Mapping finger movement representation in focal hand dystonia

Introduction: Representational abnormalities in the motor as well as in the somatosensory cortex may be related to the pathophysiology of focal dystonia such as writer's cramp (WC). Previously, we have shown that finger movements evoked by transcranial magnetic stimulation (TMS) are organized somatotopically and exhibit modular properties (Gentner and Classen 2006). The central nervous system may control finger movements by combining a limited number of such neuro-motor modules. We investigated motor representation (somatotopy and modular properties) of the hand muscles of patients with WC. Methods: TMS-evoked f…