Clinical rating of dyskinesias in Parkinson's disease: Use and reliabilityof a new rating scale

Drug-induced dyskinesias (DID) manifested as hyperkinetic and/or dystonic m ovements or postures are common problems in Parkinson's disease (PD). Novel therapeutic interventions may offer possibilities to counteract these comm on adverse effects of an otherwise necessary treatment. To be able to evalu ate the effects of such interventions on DID, reliable and relevant clinica l assessment tools are needed. We tested the inter- and intrarater reliabil ity of a new clinical dyskinesia rating scale consisting of separate rating s of different body parts, including lateralization and separate ratings of dystonia and hyperkinesias. Interrater reliability was tested both with an d without a defined scoring code and clarification of the dystonia section. The nondefined version was also tested for intrarater reliability. Thirtee n raters independently reviewed 23 videotape sequences showing PD patients performing standardized motor tests. Inter- and intrarater agreement was si gnificant in all evaluations, and no differences were detected when compari ng ratings performed with the defined and nondefined version of the scale. The rationale for, and the role and use of, the present scale are addressed .