Chapter 11 Cerebral Palsy
PATHOPHYSIOLOGY
Cerebral palsy (CP) is a nonspecific term used to characterize abnormal muscle tone, posture, and coordination caused by a nonprogressive lesion or injury that affects the immature brain. CP may result from a variety of prenatal, perinatal, and postnatal factors, although CP results most commonly from either existing perinatal brain abnormalities or postnatal injury. The actual brain abnormality may arise from a variety of causes: anatomical malformations of the brain, atrophy, vascular occlusion, loss of neurons, or low brain weight. Anoxia, which is often secondary to other causative mechanisms, is the most significant factor in the pathologic state of brain damage. Predisposing risk factors include multiple-gestation births, maternal infections, and maternal and fetal thrombophilic conditions. CP is frequently classified according to the functional categories used to describe the neuromuscular abnormalities or dysfunction. Clinical classification of CP is presented in Box 11-1.
Box 11-1 Clinical Classification of Cerebral Palsy
1. Spastic cerebral palsy (CP) is the most common form (80% of cases). It is characterized by hypertonicity and poor postural control, balance, and coordination. Gross and fine motor skills are impaired. Spastic CP is further classified according to the part of the body affected:
2. Dyskinetic/Athetoid CP is characterized by a movement disorder and results from Rh incompatibility and hypoxic ischemic encephalopathy. Characteristics include the following:
3. Ataxic CP is characterized by a wide-based gait, and rapid, repetitive movements that are poorly performed.
4. Mixed type/dystonic—combination of spasticity and athetosis.
