Cerebral palsy is a general term describing conditions that cause movement problems. The most common type is spastic cerebral palsy where the muscles are stiff and rigid in one or more limbs. The underlying problem is damage to, or faulty development of, part of the brain. This usually occurs sometime before birth. Cerebral palsy ranges from mild to severe. In some cases there are associated problems such as learning difficulties and epilepsy. The main aim of treatment is to limit limb deformities as far as possible, and to minimise any disability.
What is cerebral palsy?
Cerebral is another word for the brain. Palsy means a complete or partial loss of the ability to move a body part. So cerebral palsy means loss of ability to move a body part because of a problem with the brain.
Cerebral palsy is not a single condition. It is an umbrella term used to describe a group of conditions that cause movement problems. Although the main problem is with the muscles in one or more parts of the body, the condition is caused by damage or faulty development in a part of the brain. The part of the brain affected is that which sends messages to muscles. It controls movement and co-ordination. The damage or faulty development usually occurs as a baby is developing in the womb. Sometimes it occurs during, or shortly after, birth.
If someone has cerebral palsy, it means that they are not able to control some of the muscles in their body in the normal way. Depending on the type of cerebral palsy and the area of brain affected, a child may not be able to walk, move, talk, eat, or play in the same ways as other children.
The following are more technical medical definitions of cerebral palsy:
- "Cerebral palsy is an umbrella term covering a group of non-progressive, but often changing, motor impairment syndromes secondary to lesions or anomalies of the brain arising in the early stages of development." (Mutch et al, 1992)
- "Cerebral palsy describes a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain." (Bax et al from International Workshop on Definition and Classification of Cerebral Palsy, 2004)
What are the main types of cerebral palsy?
Cerebral palsy is classified into four main types - spastic, athetoid, ataxic and mixed. The type of cerebral palsy that occurs depends on the exact part of the brain that is affected.
Spastic cerebral palsy
This type of cerebral palsy occurs in about 7 in 10 cases. Spastic means that the affected muscles are more stiff than normal. How stiff an affected arm or leg is, can vary greatly from case to case. Movements of an affected arm or leg are stiff and jerky. Some muscles may become permanently shortened and stiff. This is called contracted.
There are different words that are used to describe the type of types of spastic cerebral palsy. For example:
- Hemiplegia - means that the leg and arm of one side of the body are affected.
- Diplegia - mans that both legs are affected. Arms are not affected or are only mildly affected.
- Quadriplegia - means that both arms and legs are affected. Arms are equally or more affected than legs.
Athetoid or dyskinetic cerebral palsy
This type occurs in about 2 in 10 cases. Some people with this type of cerebral palsy have slow, writhing movements of the hands, arms, feet, or legs. Some people have sudden muscle spasms. These movements cannot be controlled and so are involuntary. Sometimes the tongue or facial muscles are affected. The stiffness (tone) of the muscles can vary from too high to too low. As a result, people with athetoid cerebral palsy have difficulty in staying in one position. They may also be unable to use their arms or hands properly - for example, to hold objects.
Ataxic cerebral palsy
This type occurs in less than 1 in 10 cases. People with ataxic cerebral palsy have difficulties with balance and fine movement. This can mean loss of balance or being unsteady when walking. It could also make doing fine tasks with their hands difficult, such as writing. The muscle tone is usually decreased. That is, they do not tend to be stiff.
Mixed cerebral palsy
People with mixed cerebral palsy have a combination of two or three of the above types. It is most often a combination of spastic and athetoid cerebral palsy, which results in stiff muscle tone and involuntary movements.
How serious is cerebral palsy?
Cerebral palsy can range in severity from mild to severe. For example, a person with mild spastic hemiplegia is likely to be fully mobile, active and independent, but have a slightly abnormal walking movement (gait). He or she may have some difficulty in using one hand, and one foot may drop or drag. At the other extreme, someone with severe quadriplegia will be wheelchair-bound and need help with daily living tasks. Many people are in between these two extremes. Everyone is different and needs assessing by a specialist team.
It may seem surprising that in the definition of cerebral palsy it is said to be a non-progressive disorder. But this means that the damage to the brain is done and the damage doesn't worsen. (This is in contrast to some other brain disorders of children.) However, the effect on the body is progressive in that the spasticity of the muscles can have a progressive effect on bones and joints. For example, the stiffness of the muscles in spastic cerebral palsy can gradually lead to permanent fixed contractures of joints in arms and legs. Some joints may eventually become fixed in a flexed position as a child becomes older. A main aim of treatment for spastic cerebral palsy is to keep to a minimum the effects of the muscle stiffness.
What causes cerebral palsy?
In most cases the cause of the damage to the brain is not known. Many times it may simply be a chance error in the way the brain develops. Genetic (hereditary) factors may play a part. However, some factors are known to increase the risk of developing cerebral palsy:
- Preterm birth (premature babies) - in particular, babies born before 28 weeks of development.
- Babies that are part of twins, triplets, or more.
- Infections of the pregnant mother, such as rubella, chickenpox and toxoplasmosis, may be a cause in some cases.
- Severe jaundice in a newborn baby can be a cause.
- There is an increased risk of having a child with cerebral palsy in mothers who smoke, drink a lot of alcohol, or take street drugs such as cocaine.
It was thought that problems with labour and delivery were the main cause of cerebral palsy. However, this is now known to be incorrect. It is thought that less than 1 case in 10 is due to problems around the birth of a baby. For example, severe prolonged lack of oxygen during birth may be a cause in a small number of cases.
Problems can occur after birth. For example, meningitis or other brain infections that occur in young babies can cause brain damage resulting in cerebral palsy.
How common is cerebral palsy?
About 1 in 500 babies born in the UK have cerebral palsy. The number of cases per year (the incidence) has not changed much over the period of 50 years or so. The health and care of mothers have improved in this time and some causes of cerebral palsy have decreased. However, more babies are being born prematurely and surviving. A proportion of these will have cerebral palsy. This (together with the cause in most cases not being known) is probably why the number of cases has not changed much over the period of 50 years or so.
How is cerebral palsy diagnosed?
Cerebral palsy is not usually diagnosed at birth. Babies with severe cerebral palsy may have signs at birth that are obvious, such as very abnormal muscle tone. However, most children are diagnosed between the ages of six months and two years. The first thing that is usually noticed is that a child is not developing at the normal rate. The muscle tone may feel abnormal, or the baby may start to have abnormal movements.
As a rough guide, a child with normal development will be usually be able to:
- Sit unaided at six months.
- Crawl by eight months.
- Pull to stand by 12 months.
- Walk by 15 months.
There are variations and some babies are normal, but late developers. However, a child who is late in these developmental milestones should usually be assessed for cerebral palsy. The diagnosis can usually be made by a child specialist, from the symptoms, signs and delay in development.
Additional tests such as a brain scan may be done.
Other problems associated with cerebral palsy
Sometimes the damage to the brain affects other aspects of brain function, as well as problems with muscles.
About half of children with cerebral palsy have some degree of learning difficulty. The severity can vary. The other half will have normal intelligence or above. About half of children will have some degree of speech problems. Sometimes a child with difficulty in speaking may be thought of as having low intelligence, whereas in fact they have normal or high intelligence. About 1 in 3 people with cerebral palsy will also have epilepsy. Some children also have problems with hearing, vision, eating and drinking.
What is the treatment for cerebral palsy?
Children with cerebral palsy should be under the care of a specialist team which includes various healthcare professionals such as doctors, nurses, physiotherapists, occupational therapists and speech therapists. There is no cure for cerebral palsy but much can be done to limit the degree of disability that may have occurred if treatment had not been given.
The mainstay of treatment is physiotherapy. One main aim of physiotherapy is to (as far as possible) prevent or limit the contractures and limb deformities that can occur with spastic cerebral palsy.
A physiotherapist may use various techniques such as exercises, mobility training, orthotics (braces, splints, etc), and other equipment. A physiotherapist can show parents and carers the correct positioning of joints and stretching exercises to do. If advised, these must be done regularly for the best chance of minimising problems. Another aim is to enhance children's independence skills, such as moving on the floor, dressing and feeding independently.
Medicines usually have a limited role. For example, botulinum toxin injections (in conjunction with physiotherapy) are used in some cases to relax spastic muscles. The most commonly injected muscles are the hamstrings, calf muscles and muscles that pull the hips together (hip adductors). The effect of a botulinum injection lasts 3-6 months.
Other muscle-relaxing medicines such as baclofen are sometimes used. Children with associated epilepsy need medicines to prevent seizures.
Depending on the type and degree of muscle contracture, an operation may help - for example, an operation to loosen tight muscles or to correct a joint deformity. The aim is to give more flexibility and control of the affected limbs and joints. Most operations are performed on the muscles around the hips, knees, and ankles.
Other treatments and therapies
These may include: occupational therapy, speech therapy, vision aids, dentistry, communications aids, nutritional advice and promoting sport. Assistive technology is being increasingly used. There is a range of devices and gadgets that can help with communication, mobility and daily tasks.
What is the outlook (prognosis)?
As mentioned above, the severity of cerebral palsy can range from mild to severe. It is difficult to predict the future for each individual case. "Will my child be able to walk?" is one common question that parents ask. This may be difficult to answer when the child is very young, but as a very general guide:
- Almost all children with hemiplegia will walk.
- About 3 in 4 diplegic children will walk.
- Less than 1 in 4 quadriplegic children will walk.
This is very general. Your specialist will be able to give advice on your individual case. Also, treatment such as physiotherapy can make a difference to the eventual outcome.
Dr Tim Kenny
Dr Hayley Willacy
Dr Helen Huins