Spina Bifida is a gap in the spinal column which allows the nerves that run through the spine to herniate through this space. The nervesend up being splayed out through the skin. The function of these nerves is affected, so a patient with spina bifida may have neurological problems with the nerves running past this gap.

The usual effects are on leg function, bowel and bladder function, and in males on erectile function.

Development of the Central Nervous System

The central nervous system (CNS) and spine develop between the 14th and 28th day after conception. The CNS and skin develop from the same tissue (neuro-ectoderm). As development occurs the nervous system and skin split and migrate away from each other. If the "splitting" is incomplete then the skin can drag the nerves with it and thus they end up on the "outside". This on going connection also stops the normal spine closing around the nervous tissue. This is the derivation of the term spina bifda (bifid spine). If the connection persists in the head the lesion formed is an encephlocoele, if it pesrists in the spine it is a spina bifida.

Classification of Spina Bifida

There are varoius degrees of spina bifida:

• Spina Bifida Occulta (incomplete fusion of bone, no neurological effects)
• Meningocoele (herniation of fluid sca surrounding the nerves, mild)
• Myelomeningocoele (herniation of nerves, severe effects) 

Causes of Spina Bifida

The causes are not known. It is felt that an incresae in the dietry folic acid content PRE-CONCEPTION may decrease then incidence of spina bifida. The risk is also increased if there is a history of spina bifida in the family.

Antenatal Screening

Alpha feto protein can be used as a marker during pregnancy to check for the probability of spina bifida. Ultrasound scanning should show any abnormalities, from early on in pregnancy. Foetal MRI scanning is also available and is something I use frequently to assess the child in utero. 

Associated Abnormalities

This discussuion only applies to the open (meningocoele and myelomeningocoele) spina bifida patients.

• Paralysis (legs)
• Incontinence (no bladder or bowel control)
• Hydrocephalus (80% of patients with open spina bifida have hydrocephalus)
• Chiari Malformation (by definition all patients have a Chiari 2 malformation)
• Syringomyelia (a significant minority of patients develop a cyst in the spinal cord)

Treatment

• Antenatal screening
• Delivery by elective cesarian section in a neurosurgical unit
• Closure of open myelomeningocoele within 24 hours
• Treatment of hydrocephalus asap
• Neuro-axis MRI within firts 3 months of life
• Follow up with urology team and urodynamics
• Early intermittant self-catheretisation
• Neurosurgical follow up
• Referral to ASBAH