Auditory brain-stem response in patients with acoustic neuromas. Wave presence and absence.

Auditory brain-stem response (ABR) waveforms from 61 patients with eighth nerve or cerebellopontine angle tumors were analyzed for wave presence or absence. Eighteen patients yielded ABRs lacking any readable waves; 27 patients revealed ABRs in which waves were partially present (ie, one or two waves present); and 16 patients demonstrated ABRs with all waves (I, III, and V) present. In the partially present ABR group, waves I and V were most prevalent. The group lacking waves (absent ABR group) had significantly poorer hearing sensitivity and larger tumors than the partial ABR group. Various additional group comparisons for hearing sensitivity and tumor size did not yield any significant differences among the three groups.