Which is described as the most severe form, with nerve tissue fully exposed?

• A. Meningocele
• B. Myelomeningocele
• C. Myeloschisis
• D. Occulta

Answer: (C)

The most severe form of neural tube defect described here is myeloschisis, where the neural tissue is exposed on the surface of the spinal area because the neural tube fails to close completely. This leaves raw, unm proteccióned neural tissue exposed to the environment, often with little to no overlying skin or sac. The result is a high risk of infection and significant neurological impairment because the exposed tissue can be damaged and does not form a proper organized spinal cord structure.

Other forms in the spectrum are less severe in terms of tissue exposure. Occulta is a hidden defect with no outward protrusion. A meningocele involves meninges protruding through a vertebral defect, sometimes with a sac, but neural tissue is not openly exposed. A myelomeningocele includes both meninges and spinal cord/nerve tissue in a sac, but there is typically some covering, whereas myeloschisis lacks that protection and has exposed neural tissue along the surface.