Hemilingual spasm: a new neurosurgical entity? Case report.

Hemilingual spasm is a little-known movement disorder, presenting as intermittent paroxysmal involuntary contractions of half of the tongue muscles. The authors report a case of hemilingual spasm caused by an arachnoid cyst. After marsupialization of the cyst, the patient's symptoms immediately resolved. There has been no recurrence of hemilingual spasm during the follow-up period of more than 40 months.