0 It is the failure of the fusion of the vertebral arches along the midline.
Spina Bifida Occulta
• It is a defect in the fusion of spinous formations and laminae.
• However, it does not contain meninges or neural tissue.
• About 80% of these are in the lumbosacral region.
meningocele
• Herniation of the sac consisting of dura and arachnoid membrane outward from the spinal canal through localized spina bifida.
• The sac is filled with CSF and the patient has no neurological deficit.
• The patient rarely has hydrocephalus.
Meningomyelocele
• It is the presence of neural elements in the meningocele sac.
• They are often localized in the lumbar or lumbosacral region.
• Congenital anomalies seen with meningomyelocele are:
• Arnold-Chiari Type-II Malformation (most common)
• Aquaductus bifurcation
• Hydromyelia
• Hydrocephalus
Diastematomyelia (Split Cord Syndrome, Split Spinal Cord Syndrome)
• Spinal cord or cauda equina; It is characterized by the division into two different compartments by a septum consisting of bone, cartilage or fibrous tissue and surrounded by a dural sheath.