• Twins had congenital hyperthyroidism and delayed cerebral development manifested as ventriculomegaly, increased space in the interhemispheric fissure, and an exaggerated gyral pattern on cranial computed tomographic scans. At 3½ years of age, both children had delayed development. Fetal and neonatal hyperthyroidism may interfere with normal brain growth and maturation with both neuroanatomic and developmental sequelae.
(Am J Dis Child 1983;137:842-845)