[Using brainstem auditory evoked potentials in cerebellopontine angle tumors (author's transl)].

The brainstem electric responses on acoustic stimulation are recorded on 37 patients with verified cerebellopontine angle tumors. These responses are compared with those of 101 normal hearing young adults and those of 47 patients with cochlear hearing loss. The Interval between the latency of the first wawe (acoustic nerve) and the fifth (midbrain) or I-V delay is related to the lesion location. The I-V delay is increased in retro-cochlear hearing loss and not different of the normal in cochlear hearing loss. The delay variation is best seen by comparing the I-V delay for the two ears. The interaural I-V delay difference (ITI-V) is normally less than 0,3 msec and is greater than or equal to 0,35 ms in the tumor group. The use of ITI-V increases the reliability of the test. We have neither false positive nor false negative findings. We now use brainstem electric responses as a routine part of our office practice of neuro-otology.