spina bifida occulta

Last reviewed 06/2022

Spina bifida occulta is a failure of fusion of the vertebral spines (usually L5 and S1). It occurs in about three percent of the population and is rarely associated with neurological abnormalities.

A bony anomaly may be seen radiologically.

Those with an additional lumbosacral cutaneous abnormality - a tuft of hair, sinus or port wine stain - have a high incidence of related underlying defects:

• diastomatomyelia
• lipoma
• dermoid cyst

Neural abnormalities, though rare, may occur during growth because of spinal cord tethering. Disturbances of micturition or deformity in the feet or gait require investigation if spina bifida occulta is present.