- A rare neural tube defect that combines extreme retroflexion (backward bending) of the head with severe defects of the spine. The affected infant tends to be short, with a disproportionately large head. The diagnosis can be made immediately after birth because the head is so severely retroflexed (bent back) that the face looks upward. The skin of the face is connected directly to the skin of the chest and the scalp is directly connected to the skin of the back. Generally, the neck is absent. Most individuals with iniencephaly have other associated anomalies such as anencephaly, cephalocele (a disorder in which part of the cranial contents protrudes from the skull), hydrocephalus, cyclopia, absence of the mandible (the lower jaw bone), cleft lip and cleft palate, cardiovascular disorders, diaphragmatic hernia, and gastrointestinal malformation. The disorder is more common among females. The prognosis (outlook) for those with iniencephaly is extremely poor. Newborns with iniencephaly seldom live more than a few hours. The distortion of the fetal body may also pose a danger to the mother's life.
* * *Malformation consisting of a cranial defect at the occiput, with the brain exposed; often in combination with a cervical rachischisis and retroflexion. [G. inion, back of the head, + enkephalos, brain]
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* * *in·i·en·ceph·a·ly (in″e-ən-sefґə-le) [ini- + Gr. enkephalos brain] a developmental anomaly characterized by enlargement of the foramen magnum and absence of the laminae and spinous processes of the cervical, dorsal, and sometimes lumbar vertebrae, with vertebrae reduced in number and irregularly fused, the brain and much of the spinal cord occupying a single cavity.
Medical dictionary. 2011.