Spina bifida is a birth defect that occurs when the tissue surrounding the spinal cord does not close properly. It is one of several disorders known as neural tube defects. Neural tube defects occur in about one out of every 1,000 births and spina bifida affects seven out of every 10,000 births. Spina bifida is the most common neural tube defect.
Spina bifida (Latin for "cleft spine") happens during the first month of pregnancy when the child has an incomplete and improper closure of the spine. Some infants are born with an opening in the back, exposing the spinal nerves. This may cause serious damage to the nerves and the spinal cord. Other complications are hydrocephalus (buildup of fluid in the brain), urinary and bladder problems, and learning disabilities.
There are three types of spina bifida. The mildest form, spina bifida occulta, is usually caused by a malformed vertebra (spinal bones) that is covered with skin. Most children with spina bifida occulta will have no symptoms and live completely normal lives. Meningocele and myelomeningocele are the other types, collectively known as spina bifida manifesta. Meningocele is when the spinal cord develops normally, but the membranes that cover the brain and spinal cord (called the meninges) stick out from the opening in the spine. Myelomeningocele is the most severe type of spina bifida in which the meninges and the spinal cord do not develop properly and can stick out of the open lesion.
With surgical treatment, most children will survive into adulthood. About 80% will have normal intelligence and almost 75% will be able to participate in sports and recreational activities. However, some will have complete paralysis of the legs. These children will depend on a wheelchair to move around but may still be able to live long and healthy lives.
α-fetoprotein, alpha-fetoprotein, amniocentesis, Chiari II malformation, folic acid, hydrocephalus, maternal serum alpha fetoprotein (MSAFP), meninges, meningocele, 5-methyltetrahydrofolate-homocysteine methyltransferase reductase gene (MTRR or MTR gene), myelomeningocele, neural tube defect, spina bifida manifesta, spina bifida occulta.
types of the disease
Spina bifida occulta: Spina bifida occulta (meaning "hidden") is the most common and the mildest form of spina bifida. It occurs in about 3-5% of patients and the malformation is usually covered by the skin. The defect is usually a minor gap in a few of the vertebrae, which are the small bones that make up the spine. In later childhood or adulthood, progressive neurological deterioration may become apparent; however, it can be so mild that there is no disturbance in spinal function. Some signs may be seen with close examination of the back. These include dimpled, thickened, pigmented (colored), or hairy skin where the defect is covered or soft swelling over the spine (composed of fatty tissue). It may be diagnosed at any age, and some people with occulta may go their whole lives without ever knowing they have it.
Spina bifida meningocele: This type, along with myelomeningocele, is collectively known as spina bifida manifesta. Meningocele accounts for 4% of all spina bifida manifesta cases. In this type, the coating that protects the central nervous system, known as the meninges, is pushed through an open part of the spine. There is usually a sac filled with cerebrospinal fluid (the fluid found around the spinal cord and brain), and it may or may not be covered by skin. Usually, there is no nerve damage and a person may have minor disabilities.
Spina bifida myelomeningocele: Myelomeningocele is also a type of spina bifida manifesta and accounts for 96% of manifesta cases. This form of spina bifida is the most serious and causes nerve damage and more severe disabilities. Like meningocele spina bifida, there is a sac that pushes through an open part of the spine. This sac contains meninges, spinal nerves, and can even contain the spinal cord itself. It can cause partial or complete paralysis to any part of the body below the opening. Some patients are unable to walk and may experience urinary and bowel problems.