What Is Cerebral Palsy?

Medically Reviewed by Poonam Sachdev on September 29, 2021
7 min read

Cerebral palsy (CP) is a group of disorders that affect balance, movement, and muscle tone. “Cerebral” means the disorder is related to the brain, and “palsy” refers to weakness or a muscle problem.

CP starts in the area of the brain that controls the ability to move muscles. Cerebral palsy can happen when that part of the brain doesn’t develop as it should, or when it is damaged right around the time of birth or very early in life.

Most people with cerebral palsy are born with it. That’s called “congenital” CP. But it can also start after birth, in which case it’s called “acquired” CP.

People with cerebral palsy can have mild issues with muscle control, or it could be so severe that they can’t walk. Some people with CP have difficulty speaking. Others have intellectual disabilities, while many have normal intelligence.

CP is divided into four main types, based on the movement involved:

  • Spastic cerebral palsy
  • Dyskinetic cerebral palsy
  • Ataxic cerebral palsy
  • Mixed cerebral palsy

Spastic cerebral palsy

The most common kind is spastic CP. If you have it, your muscles are stiff or tight, or they spasm.

Doctors break down spastic CP into three groups:

  • Spastic diplegia mostly involves muscle stiffness in the legs. Tight muscles in your legs and hips might cause trouble walking because your legs turn in at the knees. This is also called scissoring.
  • Spastic hemiplegia means one side of your body is affected. Your arm and leg on that side may be shorter and thinner, which might cause you to walk on your tiptoes. Some people with this type have a curved spine, called scoliosis. Seizures and speech problems can also be part of spastic hemiplegia.
  • Spastic quadriplegia means all of your limbs are affected, as well as your torso and your face. You may also have seizures and trouble speaking if you have this type of CP. It’s the most serious kind of spastic CP.

Dyskinetic cerebral palsy

If you have dyskinetic CP, your muscle tone might be too tight or too loose. Your movements are uncontrolled: slow and twisting, or quick and jerky. If the muscles in your face or mouth are affected, you might frown, drool, and have trouble speaking.

Dyskinetic CP breaks down further into these types:

  • Athetoid. Movements are writhing, slow, and curvy.
  • Choreoathetoid. Movements are aimless and not controlled.
  • Dystonic. Muscle tone is not normal.

Ataxic cerebral palsy

Ataxic CP, which is rare, causes problems with coordination and balance. You might be unsteady when you walk. You might also shake, which could make it hard to do tasks that need steadiness, such as writing.

Mixed cerebral palsy

People with this type of CP have symptoms of more than one type. Most people with mixed CP have a combination of spastic and dyskinetic.

Doctors can’t always figure out exactly what has happened to damage the brain or disrupt development, causing CP.

Some of the problems that can damage the brain or disrupt its growth include:

  • Bleeding in the brain while the baby is in the womb, during birth or afterward
  • A lack of blood flow to important organs
  • Seizures at birth or in the first month of life
  • Some genetic conditions
  • Traumatic brain injuries

Because there are very mild and very severe forms of cerebral palsy, a wide range of symptoms could signal this condition. Often, delays in baby milestones that are linked to muscle usage may be signs of CP. Examples include rolling over, sitting up, standing, and walking. But not all delays in milestones mean your baby has cerebral palsy.

Some symptoms may show up at birth, while others may take longer to appear. In babies younger than 6 months, those signs include:

  • When you pick your baby up from sleeping (on their back), their head falls backward.
  • They feel stiff or floppy.
  • When cradled in your arms, they extend their back and neck, almost as if pushing away from you.
  • When you pick them up, their legs get stiff and cross over each other (“scissor”).

If your baby is older than 6 months, warning signs can include:

  • They can’t roll over.
  • They can’t bring their hands together.
  • They have trouble bringing their hands to their mouth.
  • When they reach, it’s with only one hand. The other stays in a fist.

If your baby is older than 10 months, watch for these signs:

  • They crawl by pushing off with one hand and one leg while dragging the other side of their body.
  • They don’t crawl on all fours but scoots instead, or they hop on their knees.

If your baby is more than 1 year old and can’t stand without support or crawl, those are also possible signs of CP.

Some babies are diagnosed with CP soon after they’re born. Others aren’t diagnosed until years later.

A doctor may first notice problems with your baby’s movements or muscle tone. If you notice any problems like these at home, discuss what you see with the doctor.

Cerebral palsy doesn’t get worse as time passes, but often, symptoms aren’t noticed right away. For example, you won’t know that a 3-month-old can’t walk, so symptoms are usually recognized later.

At every scheduled visit, the doctor will check to see if your baby is keeping up with their milestones or if they're delayed. They’ll watch how your baby moves to see if it’s the normal range. And they’ll ask if you have any concerns.

Your doctor can measure subtle changes over time. It may be harder for a doctor to know for sure if a 9-month-old has a delay than if a 2½-year-old has a delay, because it’s more likely that an earlier delay will be less obvious than a later one. This is why some children aren’t diagnosed until they’re older. Most children with cerebral palsy are diagnosed by the time they’re 2 years old. But if your baby’s symptoms are mild, they might not be diagnosed before they’re 4 or 5.

When a doctor suspects that your child has CP, they may suggest that you see a specialist like a neurologist (an expert on the brain and nerves) or a doctor who has special training in child development.

The doctor will do a physical exam and watch your child’s movements. They’ll ask about your child’s health history, and they’ll want to hear any concerns that you have about the way your child moves. They may need to also order tests to check for problems. These include:

  • Blood tests. Other health problems may cause symptoms that can look like CP. Your doctor may offer blood tests to rule out other conditions.
  • CT scan. A CT scan uses X-ray technology to make images of the brain.
  • MRI uses a strong magnet, not X-rays. It uses no radiation and can make higher-quality images than a CT scan. This can be helpful if the damage is hard to detect, but it may not always be needed.
  • Ultrasounduses sound waves to make an image of your baby’s brain. It may not be as helpful as an MRI at finding slight problems in the brain, but it’s an easier test for your baby to take. It can be done only in very young babies, before the soft spot gets too small.
  • EEG (electroencephalogram). For this test, small electrodes will be stuck to your baby’s head to measure their brain waves. Sometimes, this exam can help diagnose epilepsy (seizure disorder), which is somewhat common in children with cerebral palsy.

Your doctor will look at the brain images and other test results. They’ll also review their exams of your baby over time, any milestone delays that they've had, plus what you’ve noticed at home.

Once your child is diagnosed with CP, they can begin to receive treatment. There is no cure, but your doctor may recommend physical therapy and muscle training.

You may have a condition while you’re pregnant that can increase the chances your baby will have CP. Among them are:

  • Being pregnant with multiples, such as twins or triplets
  • Having a health issue such as seizures or a problem with your thyroid gland
  • Having blood that’s not compatible with your baby’s, which is also called Rh disease
  • Coming in contact with a toxic substance such as mercury, which is found in some kinds of fish

Certain infections and viruses, when they strike during pregnancy, can increase the risk your baby will be born with cerebral palsy. They include:

Just as some illnesses in mothers raise the chances of CP, so do some infections in babies. Here are some of them:

  • Bacterial meningitis. It causes swelling in the brain and tissues around the spinal cord.
  • Viral encephalitis. This also can cause swelling around the brain and spinal cord.
  • Severe jaundice (yellowing of the skin). This condition occurs when excessive bilirubin, a yellow pigment, accumulates in the blood.

Certain problems that happen in childbirth can also increase the risk of cerebral palsy. They include:

  • Premature birth.This means any time under 37 weeks into the pregnancy.
  • Breech position. This means a baby is settled feet-first rather than headfirst when labor begins.
  • Low birth weight. If your baby is less than 5.5 pounds, the chances for CP go up.
  • Complicated labor and delivery. This means problems with your baby’s breathing or circulatory system.