Spinal and cranial neural tube defects.

Developmental lesions of the central nervous system with failure of normal midline fusion are often referred to as being dysraphic and vary from inapparent and insignificant to a massive deformity incompatible with survival. Several different schemata are used to classify this wide variety and often complex set of malformations; however, the nomenclature is confusing and even contradictory. As most of these congenital lesions of clinical significance involve an aberration in the formation of the neural tube, it is suggested that the term neural tube defects (NTD) be used to characterize this entire group of anomalies. From a practical clinical standpoint, NTD can be subdivided into three main groupings: open spinal NTD, closed spinal NTD, and cranial NTD. This article briefly covers the epidemiology, embryology, classification, clinical presentation, and management of this group of congenital lesions.