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

Introduction: 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. Methods: SDH activity and myofiber areas of type 1 and 2A fibers were measured in semitendinosus biopsies of both groups (n=5/group). Results: SDH activity was approximate to 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. Conclusions: 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 Nerve55: 122-124, 2017