It is a congenital problem, present before birth, and it is caused by the incomplete closing of the embryonic neural tube. It is a neural tube defect.
There are four main types of spina bifida: myelomeningocele, spina bifida occulta, closed neural tube defects, and meningocele. Myelomeningocele is the most serious type, and symptoms can be severe. In spina bifida occulta, symptoms may be barely noticeable.
Surgery and other treatment options can improve the quality of life for a person with severe symptoms. This article will look at the symptoms, causes, and treatment for the most serious type, myelomeningocele.
- Spina bifida is a congenital condition in which the spinal column is exposed.
- Myelomeningocele is the most serious type and it is present around 60 births in every in 100,000.
- Exposure means the spinal column is more at risk of infection.
- Excess cerebrospinal fluid can build up and result in hydrocephalus, and this increases the chances of learning difficulties.
- A low intake of folic acid before and during pregnancy has been linked to spina bifida.
- Treatment options include surgery, physical therapy, and assistive devices.
What is spina bifida?
In spina bifida, a split in the vertebral column leaves the neural tube exposed.
During the first month after conception, the embryo develops a primitive tissue structure known as the neural tube.
This structure gradually develops into bones, nerves, and tissue. These eventually form the nervous system, the spinal column, and the spine, a ridge of bone that protects and surrounds the nerves.
In spina bifida, the neural tube and spinal column do not develop properly. The spine does not close fully, and the spinal column remains exposed along several vertebrae.
A sac forms on the fetus' back as the membranes and spinal cord push out. The sac may be covered with meninges, or membranes.
Out of 4 million babies born in the United States (U.S.) each year, spina bifida affects between 1,500 and 2,000 of them.
There are four main types of spina bifida:
Occulta: This is the mildest form. Most patients have no neurological signs or symptoms. There may be a small birthmark, dimple or tuft of hair on the skin where the spinal defect is. The person may never know they have spina bifida unless a test for another condition reveals it by chance.
Closed neural tube defects: In this version, there can be a variety of potential defects in the spinal cord's fat, bone, or meninges. In many cases, there are no symptoms; however, in some, there is partial paralysis and bowel and urinary incontinence.
Meningocele: The spinal cord develops normally, but the meninges, or protective membranes around the spinal cord, push through the opening in the vertebrae. The membranes are surgically removed, usually with little or no damage to nerve pathways.
Myelomeningocele: Myelomeningocele is the most severe form of spina bifida. In this condition, the spinal cord is exposed, causing partial or complete paralysis of the body below the opening. The symptoms are outlined in detail below.
An infant who is born with spina bifida may have or develop:
- weakness or paralysis in the legs
- urinary incontinence
- bowel incontinence
- a lack of sensation in the skin
- a build up of cerebrospinal fluid (CSF), leading to hydrocephalus, and possibly brain damage
The nervous system will also be more prone to infections, some of which can be life-threatening.
CSF is a watery fluid that flows through the cavities inside the brain and also around the surface of the brain and the spinal cord. If there is too much CSF, this can lead to hydrocephalus, pressure on the brain, and ultimately brain damage.
If the opening in the vertebrae occurs at the top of the spine, there is a higher chance of complete paralysis in the legs and other problems with movement elsewhere in the body. If the openings are in the middle or the base of the spine, symptoms tend to be less severe.
Symptoms of myelomeningocele
Myelomeningocele is the most severe form of spina bifida. If hydrocephalus is present, it increases the chance of learning problems. A range of symptoms can occur.
Cognitive symptoms: Awareness, thinking, learning, judging and knowing are known as cognition. Problems in the neural tube can have a negative impact on brain development. If the brain's cortex, and especially the frontal part, does not develop properly, cognitive problems can arise.
Type 2 Arnold-Chiari malformation: This is an abnormal brain development involving a part of the brain known as the cerebellum. This may cause hydrocephalus. It can affect language processing and physical coordination.
Learning difficulties: People with spina bifida have normal intelligence. However, learning difficulties can occur, leading to problems with attention, solving problems, reading, understanding spoken language, making plans, and grasping abstract concepts.
Coordination: There may also be problems with visual and physical coordination. Doing up buttons or shoelaces can be difficult.
Paralysis: Most patients have some degree of paralysis in their legs. In cases of partial paralysis, leg braces or a walking stick may be necessary. A person with total paralysis will need a wheelchair. If the lower limbs are not exercised, they can become weak, leading to dislocated joints and misshapen bones.
Bowel and urinary incontinence: These are common.
Meningitis: There is a higher risk of meningitis among people with spina bifida. This can be life-threatening.
Skin can be more easily damaged if the person lacks sensation in the legs. They may injure or burn themselves without realizing.
Treatment depends on several factors, mainly how severe the signs and symptoms are.
Surgery to repair the spine: This can be done within 2 days of birth. The surgeon replaces the spinal cord and any exposed tissues or nerves back into the newborn's body. The gap in the vertebrae is then closed and the spinal cord sealed with muscle and skin.
If bone development problems occur later, such as scoliosis or dislocated joints, further corrective surgery may be needed. A back brace can help correct scoliosis.
Prenatal surgery: The surgeon opens the uterus and repairs the spinal cord of the fetus, usually during week 19 to 25 of pregnancy. This type of surgery may be recommended to reduce the risk of spina bifida worsening after delivery.
Cesarian-section birth: If spina bifida is present in the fetus, delivery will probably be by cesarean section. This is safer for the exposed nerves.
Hydrocephalus: Surgery can treat a buildup of cerebrospinal fluid in the brain. The surgeon implants a thin tube, or shunt, in the baby's brain. The shunt drains away excess fluid, usually to the abdomen. A permanent shunt is usually necessary.
Further surgery may be needed if the shunt becomes blocked or infected, or to install a larger one as the child grows.
Physical and occupational therapy
Physical therapy: This is vital, as it helps the individual become more independent and prevents the lower limb muscles from weakening. Special leg braces may help keep the muscles strong.
Assistive technologies: A patient with total paralysis of the legs will need a wheelchair. Electric wheelchairs are convenient, but manual ones help maintain upper-body strength and general fitness.
- Leg braces can help those with partial paralysis.
- Computers and specialized software may help those with learning problems.
Occupational therapy: This can help the child perform everyday activities more effectively, such as getting dressed. It can encourage self-esteem and independence.
Treatment for urinary incontinence
A urologist will carry out an assessment and recommend appropriate treatment.
Clean intermittent catheterization (CIC): This is a technique to empty the bladder at regular intervals. The child or a parent or carer learns to place the catheter through the urethra and into the bladder to empty it.
Anticholinergics: These drugs are normally prescribed for adults with urinary incontinence, but a doctor child may prescribe it for a child. They increase the amount of urine the bladder can hold and reduce the number of times the child has to pee.
Botox injection: If the child's bladder contracts abnormally, known as a hyper-reflexic bladder, the doctor may recommend a botulinum toxin (botox) injection to paralyze the muscles. If it works, treatment will be repeated every 6 months.
Artificial urinary sphincter (AUS): This surgically implanted device has a silicone cuff, surrounded by a liquid, a pump, and a balloon. It is attached to the urethra and the balloon is placed in the abdomen. The pump is placed under the skin of the scrotum in males and under the skin of the labia in females. When the child wants to urinate they press the pump, which temporarily empties the fluid from the cuff into the balloon, releasing the pressure on the cuff and opening the urethra, allowing urine to be released. It may not be suitable for younger boys who have not yet reached puberty.
Mitrofanoff procedure: The surgeon removes the appendix and creates a small channel, the Mitrofanoff channel, which ends at an opening, or stoma, just below the belly button. The child can place a catheter into the stoma to release urine and empty the bladder.
Long-term use of antibiotics may be necessary to prevent urinary tract and kidney infections.
Treatment for bowel incontinence
A special diet and some toilet training techniques may be needed. Other treatment options include surgery.
Anal plugs: These are made of foam and inserted into the anus to prevent soiling. When the plug gets wet, it expands, blocking the passage of any feces and liquid. Anal plugs work for about 12 hours. They can be removed by pulling an attached string.
Enema: Children who have not responded to treatments may benefit from enemas, which clean out the bowel for 2 to 3 days.
Surgery for bowel incontinence: If none of these treatments are effective, the doctor may recommend surgery.
Antegrade continence enema (ACE): The appendix is used to create a channel between the bowel and the abdomen. This channel ends at an opening, or stoma, in the surface of the abdomen. If a catheter is inserted into the stoma, liquids can pass through the catheter, into the stoma and into the bowel to flush out its contents through the anus.
Colostomy or ileostomy: A colostomy involves diverting a section of the colon so that it connects to a stoma, which is attached to a pouch. The pouch collects stools. If the diversion is at the end of the small intestine, the procedure is called an ileostomy.
A child with spina bifida may need help from a number of specialists, including a pediatrician, a neurosurgeon, a urologist, and an orthopedist.
Tests and diagnosis
Most cases of spina bifida are detected by a routine ultrasound scan during pregnancy.
Testing for spina bifida and other problems can be done during pregnancy, but these tests are not 100 percent accurate.
Maternal serum alpha-fetoprotein (MSAFP) test
This is a blood test that assesses for alpha-fetoprotein (AFP), a protein that the fetus produces.
AFP does not usually enter the mother's bloodstream. If it does, it usually means the fetus has abnormally high levels and probably a neural tube defect. This could indicate anencephaly, an incomplete skull and underdeveloped brain, or spina bifida.
Sometimes, AFP levels are normal but the fetus has spina bifida. In other case, AFP levels are high but the fetus is healthy.
If AFP levels are high, the doctor will order another blood test. If they are still high, further tests, including an ultrasound scan will be ordered to try to find out why AFP is high and to check for signs of spina bifida.
AFP levels may also be high if:
- there is more than one fetus
- there has been a miscalculation of gestational age
Other tests performed during pregnancy are the triple screen or quadruple (quad) screen.
If the ultrasound scan is normal but AFP levels are high, the doctor may recommend amniocentesis. A sample of fluid is removed from the amniotic sac and tested for AFP levels.
If the fetus has a neural tube defect, there will be will high levels of AFP in the amniotic fluid that surrounds them.
If AFP levels are high, the doctor will carry out another test to confirm.
Causes and risk factors
It is unclear exactly what causes spina bifida. Scientists say it is most likely due to a combination of inherited, or genetic, environmental and nutritional factors.
If the spine of the fetus does not close fully, spina bifida can result.
Folic acid: Spina bifida is more likely if a mother does not have enough folic acid during the pregnancy, although the reason is unclear. All women of reproductive age should make sure their folic acid intake is adequate. Since the introduction of folic acid recommendations in the U.S. in 1992, the number of births involving neural tube defects has fallen.
Plant proteins, iron, magnesium, and niacin: A low intake of these nutrients before conception may be associated with an increased risk of neural tube defects by two to five times.
Family history: If one infant is born with spina bifida, there is a 4 percent chance that a future sibling will have the same condition.
Diabetes: A woman who has diabetes is more likely to have a baby with spina bifida, than one who does not.
Obesity: A woman whose body mass index (BMI) is 30 or above has a higher risk of having a baby with spina bifida.
Since the cause of spina bifida is unknown, it is difficult to prevent it, but folic acid and tests during pregnancy can help.
Leafy green vegetables are a good source of folic acid.
Folic acid: Women of reproductive age should consume 400 micrograms (mcg) a day of folic acid, a nutrient that is key to healthy fetal development. Sources include dark green, leafy vegetables, egg yolks, some fruits, and fortified cereal products. Women who are pregnant or trying to become pregnant should take a 400 mcg folic acid supplement daily.
Tests: Undergoing tests for neural tube defects and other problems during pregnancy can also reduce the risk and enable preventive action to be taken.
A woman who has spina bifida or who has a child with the condition is at higher risk of having another child with spina bifida. She may be advised to take extra folic acid before conceiving again.
Around 50 years ago, most infants would not survive beyond their first 12 months, but most people with spina bifida now survive well into adulthood, and a considerable number can live independently.
Most children with spina bifida have normal intelligence, can walk, and attend a mainstream school. However, some may need extra support for learning difficulties and physical problems, such as incontinence.
Around 166,000 people are living with spina bifida in the U.S., and help and support are available.
For those who need more information about spina bifida, the National Institute of Neurological Disorders and Stroke (NINDS) provide a list of useful organizations for contact for information, support, and research programs.