Acoustic tumor with hearing loss of sudden onset and recovery.

In many cases of acoustic tumor the hearing loss is gradually progressive, but some cases of acoustic tumor show a sudden onset of hearing loss. In this paper we report two interesting cases of acoustic tumors which were diagnosed as sudden deafness at the first examination. Being treated with steroid hormones, their hearing was partially recovered. But the hearing loss recurred in both cases. At the second examination, CT showed the cerebellopontine angle tumors. So it was emphasized that careful questioning as well as the caloric test and the auditory brainstem response (ABR) was important. If one of these tests shows abnormality, the patient should be examined by the CT scan. The same may be said of patients who show recovery due to steroid hormone therapy.