Meningocele Health Dictionary

Congenital abnormalities resulting from the failure of the NEURAL TUBE to form normally. The resulting conditions include SPINA BIFIDA, MENINGOCELE and defects in the bones of the SKULL.... neural tube defects

This is one of the most common of the congenital (present at birth) malformations. It is one of the three types of neural-tube anomaly, the other two being ANENCEPHALY and cranium bi?dum. It takes two main forms – spina bi?da occulta being much the commoner. There is a de?cit in the posterior part of the SPINAL COLUMN, usually in the LUMBAR region, and it is generally asymptomatic unless the underlying spinal cord is affected. Occasionally it is associated with a hairy patch or birthmark on the back, and a few children develop a mild spastic gait or bladder problems.

Much more serious is spina bi?da cystica, in which the spinal-wall defect is accompanied by a protrusion of the spinal cord. This may take two forms: a meningocele, in which the MENINGES, containing CEREBROSPINAL FLUID, protrude through the defect; and a meningomyelocele, in which the protrusion contains spinal cord and nerves.

Meningocele is less common and has a good prognosis. HYDROCEPHALUS and neurological problems affecting the legs are rare, although the bladder may be affected. Treatment consists of surgery which may be in the ?rst few days of life or much later depending upon the precise situation; long-term follow-up is necessary to pick up any neurological problems that may develop during subsequent growth of the spine.

Meningomyelocele is much more serious and more common, accounting for 90 per cent of all cases. Usually affecting the lumbo-sacral region, the range of severity may vary considerably and, while early surgery with careful attention in a minor case may achieve good mobility, normal bladder function and intellect, a more extensive protrusion may cause complete ANAESTHESIA of the skin, with increased risk of trauma; extensive paralysis of the trunk and limbs, with severe deformities; and paralysis and insensitivity of the bladder and bowel. Involuntary movements may be present, and hydrocephalus occurs in 80 per cent of cases. The decision to operate can only be made after a full examination of the infant to determine the extent of the defect and any co-existent congenital abnormalities. The child’s potential can then be estimated, and appropriate treatment discussed with the parents. Carefully selected patients should receive long-term treatment in a special centre, where full attention can be paid to all their various problems.

There is growing evidence of the value of vitamin supplements before and during pregnancy in reducing the incidence of spina bi?da. Parents of affected infants may obtain help, advice, and encouragement from the Association for Spina Bi?da and Hydrocephalus which has branches throughout the country, or the Scottish Spina Bi?da Association.... spina bifida

A developmental failure affecting the spinal cord or brain of the embryo. The most serious defect is anencephaly (total lack of a brain), which is fatal. More common is spina bifida, in which the vertebrae do not form a complete ring around the spinal cord. Spina bifida can occur anywhere on the spine, but it is most common in the lower back.

There are different forms of spina bifida. In spina bifida occulta, the only defect is a failure of the fusion of the bony arches behind the spinal cord, which may not cause any problems. When the bone defect is more extensive, there may be a meningocele, a protrusion of the meninges, or a myelomeningocele, a malformation of the spinal cord. Myelomeningocele is likely to cause severe handicap, with paralysis of the legs, loss of sensation in the lower body, hydrocephalus, and paralysis of the anus and bladder, causing incontinence. Associated problems include cerebral palsy, epilepsy, and mental handicap.

Surgery is usually performed a few days after birth. In mild cases, the defect can usually be corrected, but in myelomeningocele, some handicap will remain.

Genetic factors play a part in neural tube defects, which show multifactorial inheritance. Couples who have had an affected child or who have a family history of neural tube defects should seek genetic counselling. The risk of a neural tube defect occurring can be substantially reduced if the mother takes folic acid supplements for a month before conception and during the early part of the pregnancy.

Ultrasound scanning and amniocentesis allow accurate antenatal testing for neural tube defects.... neural tube defect