Cerebral Palsy (CP)
Some people with CP have associated disorders, such as impaired intellectual development, seizures, failure to grow and thrive, and vision and sense of touch problems.
Roughly a third of patients with CP also have mild intellectual impairment; another third are moderately or severely impaired; and the remainder, intellectually normal. Mental impairment is most common in children with spastic quadriplegia.
As many as half of all patients with cerebral palsy have seizures in which uncontrolled bursts of electricity disrupt the brain’s normal pattern of electrical activity. Seizures that recur without a direct trigger, such as a fever, are classified as epilepsy. Seizures generally are tonic-clonic or partial.
- Tonic-clonic seizures spread throughout the brain, typically causing the patient to cry out, followed by unconsciousness, twitching legs and arms, convulsive body movements, and loss of bladder control.
- Partial seizures are confined to one part of the brain and may be simple or complex. Simple partial seizures cause muscle twitching, chewing movement, and numbness or tingling. Complex partial seizures can produce hallucinations; staggering, random movement; and impaired consciousness or confusion.
Children with moderate-to-severe cerebral palsy, especially those with spastic quadriplegia, often experience failure to grow or thrive—infants fail to gain weight normally; young children may be abnormally short; and teenagers may be short for their age and may have slow sexual development. These phenomena may be caused by a combination of poor nutrition and damage to the brain centers that control growth.
Some patients, particularly those with spastic hemiplegia, have muscles and limbs that are smaller than normal. Limbs on the side of the body affected by CP may grow slower than those on the other side. Hands and feet are most severely affected. The affected foot in cases of hemiplegia usually is the smaller of the two, even in patients who walk, suggesting the size difference is due not to disuse but to a disrupted growth process.
Vision and hearing problems are more common in people with cerebral palsy than in the general population. Differences in the left and right eye muscles often cause the eyes to be misaligned. This condition, called strabismus, causes double vision; in children, however, the brain often adapts by ignoring signals from one eye. Because strabismus can lead to poor vision and impaired depth perception, some physicians recommend corrective surgery.
Patients with hemiparesis may have hemianopia, a condition marked by impaired vision or blindness in half of the visual field in one or both eyes. A related condition, called homonymous hemianopia, causes impairment in the right or left half of the visual fields in both eyes.
Sensations of touch or pain may be impaired. A patient with stereognosis, for example, has difficulty perceiving or identifying the form and nature of an object placed in their hand using the sense of touch alone.
Hip dislocation, curvature of the spine (scoliosis), incontinence, constipation, tooth decay (dental caries), bronchitis, skin sores, and asthma are other complications commonly experienced by people with CP.
Cerebral palsy involves insult to the higher brain centers such as cerebral cortex and/or corticospinal tracts (spastic), basal ganglia (athetoid), and cerebellum (ataxic). Spastic CP involves the descending tracts (corticospinal tract) that provide inhibition to the reflex arc. The spasticity results because there is too much facilitatory input from the spinal reflex arc generated by a stretch put on the muscle spindle. The spindle sends information to the spinal cord that usually is controlled by the descending tracts. When there is an injury to these tracts, there is an uncontrolled facilitation that causes the muscle to contract to take up the length on the spindle.
The basal ganglia, a contributor to the extrapyramidal system, is a major center for movements related to posture, automatic movements (such as reciprocal arm swing during gait), and skilled volitional movements. It also monitors progress of movements and execution of learned motor plans. Insults to this area result symptoms such as akinesia, difficulty starting and stopping motion, rigidity, tremor or chorea. The cerebellum is the center for coordination of movement. In cerebral palsy, insults to this area result in such symptoms as hypotonia, disorders of balance and proprioception, ataxia, tremors, and dysmetria.