Comparison of a timed motor test battery to the Unified Parkinson's Disease Rating Scale‐III in Parkinson's disease

Abstract

The most widely used scale currently available for the clinical evaluation of motor dysfunction in Parkinson's disease (PD)-the Unified Parkinson's Disease Rating Scale-III (UPDRS-III) -is time-consuming, subjective, and has suboptimal sensitivity. A brief timed motor test (TMT) battery could possibly overcome these drawbacks. Two hundred eighty-eight PD patients (disease duration 3.1 years; preceding dopaminergic treatment initiation) were assessed with the UPDRS-III and nine TMTs based on aspects of (a) walking, (b) writing, (c) single and double-handed pegboard performance, (d) finger tapping, and (e) rapid alternating forearm movements. We investigated validity, reliability, responsiveness, and feasibility. Completing the TMT battery took less than 5 minutes. The TMT correlated well with UPDRS-III and disease duration. Two factors explained 61% of the TMT variance, the first represented mainly upper extremity function, the second mainly axial/lower extremity function. Cronbach's alpha was equal for the TMT and the UPDRS-III (0.8). Test-retest reliability of the TMT sumscore was 0.93 to 0.89 for measurements separated by 3 up to 24 months, whereas UPDRS-III correlations were 0.88 to 0.84. At group level, a trial using "change from baseline" as endpoint requires only 75% of the patients needed with the UPDRS-III when applying the TMT battery, and 57% using the pegboard dexterity test. At patient level, TMT and UPDRS-III were equally responsive. The TMT battery described here is valid, reliable, and feasible. Compared to the UPDRS-III, it is more objective and more sensitive to change. Therefore, it could be a useful tool for both practical and scientific purposes. (c) 2008 Movement Disorder Society.