title: Transcranial direct current stimulation for the treatment of focal hand dystonia.
abstract: The treatment of writer's cramp, a task-specific focal hand dystonia, needs new approaches. A deficiency of inhibition in the motor cortex might cause writer's cramp. Transcranial direct current stimulation modulates cortical excitability and may provide a therapeutic alternative. In this randomized, double-blind, sham-controlled study, we investigated the efficacy of cathodal stimulation of the contralateral motor cortex in 3 sessions in 1 week. Assessment over a 2-week period included clinical scales, subjective ratings, kinematic handwriting analysis, and neurophysiological evaluation. Twelve patients with unilateral dystonic writer's cramp were investigated; 6 received transcranial direct current and 6 sham stimulation. Cathodal transcranial direct current stimulation had no favorable effects on clinical scales and failed to restore normal handwriting kinematics and cortical inhibition. Subjective worsening remained unexplained, leading to premature study termination. Repeated sessions of cathodal transcranial direct current stimulation of the motor cortex yielded no favorable results supporting a therapeutic potential in writer's cramp.
authors.affiliation: Medical Neurology Branch, National Institutes of Health, Bethesda, Maryland, USA. David.Benninger@chuv.ch
authors.forename: David H
authors.initials: DH
authors.lastname: Benninger
authors.forename: Mikhail
authors.initials: M
authors.lastname: Lomarev
authors.forename: Grisel
authors.initials: G
authors.lastname: Lopez
authors.forename: Natassja
authors.initials: N
authors.lastname: Pal
authors.forename: David A
authors.initials: DA
authors.lastname: Luckenbaugh
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D004311:Double-Blind Method; D020821:Dystonic Disorders / Q000628:therapy*; D005260:Female; D006236:Handwriting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D009482:Neurophysiology / Q000379:methods; D010147:Pain Measurement; D050781:Transcranial Magnetic Stimulation / Q000379:methods*