<prompt> Myelomeningocele most commonly involves which region of spine:Cervico-dorsalDorsolumbarLumbosacralSacro-coccygeal  <response>: c. LumbosacralRef: Nelsons 20e p 2802-2803Myelomeningocele involves lumbosacral region 75 of casesAppearance: a sac-like cystic structure with remnants of neural tissue visible beneath the membrane, which occasionally ruptures and leaks CSF or an exposed flat neural placodeHydrocephalus with a type II Chiari malformation develops in 80 of patients with MMCThe lower the deformity in the neuraxis, the less likely is the risk of hydrocephalus. 