Which spinal defect is defined by the failure of the lumbar vertebrae to fuse and is typically asymptomatic?

Which spinal defect is defined by the failure of the lumbar vertebrae to fuse and is typically asymptomatic?

• A. Meningocele
• B. Spina bifida occulta
• C. Spinal lipoma
• D. Meningomyelocele

Answer: (B)

Spina bifida occulta is a spinal defect where the posterior parts of the lumbar vertebrae fail to fuse, creating a bony gap in the vertebral arch. Because the neural tissue and meninges stay in place and do not herniate, there is usually no neurologic deficit, so the condition is typically asymptomatic and often found incidentally on imaging or recognized by a subtle skin marker like a small dimple or tuft of hair on the lower back. This contrasts with other defects where meninges or spinal cord protrude through the vertebral defect (leading to neurological symptoms), such as when there is a meningocele or meningomyelocele, and with spinal lipoma, which involves fatty tissue that can tether the cord rather than just a bony fusion issue.

Spina bifida occulta is a spinal defect where the posterior parts of the lumbar vertebrae fail to fuse, creating a bony gap in the vertebral arch. Because the neural tissue and meninges stay in place and do not herniate, there is usually no neurologic deficit, so the condition is typically asymptomatic and often found incidentally on imaging or recognized by a subtle skin marker like a small dimple or tuft of hair on the lower back. This contrasts with other defects where meninges or spinal cord protrude through the vertebral defect (leading to neurological symptoms), such as when there is a meningocele or meningomyelocele, and with spinal lipoma, which involves fatty tissue that can tether the cord rather than just a bony fusion issue.