Cerebral Palsy

In the 1860s, an English surgeon named William Little wrote the first medical descriptions of a puzzling disorder that struck children in the first years of life, causing stiff, spastic muscles in their legs and, to a lesser degree, their arms. These children had difficulty grasping objects, crawling, and walking. They did not get better as they grew up nor did they become worse. Their condition, which was called Little's disease for many years, is known as spastic diplegia. It is just one of several disorders that affect control of movement and are grouped together under the term cerebral palsy.

Because it seems that many of these children were born following complicated deliveries, Little suggested their condition resulted from a lack of oxygen during birth. This oxygen shortage damaged sensitive brain tissues controlling movement, he proposed. But in 1897, the famous physician Sigmund Freud disagreed. Noting that children with cerebral palsy often had other problems such a mental retardation, visual disturbances, and seizures, Freud suggested that the disorder might sometimes have roots earlier in life, during the brain's development in the womb. "Difficult birth, in certain cases," he wrote, "is merely a symptom of deeper effects that influence the development of the fetus."

Despite Freud's observation, the belief that birth complications cause most cases of cerebral palsy was widespread among physicians, families, and even medical researchers until very recently. In the 1980s, however, scientists analyzed extensive data from a government study of more than 35,000 births and were surprised to discover that such complications account for only a fraction of cases -- probably less than 10 percent. In most cases of cerebral palsy, no cause could be found. These findings from the National Institute of Neurological Disorders and Stroke (NINDS) perinatal study have profoundly altered medical theories about cerebral palsy and have spurred today's researchers to explore alternative causes.

At the same time, biomedical research has also led to significant changes in understanding, diagnosing, and treating persons with cerebral palsy. Identification of infants with cerebral palsy very early in life gives youngsters the best opportunity for developing to their full capacity. Biomedical research has led to improved diagnostic techniques -- such as advanced brain imaging and modern gait analysis -- that are making this easier. Certain conditions known to cause cerebral palsy, such as rubella (German measles) and jaundice, can now be prevented or treated. Physical, psychological, and behavioral therapy that assist with such skills as movement and speech and foster social and emotional development can help children who have cerebral palsy to achieve and succeed. Medications, surgery, and braces can often improve nerve and muscle coordination, help treat associated medical problems, and either prevent or correct deformities.

What Is Cerebral Palsy?

Cerebral palsy is an umbrella-like term used to describe a group of chronic disorders impairing control of movement that appear in the first few years of life and generally do not worsen over time. The term cerebral refers to the brain's two halves, or hemispheres, and palsy describes any disorder that impairs control of body movement. Thus, these disorders are not caused by problems in the muscles or nerves. Instead, faulty development or damage to motor areas in the brain disrupts the brain's ability to adequately control movement and posture.

Symptoms of cerebral palsy lie along a spectrum of varying severity. An individual with cerebral palsy may have difficulty with fine motor tasks, such as writing or cutting with scissors; experience trouble with maintaining balance and walking; or be affected by involuntary movements, such as uncontrollable writhing motion of the hands or drooling. The symptoms differ from one person to the next, and may even change over time in the individual. Some people with cerebral palsy are also affected by other medical disorders, including seizures or mental impairment. Contrary to common belief, however, cerebral palsy does not always cause profound handicap. While a child with severe cerebral palsy might be unable to walk and need extensive, lifelong care, a child with mild cerebral palsy might only be slightly awkward and require no special assistance. Cerebral palsy is not contagious nor is it usually inherited from one generation to the next. At this time, it cannot be cured, although scientific research continues to seek improved treatments and methods of prevention.

How Many People Have This Disorder?

The United Cerebral Palsy Associations estimate that more then 500,000 Americans have cerebral palsy. Despite advances in preventing and treating certain causes of cerebral palsy, the number of children and adults it affects has remained essentially unchanged or perhaps risen slightly over the past 30 years. This is partly because more critically premature and frail infants are surviving through improved intensive care. Unfortunately, many of these infants have developmental problems of the nervous system or suffer neurological damage. Research is under way to improve care for these infants, as in ongoing studies of technology to alleviate troubled breathing and trials of drugs to prevent bleeding in the brain before or soon after birth.

What Are the Different Forms of Cerebral Palsy?

Spastic diplegia is only one of several disorders called cerebral palsy. Today doctors classify cerebral palsy into four broad categories -- spastic, anthetoid, ataxic, and mixed forms -- according to the type of movement disturbance.

• Spastic cerebral palsy: In this form of cerebral palsy, which affects 70 to 80 percent of patients, the muscles are stiffly and permanently contracted. Doctors will often describe which type of spastic cerebral palsy a patient has based on which limbs are affected. The name given to these types combine a Latin description of affected limbs with the term "plegia" or "paresis," meaning paralyzed or weak.

  When both legs are affected by spasticity, they may turn in and cross at the knees. This abnormal leg posture, called scissoring, can interfere with walking.

  Individuals with spastic hemiparesis may also experience hemiparetic tremors, in which uncontrollable shaking affects the limbs on one side of the body. If these tremors are severe, they can seriously impair movement.

• Athetoid, or dyskinetic, cerebral palsy: This form of cerebral palsy is characterized by uncontrolled, slow, writhing movements. These abnormal movements usually affect the hands, feet, arms, or legs and, in some cases, the muscles of the face or tongue, causing grimacing or drooling. The movements often increase during periods of emotional stress and disappear during sleep. Patients may also have problems coordinating the muscle movements needed for speech, a condition known as dysarthria. Athetoid cerebral palsy affects about 10 to 20 percent of patients.

• Ataxic cerebral palsy: This rare form affects balance and coordination. Affected persons may walk unsteadily with a wide-based gait, placing their feet unusually far apart, and experience difficulty when attempting quick or precise movements, such as writing or buttoning a shirt. They may also have intention tremor. In this form of tremor, beginning a voluntary movement, such as reaching for a book, causes a trembling that affects the body part being used. The tremor worsens as the individual gets nearer to the desired object. The ataxic form affects an estimated 5 to 10 percent of cerebral palsy patients.

• Mixed forms: It is common for patients to have symptoms of more than one form of cerebral palsy mentioned above. The most common combination includes spasticity and athetoid movements but other combinations are possible.

What Other Medical Disorders Are Associated with Cerebral Palsy?

Many individuals who have cerebral palsy have no associated medical disorders. However, disorders that involve the brain and impair its motor function can also cause seizures and impair an individual's intellectual development, attentiveness to the outside world, activity and behavior, and vision and hearing. Medical disorders associated with cerebral palsy include:

• Mental impairment. About one-third of children who have cerebral palsy are mildly intellectually impaired, one-third are moderately or severely impaired, and the remaining third are intellectually normal. Mental impairment is more commonly seen in children with spastic quadriplegia.

• Seizures or epilepsy. As many as half of all children with cerebral palsy have seizures. During a seizure, the normal, orderly pattern of electrical activity in the brain is disrupted by uncontrolled bursts of electricity. When seizures recur without a direct trigger, such as fever, the condition is called epilepsy. In the person who has cerebral palsy and epilepsy, this disruption may be spread throughout the brain and cause varied symptoms all over the body -- as in tonic-clonic seizures -- or may be confined to just one part of the brain and cause more specific symptoms -- as in partial seizures.

  Tonic-clonic seizures generally cause patients to cry out and are followed by loss of consciousness, twitching of both legs and arms, convulsive body movements, and loss of bladder control.

  Partial seizures are classified as simple or complex. In simple partial seizures, the individual has localized symptoms, such as muscle twitches, numbness, or tingling. In complex partial seizures, the individual may hallucinate, stagger, perform automatic and purposeless movements, or experience impaired consciousness or confusion.

• Growth problems. A syndrome called failure to "thrive" is common in children with moderate-to-severe cerebral palsy, especially those with spastic quadriparesis. Failure to thrive is a general term physicians use to describe children who seem to lag behind in growth and development despite having enough food. In babies, the lag usually takes the form of too little weight gain; in young children, it can appear as abnormal shortness; in teenagers, it may appear as a combination of shortness and lack of sexual development. Failure to thrive probably has several causes, including, in particular, poor nutrition and damage to the brain centers controlling growth and development.

  In addition, the muscles and limbs affected by cerebral palsy tend to be smaller than normal. This is especially noticeable in some patients with spastic hemiplegia, because limbs on the affected side of the body may not grow as quickly or as large as those on the normal side. This condition usually affects the hand and foot most severely. Since the involved foot in hemiplegia is often smaller than the unaffected foot even among patients who walk, this size difference is probably not due to lack of use. Scientists believe the problem is more likely to result from disruption of the complex process responsible for normal body growth.

• Impaired vision or hearing. A large number of children with cerebral palsy have strabismus, a condition in which the eyes are not aligned because of differences in the left and right eye muscles. In an adult, this condition causes double vision. In children, however, the brain often adapts to the condition by ignoring signals from one of the misaligned eyes. Untreated, this can lead to very poor vision in one eye and can interfere with certain visual skills, such as judging distance. In some cases, physicians may recommend surgery to correct strabismus.

  Children with hemiparesis may have hemianopia, which is defective vision or blindness that impairs the normal field of vision. For example, when hemianopia affects the right field of vision, a child looking straight ahead might have perfect vision except on the far right. In homonymous hemianopia, the impairment affects the same part of the visual field of both eyes.

  Impaired hearing is also more frequent among those with cerebral palsy than in the general population.

• Abnormal sensation and perception. Some children with cerebral palsy have impaired ability to feel simple sensations like touch and pain. They may also have stereognosia, or difficulty perceiving and identifying objects using the sense of touch. A child with stereognosia, for example, would have trouble identifying a hard ball, sponge, or other objects placed in his hand without looking at the object.

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.