The severity of the symptoms of spina bifida (myelomeningocele) usually depends on the following two factors:
- Where on the spine the opening occurs: an opening at the top of the spine is more likely to cause total paralysis (weakness) of the lower limbs and other mobility difficulties, compared with openings in the middle or at the base of the spine.
- Whether the baby also develops hydrocephalus (excess fluid on the brain): the baby is more likely to have learning disabilities if he or she develops hydrocephalus.
Types of symptoms
Spina bifida can cause a wide range of symptoms that can be grouped into three general categories:
- cognitive symptoms, such as difficulty reading or solving problems
- mobility symptoms, such as paralysis and muscle weakness
- bladder and bowel symptoms, such as bowel incontinence and urinary incontinence
Cognitive symptoms
The defects that occur in the neural tube also affect the development of the brain. The cortex (main part) of the brain may not fully develop in the structured, layered pattern it should, especially the frontal part. This leads to some cognitive problems. Abnormal brain development may also include Type 2 Arnold-Chiari malformations involving the cerebellum.
The cerebellum is the main area of the brain that is affected. It is the part of the brain that is thought to be responsible for important cognitive functions including:
- language processing
- physical co-ordination
Further brain damage can occur if hydrocephalus places excess pressure on the brain.
About 6 out of 10 children with spina bifida will have normal intelligence, although just over half of these will have some type of learning disability. A learning disability is a condition that affects how someone learns, understands and communicates. For more information, see the Live Well article What is a learning disability?
Children with spina bifida may have some specific learning disabilities. These include:
- a short attention span
- difficulty solving problems
- difficulty reading
- difficulty understanding some spoken language, particularly complicated language or rapid conversations between a group of people
- difficulty organising activities or making detailed plans
- difficulty understanding abstract concepts, such as logic or cause and effect
- difficulty with visual and physical co-ordination, for example tasks such as tying shoelaces or fastening buttons
Mobility symptoms
The brain controls all the muscles in the body with the nerves that run through the spinal cord. Any damage to the nerves can result in problems controlling the muscles.
Most children with spina bifida will experience some degree of paralysis in their lower limbs. If a child with spina bifida is partially paralysed, they may need to use a leg brace or a walking cane to help with their mobility. In cases of total paralysis, the child will require a wheelchair.
Paralysis can also cause other, associated problems. For example, as the muscles in the legs are not being used regularly, they can become severely weakened. As the muscles support the bones this weakness can affect bone development. This can result in:
- dislocated joints
- misshapen bones
- abnormal curvature of the spine (scoliosis)
See the Health A-Z topic about Paralysis for more information about the condition.
Bowel and bladder symptoms
As well as controlling your limbs, the nerves that run through your spinal cord also control your bowel and bladder. Specifically, they help to control the muscles of the sphincters that are found both in the bladder and the bowel.
Sphincters are rings of muscle that act as gates. They contract (squeeze shut) to keep urine and stools (faeces) in, and relax to let urine and stools out. Most people with spina bifida have limited or no control over their sphincter muscles. As a result of this, they experience urinary and bowel incontinence.
Urinary incontinence can take the form of a constant slow dribble of urine from the bladder.
If a child has bowel incontinence, they may experience periods of constipation (inability to empty their bowels) because they are unable to use their sphincter muscles to push stools out of their bowel. This can then be followed by episodes of diarrhoea (loose, watery stools) or soiling due to stools overflowing from the bowel.
See the Health A-Z topics about Bowel incontinence and Urinary incontinence for more information about these conditions.
