Corpus Callosum Diffusion Restriction in Neonatal Congenital Myotonic Dystrophy.

Congenital myotonic dystrophy (CDM) is the most severe form of myotonic dystrophy type 1 (DM1), typically presenting in the neonatal period with hypotonia, respiratory distress, and feeding difficulties. Neuroimaging findings in neonates with CDM are rarely described. We present a genetically confirmed case of CDM in a neonate who demonstrated restricted diffusion in the genu and splenium of the corpus callosum (CC). The patient developed respiratory failure at three weeks of age and required mechanical ventilation. The brain MRI performed 11 days after onset revealed restricted diffusion in the genu and splenium of the CC. The follow-up imaging at four months showed resolution of diffusion restriction and mild atrophy of the genu. Genetic testing confirmed CDM with 1000-1150 trinucleotide (CTG) repeats. We considered that the diffusion restriction observed in this patient may have been evidence of hypoxic-ischemic encephalopathy associated with slowly progressive respiratory failure in CDM.