Congenital muscular dystrophies (central nervous system manifestations)

Congenital Muscular Dystrophies (CMDs) are group of autosomal recessive myopathies presenting  at birth with hypotonia.

Pathology

• mutations in molecules (merosin: laminin- α2) with roles in cell migration and connection
• autosomal recessive
• muscle biopsy: Mildmild to moderate dystrophic changes, +- inflammatory infiltrate, +- absent staining laminin- α2

Staging and classification

• CMD 1: abnormal white matter varies from mild (CMD1 merosin {+}) to moderate severe (CMD 1 merosin {-})
• CMD 2: Fukuyama CMD (FCMD): Moderate dysplasia of cerebral neocortex and cerebellum, abnormal white matter.
• CMD 3: Santavuori muscle-eye-brain (MEB) Finnish-type, less severe than CMD 4, with ventriculomegaly, vermian hypogenesis, dysplastic cortex, patchy abnormal white matter +- callosal dysgenesis
• CMD 4: Walker-Warburg syndrome, most severe , with cobblestone brain, massive ventriculomegaly with absent/abnormal callosum, no myelin, kinked pons midbrain, vermian hypoplasia +- cephalocele

Clinical presentation

• hypotonia (floppy baby)
• developmental delay
• seizures
• poor vision

Radiological findings

• cobblestone brain
•  myelination defects
•  Z-shaped brainstem/hypoplastic vermis
• venticulomegaly
• callosal agenesis/hypogenesis