Topodiagnosis of lesions in Bell's palsy.

Combined measurements of reflexive lacrimation, stapedial reflex, and electrically induced taste give an indication of the site and extent of intratemporal lesions of the facial nerve. Using refined test batteries, we established the presence of intratemporal lesions in Bell's palsy in 80 patients with facial paralysis. In the acute stage of Bell's palsy, suprastapedial lesions predominated and the occurrence of a suprageniculate lesion was not rare. In the subacute stage, the lesions proximal to the stapedial nerve tended to subside and infrastapedial lesions increased. In 60% of 53 patients with denervation verified by electrodiagnostic examinations, the suprastapedial lesion was responsible for degeneration of the nerve. In the other 40%, degeneration involved the infrastapedial segment.