Microscopic and molecular aspects of skeletal muscle alterations in cerebral palsy.

The review highlights that most included studies used control samples from children undergoing anterior cruciate ligament reconstruction or with idiopathic scoliosis, which may independently affect muscle parameters. Biopsies are rarely treatment-naive, often reflecting varied histories of botulinum toxin, casting, or surgery, making it difficult to isolate the effects of cerebral palsy itself. There is substantial heterogeneity in the muscle groups sampled across studies, and microstructure varies significantly between muscles, limiting generalizability. Many studies have small sample sizes and methodological differences in histochemical analysis, leading to inconsistent findings on average fibre size and type distribution.

The authors declared no conflicts of interest. The work was funded by various Swedish foundations and research councils, including Karolinska Institutet and the Wenner-Gren Foundation.

Do not interpret the increased variability in fibre size as a consistent reduction in muscle mass. The review explicitly states that average fibre cross-sectional area differences between cerebral palsy and typically developing controls are inconsistent and often confounded by methodological issues and age matching.