Auditory brainstem responses in leptomeningeal metastatic spread. Presentation of 2 cases.
Auditory brainstem responses (ABRs) were recorded in 2 patients with hearing loss caused by leptomeningeal metastatic spread. These recordings showed similar characteristic findings. The absolute latencies of wave V and interwave latencies I-V were exceedingly increased. Definite effects on the wave morphology and latency of wave V were observed with the use of high repetition rates. It is surmised that the hearing loss caused by leptomeningeal metastatic spread is mainly an effect on the auditory nerve and/or the cochlear nucleus. ABR examination is of clinical value in detecting functional abnormalities resulting from leptomeningeal metastatic spread.