[Bilateral hemifacial spasm: eight personal case reports].

Introduction: Hemifacial spasms consist in tonic clonic, involuntary, asymmetrical and asynchronous contractions in the territory innerved by the facial nerve. Several different causes may give rise to this disorder, the most frequent of which are vascular abnormalities in the cerebellopontine angle. Its clinical features and electrophysiological studies are commonly used in diagnosis and its etiological diagnosis is most frequently performed by means of magnetic resonance imaging.