Clinical and neuroimaging study of central nervous system in congenital myotonic dystrophy

We present the clinical and neuroimaging findings of five patients (four ma les, one female; mean age 12 years) affected by congenital myotonic dystrop hy and the correlation with their molecular genetic analysis. At birth all five presented severe muscular weakness and hypotonia, associated with feed ing difficulties and respiratory distress. In the same patients, congenital clubfoot or more generalized arthrogryposis was also evident. Lymphocyte D NA was characterized in each by a CTG repeat longer than 1300 in the region of the myotonic dystrophy gene in chromosome 19. The patients' neurologica l condition was evaluated by clinical examination, intelligence tests, elec troencephalography, and brain magnetic resonance imaging. All five suffered from some impairment of intellectual function (IQ ranged from 52 to 79). I n three a longitudinal evaluation of the cognitive deficit detected no dete rioration. In all patients magnetic resonance imaging showed some degree of ventricular dilatation, loosely correlated to the cognitive impairment; in three there was hypoplasia of the corpus callosum and in two mild abnormal ities of supratentorial white matter. The relationship between the size of the CTG repeat expansion found in lymphocyte DNA and the cerebral abnormali ties appeared inconsistent in this unusual myoencephalopathy of the newborn .