NORMAL-HEARING IN ACOUSTIC NEUROMA PATIENTS - A CRITICAL-EVALUATION

A series of 128 acoustic neuromas (ANs) managed in our center in the l ast 6 years were evaluated. Sixteen cases (12.5%) were found to have n ormal pure tone audio-grams comparatively younger age was an important characteristic of these patients. Tinnitus, dysequilibrium, and subje ctive hearing loss or distortion were their most common complaints. Pu re tone audiometry showed a mean pure tone average of 14.5 dB. Speech discrimination score and performance intensity phonetically balanced i ndex were very insensitive and showed very high false-negative results . Auditory brainstem responses proved to be a reliable test, being pos itive in 93.8% of cases. The mean tumor size did not show any signific ant difference when compared with acoustic neuroma cases with abnormal hearing. The combination of otologic and neurotologic symptoms in a y oung patient should prompt the clinician to investigation further even if hearing is within normal limits. A high index of suspicion is a pr erequisite for the early diagnosis of such subtle lesions.