadic eye movement was not. We speculated that disorders of eye movements were caused by a lesion of the flocculus or its connection to the vestibular nuclei. MRI findings : MRI showed a tumor of the fourth ventricle, compressing the right cerebellar peduncle. Neurological findings corresponded with MRI findings. We conclude that the vertigo was due to vertebrobasilar insufficiency or endolymphatic hydrops caused by disturbance of CSF flow.
Clinical vestibular and auditory studies were done on 17 patients with vestibular Meniere's disease characterized by recurrent episodes of vertigo. According to the duration of the vertigo attack, the subjects were dividided into two groups. Four of eight patients in the group with long duration of vertigo (more than 10 minutes) showed fluctuating hearing loss in the lower frequency ranges and later develo ped typical Meniere's disease. All of them exhibited canal paresis and three of them have predominance of -SP in the affected ear. We concluded that in patients with vestibular Meniere's disease with long vertigo attacks and predominance of -SP and canal paresis, vestibular symptoms would probably be followed by the development of typical Meniere's disease.
-SP/AP ratios were investigated in two patients with Meniere's disease by extratympanic electrocochleography. In case 1, a 46-year-old female, the -SP/AP ratio in two different bursts of vertigo attacks was 0.73 and 0.70, and 0.72 and 0.70, respectively, several hours before and after a vertigo attack. When she was symptom-free, the -SP/AP ratios were 0.57 or 0.58. In case 2, a 43-year-old male, the -SP/AP ratio during vertigo was 0.52 ; it returned to 0.27 after the intravenous administration of steroid.
Click-evoked otoacoustic emissions were recorded from 28 ears of 20 patients with Meniere's disease. Evoked otoacoustic emissions (EOAEs) were present in 27 ears, although ears with hearing loss exceeding 40 dB HL were included. EOAEs recorded were examined by 100 Hz narrow-band EOAE analysis. This analysis permits easy detection of weak echoes in patients with severe hearing loss and aids in the analysis of characteristics of EOAEs which are composed mainly of fast and slow components. In general, the duration of EOAEs tended to be shorter in the ears of patients with Meniere's disease. There-fore, slow component with longer latency were diminished in amplitude even in patients with slight deafness. In ears with advanced deafness, the slow component disappeared and only the fast component with shorter latency persisted ; ultimately the fast component also disappeared if the hearing was severely impaired. These results suggest the possibility of the clinical application of EOAEs in the diagnosis of Meniere's disease.
The trapezoid rotation test (±2, 4, 6, 8, and 10°/ sec2) with Contraves' computerized rotary chair sys-tem was performed in 37 patients with sudden deafness and vertigo and in 2 patients with vestibular neuronitis. The test results were classified into four types: 1) contralateral labyrinthine preponderance (LPc), 2) ipsilateral labyrinthine preponderance (LPi), 3) recruitment (Rec), and 4) normal. A correlation of subjective symptoms and shifts in the 4 types of test results during the clinical course showed 4 stages in the development of unilateral vestibular disorder with vertigo : (i)initial onset of LPc type (ii)shift to LPc type from LPi type (iii)shift to LPi type from LPc type (iv)shift to LPi type from atypical LPc type In the stage of appearance of the Rec or normal type, vertigo was not a complaint.
Schüller projection films and CTs encompassing the lateral semicircular canal were obtained in 22 patients with unilateral Meniere's disease ; similar procedures were performed on 16 patients with unilateral chronic otitis media as controls. The distance between the posterior semicircular canal and the posterior petrous surface (P-P distance) was measured in the CTs, and the distance between the capsula ossea labyrinthi and the sigmoid plate (C-S distance) in the Schuller projections. The statistical differences between the affected ears and the non-affected ears were then calculated in both Meniere's disease and chronic otitis media. The correlation between the P-P distance and the C-S distance was also determined. 1) In the affected ears in unilateral Meniere's disease, P-P and C-S distances was significantly shorter than in the non-affected ears. No correlation was found between the P-P distance and the C-S distance. 2) The C-S distance was shortest in the affected ears of patients with chronic otitis media. The C-S distance appeared to be influenced by middle ear infection : apparent differences due to the radiological projection angle must be taken into consideration. 3) The P-P distance appears to be more useful than the C-S distance for the evaluation of Meniere's disease.
Seventy-one patients with unilateral definite Meniere's disease and 11 with bilateral Meniere's disease were analyzed with respect to the degree of pneumatization of mastoid air cells and the distance from the sigmoid sinus to the vestibule in the Schuller's view. The results were compared with those from 70 non-Meniere patients with vertigo and 26 healthy subjects without vertigo. Roentgenograms were collected from 14 universities and three hospitals affiliated with the Japan Research Committee of Vestibular Diseases. The degree of pneumatization of the affected ear was not significantly less than of the contralateral healthy ear or the ears of non-Meniere pa-tients with vertigo or of the healthy control group. The mean distance from the sigmoid plate to the posterior bony wall of the vestibule, which is assumed to reflect the length of the vestibular aqueduct, was 5.4 mm the affected ear, and 5.5 mm in the unaffected in the patients with Meniere's disease, 5.1 mm in non-Meniere's disease patients and 5.3 mm in the healthy controls. There were no significant differences among these groups. These results do not agree with those of some other investigations in which poor mastoid pneumatization and a short vestibular aqueduct were found to be causative factors in Meniere's disease. A possible explanation for this discrepancy is that not all endolymphatic hydrops histologically diagnosed in Meniere's disease is caused by the dysfunction of resorption of endolymph in poorly developed endolymphatic sacs. Therefore, other etiologic factors, such as immunological deficits, should be considered.
The width of the external aperture of the vestibular aqueduct was measured in patients with Meniere's disease in three-dimensional images. The aperture on the side affected by Meniere's disease was significantly narrower than in normal ears or ears with chronic otitis media. The aperture on the opposite (healthy) ear in unilateral Meniere's disease was also significantly narrower than that in normal ear or with chronic otitis media. Thus, it appears that the aqueduct in Meniere's disease is incompletely developed and that this abnormality is related to the pathogenesis. Also, in unilateral Meniere's disease the opposite ear is at high risk of developing the disease eventually.
In comparison with computed tomography (CT), magnetic resonance imaging (MRI) offers high spatial resolution without bone artifacts. Accordingly, MRI has the potential to image the soft tissue of the human inner ear which is surrounded by the temporal bone. In the present study we combined a 2.11 T MRI and personal computer aided three-dimensional (3-D) reconstruction system to obtain 3-D reconstructed images of the human inner ear. All key structures of the inner ear were visualized precisely. We could rotate the reconstructed images in any direction and understand the spatial relationship of each inner ear structure intuitively. Computer-aided 3-D reconstruction from histological sections of the temporal bone is a useful way to demonstrate the complex spatial structures of the inner ear. The results suggest that MRI combined with 3-D reconstruction can provide 3-D reconstructed images similar to those obtained by histological sectioning and can be used clinically to detect small lesion of the inner ear.
In 68 patients with sudden deafness treated with steroids and five patients received no steroids, symptoms disappeared in the following order : 1) sensation of whirling, 2) gaze nystagmus, 3) positional nystagmus, and 4) dizziness and head-shaking nystagmus. Group A patients were given steroids only, group B patients received steroids and anti-vertigo drugs. In group A, the sensation of whirling disappeared 2.0 days after the start of treatment, gaze nystagmus 5.0 days, positional nystagmus 10.8 days, dizziness 23.4 days, and head-shaking nystagmus 23.3 days. In group B, the sensation of whirling disappeared 5.5 days, gaze nystagmus 4.1 days, positional nystagmus 6.8 days, dizziness 20.5 days, and head-shaking nystagmus 19.8 days. These differences between the two groups are not significantly different, although group B patients had more severe symptoms than group A patients. Positional nystagmus and head-shaking nystagmus tests were useful in assessing the effect of steroids on vertigo caused by sudden deafness. The sensations of vertigo varied considerably among the patients.
The clinical effects of long-term steroid medication for Meniere's disease were studied in 13 patients, 8 with unilateral Meniere's disease and 5 with bilateral Meniere's disease. Betamethazone (1.5 mg) was given orally at the start of therapy. The patients were followed for 24 months. The results were evaluated in accordance with the 1985 criteria established by the American Academy of Otolaryngology, Head and Neck Surgery (AAO-HNS). 1) Vertigo : Complete control of definite vertigo attacks was achieved in one patient (800), substantial control in 10 patients (76%), limited control in one patient (800), and insignificant control in one patient (8%). 2) Hearing loss : Hearing improved in 2 ears (11%), remained unchanged in 12 ears (67%), and worsened in 4 ears (22%). There were no side effects. These results are superior to those obtained with conventional treatments. We conclude that steroid treatment is benficial for patients with Meniere's disease.
The authors have previously reported a study in which autonomic function was evaluated by thermography in an examination of the effect of transdermal scopolamine (TTS scopolamine) on the autonomic nervous system. We found that TTS scopolamine inhibits vestibular autonomic reflexes but does not af-fect the somatic autonomic reflex system. In the present study, we tested the effect of TTS scopolamine on the response to caloric stimulation, metopic cooling stimulation, podalic cooling stimulation and on un-stimulated CV %. The results showed that only in caloric stimulation the amplitude of the cutaneous temperature variation significantly reduced after the dermal application of TTS scopolamine. No significant temperature differences were noted with metopic cooling stimulation, podalic cooling stimulation or un-stimulated CV %. Thus, as in the previous study, the results indicate that the TTS-scopolamine inhibits vestibular reflexes but does not affect the somatic reflex system. The present results also suggest that inhibitory effects no the pathway from the medullary respiratory control centers to the endings of vagal efferent fibers are slight.
The clinical effects of bifemelane hydrochloride on hearing loss were investigated in 16 patients with Meniere's disease (27 ears). The dosage was 150 mg of bifemelane hydrochloride (Alnert(R)) daily for 8 weeks to 10 months. The control group consisted of 26 patients with Meniere's disease (40 ears). 1. Improvement of the hearing level was seen in 44.4 % of the ears of those treated with bifemelane hydrochloride at the 8 week point, when all subjects were examined. Great improvement was noted in 7.4% of the ears, moderate improvement in 3.7%6, and slight improvement in 33.3%. These results were significantly higher than those of the control group. Moreover, some level of improvement was seen in a total of 60.0% of 15 ears in 10 patients who received bifemelane for more than 5 month. 2. The degree of improvement in hearing levels were greater in those with less than 60 dB hearing than in those with 60 dB and over hearing at the time of the 8 week examination. 3. The efficacy of bifemalane hydrochloride was unrelated to the patient's age.
In order to theoretically establish a rehabilitation method for patients suffering from sequelae due to vestibular dysfunction, an instruction for gait correction has been prepared and its efficacy was examined in terms of subjective symptoms and objective findings with the use of a simplified and portable type of gaitcorder. Correction instructions were given to eight patients with sequelae due to vestibular dysfunction due to different causes. They had been unable to return to normal social activity before the appropriate correction instructions. However, within 1 to 3 months the efficacy of this gait correction rehabilitation was observed, and all eight patients recovered and eventually returned to normal social activity. The usefulness of this gait correction was confirmed. The simplified gaitcorder used in this study is easy to carry and was proved to be useful in terms of temporal and distance factors in gait analysis.
Autogenic training (AT), introduced by Schultz and Luthe, is a very popular therapeutic technique in psychosomatic medicine. AT consists of 6 standard somatic exercise steps (heaviness of limbs, warmth of limbs, focus of attention on heart rate, focus of attention on respiration, warmth of solar plexus, coolness of forehead). It is said that AT achieves psychosomatic relaxation by the self-regulation of neuro-vegetative functions. We examined the effect of AT in 11 patients whose vertigo was difficult to control with medication. Eight patients (72.7%) improved. Especially in patients who were able to master the second step of AT (warmth of limbs) or higher steps, the effect was marked. We conclude that AT is a useful technique, and psychosomatic relaxation is important for patients with vertigo.
In a previous study we exposed guinea pigs with experimental endolymphatic hydrops to sound and reported blood sludging in the upper turn of the cochlea. In the present study, glycerol administered before sound exposure reduced endolymphatic hydrops wi-thout blood sludging or circulatory disturbances in the upper cochlear turn. Thus, circulation in the upper turn is disturbed only when endolymphatic hydrops and sound exposure are present. Next, guinea pigs with endolymphatic hydrops were exposed to sounds of diffierent frequencies and to rock music. It was found that the upper turn is easily injured in the presence of endolymphatic hydrops.
The temporal bones of 24 aged cadavers were examined histologically during the last five years. In 18 cases there was a history of "vertigo". The Distension of Reissner's membrane was present in 26 of the 29 cochleae examined from those with "vertigo" and in 5 of the 9 cochleae of the controls. The degree of hydrops in the cochleae of those with a history of "vertigo" was severer than that in the cochleae of the controls. The temporal bones of two SHR rats with a kind of "vertigo" were also examined histologically. The cochlear structure of the affected side was destroyed and replaced by fibrotic cells in one rat. In one turn of the cochlea on this side, a mass of coagulated blood and fibrosis was observed in the same region, presumably caused by intracochlear bleeding due to hypertension. Ultrastructural studies are needed to clarify those pathological findings.
Ten minutes after an intravenous injection of HRP, guinea pigs were killed by decapitation. The bullas were removed and opened, and the cochleas were fixed by perilymphatic infusion with glutaraldehyde. Blood shudging and considerable HRP leagage were observed in the capillaries of the stria vascularis. When blood was replaced with plasma expander, blood sludging did not appear after decapitation because few blood cells remained in the capillaries. Moreover, HRP leakage was scarecely observed in the strial capillaries. Even if the strial capillaries were contracted by the decapitation, HRP leakage did not occur without blood sludging. The high pressure between capillary endothelium and blood cells produces many marginal bolds, which efficiently transport HRP out of the capillaries.
The effects of prednisolone on the neurons in the medial vestibular nucleus (MVN) were investigated by electrophysiological methods in anesthetized cats, since the drug is known to be effective in the treatment of vertigo in some diseases, such as Meniere's disease. Extracellular neuronal activity in the MVN recorded with a glass-insulated silver wire microelectrode attached along a seven-barreled micropipette containing prednisolone hydrochloride (0.1 M), monosodium glutamate (1 M), glutamic acid diethylester (0.05 M), or CoCl2 (0.1 M). These chemicals were applied microiontophoretically to the target neuron being recorded. The MVN neurons were classified as type I or type II neurons according to their responses to horizontal and sinusoidal rotation. The effects of the drugs on type I neurons were examined. The intravenous injection of prednisolone up to 5 mg/kg induced an increase in spontaneous and rotation-induced firing in 5 of 7 neurons tested. Microiontophoretically applied prednisolone in doses of 50-200 nA dose-dependently increased spontaneous and rotation-induced firing in 19 of 25 neurons examined ; the firing of 5 of the remaining 6 neurons was unaffected by the drug up to 200 nA, and in only one neuron it was decreased. Prednisolone-induced increase in firing of the MVN neurons was not affected by the iontophoretic application of GDEE, which inhibited glutamate-and rotation-induced firing. Microiontophoretically applied Co2+" did not affect prednisolone-, glutamate-, or rotation-induced firing. These results suggest that prednisolone acts directly on the MVN neuron membrane and activates neuronal excitability.
To measure ion transport through a membranous labyrinth, we devised a micro chamber unit consisting of a micro chamber, a circulation pump and a storage tank. A cellulose triacetate membrane was inserted to divide the chamber into two circuits. One circuit was filled with physiological saline, the other with 5% glucose solution. We measured the passive transport of Na+ through the membrane, then tested it under various conditions simulating those in the human membranous labyrinth. The suitable conditions were 7 mm for the diameter of the chamber and 10 Ml/min for the circulation rate.
To examine the role of the superior cervical ganglin (SCG) in the blood flow to the inner ear, we conducted two experiments: unilateral ganglionectomy and unilateral electrical stimulation of the SCG. The blood flow was demonstrated by immunofluorescence with kanamycin sulfate (KM) as the tracer and anti-KM serum. Unilateral ganglionectomy had no appreciable effect on fluolescence in the stria vascularis or the macula utriculi. On the other hand, electrical stimulation reduced fluolescence in the macula utriculi, although there was no change in the stria vascularis. These results suggest that unilateral ganglionectomy has no effect on the blood flow in the inner ear, and that electrical stimulation can reduce blood flow in the macula utriculi.
In this investigation of response decline (RD) phenomenon of the vestibulo-ocular reflex (VOR), five healthy squirrel monkeys were rotated repeatedly in a darkroom. First they were rotated clockwise for 5 sec at a constant angular acceleration of +20°/sec2, then decelerated slowly to the zero point by subliminal clockwise rotation of -0.4°/sec2. This rotation was repeated 20 times a day for 2 weeks. The constant angular acceleration test performed after repetition of the rotatostimulation showed "directional preponderance (DP) to the left", which was caused by the RD phenomenon in the slow phase eye velocity (SEV) of right beating nystagmus. However, significant DP was not observed in other nystagmus parameters, such as "duration", "jerk number", and "quick phase velocity". The DP of SEV tended to decrease during a rest of 24 hours after stimulation and disappeared completely after a rest of 2 weeks.
The effect of blood pressure (BP) changes on cochlear blood flow (CoBF) was investigated in anesthetized ginea pigs. CoBF was measured by the laser Doppler (LD) technique while systemic BP was modulated by intravenous infusions of norepinephrine or by the removal of whole blood. CoBF changed passively in the mean BP range of 40 to 90 mmHg, however, it showed effective autoregulatory function when BP decreased below 40 mmHg. In the guinea pigs with unilaterally obliterated endo-lymphatic sac and duct, the decrease in CoBF 3 to 7 months after surgery was larger on the operated side than on the intact side. This suggests that autoregulatory function for CoBF is impaired in the hydropic ear.