By Ms Viveka Chattopadhyay
It is important to understand that the term cerebral palsy is more of a description and not a specific diagnosis.It is a developmental disability in that it influences the way children develops. CP manifests itself very early in childhood development, usually before 18 months of age, with delayed or aberrant motor progress.
Cerebral means – brain Palsy means lack of muscle control.
The most accepted definition of cerebral palsy is “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”
A Lesion is any abnormality in the brain structure or function. The lesion is non-progressive but acts upon an immature brain interfering with its normal process of communication
It is a disability that affects movement and body position. It comes from brain damage that happened before the baby was born, at birth, or as a baby. The whole brain is not damaged, only parts of it, mainly parts that control movements. Once damaged, the parts of the brain do not recover, nor do they get worse.
Each child with cerebral palsy is different. The symptoms could vary from being mild- a slight awkwardness of movement of hand control to severe -virtually no muscle control, profoundly affecting movement and speech.
Classification of cerebral palsy
While the popular name for children with cerebral palsy is “spastic” it is not correct. Spastic cerebral palsy is just one category
Cerebral Palsy can be classified according to:
- The type of motor disorder (spasticity, dyskinesia, ataxia or mixed),
- The distribution of the motor disorder (hemiplegia, diplegia, quadriplegia) and
- The severity of the motor disorder
What is muscle tone?
Postural tone or muscle tone is the state of tension of muscles at rest and when we move – regulated under normal circumstances subconsciously in such a way that the tension is sufficiently high to withstand the pull of gravity i.e. to keep us upright but is never too strong to interfere with our movement
Muscle tone is what enables us to keep our bodies in a certain position or posture e.g. sit with our backs straight and head up.
For example when you extend your leg you must shorten or increase the tone of your thigh muscle while at the same time you are lengthening or reducing the tone of the muscles at the back of your leg. To complete a movement smoothly the tone in all muscle groups involved must be balanced.
Children with cerebral palsy have damage to the area of the brain that controls muscle tone. As a result they may have
- Increased tone leading to stiffness or hypertonia
- Reduced tone leading to floppiness or hypotonic
- Combination of the two – fluctuating tone
- Rigidity – sustained stiffness of limb
- Spasm – involuntary and possibly painful contractions of the muscles
- Tremors – repeated rhythmic uncontrolled movements of parts of the body
Classification of Cerebral Palsy
- Spasticity or hypertonic –
- Hypotonic –
- Fluctuating tone
- Dystonia - is sustained muscle contraction causing twisting and repetitive movements or abnormal postures. It can be seen in involuntary movements of the eyes, mouth neck, trunk arms, or legs.
- ATHETOID - is slow, writhing movement of face and extremities.
- Chorea – is brief, irregular movements.
- Ataxia – with or without spasticity
CP can further be classified according to the topography of the neuromuscular involvement:
- Hemiplegia: affects one side of the body
- Paraplegia or Diplegia: affects both legs (sometimes slight involvement in other extremities)
- Quadriplegia: affects all 4 extremities equally, as well as the trunk
- Triplegia – two sides affected but three limbs are involves usually one upper limb and both lower limbs
- Monoplegia (very rare): Involvement of only 1 extremity
So we can see that there are different classifications of cerebral palsy. Each of these types has different characteristics which will be dealt with in another article.
Mutch L, Alberman E, Hagberg B, Kodama K, Perat M V,. "Cerebral Palsy Epidemiology: Where are We Now and Where are We Going?" Developmental Medicine & Child Neurology 34.6 (1992).