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