What is Spina Bifida

Spina bifida means 'split spine'. There are 33 vertebrae in the spine - if one or more of these don't form properly in early pregnancy, the nerves in the spine may be unprotected, leading to damage of the central nervous system.

This damage may cause mobility difficulties, bladder and bowel problems and, in more severe cases, paralysis below the affected part of the spine.

Disruption of the nervous system depends on how high up the spine the problem lies and how well the spinal cord below the defect works.

The cause of spina bifida is unknown, but it's thought to result from a combination of genetic and environmental factors.

Faults in the LPP1 gene have recently been identified as contributing to a severe form of the condition. A couple with an affected child has a one in 25 chance of another - and an affected person has a one in 25 risk of having an affected child.

In spina bifida occulta, which affects up to one in ten people, there may be visible signs of a dimple or small hair growth on the back. This is a mild form and rarely causes disability. In spina bifida cystica there is a sac or cyst (like a blister) on the back, covered by a thin layer of skin. The sac contains tissues that cover the spinal cord, cerebrospinal fluid and sometimes even the nerves and tissues of the spinal cord itself.

Antenatal blood tests can indicate the condition during pregnancy and 90 per cent of cases are picked up during ultrasound scans. If the defect is minor, usually no treatment is necessary. If the defect is more serious, then surgery to repair it is often performed.

In cases where hydrocephalus is present, surgery is sometimes necessary to drain the cerebrospinal fluid that builds up. Normally, this fluid would flow from the brain down the spinal column before being absorbed into the bloodstream, but if the spinal cord is damaged it can't escape. Physiotherapy helps with mobility. Regular use of a urinary catheter may be needed if there are difficulties passing urine normally. Emotional support is important, and special teaching may be necessary.

Taking a folic acid supplement from at least one month before conception through to the end of the 12th week of pregnancy can reduce the risk of spina bifida by up to 70 per cent. It's recommended that women of child-bearing age take a 400mcg supplement of folic acid every day, in addition to a dietary intake of 200mcg folic

Different types

Spina bifida occulta

Occulta is Latin for "hidden." This is one of the mildest forms of spina bifida although the degree of disability can vary depending upon the location of the lesion bone. In occulta there is no opening of the back, but the outer part of some of the vertebrae are not completely closed. The split in the vertebrae is 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, a lipoma, a dermal sinus or a birthmark.

Many people with the mildest form of this type of spina bifida do not even know they have it(Sufferers of spina bifida occulta have been noted to have achieved careers as demanding as the British Special Air Service - even with tethering), or symptoms do not appear until later in life. People with spina bifida occulta may suffer from a tethered cord from (diastematomyelia) or the lipoma in lipomyelomeningocele, when the spinal cord gets trapped below the affected level of the growing spine. This may cause neurological problems of the legs and bladder.

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.

Spina bifida cystica (myelomeningocele)

In this, the most serious form, the unfused portion of the spinal column allows the spinal cord to protrude through an opening in the overlying vertebrae. The meningeal membranes that cover the spinal cord may or may not form a sac enclosing the spinal elements. Superficially, the cyst may resemble an unrelated defect, sacrococcygeal teratoma. Spina bifida with myeloschisis is the most severe form of spina bifida cystica. In this defect, the neural folds fail to meet and fuse leaving the spinal cord open and the involved area represented by a flattened, plate-like mass of nervous tissue with no overlying skin or membrane. The unfused elements of the spinal cord can be surgically closed along with the overlying muscle and skin shortly after birth (see treatment section below).

The incompletely closed portion of the spinal cord and the nerves which 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 higher the level of the defect the more severe the associated nerve dysfunction and resultant paralysis. People may have ambulatory problems, loss of sensation, deformities of the hips, knees or feet and loss of muscle tone. Depending on the location of the lesion, intense pain may occur originating in the lower back, and continuing down the leg to the back of the knee.

Most children and adults with this condition experience problems with bowel and bladder control since the nerves which control these functions originate at the lowest part of the spinal cord. This may result in incontinence from neurogenic bladder.

Many individuals with spina bifida will have an associated abnormality of the cerebellum, called the Arnold Chiari II malformation. In affected individuals the back portion of the brain is displaced from the back of the skull down into the upper neck. In approximately 90 percent of the people with myelomeningocele, or hydrocephalus will also occur because the displaced cerebellum interferes with the normal flow of cerebrospinal fluid.

The myelomeningocele (or perhaps the scarring due to surgery) tethers the spinal cord to the enveloping vertebra. In some individuals this causes significant traction on the spinal cord and can lead to a worsening of the paralysis, scoliosis, back pain, or worsening bowel and/or bladder function.

Meningocele

The least common form of spina bifida is a posterior meningocele (or meningeal cyst). In a posterior meningocele, the outer faces of some vertebrae are open (unfused) and the meninges are damaged and pushed out through the opening, appearing as a sac or cyst which contains cerebrospinal fluid. The spinal cord and nerves are not involved and their function is normal.

In an anterior meningocele, the inner faces of vertebrae are affected and the cyst protrudes into the retroperitoneum or the presacral space. Apart from spina bifida, causes of meningocele include teratoma and other tumors of the sacrococcyx and of the presacral space, and Currarino syndrome. Usually a meningocele has no negative long-term effects, although there are reports of tethered cord.

True Life Account