What is Spina Bifida?
Spina bifida literally means ‘split spine’
Spina bifida is a relatively common condition, which affect about one in every 1,000 children born per year in Ireland. Ireland has once of the highest incidences of spina bifida births in the world. Spina is the most common neural tube defect (NTD) which causes incomplete development of the spinal cord.
The Central Nervous System (CNS)
The nervous system is essentially a biological information highway, and is responsible for controlling all the biological processes and movement in the body. At the centre of this system is the Central Nervous System (CNS), consisting of the brain and the spinal cord. It is responsible for receiving and interpreting messages, and also sends out messages, either consciously or unconsciously.
The spine is made up of separate bones called vertebrae, which normally cover and protect the spinal cord. With spina bifida, some of these vertebrae are not completely formed. Instead, they are split and the spinal cord and its coverings usually protrude through a sac-like bulge on the back, covered by a thin membrane.
The Neural Tube
In the developing vertebrae, the neural tube is the embryo’s precursor to the central nervous system. The CNS and spine develops between the 14th and 23rd day after conception. Spina bifida occurs when the neural tube fails to close correctly. The vertebrae also fail to close in complete rings around the affected portion of the spinal cord. This leaves a gap posteriorly (at the back), involving one or more vertebrae. Spina bifida may occur in one or more of the vertebrae but it is most common around waist-level.
Types of Spina Bifida
Spina Bifida Occulta
This is known by some people as ‘hidden’ spina bifida. The split of the bone of the spine is small and the spinal cord and main nerves cannot bulge out and so little or no damage is done. The only thing to see on the back may be a dimple, tuft of hair, or a red mark. Someone with spina bifida occulta may not have any problems at all and probably wouldn’t know they had this condition unless an x-ray of the back was taken. Antenatal tests usually do not detect this type of spina bifida before birth.
When more than one vertebrae is involved and these vertebrae have not developed fully, spina bifida occulta can be referred to as Occult Spina Dysraphism (OSD). This may cause the person’s back to be slightly short and often stiff. The natural curves of the back may be exaggerated and there may be an abnormal curvature of the spine or a bony protrusion in the midline of the back. There may be a bony peg at one level of the spinal canal, or a fibrous band running across it and dividing it in two. The spinal cord may become excessively wide because of abnormal fat or fibrous tissue lying inside the spinal cord.
Meningocele (Pronounced men-in-jo-seal)
In this type of spina bifida, the split in the bones is not big enough for the spinal cord to come through but a ‘balloon’ of skin filled with fluid and blood vessels bulges out. This fluid which comes from around the spinal column is called cerebrospinal fluid (CSF). Usually the nerve supply is not affected. The degree of disability is usually less severe than myelomeningocele, but can only be determined as the child develops.
Myelomeningocele (Pronounced my-lo-men-in-jo-seal)
This is the most common form of spina bifida. The areas affected are dependent on the location of the split. The split contains the spinal cord and nerves are held in the sac which will also be filled with fluid. The spinal cord and nerves become exposed and the degree of damage will determine the extent of the disability. A myelomeningocele is most frequently found in the lumbar area, but can occur anywhere along the spine.
Encephalocele (Pronounced en-cef-a-lo-seal)
In the minority of cases of NTDs, the split is high up and involves the back of the head (skull). There is a balloon-like swelling but this does not contain important nerves of the spinal column. Some encephaloceles are small, covered with skin and the children usually grow up without major implications. Sometimes, however, it is large and may contain some of the brain and this can severely affect the baby’s eyesight and can cause learning disabilities. Sometimes, however, they can contain large volumes of brain tissue, so that the remaining brain is small, poorly developed and severely hydrocephalic.
Anencephaly (Pronounced an-en-cef-a-lee)
Anencephaly results in only minimal development of the brain. Often the brain lacks part or all of the cerebrum (the area of the brain that is responsible for thinking, vision, hearing, touch, and movement). Due to the extent of under-development of the brain, babies affected by this condition are unlikely to survive outside the uterus, may be stillborn, or die shortly after birth. Treatment is supportive.
What are the Effects of Spina Bifida?
In the past, spina bifida was considered to be potentially fatal. Yet with a greater level of medical understanding, it is now possible to treat symptoms and create a higher quality of life.
The effects of spina bifida vary enormously, depending on the type, the location, and the severity of the condition. There are a number of lifestyle and treatment factors to take into consideration when focusing on a higher quality of life.
A small minority of people with spina bifida are allergic to latex. This is an allergy to products made from natural rubber latex. Products made from natural rubber latex usually contain a number of chemicals and some people are allergic to the chemicals rather than the latex itself.
Sex and Reproduction
The male and female reproductive organs develop normally in the person with spina bifida. Nerve damage may, in some cases, affect the function of the reproductive organs. The desire to have sexual intercourse or a sexual relationship can be as strong in someone with spina bifida as anyone else. Many people with spina bifida and hydrocephalus live happily with a partner enjoying a satisfying sexual relationship, and have families of their own. It is advisable to take the higher dose (5 milligrams) of folic acid prior to conception. Urinary and bowel incontinence can be an issue, but they do not make sexual relations impossible.
A pressure sore is a sore on an area of skin where there is continuous heavy pressure, leading to a reduced flow of blood to the area causing tissue to erode and die. People with spina bifida, especially wheelchair users, are prone to developing pressure sores because of insensitive skin or paralysis.
Paralysis and loss of Sensation
In the case of myelomeningocele the spinal cord protrudes from the spine throughout the pregnancy and is closed by surgery shortly after birth. As a result, the spinal cord is almost invariably damaged and defective, the nerves being disorganised and broken. As a result, messages from the brain (controlling and initiating movement) and those from the body to the brain (giving the sensations of touch, pain, and position) are impaired. However, paralysis, muscle weakness, and loss of sensation occur only at the level of the lesion and downward. Due to lack of skin sensation and decreased mobility, skin tissue breakdown may occur resulting in pressure sores. IN most cases the head, upper trunk, and arms are not affected. The level of impairment varies considerably depending on location and nerves involved.
Lack of Bladder and Bowel Control (Incontinence)
The nerves that control the bladder and bowel are located in the lowest region of the spinal cord. Consequently, incontinence is a major problem particularly in the case of myelomeningocele. Lack of bladder control presents two immediate dangers: infection and back pressure on the kidneys which, without proper management, can lead to renal problems.
Hydrocephalus literally means ‘water on the brain’ and is a potentially dangerous condition involving excessive accumulation of spinal fluid within the brain caused either by over production of the fluid or more usually by an obstruction to its normal circulation. While it is a complication of spina bifida occurring in approximately 90% of cases, hydrocephalus is by no means exclusive to spina bifida.
Scoliosis describes a “twist” or curvature in the spine. Scoliosis can occur relatively commonly in a person with spina bifida, due to the spine not forming completely and therefore causing the spine to twist.
Obesity is one of the most common nutritional problems in people with spina bifida. Obesity may be a cosmetic concern for affected individuals. More importantly, however, obesity is a major health threat. In adults, obesity has been linked to high blood pressure, diabetes, osteoarthritis, abnormal cholesterol metabolism, heart disease, sleep apnoea, and psychological problems. Similar health consequences occur for children and adolescents who are obese. Psychological problems are of special concern for developing children, who may be negatively stigmatised by others if they are obese and thus develop poor self-esteem, greater risk for isolation from peers, and depression.
Individuals with spina bifida may become more prone to mental health issues including depression and anxiety. This can present as mood swings, lower self-worth, self-hatred, self-harming, aggressive behaviour, insomnia, and lack of motivation. Professional help may be needed to cope with these symptoms.
Spina Bifida Hydrocephalus Ireland (SBHI) offers a number of supports to individuals, families, carers, and professionals through our Family Support Service. Please see our Family Support Service leaflet for more information.