CEREBRAL PALSY
Definition
Cerebral palsy (CP) has been used as an umbrella term for varying disorders. Loosely translated, CP means "brain paralysis." Generally, it refers to motor or postural abnormalities that are noted during early development. These anomalies are thought to be associated with prenatal, perinatal, or postnatal events of varying aetiologies (often multifactorial in nature). CP is defined as a persistent disorder of movement and posture caused by non-progressive defects or lesions of the immature brain. A clinical presentation of CP may result from an underlying structural abnormality of the brain; early prenatal, perinatal, or postnatal injury due to vascular insufficiency; toxins or infections; or the pathophysiologic risks of prematurity. Evidence suggests that prenatal factors result in 70-80% of cases of CP. In most cases, the exact cause is unknown but is most likely multifactorial. During the prenatal period, abnormal development may occur at any time (whether due to a genetic abnormality, toxic or infectious aetiology, or vascular insufficiency).
Aetiology / Risk Factors
- Premature delivery
- Injury to the infant during or prior to birth
- Loss of oxygen supply to the infant during or prior to birth
- Kernicterus (CP from acute hyperbilirubinaemia)
- Incidence 1.5-2.5 per 1000 live births
Maternal risk factors include:
- Maternal thyroid disorder, long menstrual cycle, previous pregnancy loss, previous loss of newborn, maternal mental retardation, maternal seizure disorder, and history of delivering a child of less than 2000g birth weight or with motor deficit, mental retardation, or sensory deficit
Pregnancy risk factors include:
- Polyhydramnios, treatment of the mother with thyroid hormone, treatment of the mother with oestrogen or progesterone, a foetus with congenital malformation, maternal seizure disorder, severe proteinuria, high blood pressure, and bleeding in the third trimester.
Symptoms & Signs
Classic presentations of CP include the following:
Spastic hemiplegic
- One-sided upper motor neuron deficit
- Arm generally affected more than the leg; possible early hand preference or relative weakness on 1 side
- Oromotor dysfunction
- Specific learning disabilities
- Possible unilateral sensory deficits
- Visual field deficits (e.g., homonymous hemianopia) and strabismus
- Seizures
Spastic diplegic
-
Upper motor neuron findings in the legs more than the arms
- Scissoring gait pattern with hips flexed and adducted, knees flexed with valgus and ankles in equinus (resulting in toe-walking)
- Learning disabilities and seizures less commonly than in spastic hemiplegia
Dyskinetic (extrapyramidal)
- Early hypotonia with movement disorder emerging when aged 1-3 years
- Arms more affected than legs
- Deep tendon reflexes usually normal to slightly increased
- Some spasticity
- Oromotor dysfunction
- Gait difficulties
- Truncal instability
- Risk of deafness in those affected by kernicterus