Fig. 1.

UPDRS dyskinesia score and % dyskinesia on time is reduced by low-dose ketamine infusion in case No. 1. The graph (a) shows the UPDRS dyskinesia score (sum of items 32–34) before, during and after the low-dose ketamine infusion (starting dose: 0.05 mg/kg/h; maximal dose: 0.3 mg/kg/h, for 50 h). The charts in b–d show the % time the patient spent in on, off, or dyskinetic on time, or was asleep during 24 h, based on the patient diary. In b, the average of 4 days pre-K is shown, and in c, the average of the 1st week post-K. In d, the average of weeks 2–4 post-K is depicted, and during this time, the LID had completely resolved. K = 50-hour low-dose intravenous ketamine infusion.