Brain magnetic resonance imaging abnormalities in merosin-positive congenital muscular dystrophy.

We report the brain magnetic resonance imaging (MRI) findings in 23 patients with merosin-positive congenital muscular dystrophy (CMD). Twelve patients had normal scans. Eight other children had essentially normal scans but showed mild non-specific periventricular white matter changes. Three children had structural abnormalities on imaging. The first patient, a 15-month-old boy with hypotonia, muscle weakness and global development delay, had moderate cerebellar atrophy and mild dilatation of the lateral ventricles. The second child, a 3-year-old ambulant girl with subtle learning problems, had mild cerebellar hypoplasia and a large subarachnoid space when scanned at 16 months. The third patient, a 15-year-old ambulant male with normal intelligence and complex partial seizures, had polymicrogyria of both temporoparietal lobes on brain MRI. The clinical features and motor ability of children with merosin-positive CMD are variable, although usually milder than merosin-deficient CMD. Our findings confirm that central nervous system involvement can occur in some merosin-positive cases. We suggest performing brain MRI in children with merosin-positive CMD, as this may help in our understanding of this very heterogeneous disease.