Spastic cerebral palsy
Spastic cerebral palsy
Spastic cerebral palsy (CP) is a disorder in which brain damage results in a movement disability.
Cerebral palsy is a nonprogressive disorder of movement and/or posture caused by a brain abnormality. It is evident before the age of two. There are several types of CP, but spastic CP is the most common—about 60%. The term "spasticity" refers to increased muscle tone (stiffness), leading to uncontrolled, awkward movements.
Only about 2% of cases of CP are believed to result from genetic causes. Most cases of CP are associated with risk factors such as low birth weight, premature birth, and lack of oxygen at birth. Multiple births (such as twins or triplets) also have an increased risk. A genetic cause is more likely if these risk factors are not present. If the paralysis and spasticity are symmetrical—that is, if both sides of the body are similarly affected—then the condition is more likely to be genetic in nature. Mental retardation is usually, but not always, associated with genetic forms. Researchers have not yet found which gene is associated with the disease.
CP has an overall incidence of one in 250 to 1,000 births. Most forms of CP that are genetic have an autosomal recessive pattern of inheritance . This means that in order for a child to have the disorder, they must inherit one altered copy of the causative gene from each parent. A person who has only one altered copy of the disease gene is called a carrier. Two carriers have a 25% chance of having a child with CP with each pregnancy. As studied in the British Pakistani population, a consanguineous marriage—marriage between relatives—appears to increase the prevalence of a genetic form of spastic CP.
Signs and symptoms
CP may not be noticed immediately after birth. Children with CP are slow to meet developmental motor milestones, which are expected ages at which certain mobility skills are achieved. These milestones include reaching for toys, sitting, and walking. People with CP also have abnormal muscle tone (increased in spastic CP), abnormal or uncontrolled movements, and abnormal reflexes. The spasticity may not be present at birth but usually develops during the first two years of life. Many children with spastic CP have normal intelligence, but mental retardation does occur, especially in inherited forms of the disease. Depending on the severity and extent of the paralysis, some affected individuals can walk (often late and with crutches or walkers), while others with more severe disability cannot walk at all. Seizures are not uncommon in individuals with CP.
A diagnosis of spastic CP is based on delay in or lack of meeting developmental motor milestones, along with the presence of abnormal muscle tone, movements, and reflexes. Since the exact gene causing some cases of symmetric spastic CP has not yet been identified, molecular testing is not available at this time. Since CP-like symptoms can be found in other genetic conditions, chromosome testing and molecular testing for other suspected conditions may help determine the cause of the CP-like symptoms. Testing may also enable other family members to be tested to see if they carry the condition, and to allow a fetus to be diagnosed prenatally. Prenatal diagnosis of known genetic conditions can be accomplished using procedures such as chorionic villi sampling, in which cells from the placenta are studied; and amniocentesis , in which skin cells from the fluid surrounding the fetus are studied.
Treatment and management
Treatment of spastic CP is focused on maximizing mobility through physical therapy, and/or providing necessary physical support using devices such as splints, walkers, and wheelchairs. Speech and occupational therapy are sometimes useful as well. Certain types of surgery of the bone, nerves, tendon, and brain tissue can correct abnormalities, improve mobility, and reduce spasticity. Orthodontic work on the teeth is often indicated in children with CP. Some level of special educational services is usually required.
Spastic CP is not a progressive condition, so living into old age is possible. However, complications such as reduced mobility, mental retardation, feeding difficulties, and respiratory infections can reduce the lifespan. More severe disabilities are associated with greater decreases in life expectancy, but at least half of people with CP live to at least age 35.
Geralis, Elaine, ed. Children with Cerebral Palsy: A Parents' Guide. Bethesda, MD: Woodbine House, 1991.
Miller, Freeman, and Steven J. Bachrach. Cerebral Palsy: A Complete Guide for Caregiving. Baltimore: Johns Hopkins University Press, 1995.
McHale, D.P., et al. "A Gene for Autosomal Recessive Symmetrical Spastic Cerebral Palsy Maps to Chromosome 2q24-25." American Journal of Human Genetics 64 (1999): 526-532.
United Cerebral Palsy Association, Inc. (UCP). 1660 L St. NW, Suite 700, Washington, DC 20036-5602. (202)776-0406 or (800)872-5827. <http://www.ucpa.org>.
Toni I. Pollin, MS, CGC