Associated impairments and medical complications
Children with meningomyelocele are likely to have bowel problems secondary to uncoordinated bowel contractions, ineffective closure of the anal sphincter and loss of rectal sensation. This results in constipation and “overflow incontinence” and soiling.
Children with a meningomyelocele can have a normal IQ and some have mild learning disability. A few have severe learning disability and this is usually due to shunt infection (if they have hydrocephalus) or prenatal hydrocephalus.
Even if they have a normal IQ, they tend to have impairments in perceptual skills, organisational abilities, attention span, speed of motor response, memory and hand function and many have a specific learning disability such as dyslexia (difficulty with reading), dyscalculia (difficulty with maths) and dysgraphia (difficulty with writing).
They usually have more difficulty with maths than reading. They also often have difficulty with planning, initiating and sequencing tasks. About one third of children with meningomyelocele have ADHD.
About 15% of children with meningomyelocele develop epilepsy. Seizures are usually generalised tonic clonic and respond well to anti – epileptic medication. A blocked or infected shunt in children with hydrocephalus may result in a new type of seizure developing or an increase in seizure frequency.
More than half of children with open defects develop an allergy to latex. It is more common in children who have had frequent surgical procedures and the risk increases as the child gets older. It may be life threatening. Rarely children with latex allergy have sensitivities to certain foods such as bananas, water chestnuts, tomatoes and kiwi fruits.
Meningomyeloceles at higher levels are associated with greater muscular weakness and greater mobility impairment. All children will have significant delay in walking. Most children will not be able to walk independently after adolescence.
| Level of defect | Mobility status |
|---|---|
| Thoracic (T1 - 12 ) or upper lumbar (L1 - 2) level | Unlikely to be able to walk but some may do so with considerable bracing and support. Most use a wheelchair within a few years of birth. |
| L3 – L4 level | Able to walk but often require bracing up to the hip and crutches. As they approach adolescence they are likely to rely increasingly on a wheelchair. In adult life almost all use wheelchairs. |
| Low lumbar (L5) or sacral level | Usually learn to walk well by the age of 2 or 3 years with ankle bracing or no bracing at all. In adult life most able to walk independently but many elect to use a wheelchair if walking for considerable distances. |
Other factors that affect mobility include cognitive function, complications including joint contractures and shunt infections, involvement of the parents and the treatment programme.
Children with high level defects are unlikely to walk, although their mobility is likely to be better if they have no cognitive impairment, undertake regular walking exercises and have parents who are committed to the exercises. Children with high level defects and significant cognitive impairment are unlikely to walk and should commence early wheelchair training.
Children with meningomyelocele have primary musculoskeletal problems that include muscle weakness, reduced joint mobility and leg movement and reduced sensation and awareness of the legs and severity of these depend upon the level of the lesion. As a consequence, they may have secondary problems which include joint stiffness, loss of muscle length, contractures and deformities, that include spinal deformities. These problems may deteriorate with age.
Joint deformities include club foot (talipes equinovarus) and hip deformities, for example fixed flexion deformity or predisposition to dislocation of the hip.
Children with meningomyelocele are also prone to osteoporotic fractures because of loss of muscle strength and inactivity. Fractures may occur after orthopaedic surgery, especially after prolonged casting.
As people with spina bifida age, they may develop osteoarthritis of the hips and knees secondary to abnormal sensation and gait. Almost 90% of children with a meningomyelocele above the sacral level have a spinal deformity. These include scoliosis (curvature), kyphosis (hump) or kyphoscoliosis (combination of the two). They may be present before birth (congenital) or develop later in childhood (acquired). If untreated, spinal deformities may interfere with sitting, walking and possibly breathing. Spinal deformities may be painful, and the pain may interfere with function.
A deterioration in strength and bowel or bladder function may be due to one of following reasons -:
- Malfunctioning or blocked ventricular shunt
- Tethered spinal cord
- Rarely syringomyelia (development of cysts in the centre of the spinal cord)
The Chiari II malformation may also become symptomatic.
If identified early, all of these problems may require treatment.
Children with meningomyelocele are prone to develop pressure sores (decubitus ulcers) on weight bearing surfaces, for example feet and buttocks, because of insensitivity to pain. These become more frequent during adolescence. Preventative measures are most important together with early treatment. Failure to treat early may require prolonged hospitalisation.
Physical difficulties can lower the child’s self esteem and impair the establishment of peer relationships. Depression is likely to be more common in children with meningomyelocele than the general population.
Children with myelomeningocele frequently have disordered sleeping. This may be due to factors such as pain, spasticity etc. It may cause affected children to be tired during the day, affecting their concentration and their ability to function at school.
The nerves that control the bladder and rectum leave the spinal cord in the lower sacrum. For this reason virtually all children with meningomyelocele, (including those with sacral lesions and normal leg movement) have bladder and bowel dysfunction. They tend to be incontinent of urine and are also unable to completely empty the bladder which may predispose to infections of the bladder and kidneys and long term kidney damage.
Children with meningomyelocele have a higher incidence of malformations of the kidneys, such as horseshoe kidney and absent kidney than the general population.
About 20% of children with meningomyelocele have a squint (strabismus). Squint can also result from a rise in intracranial pressure caused by a malfunctioning shunt. Visual impairment can also be caused by an abnormality of the visual gaze centre in the brain resulting in squint or nystagmus.
Weight, stature and endocrine abnormalities
Children with meningomyelocele are at increased risk for obesity (about two thirds are significantly overweight). They are also at increased risk for short stature, growth hormone deficiency and other endocrine abnormalities.
