Spina bifida is a birth defect in which there is incomplete closing of the spine and the membranes around the spinal cord during early development in pregnancy.
Spina bifida occulta 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. 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, 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. 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.
Meningocele
A posterior meningocele or meningeal cyst is the least common form of spina bifida. In this form, a single developmental defect allows the meninges to herniate between the vertebrae. As the nervous system remains undamaged, individuals with meningocele are unlikely to suffer long-term health problems, although cases of tethered cord have been reported.
Myelomeningocele
Myelomeningocele (MMC), also known as meningomyelocele, is the type of spina bifida that often results in the most severe complications and affects the meninges and nerves. In individuals with myelomeningocele, the unfused portion of the spinal column allows the spinal cord to protrude through an opening. Myelomeningocele occurs in the third week of embryonic development, during neural tube pore closure. MMC is a failure of this to occur completely.The meningeal membranes that cover the spinal cord also protrude through the opening, forming a sac enclosing the spinal elements, such as meninges, cerebrospinal fluid, and parts of the spinal cord and nerve roots. Myelomeningocele is also associated with Arnold–Chiari malformation, necessitating a VP shunt placement. Toxins and conditions associated with MMC formation include: calcium-channel blockers, carbamazepine, cytochalasins, hyperthermia, and valproic acid.
Myelocele
Spina bifida with myelocele is the most severe form of myelomeningocele. In this type, the involved area is represented by a flattened, plate-like mass of nervous tissue with no overlying membrane. The exposure of these nerves and tissues make the baby more prone to life-threatening infections such as meningitis.
Teratoma and other tumors of the sacrococcyx and of the presacral space, and Currarino syndrome.
A meningocele may also form through dehiscences in the base of the skull. These may be classified by their localisation to occipital, frontoethmoidal, or nasal. Endonasal meningoceles lie at the roof of the nasal cavity and may be mistaken for a nasal polyp. They are treated surgically. Encephalomeningocele are classified in the same way and also contain brain tissue.
The protruding portion of the spinal cord and the nerves that originate at that level of the cord are damaged or not properly developed. As a result there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect. Thus, the more cranial the level of the defect. The more severe the associated nerve dysfunction and resultant paralysis may be.
Spina bifida may cause minimal symptoms or minor physical disabilities. But severe spina bifida can lead to more significant physical disabilities. Severity is affected by:
Folic acid, taken in supplement form starting at least one month before conception and continuing through the first trimester of pregnancy, greatly reduces the risk of spina bifida and other neural tube defects.
Having enough folic acid in your system by the early weeks of pregnancy is critical to prevent spina bifida. Because many women don’t discover that they’re pregnant until this time, experts recommend that all women of childbearing age take a daily supplement of 400 micrograms (mcg) of folic acid.
Several foods are fortified with 400 mcg of folic acid per serving, including:
Folic acid may be listed on food packages as folate, which is the natural form of folic acid found in foods.
Adult women who are planning pregnancy or who could become pregnant should be advised to get 400 to 800 mcg of folic acid a day.
Your body doesn’t absorb folate as easily as it absorbs synthetic folic acid, and most people don’t get the recommended amount of folate through diet alone, so vitamin supplements are necessary to prevent spina bifida. And it’s possible that folic acid will also help reduce the risk of other birth defects, including cleft lip, cleft palate and some congenital heart defects.
It’s also a good idea to eat a healthy diet, including foods rich in folate or enriched with folic acid. This vitamin is present naturally in many foods, including:
If you have spina bifida or if you’ve previously given birth to a child with spina bifida, you’ll need extra folic acid before you become pregnant. If you’re taking anti-seizure medications or you have diabetes, you may also benefit from a higher dose of this B vitamin. Check with your doctor before taking an additional folic acid supplement.
Three tests can check for spina bifida and other birth defects while the baby is still in the womb:
Sometimes, spina bifida is diagnosed after a baby is born — usually if the mother didn’t get prenatal care or the ultrasound didn’t show anything wrong.
The doctor probably will want to get X-rays of the baby’s body and do a magnetic resonance imaging (MRI) scan, which uses strong magnets and radio waves to get more detailed images.
Doctors can operate on babies when they’re just a few days old or even while they’re still in the womb. If the baby has meningocele, about 24 to 48 hours after birth, the surgeon will put the membrane around the spinal cord back in place and close the opening.
If the baby has myelomeningocele, the surgeon will put the tissue and spinal cord back inside the baby’s body and cover it with skin.
Sometimes the surgeon will also put a hollow tube into the baby’s brain called a shunt to keep water from collecting on the brain (called hydrocephalus). This is also done 24 to 48 hours after the baby’s born.
Surgery sometimes can be done while the baby is still in the womb. Before the 26th week of pregnancy, the surgeon goes into the mother’s womb and sews shut the opening over the baby’s spinal cord. Children who have this type of surgery seem to have fewer birth defects. But it’s risky to the mother and makes it more likely that the baby will be born too early.
After these surgeries, others may be needed to correct problems with feet, hips, or the spine or to replace the shunt in the brain. Between 20% and 50% of children with myelomeningocele may also have something called progressive tethering, which is when their spinal cords get fastened to the spinal canal. (Normally, the bottom of the spinal cord floats freely in the spinal canal.) As the child grows, the spinal cord stretches, and that causes a loss of muscle and bowel or bladder problems. Surgery may be needed to fix that as well.
Some people with spina bifida need crutches, braces, or wheelchairs to move around, and others need a catheter to help with their bladder issues.
Orthopedic Ambulatory supporting devices