Testing functional performance in people with Parkinson disease

Although the Unified Parkinson's Disease Rating Scale (UPDRS) is the most common performance measure for people with Parkinson disease (PD), the Berg Balance Scale (BBS), Forward Functional Reach Test (FFR), Backward Functional Reach Test (BFR), Timed "Up & Go" Test (TUG), and gait speed may be used to quantify some aspects of functional performance not measured by the UPDRS. The purpose of this study was to describe the relationship among a set of tests of balance, walking performance, and mobility in people with PD.

Twenty-five community-dwelling adults (11 female, 14 male) with a diagnosis of PD were recruited from PD support groups in southeastern Wisconsin and consented to participate in the study. The mean age of the participants was 76 years (SD=7). The average Hoehn and Yahr Stage Scale score was 2.

Functional abilities of each subject were assessed with the UPDRS, BBS, FFR, BFR, TUG, and gait speed. Spearman and Pearson correlations were performed.

The UPDRS total score was correlated with the BBS (r=-.64, P<.001), FFR (r=-.52, P<.05), and TUG (r=.50, P<.05) measurements. The BBS is the only test of functional performance where scores correlate with all other functional tests and the UPDRS.

The UPDRS total score may not reflect a comprehensive measure of mobility in people with PD. Because the BBS scores correlate both with UPDRS scores and with scores of all other tests of functional performance, the BBS appears to be a good overall measure of function in this population.