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

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. (c) 2007 Movement Disorder Society.