Hemifacial spasm due to a tentorial paramedian meningioma: a case report.

Hemifacial spasm (HFS) is a movement disorder characterised by involuntary paroxysmal facial movements that usually involve the orbicularis oculi and then spread to the other facial muscles. A microvascular compression and demyelination of the seventh nerve at its exit from the brain stem is considered to be the main aetiology of HFS. In addition to rare idiopathic (cryptogenetic) cases, others causes of HFS exist: tumours or vascular malformations have been described, of both the ipsilateral and contralateral cerebellopontine angle (CPA). However, space-occupying lesions in locations other than CPA are usually not thought to be responsible for HFS. Here we describe the case of a 45-year-old woman suffering from HFS, who dramatically improved after surgical removal of a tentorial paramedian meningioma.