Cerebral palsy is a group of disorders that affect movement and muscle tone or posture. It's caused by damage that occurs to the immature brain as it develops, most often before birth.
Signs and symptoms appear during infancy or preschool years. In general, cerebral palsy causes impaired movement associated with abnormal reflexes, floppiness or rigidity of the limbs and trunk, abnormal posture, involuntary movements, unsteady walking, or some combination of these.
People with cerebral palsy can have problems swallowing and commonly have eye muscle imbalance, in which the eyes don't focus on the same object. They also might have reduced range of motion at various joints of their bodies due to muscle stiffness.
Cerebral palsy's effect on function varies greatly. Some affected people can walk; others need assistance. Some people show normal or near-normal intellect, but others have intellectual disabilities. Epilepsy, blindness or deafness also might be present.
Signs and symptoms can vary greatly. Movement and coordination problems associated with cerebral palsy include:
- Variations in muscle tone, such as being either too stiff or too floppy
- Stiff muscles and exaggerated reflexes (spasticity)
- Stiff muscles with normal reflexes (rigidity)
- Lack of balance and muscle coordination (ataxia)
- Tremors or involuntary movements
- Slow, writhing movements
- Delays in reaching motor skills milestones, such as pushing up on arms, sitting up or crawling
- Favoring one side of the body, such as reaching with one hand or dragging a leg while crawling
- Difficulty walking, such as walking on toes, a crouched gait, a scissors-like gait with knees crossing, a wide gait or an asymmetrical gait
- Excessive drooling or problems with swallowing
- Difficulty with sucking or eating
- Delays in speech development or difficulty speaking
- Learning difficulties
- Difficulty with fine motor skills, such as buttoning clothes or picking up utensils
Cerebral palsy can affect the whole body, or it might be limited primarily to one limb or one side of the body. The brain disorder causing cerebral palsy doesn't change with time, so the symptoms usually don't worsen with age.
However, as the child gets older, some symptoms might become more or less apparent. And muscle shortening and muscle rigidity can worsen if not treated aggressively.
Brain abnormalities associated with cerebral palsy might also contribute to other neurological problems, including:
- Difficulty seeing and hearing
- Intellectual disabilities
- Abnormal touch or pain perceptions
- Oral diseases
- Mental health conditions
- Urinary incontinence
When to see a doctor
It's important to get a prompt diagnosis for a movement disorder or delays in your child's development. See your child's doctor if you have concerns about episodes of loss of awareness of surroundings or of abnormal bodily movements, abnormal muscle tone, impaired coordination, swallowing difficulties, eye muscle imbalance or other developmental issues.
Cerebral palsy is caused by an abnormality or disruption in brain development, most often before a child is born. In many cases, the cause isn't known. Factors that can lead to problems with brain development include:
- Gene mutations that lead to abnormal development
- Maternal infections that affect the developing fetus
- Fetal stroke, a disruption of blood supply to the developing brain
- Bleeding into the brain in the womb or as a newborn
- Infant infections that cause inflammation in or around the brain
- Traumatic head injury to an infant from a motor vehicle accident or fall
- Lack of oxygen to the brain related to difficult labor or delivery, although birth-related asphyxia is much less commonly a cause than historically thought
A number of factors are associated with an increased risk of cerebral palsy.
Certain infections or toxic exposures during pregnancy can significantly increase cerebral palsy risk to the baby. Infections of particular concern include:
- Cytomegalovirus. This common virus causes flu-like symptoms and can lead to birth defects if a mother has her first active infection during pregnancy.
- German measles (rubella). This viral infection can be prevented with a vaccine.
- Herpes. This can be passed from mother to child during pregnancy, affecting the womb and placenta. Inflammation triggered by infection can damage the unborn baby's developing nervous system.
- Syphilis. This is a sexually transmitted bacterial infection.
- Toxoplasmosis. This infection is caused by a parasite found in contaminated food, soil and the feces of infected cats.
- Zika virus infection. Infants for whom maternal Zika infection causes their head size to be smaller than normal (microcephaly) can develop cerebral palsy.
- Other conditions. Other conditions that can increase the risk of cerebral palsy include thyroid problems, intellectual disabilities or seizures, and exposure to toxins, such as methyl mercury.
Illnesses in a newborn baby that can greatly increase the risk of cerebral palsy include:
- Bacterial meningitis. This bacterial infection causes inflammation in the membranes surrounding the brain and spinal cord.
- Viral encephalitis. This viral infection similarly causes inflammation in the membranes surrounding the brain and spinal cord.
- Severe or untreated jaundice. Jaundice appears as a yellowing of the skin. The condition occurs when certain byproducts of "used" blood cells aren't filtered from the bloodstream.
- Bleeding into the brain. This condition is commonly caused by the baby having a stroke in the womb.
Other factors of pregnancy and birth
While the potential contribution from each is limited, additional pregnancy or birth factors associated with increased cerebral palsy risk include:
- Breech presentation. Babies with cerebral palsy are more likely to be in this feet-first position at the beginning of labor rather than being headfirst.
- Low birth weight. Babies who weigh less than 5.5 pounds (2.5 kilograms) are at higher risk of developing cerebral palsy. This risk increases as birth weight drops.
- Multiple babies. Cerebral palsy risk increases with the number of babies sharing the uterus. If one or more of the babies die, the survivors' risk of cerebral palsy increases.
- Premature birth. Babies born fewer than 28 weeks into the pregnancy are at higher risk of cerebral palsy. The earlier a baby is born, the greater the cerebral palsy risk.
Muscle weakness, muscle spasticity and coordination problems can contribute to a number of complications either during childhood or in adulthood, including:
- Contracture. Contracture is muscle tissue shortening due to severe muscle tightening (spasticity). Contracture can inhibit bone growth, cause bones to bend, and result in joint deformities, dislocation or partial dislocation.
- Premature aging. Some type of premature aging will affect most people with cerebral palsy in their 40s because of the strain the condition puts on their bodies.
- Malnutrition. Swallowing or feeding problems can make it difficult for someone who has cerebral palsy, particularly an infant, to get enough nutrition. This can impair growth and weaken bones. Some children need a feeding tube to get enough nutrition.
- Mental health conditions. People with cerebral palsy might have mental health conditions, such as depression. Social isolation and the challenges of coping with disabilities can contribute to depression.
- Heart and lung disease. People with cerebral palsy may develop heart disease and lung disease and breathing disorders.
- Osteoarthritis. Pressure on joints or abnormal alignment of joints from muscle spasticity may lead to the early onset of this painful degenerative bone disease.
- Osteopenia. Fractures due to low bone density (osteopenia) can stem from several common factors such as lack of mobility, nutritional shortcomings and anti-epileptic drug use.
Most cases of cerebral palsy can't be prevented, but you can lessen risks. If you're pregnant or planning to become pregnant, you can take these steps to keep healthy and minimize pregnancy complications:
- Make sure you're vaccinated. Getting vaccinated against diseases such as rubella, preferably before getting pregnant, might prevent an infection that could cause fetal brain damage.
- Take care of yourself. The healthier you are heading into a pregnancy, the less likely you'll be to develop an infection that results in cerebral palsy.
- Seek early and continuous prenatal care. Regular visits to your doctor during your pregnancy are a good way to reduce health risks to you and your unborn baby. Seeing your doctor regularly can help prevent premature birth, low birth weight and infections.
- Practice good child safety. Prevent head injuries by providing your child with a car seat, bicycle helmet, safety rails on beds and appropriate supervision.
- Avoid alcohol, tobacco and illegal drugs. These have been linked to cerebral palsy risk.