Cerebral Palsy (CP) is the most common physical disability in childhood, yet it remains one of the most clinically heterogeneous and complex conditions managed by physical therapists. Defined as a group of permanent disorders of the development of movement and posture, causing activity limitations that are attributed to non-progressive disturbances occurring in the developing fetal or infant brain, CP is more than just a motor disorder. It is a constellation of associated impairments, including disturbances of sensation, cognition, communication, perception, and behavior, often compounded by secondary musculoskeletal complications. The modern physiotherapist's approach must transcend traditional impairment-based models and adopt a comprehensive, goal-directed, and family - centered strategy rooted in neuroplasticity.
Understanding the timing and nature of the brain insult is critical, as it often correlates with the clinical phenotype and potential for secondary complications. CP is a non-progressive condition, meaning the initial brain lesion does not worsen over time, but the clinical presentation evolves as the child grows and stresses are placed on the musculoskeletal system.
2.1 Classification by Timing of Injury The etiology of CP is typically classified based on when the brain injury is believed to have occurred:
2.1.1 Prenatal (Approximately 75%): Injuries occurring before birth, often during the second and third trimesters. Causes: Genetic disorders, maternal infections (e.g., Cytomegalovirus, Rubella), maternal health issues (e.g., severe preeclampsia, thyroid disease), placental insufficiency leading to intrauterine growth restriction (IUGR), and specific cerebral malformations. Periventricular Leukomalacia (PVL), the most common lesion, involves damage to the white matter surrounding the lateral ventricles, often correlating with diplegia due to the proximity of the descending motor tracts for the lower extremities.
2.1.2 Perinatal (Approximately 10-15%): Injuries occurring during the birth process. Causes: Asphyxia (Hypoxic-Ischemic Encephalopathy - HIE) due to complicated delivery, severe jaundice (kernicterus), and intracranial hemorrhage (IVH or germinal matrix hemorrhage, especially in premature infants).
2.1.3 Postnatal (Approximately 5-10%): Injuries occurring after birth, typically within the first two years of life while the brain is still undergoing rapid development. Causes: Severe head trauma, infections (e.g., meningitis, encephalitis), cerebral vascular accidents (strokes) due to genetic or acquired coagulation disorders, or severe dehydration.
2.2 Neuroimaging Correlates Specific neuroimaging findings often correspond to the clinical motor type:
PVL: The hallmark of spastic diplegia. Basal Ganglia Lesions (e.g., Kernicterus): Correlated with Dyskinetic CP (Athetoid or Dystonic).
Cerebellar Hypoplasia or Infarct: Correlated with Ataxic CP.
Cortical Malformations (e.g., Lissencephaly, Polymicrogyria): Associated with more severe and diffuse involvement, often seen in Spastic Quadriplegia.
CP is clinically classified using four primary features. A thorough assessment must document all four aspects for a complete picture.
3.1 Classification by Motor Type (The Traditional Core) This is based on the predominant quality of movement disturbance: 3.1.1 Spastic CP (70-80%): Characterized by increased muscle tone (hypertonia) that is velocity-dependent (resistance increases with speed of passive stretch). This results from damage to the motor cortex or white matter tracts. Subdivided by affected limbs:
Spastic Hemiplegia: One side of the body (typically the upper extremity is more involved).
Spastic Diplegia: Predominantly lower extremities, often associated with PVL. Upper extremities are mildly affected.