Clinical pattern and risk factors for dyskinesias following fetal nigral transplantation in Parkinson's disease: a double blind video-based analysis.

The objective of this study is to assess dyskinesias in 34 Parkinson's disease patients randomized to receive bilateral fetal nigral transplantation with 4 donors per side (12), 1 donor per side (11), or placebo (11). Videotape recordings were performed at the baseline, 3, 6, 12, 18, and 24 month visits during the "practically defined off" (12 hours after last evening dopaminergic therapy) and "best on" (best response following morning dopaminergic therapy) states. Videotapes were analyzed in random order by a blinded investigator. Dyskinesias during "best on" (on-medication dyskinesia) were observed in all, but 1 patient at baseline, and in all patients at each subsequent visit. There were no differences between groups. No patient had dyskinesia at baseline in "practically-defined off" ("off-medication" dyskinesia). Following transplantation, off-medication dyskinesia was observed in 13 of 23 patients, but not in any patient in the placebo group (P = 0.019). There was no difference in dyskinesia score between patients in the 1 and 4 donor groups. On-medication dyskinesias were typically generalized and choreiform, whereas off-medication dyskinesias were usually repetitive, stereotypic movements in the lower extremities with residual Parkinsonism in other body regions. Off-medication dyskinesias are common following transplantation and may represent a prolonged form of diphasic dyskinesias.