Neuroradiological findings in children with congenital myotonic dystrophy.

We studied seven children with congenital myotonic dystrophy, aged 2.1-8.3 years, and the results of computed tomography and magnetic resonance imaging of the brain were analyzed and neurological development was assessed from the neonatal period. We found that ventricular dilatation that had been seen on the first day of life in two of three infants had not progressed in sequential follow-up computed tomography scans taken at intervals of one to six years. Also, in T2-weighted magnetic resonance imagings, areas of periventricular hyperintensity were identified in all children, as well as areas of subcortical hyperintensity in one child. Further, an asphyxial episode had occurred at birth in five patients and the extent of the periventricular hyperintensity was found to correlate significantly with Apgar scores, indicating that the degree of perinatal asphyxia that had occurred was responsible for the abnormalities uncovered by the magnetic resonance imagings. However, there was no correlation between the neurodevelopment outcome and the extent of the periventricular hyperintensity or ventriculomegaly. Therefore, in patients with congenital myotonic dystrophy, a neonatal episode of asphyxia can be responsible for a finding of periventricular hyperintensity, but it is unlikely that an integral part of the mental retardation is attributable to brain damage due to perinatal asphyxia.