PROGRESSING CASES FROM LOW TONE SUDDEN DEAFNESS TO MENIERE'S DISEASE

COCHLEAR IMPAIRMENT IN THE SO-CALLED PRE-MENIERE'S DISEASE PERIOD

Abstract

Among 80 patients with low tone sudden deafness (LTSD) who visited our department over the past 15 years, there were 6 cases (7.5%) who subsequently progressed to Meniere's disease. The clinical and audiological processes of the 6 patients were studied in detail and the following results were obtained.
(1) In these 6 patients, the time between onset of LTSD and the diagnosis of Meniere's disease ranged from 4 months at the shortest to 6 years and 8 months at the longest, 2 years and 9 months on average.
(2) Two pattern types were seen in the change from LTSD to Meniere's disease: changing within a short period of time after recurrence of an LTSD-like attack, and changing after more than one year without recurrent attack.
(3) The monoattack-nonrecovered type of LTSD and the recurrent type of LTSD within three months after the onset (short-term prognosis) frequently progressed to Meniere's disease.
(4) There were no close relationships between subjective symptoms and audiological features in the pre-Meniere's disease period (from the onset of LTSD to the recurrence of vertigo with cochlear symptoms).
(5) The 6 patients showed various audiogram shapes at the time of progression to Meniere's disease; 3 cases with the slightly rising type, 1 with the high frequency-impaired type, and 2 with the moderate, gradual and flat type.
(6) Of the 6 patients, 3 had good hearing during long term observation. At least 2 patients seemed to have the mild type of Meniere's disease.
From the results mentioned above, endolymphatic hydrops was considered to be a likely possible cause of LTSD, especially the monoattack-nonrecovered and recurrent types of LTSD. Though the patients with Meniere's disease who had cochlear symptoms prior to vertigo were suspected to have LTSD-like hearing impairment at the time, it seemed difficult to ascertain the exact hearing impairment from their medical histories or audiological findings at the time of initial consultation.