The role of accelerometry in the assessment of cerebellar dysfunction

Learned ballistic movements display considerable variability. Far from being an artifact, this variability is an essential part of the response and provides a measure of central control of muscle activity and cerebellar integrity. We used accelerometry to measure the variability of arm rotations occasioned by step shifts in the position of a visual display. Parametric analysis of responses from 10 control subjects and 10 patients with known cerebellar deficits showed that the patients had a significant prolongation of the initial acceleration phase and a marked increase in response variability. The technique provides a tool for evaluating the outcome of therapy and studying the timing and force of rapid movements