Effect of sensory discrimination training on structure and function in patients with focal hand dystonia: A case series

Objective: To measure the effects of sensorimotor training based on the principles of neuroplasticity for patients with focal hand dystonia. Design: Case series of 3 subjects with focal hand dystonia of the left hand, compared with age-matched normative controls. Setting: Outpatient clinic. Participants: Three consecutive clinic patients-musicians with focal hand dystonia-who described a history of repetitive practice and performance (2 women; ages, 23y and 35y; 1 man; age, 24y). Intervention: Subjects were asked to stop performing the tasks that caused the abnormal movements, to participate in a wellness program (aerobics, postural exercises, stress free hand use), and to carry out supervised, attended, individualized, repetitive sensorimotor training activities at least once week for 12 weeks and reinforced daily at home. Main Outcome Measures: Standard tests documenting somatosensory hand representation, target-specific hand control, and clinical function. Results: On the affected side, the 3 subjects improved an average of 86.8% on somatosensory hand representation, 117% on target-specific performance, 23.9% on fine motor skills, 22.7% on sensory discrimination, 31.9% on musculoskeletal skills, and 32.3% on independence. All 3 subjects improved 10% or more on 90% of the subtests with 20% improvement on 50% of the subtests. Conclusion: Individuals with focal hand dystonia who have a history of repetitive hand use can improve cortical somatosensory responses and clinical motor function after individualized sensorimotor training consistent with the principles of neural adaptation.