Meningocele

Neural tube defects are the second most common type of congenital disability after congenital heart defects. Neural tube defects include meningoceles and myelomeningoceles, among others. Meningoceles are sacs of meninges containing cerebrospinal fluid that protrude into the subcutaneous tissue through a spinal defect, most of which are skin-covered. A complex meningocele is associated with other spinal anomalies, such as meningocele manque. Meningoceles are typically asymptomatic and are not associated with acute neurologic decline (see Types of Spina Bifida). Spinal dysraphism can be broadly categorized into open or closed depending on whether the lesion is covered by skin. Meningoceles and myelomeningoceles are examples of spina bifida aperta or open spina bifida. Some authors categorize meningoceles as open spina bifida, although some of these lesions are skin-covered. Spina bifida cystica is a subtype of spina bifida aperta and is characterized by a lesion within a meningeal lining, as seen in meningoceles and myleomeningoceles. An example of spina bifida aperta that does not fall under spina bifida cystica is myeloschisis, in which the spinal cord is exposed to the surface with no overlying spinal fluid sac. Spina bifida occulta, or closed spina bifida, can be seen in conditions such as split cord malformations, dorsal dermal sinus tracts, lipomyelomeningocele, and tight filum terminale. Myelomeningocele is the most common form of spina bifida, accounting for 90% of cases. Please see StatPearls' companion reference, "Myelomeningocele," for a more comprehensive discussion of that congenital disability.