Causes and Risks: The incidence of cerebral palsy is approximately 2 to 4 individuals for every 1000 births. Cerebral palsy results from injury to the cerebrum (the largest portion of the brain, involved with higher mental faculties, sensations, and voluntary muscle activities).
Initially cerebral palsy was thought to be related to birth asphyxia and trauma but in a study of 45,000 births it was shown that birth asphyxia is an uncommon cause of cerebral palsy. The cause of hypoxia (low oxygen) to the damaged areas of the brain has not been adequately made clear, but it is believed that there are predisposing factors occurring during the development of the fetus that makes it more susceptible to hypoxia. Premature infants have a slightly higher incidence of cerebral palsy. Cerebral palsy may also occur during early infancy as a result of cerebral injury caused by illnesses (encephalitis, meningitis, herpes simplex infections, and so on), head injury that results in subdural hematoma, blood vessel injuries, and many others.
Injury to the cerebrum can result in the loss of nerve functions in widely different areas. The classical finding of CP is spasticity (increased muscle tone) which may affect a single limb, one side of the body (spastic hemiplegia), both legs (spastic diplegia) or both arms and legs (spastic quadriplegia). In addition there may be partial or full loss of movement (paralysis), sensory abnormalities, and defects of hearing and vision. Speech abnormalities are common and seizures may occur. Intellectual function may range from extremely bright normal to severe mental retardation. Symptoms are usually evident before age 2 and in severe cases may appear as early as three months. Cerebral palsy is a non-progressive type of encephalopathy (injury to the brain) and symptoms directly resulting from the disease do not worsen.
Classifications of cerebral palsy include spastic, dyskinetic, ataxic, and mixed cerebral palsy. Spastic cerebral palsy includes about 50% of cases. Dyskinetic (athetoid) cerebral palsy affects about 20%. It involves development of abnormal movements (twisting, jerking, or other movements). Ataxic cerebral palsy involves tremors, unsteady gait, loss of coordination, and abnormal movements. It affects about 10%. The remaining 20% are classified as mixed, with any combination of symptoms.
Prevention: Adequate prenatal care may reduce the risk of some rare causes of cerebral palsy, however, dramatic improvements over the last 15 years in obstetrical care at delivery has not reduced the incidence of cerebral palsy. In most cases, the injury causing the disorder may not be preventable.
Symptoms:
Signs and Tests: Examination indicates delayed development of motor skills in many cases. Infantile reflexes (such as sucking and startle) may persist past the age where they usually disappear. Muscle tremor or spasticity may be evident, with a tendency of infants to tuck their arms in toward their sides, scissors movements of the legs, or other abnormal movements.
Various laboratory tests may be performed to eliminate nutritional or other causes of the symptoms.
- MRI of the head demonstrates structural or congenital abnormalities
- CT scan of the head demonstrates structural or congenital abnormalities
- hearing screen (to determine auditory status)
- visual testing (to determine visual status)
- EEG
Treatment: There is no specific cure for cerebral palsy. The goal of treatment is to maximize independence. Treatment is guided by the symptoms exhibited and may include physical therapy, braces, appropriate glasses and hearing aids, medications, special education or appropriate schooling, and, in severe cases, institutionalization.
Mainstreaming in regular schools is advised unless physical disabilities or mental development makes this impossible. Glasses, hearing aids, or other equipment must be designed specifically for the particular disabilities and may assist with communication and learning. Physical therapy, occupational therapy, orthopedic intervention, or other treatments may be appropriate.
Medications may include muscle relaxants to reduce tremors and spasticity, and anticonvulsants to prevent or reduce the frequency of seizures.
Surgery may be needed in some cases to release joint contractures which are a progressive problem associated with spasticity. Surgery may also be necessary for placement of feeding tubes and to control gastroesophageal reflux.
The stress of coping with this disorder can often be helped by joining a support group where members share common experiences and problems. See cerebral palsy - support group.
Prognosis: Cerebral palsy is a lifelong disorder. Long-term care may be required. The disorder does not affect expected length of life. The extent of disability varies.
Complications:
- seizures
- injuries from falls
- reduced mobility
- reduced communication skills (sometimes)
- reduced intellect (sometimes)
Call your health care provider if symptoms of cerebral palsy develop, especially if you know that an injury occurred during birth or early infancy.
