Which of the following is NOT a type of spina bifida aperta?

• A. Spina bifida occulta
• B. Meningocele
• C. Myelomeningocele
• D. Myeloschisis

Answer: (A)

Spina bifida aperta refers to open spinal dysraphism where meninges or neural tissue protrude through a vertebral defect. Spina bifida occulta is a closed, hidden defect: the vertebral arches don’t fuse, but there is no protrusion of meninges or neural tissue, and skin covers the area. Because of that, it is not an open lesion. The other conditions involve outward exposure or sac formation: a meningocele has meninges (and CSF) protruding through the defect; a myelomeningocele includes meninges and spinal cord tissue in a sac; and myeloschisis is an open neural plate defect with exposed neural tissue. Clinically, occulta may show a skin marker like a tuft of hair or dimple and is often asymptomatic, whereas the open forms typically present at birth with a sac or exposed tissue and can involve neurological or orthopedic issues.