Hemifacial spasm associated with an ependymal cyst in the cerebellopontine angle. Case report.

No previous case of hemifacial spasm associated with an ependymal cyst has been reported in the literature. In this article the authors report the first case in which hemifacial spasm accompanied an ipsilateral cerebellopontine angle ependymal cyst in a 27-year-old woman. Cyst fenestration and arterial decompression of the facial nerve at the root exit zone resulted in complete resolution of the patient's symptoms. A histopathological study including immunohistochemical methods identified an ependymal cyst.