This report summaries clinical studies on Meniere's disease (MD) performed in the Department of Otolaryngology, Gifu University School of Medicine.
I Criteria for the diagnosis of MD
Criteria for the diagnosis of MD are proposed. The criteria are composed of the following 3 steps. As a first step, a suspicious diagnosis of MD is made from the clinical history, i. e. (i) recurrent of paroxysmal vertigo, (ii) cochlear symptoms associated with vertigo, (iii) unknown causes, and, (iv) no other neurological symptoms, vestibulocochlear symptom only. Secondly, a definitive diagnosis of MD is made from the results of audiometric, equilibrium and neurological examinations. Finally endolymphatic hydrops is diagnosed by the glycerol test and the test related to negative SP in electrocochleogram.
II Studies on the natural course of MD
Forty patients suffering from MD were investigated.
1. The course of the disease was classified into the following 5 types from the patterns of the manifestations of the spells. Type 1: Recurrence of a definitive spell at long intervals changes to repeated slight spells at short intervals. Type 2: A definitive spell appears repeatedly in the same season once or twice every year. Type 3: Recurrence of spells gradually decreases with time. Type 4: A burst of spells occurrs continuously from the onset of the disease. Type 5: Repetition of single definitive spells and bursts of spells appear with irregular alternation.
2. On studies regarding clinical manifestation of MD, there was one patient whose diagnosis changed from Lermoyez disease to Meniere's disease. Three patients had a clinical history of sudden deafness long before the onset of vertigenous attacks of MD. Furthermore, there were eight patients with orthostatic dysregulation before the onset of MD and one patient with vertigo caused by a transient ischemic attack. These findings suggested a process of establishment of the inner ear disturbance in MD.
3. The average interval between spells distributed from less than 1 month to 29 months. It was very difficult to predict the next attack since the interval of spells in each patient was irregularly dispersed.
III Examination of predisposition to Meniere's Disease
The examination was performed in the following three steps. First general and local etiologic factors were investigated by using a questionaire made for this study. Second, internal and laboratory examinations were carried out. Third the loading equilibrium examination was done. As results, preexsistent hearing loss of long duration, head injuries long before the onset of the disease, hypotension, orthostatic dysregulation, hyperlipemia and anemia were found more frequently in patients with MD compared with control subjects. These abnormalities were estimated as predisposing factors to MD.
IV Evaluation of surgical treatment
Results of ultrasonic operation performed in our department were evaluated by the criteria of the AAOO committee on hearing and equilibrium. Ultrasonic operations were performed on twenty-five patients who were followed for from 1 to 12 years. The results were divided into four classes as follows: class A, 3(12%); class B, 10 (40%); class C, 12(48%); and class D, 0. The ultrasonic operation is applicable to patients with incapacitating vertigo non-fluctuating profound deafness and decreased labyrinthine excitability.
