Triple neural tube defect and the multisite closure theory for neural tube defects: is there an additional site? Case report.

Triple neural tube defects (NTDs) are rare; only 1 case exists in the available literature. There has been a divergent view on the etiogenesis of NTDs, and 2 main theories have been postulated: the more widely held orderly closure theory and the less accepted multisite closure theory. In this article the authors present 2 cases of patients with triple NTDs, and they examine the embryological basis of NTDs with special reference to the multisite closure theory. The patient in Case 1 had a 2-level myelomeningocele (MMC) along with an encephalocele; the patient in Case 2 had a 3-level MMC. To the authors' knowledge, this paper outlines only the second and third cases described in world literature of triple NTDs including the first case of a triple MMC. The embryogenesis of triple NTDs can be better explained by the multisite closure theory. However, it fails to adequately explain the triple MMC in Case 2, given that the closure has to proceed in an orderly manner. The authors thus propose an additional closure site to explain this.