Determinants of spontaneous extrapyramidal symptoms in elderly psychiatric inpatients diagnosed with Alzheimer's disease, major depressive disorder, or psychotic disorders.

Extrapyramidal symptoms (EPS) occur more frequently in dementia of the Alzheimer's type (DAT) than in normal aging. Other late-life mental disorders, however, have also been associated with EPS. To examine whether EPS are increased in DAT patients relative to neuropsychiatric control subjects, the authors compared EPS in 127 neuroleptic-free elderly patients diagnosed with either DAT, major depressive disorder (MDD), or a psychotic disorder (SCHIZ/DELUS). They also examined whether depressive or psychotic symptoms were associated with EPS independently of diagnosis. Severity of parkinsonian rigidity was found to be independently associated with DAT. Rank order of rigidity was DAT > MDD > SCHIZ/DELUS. Bradykinesia, although not associated with diagnostic group, was positively correlated with withdrawn depression. These findings suggest that rigidity is associated with DAT independently of any concurrent psychotic or depressive process, whereas bradykinesia does not appear to be specific to DAT among late-life neuropsychiatric illnesses.