Determinants of Tapping Speed in Normal Control Subjects and Subjects with Parkinson's Disease: Differing Effects of Brief and Continued Practice

Background: Alternate tapping speed is widely used as a measure of bradykinesia in Parkinson's disease (PD). Tapping speed in normal control subjects and factors that might influence tapping speed have not been systematically examined.

Objective: To examine the effects of age, hand dominance, and gender on tapping speed in normal control subjects and to compare the effects of practice on tapping speed in normal and PD control subjects.

Methods: Tapping speed for three sequential trials in the dominant and nondominant hand was examined in 100 normal control subjects and 60 subjects with PD. The effect of hourly practice over 26 hours (19 trials) was investigated in 14 normal and 24 PD subjects.

Results: The speed with which normal subjects alternately tapped two counters was negatively correlated with age, was greater in the dominant hand, was not related to gender, and improved with short-term practice (three trials) and with continued practice over 26 hours. Parkinsonian subjects, in general, tapped more slowly than normal control subjects and more slowly in the more affected arm. Parkinsonian subjects benefited from short-term practice as much as normal control subjects but, unlike normal control subjects, did not improve with continued practice over 26 hours.

Conclusions: Alternate tapping speed is influenced by age, hand dominance, Parkinson's disease, and practice. Subjects with PD do not benefit as much from continued practice as do normal subjects, suggesting some limitation or impairment of procedural (motor) learning in PD.