Involuntary orofacial movements in hospitalised patients with mental handicap or epilepsy: relationship to developmental/intellectual deficit and presence or absence of long-term exposure to neuroleptics.

Among 42 adult patients with mental handicap who had received treatment with neuroleptic drugs, the prevalence of orofacial dyskinesia increased with age and those with such involuntary movements were characterised by a considerably greater degree of mental handicap. Similar associations were found among a group of 15 patients with epilepsy. Two of seven other mentally handicapped patients and one of eight other epileptic patients showed indistinguishable orofacial dyskinesia, despite no record of them having received neuroleptic drugs.