Reduced motor cortex deactivation in individuals who suffer from writer's cramp.
This study investigated the neuromagnetic activities of self-paced finger lifting task and electrical median nerve stimulation in ten writer's cramp patients and fourteen control subjects. The event-related de/synchronizations (ERD/ERS) of beta-band activity levels were evaluated and the somatosensory cortical activity levels were analyzed using equivalent-current dipole modeling. No significant difference between the patients and control subjects was found in the electrical stimulation-induced beta ERS and electrical evoked somatosensory cortical responses. Movement-related beta ERD did not differ between controls and patients. Notably, the amplitude of the beta ERS after termination of finger movement was significantly lower in the patients than in the control subjects. The reduced movement-related beta ERS might reflect an impairment of motor cortex deactivation. In conclusion, a motor dependent dysregulation of the sensorimotor network seems to be involved in the functional impairment of patients with writer's cramp.
Institute of Physiology, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Yi-Jhan
YJ
Tseng
Department of Neurology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taipei, Taiwan.
Rou-Shayn
RS
Chen
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Wan-Yu
WY
Hsu
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Education and Research, Taipei City hospital, Taipei, Taiwan.
Fu-Jung
FJ
Hsiao
Institute of Physiology, National Yang-Ming University, Taipei, Taiwan; Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan; Integrated Brain Research Laboratory, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.
Yung-Yang
YY
Lin
D000328:Adult; D016477:Artifacts; D016022:Case-Control Studies; D020821:Dystonic Disorders / Q000503:physiopathology*; D004558:Electric Stimulation; D005260:Female; D005385:Fingers / Q000503:physiopathology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008475:Median Nerve / Q000473:pathology; D008875:Middle Aged; D008959:Models, Neurological; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement; D013003:Somatosensory Cortex / Q000503:physiopathology