Abnormal cortical development shown by 3D MRI in Prader-Willi syndrome.

In Prader–Willi syndrome, the neuropathologic abnormalities causative for central hypotonia or cognitive delay are largely unknown. We report a girl diagnosed with Prader–Willi syndrome in whom cranial MRI showed a diffusely abnormal cerebral gyral folding pattern strongly suggestive of a cortical malformation. The patient was born to a 27-year-old mother. The pregnancy was normal prior to a cesarean section performed at 35 weeks gestational age because of vaginal bleeding from placenta previa. Apgar scores were 4 at 1 minute and 6 at 5 minutes. The patient appeared flaccid, and her cry was weak. On day one of her life, she developed respiratory distress. She was intubated and treated with surfactant. She was profoundly hypotonic, hypersomnolent, and had difficulty in feeding during her hospital stay. No convulsive movements, prolonged apnea, or abnormal eye or facial movements were observed. On examination, her head circumference at birth was 38 cm (greater than 95th percentile) and her weight was 2.5 kg (50th to 75th percentile). Her anterior and posterior fontanelles were widely open. She had prominent forehead, low set ears, small palpebral fissures, and small …