抄録
A series of 12 cases of bilateral sudden deafness was reported. 7 cases of them had simultaneous loss of hearing in both ears and the other 5 cases had alternate onsets in certain intervals ranging from 10 months to 42 years.
The former cases showed severe deafness and similar audiograms in both ears and their prognosis was bad. On the other hand hearing of the latter cases recovered at least in the recently affected side.
The pathogenesis of bilateral sudden deafness was discussed and it was considered that sudden deafness could always be bilateral and the rare bilateral case might be the severer type of the unilateral one.
