Asymmetrical awake bruxism associated with multiple system atrophy.

We describe a 51-year-old man who developed awake bruxism during the course of multiple system atrophy. Electromyographic studies revealed side-to-side amplitude asymmetry of the bursts of motor activity. The bruxism responded favourably to low-dose levodopa-carbidopa therapy. Possible mechanisms of this rare association are discussed. Copyright 2003 Movement Disorder Society