Effects of neuromuscular electrical stimulation treatment of cerebral palsy on potential impairment mechanisms: a pilot study.
OBJECTIVE
This pilot study examined the effects of neuromuscular electrical stimulation (NMES) therapy on upper limb impairment in children with cerebral palsy, specifically addressing spasticity, heightened passive resistance to wrist rotation, coactivation, and weakness.


METHODS
Eight subjects, aged five to 15 years, with spastic hemiparesis subsequent to brain injury, participated in three months of NMES therapy, targeting the wrist flexor and extensor muscles. Maximum voluntary wrist extension range of motion against gravity, spasticity, passive torque, maximum voluntary isometric torque, and coactivation were recorded prior to, during, and at the conclusion of the therapy.


RESULTS
Seven of the eight subjects demonstrated a significant (>15 degrees) improvement in wrist extension range of motion against gravity following the NMES treatment, with an average gain of 38 degrees. Differences in spasticity (0.01 +/- 0.14 N-m, p = 0.80) and passive torque (0.03 +/- 0.11 N-m, p = 0.52) were not significant for these subjects. Isometric wrist extension torque, however, did increase significantly (p < 0.01), accompanied by a reduction in flexor coactivation (p < 0.01).


CONCLUSIONS
Evidence suggests that the NMES treatment protocol affected wrist extension by improving the strength of the wrist extensor muscles, possibly through decreased flexor coactivation. Further studies are required, however, to determine whether electrical stimulation itself or other facets of the therapy paradigm played the key role in improvement.
Kamper
Derek G
DG
Sensory Motor Performance Program, Northwestern University, Chicago, IL 606011, USA. d-kamper@northwestern.edu
Yasukawa
Audrey M
AM
Barrett
Kenley M
KM
Gaebler-Spira
Deborah J
DJ
D000293:Adolescent; D001930:Brain Injuries / Q000150:complications; D002547:Cerebral Palsy / Q000150:complications; D002648:Child; D002675:Child, Preschool; D004599:Electric Stimulation Therapy / Q000379:methods*; D004576:Electromyography; D005260:Female; D018737:Hand Strength; D006801:Humans; D008297:Male; D009128:Muscle Spasticity / Q000209:etiology / Q000534:rehabilitation*; D018908:Muscle Weakness / Q000209:etiology / Q000534:rehabilitation; D020336:Paraparesis, Spastic / Q000209:etiology / Q000534:rehabilitation*; D010865:Pilot Projects; D016059:Range of Motion, Articular; D019415:Torque; D016896:Treatment Outcome; D034941:Upper Extremity / Q000294:innervation / Q000503:physiopathology; D014955:Wrist Joint / Q000294:innervation* / Q000503:physiopathology