Merosin-negative congenital muscular dystrophy: diffusion-weighted imaging findings of brain.

Merosin-negative congenital muscular dystrophy is a rare genetic disease of childhood involving the central and peripheral nervous system. There were high signal intensities throughout the centrum semiovale, periventricular, and sub-cortical white matters on T2-weighted images in a 4-year-old girl with merosin-negative congenital muscular dystrophy. An apparent diffusion coefficient map revealed increased signal intensity and apparent diffusion coefficient values in the periventricular and deep white matters. It may be attributable to increased water content in the white matter because of an abnormal blood-brain barrier rather than to decreased or abnormal myelination.