Neurootologische Diagnostik bei Tumoren der hinteren Schädelgrube — verzögerte akustisch evozierte Potentiale auch auf der Gegenseite

Summary

From our common neurosurgic-neurootologic group of patients it is reported on those, who demonstrate that in case of tumors of the posterior cranial fossa the acoustic evoked potentials may be

• 1. normal on the healthy side,

• 2. also delayed on the healthy side and improved postoperatively,

• 3. in the healthy side delayed only postoperatively.

The respective constellation of findings is determined mainly by the localization and size of the tumor, and, thus, by the compression of the brain stem with or without occlusive hydrocephalus in the fourth ventricle. The observations suggest that mere comparison of the latency differences of both sides does not exhaust the possibilities of ERA; rather it is necessary to record the responses of both sides along the usual audiometric range of sound intensity and to correlate them to the norm latencies as well as to the individual audiometric picture.