Cerebral palsy (CP) is a general term used for a group of nonprogressive disorders of movement and posture caused by abnormal development of, or damage to, parts of the brain that control muscle movements.1 The term does not imply severity, cause, treatment, or prognosis. The overall prevalence of the condition ranges from 1.9 to 2.6 of every 1000 live-born children in the Western world.2 The rate of CP is much higher in preterm versus term infants and increases with decreasing birth weight and gestational age. It increases at the extremes of birth weight across gestational ages.3 CP is newly diagnosed in approximately 6000 infants and young children every year in the United States. This overall amount has not changed in the last 20 to 30 years, although recent studies suggest that there may be a decreasing trend.2,4,5
CP is caused by events occurring before, during, or after birth up to age 3 years.6 The etiology is multifactorial. Birth injuries such as hypoxic ischemic encephalopathy, or head injuries after delivery such as those from car accidents, child abuse, falls, or intracranial hemorrhages, can lead to CP. Illnesses such as meningitis in the first few weeks or months of life, or strokes that occur in the newborn period, may result in cerebral palsy. CP is often, but not always, diagnosed in children with congenital cerebral malformations of microcephaly or hydrocephalus. Perinatal asphyxia, intrapartum hypoxia, prematurity, intrauterine growth retardation, intrauterine infection, antepartum hemorrhage, severe placental abnormalities, and multiple pregnancies can all be associated pathologies.7 Unfortunately, the cause is not always clear.8
CP is characterized by abnormalities of movement and posture. Young children are often identified with signs of CP when motor milestones are not met. Children may also have increased (stiffness) and/or decreased tone on the motor exam or asymmetries may be found.
These children may show a lack of muscle coordination when performing voluntary movements. A young child may appear ataxic when ambulating. Spasticity may be noted as the child has stiff or tight muscles in his or her arms and/or legs, exaggerated reflexes, walking with one foot or leg dragging, toe walking, a crouched, or a "scissored" gait, and muscle tone that is either too stiff or too floppy.9 Common terms used to describe the clinical presentation of CP include static encelphalopathy, spasticity, or developmental delay.10
The classification of CP is based on the number of limbs involved and the associated resting tone, or movement abnormalities (Figure 11-1).
Delay in motor milestones or abnormal tone may be associated with CP. (A) Development of Head Control: At 1 month of age, the head lags after the shoulders, but by 5 to 6 months ...