The Pathophysiological Basis of Weakness in Children With Cerebral Palsy

Purpose: To examine the evidence concerning the neurologic and muscular pathophysiology that contributes to clinically observed weakness in children and young people with cerebral palsy (CP). Method: Literature concerning the neural or muscular changes in subjects with CP was found by searching 6 databases plus supplementary searching. Results: A final set of 51 articles was identified by 2 independent reviewers. Summary of Key Points: Muscle weakness is due to reduced central drive, possible abnormal neural maturation, insufficient and disorganized motor recruitment, impaired voluntary control, impaired reciprocal inhibition, altered setting of muscle spindles, and reinforcement of abnormal neural circuits. Muscle tissue is altered, with selective atrophy of fast fibers and altered myosin expression, changes in fiber length and cross-sectional area, changes in the length-tension curve, reduced elasticity, and impoverished muscle tissue development. Conclusion: Children with CP are weak because of both neurologic and muscular changes. (Pediatr Phys Ther 2010;22:222-233)