THE EFFECTS OF ACUTE LEVODOPA WITHDRAWAL ON MOTOR-PERFORMANCE AND DOPAMINERGIC RECEPTOR SENSITIVITY IN PATIENTS WITH PARKINSONS-DISEASE

The effects of acute levodopa withdrawal were studied in nine patients with levodopa related on-off oscillations. One patient withdrew from the study due to off period confusion and hallucinations. A marked det erioration in motor disability occurred in all patients following over night withdrawal of levodopa and a further mild delayed deterioration was present over a mean withdrawal period of 44 hours. Patients with m ore severe disease were able to tolerate levodopa withdrawal for a sho rter period of time than those with milder disease severity. The minim um therapeutic dose of subcutaneous apomorphine needed to produce a si milar improvement in patients' mobility, before and after several days of drug withdrawal, did not differ, thus providing no clinical eviden ce for alterations in striatal dopamine receptor sensitivity after acu te levodopa withdrawal.