Malformations of Ventral Induction

Congenital Brain Malformations in the Neonatal and Early Infancy Period

“…(23) Affected patients who survive birth present with hypotonia and seizures. (19,20) Semilobar holoprosencephaly…”

“…These subtypes belong to a continuous spectrum and may be difficult to distinguish. (19,20) Holoprosencephaly occurs in 1 in 10,000 live births and is the most common telencephalic developmental defect. The incidence has been reported as high as 1 in 250 conceptuses.…”

“…(21,22) Intrinsic genetic factors or extrinsic factors, such as maternal diabetes and teratogen exposure, are associated with holoprosencephaly. (19) High resolution MR imaging with thin sections in axial, sagittal, and coronal planes should be obtained to evaluate patients with suspected holoprosencephaly. Holoprosencephaly rarely may accompany other malformations, such as schizencephaly, Dandy Walker malformation or variant, Chiari malformation, cephaloceles, and rhombencephalosynapsis.…”

“…7). (19,20) Craniofacial deformities are apparent on physical exam and include premaxillary agenesis, cleft lip/palate, ocular hypotelorism, ethmocephaly, and cyclopia. Patients are typically microcephalic unless the dorsal cyst is large, in which case patients may have macrocephaly.…”

“…Patients are typically microcephalic unless the dorsal cyst is large, in which case patients may have macrocephaly. (19,20) Alobar holoprosencephaly is generally not compatible with life. Of those with severe craniofacial malformations, such as cyclopia, ethmocephaly, and cebocephaly, who survive to childbirth, nearly all die within one week.…”