Correct answer:

These defects are particularly common in the lumbosacral area, although any part of the spine may be involved. There may be an associated overlying lipoma, tuft of hair or skin dimple, which may be an important clue to the astute clinician of the underlying defect. Where nervous tissue is involved there may be paraparesis, paraplegia, sensory disturbance in the limbs and loss of sphincter control. Hydrocephalus nearly always coexists with the myelomeningocele owing to Arnold–Chiari malformation, in which the cerebellar tonsils descend below the foramen magnum with consequent obstruction of the cerebrospinal fluid pathway. As with any other congenital deformity there may be multiple developmental anomalies, e.g. congenital dislocation of the hip, talipes equinovarus, cleft lip or palate, cardiac lesions or supernumerary digits.