MOVEMENT DISORDER IN DOWNS-SYNDROME - A POSSIBLE MARKER OF THE SEVERITY OF MENTAL HANDICAP

This study examined the nature and prevalence of abnormal movements in adults with Down's syndrome and also the clinical correlates of orofa cial dyskinesia and the relationship between dyskinesia and the level of functional and intellectual disability. Movement disorder, language age, and disability were assessed in an epidemiologically based sampl e of 145 individuals with Down's syndrome. Abnormal involuntary moveme nts were common, with >90% exhibiting dyskinesia, predominantly orofac ial. Stereotypies were present in one-third of the sample. There was a n association between the severity of dyskinesia and both current lang uage age and functioning in terms of self-care and practical and acade mic skills, which suggested that dyskinesia may be a marker of the sev erity of mental handicap. The presence of dyskinesia was unrelated to neuroleptic exposure. Dyskinesia and stereotypies are very common in i ndividuals with Down's syndrome and may represent an inherent manifest ation of the disorder. The relationship between mental age and dyskine sia in Down's syndrome warrants further research.