In order to estimate the prevalence of Meniere's disease, nation-wide surveys were designed. The surveys consist of two parts, primary and secondary. In regard to primary survey, questionaires were sent to totaling 4038 clinics in the hospitals with more than 200 beds in Japan. The number of departments of clinics were as follows : 1049 otolaryngology, 1834 internal medicine, 685 brain surgery, 262 neurology, 138 psychosomatic medicine and 10 geriatricts. A questionnaire form of primary survey was quite simple only requested to answer number of patients of Meniere's disease in each clinic. Response rate was 29.8% in the departments of otolaryngology, and 19.5% in other departments during two months after sending questionnaires. After asking for answer to the primary survey again, the secondary survey will be carried out. Necessary items such as sex, age and other information for analysis will be added in the secondary survey in order to clarify the epidemiological picture of Meniere's disease.
To clarify the relationships between the stress and the vertiginous attack, changes events, which 17 patients with Meniere's disease met in their community life during recent three months, were checked out by the Environmental Change Event Inventory (including 139 items) reported by Kobayashi (1977). When they checked out, they rated the degree of subjective shock by five point scale, for defining subjective weight of stressful impact in each change event. Moreover, the weight of objective stressful impact in each change event was used which was reported under the data of 1067 respondents by Yamamoto (1972). The total number of subjectively and objectively weighted change events was computed as social stressors with the subjects which was exposed in their community life. This study revealed the following features. (1) The score of social stressors of 11 patients with Meniere's disease which were suffering from vertiginous attacks was higher than that of 6 patients with no attack. (2) The score of social stressors of patients with many attacks was high. These data suggested quantitatively that social stress might induced the vertiginous attacks with Meniere's disease.
The directional prepondance of vestibulo-ocular reflex (VOR-DP) by the pendular rotation were observed on the pigmented guinea pig after the surgical obliteration of unilateral endolymphatic sac. •Four out of five guinea pigs revealed DP to the non-operated side and one revealed to the operated side after operation. Then three guinea pig changed DP from the non-operated side to the operated side 2-6 weeks later. •The progressing stage of the experimental endolymphatic hydrops in guinea pig considered to be a model of the pre-vertigo stage of Meniere's disease.
Effects of removal of bilateral carotid sinus nerves upon the brain P02 autoregulation in conscious rabbit were studied. Following intravenous injections of phenylephrine (PE) and nitroglycein (NG), baroreflex sensitivity (BRS) was measured from changes in R-R interval per unit changes in arterial blood pressure. The reflex heart rate response to blood pressure modulation was profoundly impaired by denervation of carotid sinus nerve, and brainstem PO2 autoregulation was disturbed only when blood pressure was elevated by PE injection. In contrast, tissue P02 of normal animal was well preserved. Furthermore, passive head up tilt (45 degrees) was performed in normal and denervated rabbits. After postural changes, the transient decreases of brainstem PO2 were observed in denervated animals. However, in normal animals, PO2 showed minimum changes for tilting. Thus, our findings suggested that vertigo attack would be occurred by the ishemia in the brainstem due to an impairment of BRS.
The endolymphatic hydrops was made by the obliteration of the endolymphatic sac in 62 albino guinea pigs. AP, CM and SP were examined at the 1st, 2nd, 4th and 12th postoperative weeks and the results obtained were analysed in comparison with the audiological and electrocochleographical findings in Meniere's disease. Although abnormal SP was frequently found in the both groups, its appearance rates as a function of the time elapsed after the surgery or the first attack of Meniere's disease were different in these two groups. The AP and CM thresholds in the ani-mal were elevated with the similar time course as the progressive loss of hearing in Meniere's disease. The AP latency was prolonged in some of 12 weeks animals. This result was in accordance with that of Meniere's disease in which its prolongation was observed only in patients with long history.
Pressure difference between the endolymphatic and perilymphatic fluid may be more important than the absolute pressure value for the pathophysiology of the inner ear. In this study, endolymphatic and perilymphatic fluid pressures were measured simultaneously in guinea pigs and pressure changes on 1) postural change, 2) anoxia, 3) peroral administration of glycerol, were studied. Without loads, perilymphatic and endolymphatic pressures changed completely identically. When the body of the guinea pig was raised 30°, the endolymphatic pressure rose 0.36 mmHg and the perilymphatic pressure 0.44 mmHg. When respirator was stopped and anoxia was loaded, both pressures rose but the perilymphatic pressure rose much more about 1 mmHg than the endolymphatic pressure. With the relief of anoxia, the endolymphatic pressure rose to 7 mmHg and the perilymphatic pressure to 9 mmHg compared with the beginning and returned to the beginning state in about 6 minutes. Peroral administration of glycerol (50% glycerol, 12 ml/kg) caused pressure decrease of both endolymphatic and perilymphatic fluid but endolymphatic pressure decreased much more than that of the perilymphatic fluid. The largest pressure difference was about 2 mmHg, 30 minutes after the glycerol administration. This study showed that simultaneous recording of perilymphatic and endolymphatic pressure could reveal much more important information about the pathophysiology of the inner ear than the independent recording of both pressures.
Regulation of ion composition in the endolymph has been thought to occur mainly at the stria vascularis and the endolyphatic duct (ED) or sac (ES). And, the low level of K+ in the ES makes a sharp contrast with the high level in the cochlear duct. This difference may be explained by the ultramorpho-logical observation that the K+ of the ES was absorbed by the ED. On the other hand, there is a report showing the localization of Na+-K+ ATPase in the ES by enzyme-histochemical methods. This fact suggests that active transport takes place in the ES. Probably the ED and ES have several functions to regulate ion composition. Enzyme histochemistry does not seem sensitive enough to know the accurate localization of this enzyme. In this study using an immunohistochemical technique (immunofluorescence or ABC method), we could clearly demonstrate it along the basolateral membrane of the guinea pig ES epithelium. It was absent on the luminal side of the epithelium. These findings indicate that ion regulation in the ES may have a bearing in part on the low level of K+ in this organ. Further studies are essential for the clarification of the role of this enzyme in the ES in due consideration of the functions of the ED.
In the present study, vessel cast in the inner ear of the 14 weeks gestation in human, prepared by casting method using Mercox resin, were subjected to scanning electron microscopic examination and follwing results were obtained : (1). The vestibular vessels was completed earlier than the cochlear vessels on the 14 weeks gestation in human. (2). Immatured single layer capillary plexus was observed at the cochlear lateral wall. (3). Immatured T-shaped pattern was partially observed at the spiral lamina and the fetal spiral vessel was larger in diameter than the postnatal one. (4). In the vestibule, dense capillary nets was already completed at the each neuroepitherial areas. (5). Diameter of each capillary was irregular and also broken or tapering capillary was observed.
We described morphological study of basal artery and it's branches in gunia pig by corrosin casting technique. Results are as follows : (1). On anterior inferior cerebellar artery (AICA) branching off the basal artery (BA), individual variations and laterality were observed. (2). Internal auditory artery did not always arise from AICA but directly from BA. (3). At the CP-angle and in the internal auditory meatus, a loop formation was frequently observed. (4). On common cochlear artery and anterior vestibular artery, individual difference and asymmetric branches were observed.
The temporal bone study was performed in 6 aged cadavers, 4 of whom suffering a kind of "vertigo" in their life time and 2 as the control group. The results show that the apical turn distension of Reissner's membrane was present in 5 out of 6 cochleae in the cases with "vertigo", while it was observed in 1 out of 4 cochleae in the control group. In addition, the distension of the Reissner's membrane was found in three turns of the cochlea in one case with "vertigo". It was also revealed that the "pigmentation granules" were found more intensely in the area vascularis of the cases with "vertigo" when compared with those of control group. The relations between the origin of "pigmentation granule" and the distension of the Reissner's membrane remain the subject of ongoing study.
Some clinical and histopathologic evidences suggested that Meniere's disease would be congenitally difined entity. Interest in the present paper has focused on the incidence of distended Reissner's membrane in the temporal bones acquired from patients with congenital anomalies. Serially sectioned temporal bones were studied under the light microscope. The distension was more often observed in 15 temporal bones acquired from patients with congenital anomalies than in 19 temporal bones from normal individuals (p<0.01). Many of the ears with distended Reissner's membrane had tube-like vestibular aqueduct with wide isthmus (p<0.05).
We intended to substantiate the existence of immunoglobulins (IgG, IgM) in the lateral wall of the endolymphatic sac, which were obtained during endolymphatic sac surgery in four patients with Meniere's disease and one with delayed endolymphatic hydrops (DEH). In an immunohistochemical procedure using ABC method (Avidin-Biotin-Peroxidase Complex method), IgG was recognized in the epithelium and the subepithelial layer of the endolymphatic sac of two patients with Meniere's disease and one patient with DEH, while IgM was only in one with DEH. It is still impossible to point out the accurate site of some active immunological reactions and resultant product in the sac, however, this result would suggest that some immunological disorders might exist in the endolymphatic space including the sac its lumen, and that they might be closely related to one of the causes of endolymphatic hydrops.
During the endolymphatic sac shunt surgery for 37 cases of Meniere's disease (including 2 cases of syphilitic endolymphatic hydrops), 21 endolymphatic sac specimens were collected for immunohistopathological observation. These specimens were fixed in cold 95% alcohol, emmbeded in paraffin and processed for immunohistopathological study. They were then stained with FITC labeled goat-antihuman IgG, JgM, IgA and gamma globulin. Four specimens out of 21 showed positive finding in the immunofluorecent study and one showed brown pigmentation in the light microscopic study. One of 4 specimens, which displayed positive finding in the immunofluorecent study, showed ring structure of 3 layers. Outer layer was stained with IgM, middle layer with IgG and inner layer with IgA. This structure resembles a occuluded capillary vessel.
The uptake of cationized ferritin (CF) by the empty vesicles in the apical cytoplasm of the marginal cells of the stria vascularis and the effects of monensin and ouabain on the CF uptake were electron microscopically and morphometrically studied. When 20μg/ml CF with high (145mM) or low (15mM) Na ion concentrations were applied to the cochlea for 10 min, CF particles were found in clusters, scattered on the free-surface plasma membrane facing the endolymph, and in the caveolae of the marginal cells. They were also observed in the empty vesicles, coated vesicles and multivesicular bodies, but not in the Golgi apparatus, endoplasmic reticulum and intercellular space between cells constituting the stria vascularis. The P-face profile of the vesicles was similar to that of the caveolae with regard to the number of intramembranous particles. Monensin, which inhibits receptor-mediated endocytosis, reduced the number of CF-containing vesicles under high sodium ion concentration. These findings suggest that the empty vesicles are associated with the free-surface plasma membrane, and that they ate involved in the efficient exchange of ions between the endolymph and the marginal cells. Ouabain repressed the uptake of CF, lowering the endocochlear potential and altering the normal intracellular environment of the marginal cells. Therefore, the dynamics of the empty vesicles may be related with the sodium-pump in the basolateral infolded plasma membrane of these cells.
Histological studies were performed on the membranous labyrinths of fresh-water fish, frog and man. The thickness of membranous labyrinth was compared. The fish membranous labyrinth consisted of cartilage or cartilaginous tissue which was tough. This reason is that the fish labyrinth lacked bony labyrinth resulting in strong structure against forces from outside. This thick, cartilaginous labyrinth was also seen in frog, which has complete bony labyrinth. In man, the membranes of semicircular canal and utricle were thick, while saccular and Reissner membranes were thin. This finding may suggest a hypothesis that increase of endolymph volume takes place throughout whole labyrinth in Meniere's disease and, because of thick membranes of semicircular canal and utricle, embolymphatic hydrops is seen only in cochlea and saccule.
In order to evaluate usefullness of computed radiography (CR) in tomography of the vestibular aqueduct, visualization of the vestibular aqueduct in patients with Meniere's disease was compared between tomograms of computed and conventional radiography. Of 20 ears, 12 vestibular aqueducts (60%) were visualized in conventional tomography. On the other hand, all vestibular aqueducts were identified in tomography of computed radiography. Computed radiography seems to be superior to conventional radiography for tomography of the vestibular aqueduct.
A new stabilographical method with pressure loading to the external auditory canal (PLT) was performed in 20 normal subjects and 3 patients with Meniere's disease for the purpose of testing the pseudofistular sign. The pressure ranging from -100mmH2O to +100mmH2O or from -200mmH20 to +200mmH2O were applied to the external auditory canal and the body sways of the center of gravity to the lateral directions for 10 seconds were summated 10 times by a signalprocessor (NEC-sanei, 7TO7A). Positive response was defined as having doubles sway amplitude compaired with the average amplitude of sway without pressure loading. Positive response were observed in seven of twenty normal subjects. These positive reactions were symmetrical in both ears except one case. On the other hand, in cases of Meniere's disease, positive responses were found only in the affected ears. The positive PLT response was not changed at all when the test was repeated in a case of Meniere's disease at the stage of positive response to the grycerol test, however, in another case of Meniere's disease, disappearance of positive PLT response was observed after the puncture of the eardrum. From these findings we considered that the most effective facter of the PLT in producing the deviation was not the pressure change of the middle ear, but the movement of the ossicular chain causing displacement of the foot-plate of stapes.
To investigate the relation between the fluctuant course of hearing loss and the change of vestibular sign, the pure-tone audiometry and the trapezoid rotation test (±2, 4, 6, 8 and 10°/sec2, 10″) using Contraves' computerized rotary chair system were performed every 3 or 10 days for 10 patients of Meniere's disease. These patients experienced vertiginous attacks several times during this observation. Testing results before the attack showed exacerbation of hearing loss, and appearance of ipsilateral labyrinthine preponderance. During the glycerol test, hearing loss, especially in low frequency, was improved, and ipsilateral labyrinthine preponderance was disappeared. Exacerbation of hearing loss and appearance of ipsilateral labyrinthine preponderance were thought to be caused by development of the endolymphatic hydrops. As these findings were noticed in the preepisodic stage, they would be important indicators to predict the next attack of Meniere's disease.
Over the past several years, quantitative analysis for quantifying voluntary and involuntary eye movements has developed, accompanied with the advancement of computer technology. In our laboratory, we introduced computer aided test equipment for evaluating the vestibular function of patients with vestibular disorder. In this paper, we showed specification of this new machine and we indicated results of centric and eccentric VOR test and that of pseudo random binary sequence.
We made a follow-up study on 41 patients with unilateral profound hearing loss discovered in childhood. All consulted our clinic for hearing loss. Mean age is 16.4 years old at present, and they have been suffering from unilateral deafness for 10.0 years on average. The cause of the hearing loss was mumps in 10, head trauma in 2, rubella in 1 and juvenile unilateral hearing loss of unknown etiology in 28. Among 41 patients, 22 had experienced some kind of dizziness or vertigo, and we could perform vestibular examinations on 16 of them. Canal paresis on the deafened side was observed in 6/16 (38%). Clinical diagnosis for dizziness or vertigo of the 16 cases was orthostatic dysfunction in 11 and ipsilateral delayed endolymphatic hydrops (DEH) in 4. In the 4 cases of DEH, the result of the Schellong test was positive in 3. Dysfunction of the autonomic nervous system may have some relation to the occurrence of DEH. We diagnosed DEH by the clinical symptoms and the furosemide test (Futaki, et al: 1975). In this study on patients with unilateral deafness discovered in childhood, we found that about 10% (4/41, 9.8%) of them developed symptoms of DEH by their middle teens. In 1986 we reported 30 cases of DEH; in 24 of these cases, profound hearing loss was discovered in childhood. Among these 24 cases, 15 developed symptoms of DEH later than 16 years of age. So we estimated that the final occurrence rate of DEH in the population of unilateral deafness discovered in childhood is around 25%. We emphasize that a very intensive follow-up study is necessary in determining the occurrence rate of DEH.
1. The pupillary diameters were measured using a binocular infrared pupillograph, and the left and right differences were compared between the light and the dark conditions in 13 patients with Meniere's disease at their interval stages. However, a subject's differences in both conditions were not significant. 2. The frequency analysis of pupillary oscillations in the light was performed in a normal subject, a patient with Adie's tonic pupil and a patient with Meniere's disease at the interval stage, using fast Fourier transform method.
On the basis of our previous report that change in the R-R pattern on the ECG during the Schellong's test process depict various pathological features of autonomic nervous system, we made analysis by the same procedure in 42 cases of Meniere's disease (30 cases with and 12 cases without OD). A significant difference in the appearance ratio of four patterns was observed between 14 Schellong's test positive cases and 16 negative cases among 30 of Meniere's disease with OD (p<0.01). In the positive group, the "flattend type" accounted for 85.7% and in the negative group, the "rhythmic type" 87.5%, each being the highest frequency. In the cases without OD, on the contrary, the percentage of the "flattend type" in the Schellong's test negative group was 55.5%, the highest, showing a significance of p<0.02 from the Schellong's negative group in the cases with OD. Comparison of results with normal individuals as control and OD patients indicated the possibility of the "increased responsiveness of the sympathetic and decreased excitability of the parasympathetic nervous system" as the major autonomic nervous dysfunction inherent in Meniere's disease. The reproducibility of the R-R pattern was also studied on 14 various kind of subjects and was obtained high at 85.7% enough to clinical application.
The Kitahara endolymphatic sac operation was performed on 162 cases of Meniere's disease between 1968 and 1983. 140 of these cases were observed for periods of 24 months and upward to ascertain the effectiveness of this surgical procedure. Results were classified according to the AAOO (1972) and AAO-HNS (1985) criteria. According to the AAOO criteria, 78% of the cases showed an absence of definitive spells. According to the AAO-HNS criteria, 78% of the cases showed complete control of definitive spells, and the remaining 22% showed some degree of improvement. In 85% of the cases no hearing loss was observed. These results suggest that the Kitahara endolymphatic sac operation is effective in the treatment of both frequent vertiginous attacks and bilateral Meniere's disease. Problems with the criteria are also examined.
The blood supply of the endolymphatic sac, which has a role in the absorption of endolymph, is connected mainly to the meningeal artery separate from the branch of the cerebellar artery of the inner ear. Therefore, avoiding damage to the small vessels of the lateral wall of the sac should be important for restoring the absorptive function. In order to prevent adhesive closure of the drainage incision and restore the absorption function of the sac, we developed a new technique which restricts the drainage incision to a simple straight one on the rostral edge of the sac, and in which a drainge vein from the back of the patient's foot grafted in connection with a gelatin-film core to the incised sac. Our procedure was performed on 20 patients with Meniere's disease, who were followed up over 24 month. The results were favorable: recovery from vertago, was "complete" in 7 case (35%), "substantial" in 12 (60%), and "limited" in one case (5%) according to the new AAO-HNS formula (Miami, 1985).
The efficacy of transdermal therapeutic system scopolamine (TTS scopolamine) has been evaluated in six patients with confirmed Meniere's disease, who can recognize themselves relatively definite prodromal symptoms several hours before occurrence of intractable vertigious spell and has relatively severe autonomic nervous disorder symptoms. At onset of prodromal symptoms, one sheet of TTS scopolamine was applied to a dried postauricular skin and it was left unremoved for three days. Clinical observations suggested that TTS scopolamine could control feeling of vertigo in four of the six patients and autonomic nervous symptom in five of the six patients. The application of TTS generally alleviated the onset of scopolamine's side effects. However, adverse effect of blurred vision and dryness of the mouth were noticed.
During 1980-1985, endolymphatic mastoid shunt operations were performed in 18 cases out of 120 with definite Meniere's disease. From these follow-up studies of 18 cases, 11 were available for analysis of the 1985 AAOHNS evaluation criteria. According to this criteria, the results after the operations evaluated are as follows. 1) Vertigo: 5 cases (45.5%) had a complete control of definitive spells, and 5 cases had substantial or limited control of definitive spells for over 12 months after the surgery. 2) Hearingloss: The parameter for the assessment of hearing level is the three frequency pure-tone average at 500 Hz, 1 KHz and 2 KHz. Hearing improvement was observed in 2 cases (18.1%), and unchanged hearingloss was obtained in 4 cases. In 5 cases, hearing was worse after the operation. 3) Among many of the clinical findings in equilibrium examinations, the length of the body sway was the most appropriate parameter for evaluation of vestibular disability after our surgical procedures. This parameter corresponded with subjective symtoms, especially with vestibular disability. From these neurotological evaluation of the surgical procedures, we have concluded that the endolymphatic mastoid shunt operation was the most appropriate surgical treatment for disabling Meniere's disease from the neurotological point of view.