Dystonia of the legs induced by walking or passive movement of the big toe in a patient with cerebellar ectopia and syringomyelia.

A 45-year-old man with dystonia of the legs was found to have cerebellar ectopia and syringomyelia. Both walking and passive movements of the big toes evoked dystonic postures of the legs. Electrophysiologic studies suggested that the dystonic movements were reflex in origin. We propose that the cervical spinal cord lesion, involving propriospinal pathways, resulted in an abnormal response of spinal interneurons to peripheral stimuli.