Paediatrics: Cerebral palsy

Cerebral palsy

·  Definition: a chronic disorder of movement and/or posture that presents early (i.e. before the age of 2yrs) and continues throughout life.

·  Causation: CP is caused by static injury to the developing brain.

·  Associations: children with CP are at increased risk of impairments including vision, hearing, speech, learning, epilepsy, nutrition, and psychiatric.

·  Clinical forms: most children will have a mixed disorder, but some can have pure components of spasticitiy, choreoathatosis, or very rarely ataxia.

Spastic CP

This is the commonest label and children can be hemiplegic, diplegic, or quadriplegic. Monoplegic cerebral palsy is extremely rare, and normal-ly a misdiagnosis as the clinician has not examined the arm effectively. Spasticity is a stretch-related response characterized by a velocity-depen-dent, increased resistance to passive stretch. It is caused by disruption to the spinal reflex arc by the upper motor neuron. It will affect all the skeletal muscles and causes the following:

·  Increased tone and reflexes.

·  Clasp knife phenomenon on rapidly stretching tendons often described as a ‘catch’.

·  Leg: ankle plantar flexion, and either valgus or varus deformity of foot.

·  Hip: flexion, limited adduction, and often internal rotation.

·  Wrist: flexed and pronated.

·  Elbow: flexed.

·  Shoulder: adducted.

·  Bulbar muscles may be spastic giving dysphagia and dribbling.

Choreoathetosis

Condition presents as a 4-limb disorder with greatly increased tone while awake and less so during the early stages of sleep. These patients do not have the stretch-related response and increased reflexes of pure spastic CP. However, there may be combinations of these features in mixed CP. As the child matures they will often develop fixed reduction in joint range of movement and then the signs will be more difficult to distinguish from those of spastic CP. They almost always have bulbar problems.

Ataxic cerebral palsy

This form of CP is extremely rare and poorly understood. It is also known as the disequilibrium syndrome. Children have a congenital ataxia giving them a striking loss of balance in the early years (i.e. disequilibrium). They often have a mild diplegia and are thought to be aetiologically distinct from the other types of CP, where hypoxia and ischaemia are thought to be causal factors. It may be that congenital ataxia is a better than applying cerebral palsy—see Investigation of CP.

Investigation of CP

·  CP is a descriptive term of disability and not the cause.

The key factor is a static neurological insult.

·May well be given in the history. Beware associations being used to explain CP; factors such as prematurity may lead to complications, but the child needs a comprehensive assessment to exclude other disorders—esp. progressive ones. All children need investigation.

·History: the cause may be evident from a good history, in particular for prematurity and periods of hypoxic ischaemia.

Imaging: MRI scan of the brain, with particular reference to the pyramidal tracts in children with spasticity and the basal ganglia in others (Fig. 14.8). If there is a problem in the history, e.g. hypoxic ischaemic encephalopathy, then there should be signs of this on the imaging. Where imaging does not confirm a static insult, seek expert opinion.

Management of CP

·Complex multidisciplinary input.: the primary therapists are the child’s carers as they will provide at least 90% of the therapy to the child. In the early years, experts in speech, physiotherapy, and occupational therapy will support this treatment.

·Posture and movement: optimize function by improving symmetry, joint ranges, muscle length and power. Treatments and support include stretching exercises, orthoses (e.g. ankle foot orthosis), wheelchair for mobility, sleeping and standing systems, and botulinum toxin (Botox) to the gastrocnemius. Surgery is used as a last resort.

·Communication: with speech therapy and aids.

·Independence with a tailored educational program, aids under supervision from occupational therapy.

·Cognition and learning support: with a tailored educational programme.

·General medical: watch for seizures, constipation, malnutrition, and behavioural or psychiatric disturbance.

Note: Dopamine-responsive dystonia will very rarely present with an unexplained diplegia and normal MRI. All these children will need a trial of co-careldopa with a gradually increasing dose of up to 10mg/kg/day of the dopa component over 3mths. If there is not a significant improve-ment then the child is unlikely to be dopa-sensitive.