What is the definition of cerebral palsy (CP) and at what age is it typically defined in pediatric patients?

Definition of Cerebral Palsy

Cerebral palsy is defined as "a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain." 1

Core Diagnostic Criteria

• CP is fundamentally a clinical diagnosis based on a combination of clinical and neurological signs, not a single disease entity but rather a clinical description of children who share features of a non-progressive brain injury acquired during critical developmental periods. 1, 2

• The disorder encompasses permanent motor impairments resulting from brain disturbances that are non-progressive in nature, though secondary complications can develop over time without appropriate intervention. 1

• The brain injury or lesion must have occurred during the antenatal, perinatal, or early postnatal period of development. 2

Age of Diagnosis

Diagnosis traditionally occurs between 12 and 24 months of age, though advances now allow for earlier detection. 1

Early Detection Timeline

• Before 5 months' corrected age, the most predictive diagnostic tools include:

  • Term-age MRI (86-89% sensitivity) 1
  • Prechtl Qualitative Assessment of General Movements (98% sensitivity) 1
  • Hammersmith Infant Neurological Examination (90% sensitivity) 1

• After 5 months' corrected age, diagnosis relies on:

  • MRI (86-89% sensitivity where safe and feasible) 1
  • Hammersmith Infant Neurological Examination (90% sensitivity) 1
  • Developmental Assessment of Young Children (83% C index) 1

• Diagnosis can now be made before 6 months' corrected age using these standardized assessment tools in combination with clinical history, representing a significant advancement from historical practices. 1

Important Diagnostic Considerations

• Motor types emerge and evolve during the first 2 years of life, making early classification challenging but not impossible. 1, 3 The four motor types include spasticity (85-91%), dyskinesia (4-7%), ataxia (4-6%), and hypotonia (2%). 1

• Clinical signs and symptoms evolve before age 2 years, requiring a combination of standardized tools used in conjunction with clinical history rather than relying on a single assessment. 1

• Early diagnosis does not preclude further etiological investigation, and identifying a specific genetic or acquired cause does not exclude the CP diagnosis. 1 Approximately 14% of cases have a genetic component, and the complete causal pathway remains unclear in 80% of cases. 1