Alcohol consumption and handwriting: a kinematic analysis.

Cerebellar dysfunction is associated with deficits in the control of movement extent, as well as changes in the amplitude and relative amounts of acceleration and deceleration and action tremor. The present study sought to identify whether cerebellar symptoms occur in the handwriting of intoxicated individuals. Twenty participants in two sub-groups (alcohol dependent and non-alcohol dependent) were asked to write four cursive letter 'l's on a Wacom SD420 graphics tablet before and after consumption of a dose of vodka and orange producing a peak blood alcohol concentration of 0.048%. There was a relationship between blood alcohol concentration and stroke length. Kinematic analysis of handwriting indicated increases in the relative proportions of time spent in acceleration and increases in spectral power around 4Hz. It was found that alcohol intoxication causes symptoms of cerebellar dysfunction, and that alcohol dependent individuals had less ballistic handwriting compared to non-alcohol dependent participants.