Schizencephaly: rare cerebral malformation demonstrated by sonography.

An 820 g, 28 week , small-for-gestational-age boy was born after an uneventful but shortened pregnancy. At birth , the circumference of the infant's head (23 cm) was well below the third percentile. Transillumination of the skull was increased over the parietotemporal areas bilaterally. Initially, he had minimal spontaneous movements, little response to stimulation, absent suck reflex , minimal Moro response, and absent plantar reflexes . Subsequently, spontaneous jittery movements of all extremities developed. The baby died at 2 days of age from respiratory distress syndrome. Sonography of the infant's head was performed at 11 hr of age with a real-time unit, using a 7.5 MHz transducer focused at 3 cm. Sonograms were obtained using the anterior fontanelle as an acoustic window. Coronal and parasagittal sonograms showed enlargement of both lateral ventricles and absence of the septum pellucidum (fig . 1A). More posteriorly, large bilateral clefts in the parietotemporal cerebral mantle were demonstrated (fig. 1 C). The lateral ventricles were contiguous with these clefts, and choroid plexus extended into the left cleft (figs. 1 C and 2C). At autopsy, gross examination of the brain revealed large, bilateral, slightly asymmetric clefts, each extending about 2 cm along the midlateral surfaces of the cerebral hemispheres in a nearly horizontal orientation (fig. 2). The cortical mantle appeared to roll in at the clefts, which were filled with straw-colored cerebrospinal fluid contained by a clear, delicate pia-arachnoid membrane. On coronal section, it was evident that the clefts and both lateral ventricles were contiguous as had been shown on sonography (figs. 1 Band 10). Microscopically, the brain was severely malformed. Cortical layering was indistinct, and there was extensive polymicrogyria. The cleft walls were lined by a thick band of neural cell matrix that was contiguous with the subependymal germinal cell masses. There were numerous disorganized masses of germinal cells within the hemispheriC central white matter. The hippocampus, caudate, thalamic, hypothalamic and midbrain nuclei all had anomalous neural organization, and the corticospinal system was nearly absent.