Clinical characteristics of cerebral palsy

Cerebral palsy may present in infancy and early childhood as:

  • asymmetric movement patterns
  • delayed motor milestones
  • particular behavioural or functional issues (eg irritability, severe feeding difficulties, severe sleep disturbance)
  • decreased or increased muscle tone.

Many infants who develop cerebral palsy have normal muscle tone during their first few months of life. The onset of spasticity and dyskinesia may be gradual with dyskinesias (ie atypical involuntary movements) usually not appearing until 9 to 18 months. Some people with cerebral palsy have no other associated issues, but many have neurological, cognitive, sensory, gastrointestinal, and oral and dental health issues (see Common health problems in people with cerebral palsy).

Spinal lesions and some metabolic or progressive neurodevelopmental disorders may present in a similar manner to cerebral palsy, and must be excluded.

Cerebral palsy may be classified according to the:

Figure 1. Types of motor disorders in cerebral palsy

Spasticity

  • most common type of motor disorder; occurs in about 70% of people with cerebral palsy who describe tightness or stiffness of affected muscle groups
  • usually results from damage to the motor cortex
  • increased muscle tone has a characteristic clasp-knife quality, impaired voluntary movement, often with weakness
  • contractures, subluxations and dislocations may result from the imbalance of muscle action over joints

Dyskinesia (dystonia or athetosis)

  • occurs in about 6% of people with cerebral palsy
  • usually results from damage to the basal ganglia
  • usually affects the whole body (including all 4 limbs)
  • involuntary movements of the muscles in the trunk, arms, legs, neck and face; movements can be slow and writhing or fast and jerky, and tend to increase when the person is tense or stressed, decrease at rest and be absent in sleep
    • dystonia—sustained muscle contractions that frequently cause twisting or repetitive movements or abnormal postures
    • athetosis—slow writhing movements involving the distal parts of the limbs

Ataxia

  • occurs in about 6% of people with cerebral palsy
  • relates to damage to cerebellar function
  • characterised by disorders of balance and intention tremor

Mixed

  • a mixture of more than one type of motor disorder is common, particularly the combination of spasticity and dyskinesia
Figure 2. Gross Motor Function Classification System (GMFCS)

The Gross Motor Function Classification System Expanded and Revised (GMFCS-E&R) is a five-level tool used to categorise the gross motor function of children and young people with cerebral palsy; it can be used in children younger than 2 years and in young people up to 18 years.

By looking at movements such as sitting, walking and use of mobility devices, it can give families and health practitioners:

  • a clear description of a child’s current motor function
  • an idea of future needs of the child for equipment and mobility aids.

A child or young person older than 5 years will usually not improve their GMFCS-E&R level and will continue to require equipment suitable for that level or higher.

For more information, see here.