What type of failure occurs if the neural tube fails to close at the cranial end?

The failure of the neural tube to close at the cranial end leads to anencephaly, a serious congenital condition characterized by the absence of a major portion of the brain, skull, and scalp. This condition arises when the anterior part of the neural tube, which forms the brain, fails to develop properly. As a result, the upper neural structures do not form, leading to a very minimal or completely absent cerebral hemispheres.

Infants born with anencephaly typically have only the brainstem intact and may survive only for a short period after birth, as the condition is not compatible with long-term life. Early prenatal detection through ultrasound and maternal serum alpha-fetoprotein screening can help identify this condition.

In contrast, myelomeningocele is associated with defects in the spinal cord and occurs when the neural tube fails to close in the lower back area, spina bifida refers to similar defects but encompasses a broader range of spinal cord issues, and encephalocele involves herniation of brain tissue through a defect in the skull but does not exclusively relate to neural tube closure failure at the cranial end. Each of these conditions presents different clinical implications and anatomical concerns compared to anencephaly.