Skeletal muscle fiber‐type specific succinate dehydrogenase activity in cerebral palsy

TLDR

Children with cerebral palsy exhibit increased energy expenditure during movement, but it is unclear whether this is due to reduced skeletal muscle mitochondrial oxidative capacity. We compared fiber‑type specific succinate dehydrogenase activity and myofiber areas in semitendinosus biopsies from 5 children with CP and 5 typically developing children, finding that SDH activity was ~35 % higher in type 1 than type 2A fibers but did not differ between groups. CP children had 45 % smaller myofiber area than TD peers, and in TD children type 2A fibers were 32 % larger than type 1, yet fiber‑type specific SDH activity was similar across groups, indicating that higher energy expenditure in CP is not due to impaired mitochondrial oxidative capacity. Muscle Nerve 55:122‑124 (2016–2017).

Abstract

Children with cerebral palsy (CP) exhibit increased energy expenditure during movement, but whether this is due in part to decrements in skeletal muscle mitochondrial oxidative capacity is unknown. Accordingly, we compared fiber-type specific succinate dehydrogenase (SDH) activity in children with CP with typically developing (TD) children.SDH activity and myofiber areas of type 1 and 2A fibers were measured in semitendinosus biopsies of both groups (n = 5/group).SDH activity was ∼35% higher in type 1 compared with type 2A fibers, but there were no differences between groups. Average myofiber area was 45% smaller in CP versus TD (P < 0.05), and type 2A fibers were 32% larger than type 1 fibers (P < 0.05) only in TD children.Fiber-type specific SDH activity is similar between TD children and children with CP. This suggests that increased energy expenditure in children with CP is not related to impaired mitochondrial oxidative capacity. Muscle Nerve, 2016 Muscle Nerve 55: 122-124, 2017.