Timed tests of motor function in Parkinson's disease.

INTRODUCTION Timed tests of motor function in Parkinson's disease (PD) may be useful for the diagnosis of bradykinesia or to monitor disease progression or treatment response. However, normal ranges have not been established. AIM To define normal ranges of hand-tapping and timed walking tests in non-parkinsonian controls and compare with PD patients' performance. METHODS We recruited PD patients and age- and gender-matched controls for a prospective community-based incidence study of parkinsonian disorders in North-East Scotland. We counted the times participants tapped between two counters in 30 s. We also timed a 6m get-up-and-go test. We assessed age and gender effects and calculated 95% reference ranges for controls. We compared PD patients with controls. RESULTS We recruited 157 controls and 138 newly diagnosed, untreated PD patients (mean ages 75 and 73). The 95% control reference range for tapping scores with the dominant hand was 18-74 taps. Males and younger participants performed significantly better. PD patients performed less well (mean difference 15 taps, p < 0.001) but only 10% had tapping scores below the control range. The 95% control reference range for the get-up-and-go test was 9-27 s. Walking times increased significantly with age, but gender had no effect. PD patients were slower (median difference 4.5s, p < 0.001) but only 17% were slower than the control range. DISCUSSION Although PD patients performed more slowly than matched controls, timed tests were not helpful diagnostically because few incident patients were outside the normal reference ranges. Further work is needed on their utility in monitoring disease progression.