Clinical analysis of 76 cases with acoustic neuroma was performed. They were 43 females and 33 males, and their age distribution ranges from 11 to 71 years old. Three cases of them had bilateral acoustic neuroma (Neurofibromatosis Type II). As for chief complaint at an initial examination, cochlear symptoms such as hearing impairment, tinnitus and ear fullness were the most frequent one, followed by gait instability, paraesthesia of the face, taste disturbance and others.
Regarding the audiogram pattern, no specific pattern to indicate an acoustic neuroma was found. However sudden deafness was found in 12 cases. In spite of the anatomical location of the tumor, there were not so many audiological evidences to indicate retrolabyrinthine disorder.
In addition, abnormal occurrence rate of brainstem auditory responce was 81%, which was relatively low compared with the other reports. However radiological abnormality of the internal auditory meatus was found in 93% and canal paresis was found in 82% of 76 cases.
Based upon these results, a guideline to detect acoustic neuroma was reported.
