Focal task-specific dystonia (FTSD) of the hand and face have been well described; however, FTSD of the leg is exceedingly rare. We describe and demonstrate by videotape 2 patients with FTSD affecting the leg, in both cases triggered specifically by walking down steps. Walking on a level surface, up steps, and down steps backward, and sideways were normal. An interoceptive sensory trick (imagining walking in a different modality) led to temporary improvement. Our patients appear to demonstrated that task-specificity in focal dystonia may not be limited to skilled, rehearsed actions and that FTSD may occur in an activity that is relatively autonomic.
(c) 2007 Movement Disorder Society.