complete. ADCP is associated with injury and malformations to the extrapyramidal tracts in the basal ganglia or the cerebellum. Lesions to this region principally arise via hypoxic ischemic brain injury or bilirubin encephalopathy. Hypoxic-ischemic brain injury Hypoxic-ischemic brain injury is a form of cerebral hypoxia in which oxygen cannot perfuse to cells in the brain. Lesions in the putamen and thalamus caused by this type of brain injury are primary causes of ADCP and can occur during the prenatal period and shortly after. Lesions that arise after this period typically occur as a result of injury or infections of the brain. Cerebral cortex and white matters are often relative spared, so intelligence is often normal. Bilirubin encephalopathy Bilirubin encephalopathy, also known as kernicterus, is the accumulation of bilirubin in the grey matter of the central nervous system. The main accumulation targets of hyperbilirubinemia are the basal ganglia, ocular movement nucleus, and acoustic nucleus of the brainstem. Pathogenesis of bilirubin encephalopathy involves several factors, including the transport of bilirubin across the blood–brain barrier and into neurons. Mild disruption results in left cognition impairment, while severe disruption results in ADCP. Lesions caused by accumulation of bilirubin occur mainly in the global pallidus and hypothalamus. Disruption of the blood–brain barrier by disease or a hypoxic ischemic injury can also contribute to an accumulation of bilirubin in the brain. Bilirubin encephalopathy leading to cerebral palsy has been greatly reduced by effective monitoring and treatment for hyperbilirubinemia in preterm infants. As kernicterus has decreased due to improvements in care, over the last 50 years the proportion of children developing athetoid CP has decreased. In most cases, will have normal intelligence. Diagnosis Motor function Movement and posture limitations are aspects of all CP types and as a result, CP has historically been diagnosed based on parental reporting of developmental motor delays such as failure to sit upright, reach for objects, crawl, stand, or walk at the appropriate age. Diagnosis of ADCP is also based on clinical assessment used in conjunction with milestone reporting. The majority of ADCP assessments now use the Gross Motor Function Classification System (GMFCS) or the International Classification of Functioning, Disability and Health (formerly the International Classification of Impairments Disease, and Handicaps), measures of motor impairment that are effective in assessing severe CP. ADCP is typically characterized by an individual's inability to control their muscle tone, which is readily assessed via these classification