Cerebral Palsy (static encephalopathy)
Generic descriptive term for a broad heterogeneous group of clinical syndromes that is characterised by a chronic, static, non-progressive disorder of motor control due to an injury to the nervous system resulting in abnormalities of posture, muscle tone and motor control. Occurs in 1 to 5/1000 births – higher incidence in premature low birthweight infants.
Lesion causing cerebral palsy is non-progressive (not an active disease process), but resultant deformities can be progressive.
Aetiology:
Exact aetiology is not clear but risk factors well established
Many conditions can injure the developing brain:
• prenatal – infections (eg rubella); maternal alcohol and drug abuse; congenital deformity; genetic disorders; exposure to toxins or radiation; cerebral infarcts
• perinatal – prematurity; birth trauma; delivery complications
• postnatal – infections (eg meningitis); traumatic injury to CNS; anoxia (eg near drowning); acute metabolic disorders; blood group incompatibility
Factors associated with increased risk of cerebral palsy include
• respiratory distress syndrome
• decreased gestational age
• foetal malformations
• birth weight <2100g
• maternal intellectual impairment
• delayed first cry
• neonatal seizuresClinical features:
50% diagnosed in first 6 months.
Early diagnosis of mild cases is difficult; early clues include suspicion from perinatal history, psychomotor delay, asymmetry and retention of primitive reflexes, hypotonia, hyperreflexia, clonusTypes:
Cerebral palsy can be classified in a number of ways depending on tonus variations, distribution of tonus changes, severity, functional ability and type:Swedish Classification:
1. Spastic:
• hemiplegic (upper limb and lower limb on same side; contractures more severe distally; feet in equinus and/or varus; scoliosis is common; walking delayed); diplegic (both lower limbs more involved than upper limbs; most common type; ); monoplegic (single limb involved); triplegic; quadriplegic (all four limbs equally involved)
• can be symmetric or asymmetric
• most common type of motor dysfunction
• due to injury in pyramidal system
• usually present with hypertonia, rigidity, tendon reflexes exaggerated’ persistence of primitive reflexes
2. Dyskinetic:
• dystonic (bizarre positions and movements of limb); choreoathetotic (irregular writhing movements; variable muscle tone); hypotonic (lack or reduced muscle tone)
• impaired voluntary muscle control (slow writhing movements of flexion/extension and pronation/supination of feet and hands)
• assumed to be due to lesion in basal ganglia
3. Ataxic
• complete or partial lack of muscle coordination and decrease in proprioception balance problems
• due to injury in cerebellum
• rarer form
4. Mixed
• combination of types variety of movement disordersAssociated disabilities:
• intellectual impairments and learning disabilities are common; 65% have some degree of mental retardation (often correlates with motor handicap, but with a lot of individual variability)
• increased frequency of seizures
• up to a third have visual problems
• up to 10% have hearing defects
• 50% have speech and language problemsThe foot in cerebral palsy:
Undiagnosed mild cases may present to Podiatrist due to involvement of foot (most often a severe pes planus/pronated foot)
Pattern of foot deformity depends on type and extent of involvement. Most common is a spastic equinus caused by an unbalanced action of the extensor and flexor muscles with prolonged activity of the calf muscles
Torsional problems of the limbs are common.
Hallux valgus common- due to muscle imbalanceManagement:MultidisciplinarySocial and psychological servicesOccupational therapy -
Adaptive equipment (eg devices for standing); mobility aids (eg wheelchairs)
Night splintsBotulinum toxinCast correction
Equinus – if mild stretching and orthoses; if severe- surgeryOrthoses – used to facilitate function, inhibit reflex activity, prevention/correction of deformity
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