Cervical occult spinal dysraphism: MRI findings and the value of a vascular birthmark.

Spinal dysraphism is easily recognized in the overt form as a meningocele or myelomeningocele. The closed form or occult spinal dysraphism (OSD) can be overlooked. It occurs predominantly at the lumbosacral level, but OSD at the cervical level, although very rare, also occurs. The value of magnetic resonance imaging investigations in preparation for surgical treatment is emphasized. We discuss the value of various midline posterior skin anomalies as indicators of an underlying developmental defect in the neural axis. Hallmarks for OSD in the inferior third of the back are well known. They can also occur at the cervical level. Among these warning cutaneous midline changes, a vascular stain alone is rarely a clue for OSD whatever the spinal level involved, and specifically in the nuchal area.