Spina bifida

Spina bifida is a birth defect in which there is incomplete closing of the spine and membranes around the spinal cord during early development in pregnancy. There are three main types: spina bifida occulta, meningocele and myelomeningocele. The most common location is the lower back, but in rare cases it may be the middle back or neck. Occulta has no or only mild signs. Signs of occulta may include a hairy patch, dimple, dark spot or swelling on the back at the site of the gap in the spine. Meningocele typically causes mild problems with a sac of fluid present at the gap in the spine. Myelomeningocele, also known as open spina bifida, is the most severe form. Associated problems include poor ability to walk, problems with bladder or bowel control, accumulation of fluid in the brain (hydrocephalus), a tethered spinal cord and latex allergy. Learning problems are relatively uncommon.X-ray image of spina bifida occulta in S-1X-ray computed tomography scan of unfused arch at C1Myelomeningocele in the lumbar area(1) External sac with cerebrospinal fluid(2) Spinal cord wedged between the vertebraeThree-dimensional ultrasound image of the fetal spine at 21 weeks of pregnancyUltrasound view of the fetal spine at 21 weeks of pregnancy. In the longitudinal scan a lumbar myelomeningocele is seen.Anatomy scan of the fetal head at 20 weeks of pregnancy in a fetus affected by spina bifida. In the axial scan the characteristic lemon sign and banana sign are seen. Spina bifida is a birth defect in which there is incomplete closing of the spine and membranes around the spinal cord during early development in pregnancy. There are three main types: spina bifida occulta, meningocele and myelomeningocele. The most common location is the lower back, but in rare cases it may be the middle back or neck. Occulta has no or only mild signs. Signs of occulta may include a hairy patch, dimple, dark spot or swelling on the back at the site of the gap in the spine. Meningocele typically causes mild problems with a sac of fluid present at the gap in the spine. Myelomeningocele, also known as open spina bifida, is the most severe form. Associated problems include poor ability to walk, problems with bladder or bowel control, accumulation of fluid in the brain (hydrocephalus), a tethered spinal cord and latex allergy. Learning problems are relatively uncommon. Spina bifida is believed to be due to a combination of genetic and environmental factors. After having one child with the condition or if one of the parents has the condition, there is a 4% chance that the next child will also be affected. Not having enough folate in the diet before and during pregnancy also plays a significant role. Other risk factors include certain antiseizure medications, obesity and poorly controlled diabetes. Diagnosis may occur either before or after a child is born. Before birth if a blood test or amniocentesis finds a high level of alpha-fetoprotein (AFP), there is a higher risk of spina bifida. Ultrasound examination may also detect the problem. Medical imaging can confirm the diagnosis after birth. Spina bifida is a type of neural tube defect related to but distinct from other types such as anencephaly and encephalocele. Most cases of spina bifida can be prevented if the mother gets enough folate before and during pregnancy. Adding folic acid to flour has been found to be effective for most women. Open spina bifida can be surgically closed before or after birth. A shunt may be needed in those with hydrocephalus, and a tethered spinal cord may be surgically repaired. Devices to help with movement such as crutches or wheelchairs may be useful. Urinary catheterization may also be needed. About 15% of people have spina bifida occulta. Rates of other types of spina bifida vary significantly by country, from 0.1 to 5 per 1000 births. On average in developed countries, including the United States, it occurs in about 0.4 per 1000 births. In India, it affects about 1.9 per 1000 births. Caucasians are at higher risk compared to Black people. The term is Latin for 'split spine'. There are two types: spina bifida occulta and spina bifida cystica. Spina bifida cystica can then be broken down into meningocele and myelomeningocele. Occulta is Latin for 'hidden'. This is the mildest form of spina bifida.In occulta, the outer part of some of the vertebrae is not completely closed. The splits in the vertebrae are so small that the spinal cord does not protrude. The skin at the site of the lesion may be normal, or it may have some hair growing from it; there may be a dimple in the skin, or a birthmark. Unlike most other types of neural tube defects, spina bifida occulta is not associated with increased AFP, a common screening tool used to detect neural tube defects in utero. This is because, unlike most of the other neural tube defects, the dural lining is maintained. Many people with this type of spina bifida do not even know they have it, as the condition is asymptomatic in most cases. About 15% of people have spina bifida occulta, and most people are diagnosed incidentally from spinal X-rays.A systematic review of radiographic research studies found no relationship between spina bifida occulta and back pain. More recent studies not included in the review support the negative findings. However, other studies suggest spina bifida occulta is not always harmless. One study found that among patients with back pain, severity is worse if spina bifida occulta is present.Among females, this could be mistaken for dysmenorrhea. Incomplete posterior fusion is not a true spina bifida, and is very rarely of neurological significance.