Cerebral Palsy

Cerebral palsy is a collective term describing a heterogenous group of neurological disorders occurring due to non-progressive brain damage. Cerebral Palsy is:

Epidemiology and Risk Factors

Prevalence:

  • Occurs in ~1/500 live births
    Relatively constant despite improves in obstetric care, likely due to ↑ survival of premature infants.

Risk factors:

  • Foetal pathogenic factors
    • Microcephaly
    • Trauma
    • Low birth weight
    • Prematurity
    • Peripartum hypoxia
      ~6% of cases.
    • Low APGAR score
    • Prenatal TORCH infections
  • Maternal pathogenic factors
    • Breech
    • Pre-eclampsia
    • Peripartum haemorrhage
    • Maternal hyperthyroidism
    • Foetal alcohol syndrome

Pathophysiology

Disruption of normal developmental changes in brain structure and organisation from a variety of potential causes, although clasically due to foetal hypoxia occurring during development or delivery.

Clinical Manifestations

  • Motor
    • Muscle spasticity
      Present in 80% of patients.
      • Leads to contractures due to differential growth between long bones and spastic muscle groups
    • Fixed flexion deformities
  • Sensory
    • Visual/auditory impairment
    • Abnormal touch and pain perception
  • Intellectual impediment
    Impairment present in 60%.
    • May be difficult to separate from motor problems affecting phonation

Grading

Categorised using the Gross Motor Function Classification System (GMFCS):

  • Evaluates mobility
  • Generally will not improve after 5th year of life
  • Uses five categories:
    • Level 1
      • Can walk, run, and climb stairs without rails
      • Limited speed, balance, and coordination
    • Level 2
      • Walk in most setting, climb stairs without rails
      • Limited by long distance, uneven terrain, confined or crowded spaces
    • Level 3
      • Walk with mobility device indoors, climb stairs with rails
      • Wheelchairs for distance
    • Level 4
      • Physical assistance or motorised wheelchairs in most settings
    • Level 5
      • Transported in manual wheelchair in all settings
      • Limited ability to maintain antigravity head and trunk postures

Management

Treatment is supportive, and consists of:

  • Improving posture
    • Reducing spasticity and spasms
      • Antispasmodics
        Baclofen.
      • Denervation techniques
        • Botulinum toxin
        • Radiofrequency ablation of dorsal horn ganglia
    • Alleviating contractures
      • Tenotomies
      • Osteotomies
      • Tendon transfer/lengthening
  • Treatment of coexistent disease

Anaesthetic Considerations

  • SET
    • ICU/ desirable
      Prone to:
      • Hypoxia
        • Aspiration
        • Atelectasis
      • Hypovolaemia
      • Hypothermia
  • A
    • High aspiration risk
    • Risk of loose teeth/poor dental hygiene
  • B
    • Respiratory impairment
      Combination of muscular weakness, skeletal deformities, and recurrent aspiration pneumonia.
  • C
    • Co-existent cardiac disease
    • Generally limited cardiorespiratory reserve
  • D
    • Difficulty communicating
    • Co-existent epilepsy
      Continue antiepileptics in perioperative period.
    • Analgesia very important and can be difficult to manage
      • Difficult due to nature of surgery and communication
      • Continuous analgesia preferred
      • Muscular spasm can be painful and debilitating
        • Diazepam 0.05-0.1mg/kg Q4H
      • Epidural or regional techniques excellent to reduce spasm, pain, and opioid demand
  • E
    • Fixed flexion deformities
      Limit or restrict positioning.
    • Risk of hypothermia
      Due to low levels of body fat and muscle.
    • Use of muscle relaxants
      • No restriction on suxamethonium
      • Offset of non-depolarising agent is ↑ due to upregulation of ACh receptors
  • G
    • GORD
      Risk of aspiration.
  • H
    • ↑ blood loss
      CP muscle contracts poorly when incised, leading to much greater volumes of blood loss.
      • Group and save for any major surgery

Complications

Associated conditions:

  • Neonatal respiratory distress syndrome
  • Respiratory impairment
    • Scoliosis and spinal deformities
    • Restrictive lung disease
      May in turn lead to pulmonary hypertension, and right heart/respiratory failure.
  • GORD/recurrent aspiration
    In turn associated with chronic lung injury from repeated aspiration. May be due to:
    • Swallowing difficulties
    • Oesophageal dymotility
    • Spinal deformities
    • Weak cough
  • Epilepsy
    50% may have focal or generalised forms.

References

  1. Prosser DP, Sharma N. Cerebral palsy and anaesthesia. Continuing Education in Anaesthesia Critical Care & Pain, Volume 10, Issue 3, 1 June 2010, Pages 72–76,