Pathophysiology of writer's cramp.
Writer's cramp is a task-specific focal hand dystonia. The abnormality of task specificity is a curious one and indicates that we need to learn more about the coupling of motor programs and their effectors. Writer's cramp appears to be triggered by spending much time writing by an individual with a fertile physiological substrate for producing the disorder. The fertile background, which is likely genetic, may be a decrease of inhibition, an increase of plasticity or an impairment in sensory function. Recent pathophysiological findings have implications for new therapies.
Hallett
Mark
M
Human Motor Control Section, NINDS, NIH Building 10, Room 5N226 Bethesda, MD 20892-1428, USA. hallettm@ninds.nih.gov
D012090:Cumulative Trauma Disorders / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D020821:Dystonic Disorders / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology* / Q000628:therapy; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation; D006801:Humans; D009044:Motor Cortex / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000294:innervation; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D011984:Sensory Receptor Cells / Q000503:physiopathology; D013003:Somatosensory Cortex / Q000503:physiopathology