Which spinal defect is more common: meningomyelocele or meningocele?

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

Answer: (D)

In spinal dysraphism, the defect that includes neural tissue is more common than the one that involves only the meninges. Meningocele is a protrusion of the meninges with CSF through a vertebral defect, but the spinal cord itself remains in place. Meningomyelocele, on the other hand, involves both meninges and spinal cord/nerve roots protruding through the defect. This combination of neural tissue with the meninges is the more frequent open neural tube defect seen clinically, making meningomyelocele the better answer. (Spina bifida occulta is a milder, non-protruding form and is a distinct category.)