This document defines and describes different types of spina bifida, a congenital defect involving the posterior bony wall of the spinal canal. It notes that spina bifida occurs most commonly in the lumbosacral region due to a failure of fusion of vertebral arches during development. The main types discussed are spina bifida occulta, meningocele, myelomeningocele, syringomyelocele, and myelocele, with descriptions of their characteristics and clinical presentations. Neurological deficits vary depending on whether the spinal cord or meninges are involved in the protrusion.

1. Subash Srivastav
Asst Professor

2. Definition
 Congenital defect in the posterior bony wall of the
spinal canal involving the laminae
 Most commonly seen in the lumbosacral region

3. Development of Spinal cord
2 weeks
5 weeks

4. Development of vertebral column
 Notochord – solid rod of cells in front of neural tube
 Vertebral bodies develop around Notochord
 From each vertebral body 2 projections grow around
the neural tube to form Vertebral arch OR Neural arch
 Fusion occurs first in the Thoracic region and extends
upwards and downwards
 Failure of fusion of these arches – SPINA BIFIDA

5. Incidence
 0.1% , excluding spina bifida occulta
 Myelocele – commonest type
 Most are still born; in survivors death occurs early due
to infection

6. Types
 Spina bifida occulta
 Meningocele
 Meningomyelocele
 Syringomyelocele
 Myelocele

9. Spina bifida occulta
 Common in lumbar/sacral region
 Small gap in one of vertebral arches (frequently only
one vertebra is involved)
 Gap is filled with fibrous tissue – no protrusion of cord
or membrane
 Indicators – patch of hair, lipoma, sinus, depression
 When cord lags behind vertebral column growth –
neurological deficiencies (nocturnal eneuresis,
backache)
 Many are symptomless

10. Meningocele
 Protrusion of meninges containing only CSF – cystic
swelling which is compressible
 Overlying skin remains intact
 Common in lumbosacral region; also occipital & root
of nose
 No neurological manifestations
 If associated with hydrocephalus (Arnold Chiari synd)
 Complications – infection, rupture
 Surgery required as early as possible

11. Myelomeningocele
 Spinal cord along with meninges in the sac
 Frequently adherent to the posterior aspect of sac
 Skin maybe absent at the summit of the swelling –
infection
 Transillumination – nerves within sac
 Neurological manifestations are ALWAYS present –
B/L talipes Equino Varus, atropy of lower limbs or
paralysis of lower limbs, urinary obstruction,
hydronephrosis & UTIs
 Surgery - ASAP

12. Syringomyelocele
 Rarest variety
 Central canal of spinal cord is dilated and the spinal
cord lies within the sac together with nerves
 Gross neurological deficits and paralytic
manifestations are seen

13. Myelocele
 Most serious form
 Along with bony defect, there is defect in development
of spinal cord
 Defect discharges CSF continuously
 Most are still born, survivors die within a few days due
to infection
 Meningomyelocele – most common defect among living
children with NTD