Collagen accumulation in muscles of children with cerebral palsy and correlation with severity of spasticity

Muscle function often becomes progressively more compromised in children wi th spastic cerebral palsy, leading to reduced mobility. This study aimed to examine the role that muscle connective tissue plays in this process. Seve rity of spasticity as determined by a range of clinical measures was assess ed in 26 children (14 males 12 females; age range 4 to 17 years) with eithe r diplegic or quadriplegic cerebral palsy (CP), Muscle biopsies from the va stus laeralis muscle were obtained for biomedical and histological analysis during orthopaedic surgery as part of the child's ongoing care. Total coll agen was quantified by hydroxyproline determination. Two clinical measures of severity, Modified Ashworth Scale and Balance. were shown to have a high ly significant correlation with collagen content, and Ambulatory Status, Cl onus, and Selective Muscle Control all showed positive trends. Collagen I a ccumulated in spastic muscle's endomysium which appeared to be thickened, a nd fibrotic regions with sparse muscle fibres were evident in more severe c ases, This suggests that collagen may be involved in increases in muscle st iffness observed in spasticity, Once developed, these changes are essential ly irreversible and we suggest that future treatments should consider inclu ding prevention of muscle fibrosis.