USA Surgery Today

Myelomeningocele (MMC:Altace) is a neural tube defect in which the protective meningeal and bony coverings of the spinal cord fail to form correctly, leaving an exposed abnormal neural placode. MMC is nonlethal, but associated with high morbidity and affects 1 in 1,000 live births (84). Neurologic disabilities associated with MMC include paraplegia below the level of the lesion, urinary and fecal incontinence, sexual dysfunction, and skeletal abnormalities (85:Altace). However, there is considerable variation among these abnormalities associated with a specific defect. The deficits are believed to be multifactorial, with an inherent deficit associated with abnormal neurulation, and a postulated secondary of injury imposed by exposure of the neural placode to the amniotic environment.

Myelomeningocele can be diagnosed as early as the first trimester with US and MRI (:Altace) (84:Altace). Nearly all MMC-afflicted patients have an associated Chiari hindbrain malformation, and most also develop hydrocephalus (85). Chiari malformation is a pancerebral anomaly resulting from herniation of the medulla, cerebellar tonsils, and vermis through the foramen magnum.