Physiological localization of the facial colliculus during direct surgery on an intrinsic brain stem lesion.

We designed a method for localizing facial colliculus intraoperatively by means of weak stimulation of the 4th ventricular floor and recording the electromyographic response of the facial muscle. This method is applicable clinically to prevent 6th and 7th cranial nerve complications during direct surgery on an intrinsic lesion of the brain stem, in which the normal anatomy of the rhomboid fossa is often distorted.