[Neuropsychological investigations on short-time effects of biperiden (Akineton) in Parkinson's Disease (author's transl)].

In 10 parkinsonian patients the short-time effects of biperiden after slow, intravenous application were investigated in comparison with a placebo group. Immediately after infusion the patients, who were examined at fixed intervals using standardized tests of psychomotor function, mood, and affect, showed a marked impairment os psychomotor function and reaction time, which in time did not exceed the placebo effects. Simultaneously there could be demonstrated an increasing affective stimulation with an acceleration of operating time and improvement of mood. These findings demonstrate- analogously to the intravenous application of L-Dopa-a psychotropic effect independent of the eventual antiakinetic properties of biperiden. The frequency of exogenous psychotic reactions in patients with marked psychoorganic alteration restricts the applicability of anticholinergic drugs in the treatment of an akinetic crisis.