What Are The Causes Of Cerebral Palsy?

While it’s known that cerebral palsy occurs when a fetus or infant child’s brain doesn’t develop normally or is somehow damaged during the development process, the Centers for Disease Control and Prevention (CDC) says that the cause of this abnormal development or damage is sometimes unclear.

Generally speaking, there are two types of cerebral palsy (CP). They are congenital CP and acquired CP, and each has different potential causes.

Congenital Cerebral Palsy

A high majority of CP cases—somewhere between 85 and 90 percent—fall into the congenital cerebral palsy category, according to the CDC. It occurs as a result of abnormal brain development or brain damage that is either sustained prior to or during the birth process.

The brain damage associated with congenital cerebral palsy can occur because of a number of different reasons, from genetic factors that have somehow stunted or altered normal brain development to the newborn’s brain being deprived of oxygen while leaving the birth canal.

Unfortunately, in most instances of congenital cerebral palsy, the cause of the CP remains unknown. This can be extremely frustrating for parents searching for answers as to the exact cause of their child’s medical condition.

Acquired Cerebral Palsy

The remaining cases of CP can be categorized as acquired cerebral palsy. This type of CP is diagnosed when there is damage to the brain that occurs 28 or more days after the child’s birth.

Most of the time, this post-birth brain damage is caused by either:

  • an infection like meningitis or encephalitis
  • or injury to the child’s head region from abuse or involvement in an auto accident.

A third possible cause of acquired CP is when blood flow to the newborn child’s brain is somehow inhibited or impacted. This can occur if his or her blood doesn’t clot as it normally should, if there is a heart defect, if the infant’s blood vessels aren’t properly formed, or if the child has sickle cell disease.

4 Types of Brain Damage

Although the cause of cerebral palsy cannot always be pinpointed, there are four different types of brain damage that can result in a CP diagnosis.

  1. Cerebral dysgenesis. Cerebral dysgenesis is brain damage that occurs when there is abnormal brain development. Often referred to as brain malformation, this damage can be a result of the child’s brain not fully developing or developing abnormally. It may also occur if the brain did not have complete division or complete organization.
  2. Intrapartum asphyxia. Also known as hypoxic-ischemic encephalopathy (HIE), intrapartum asphyxia is brain damage that results from asphyxia, which is lack of oxygen to the brain. This lack of oxygen can occur while the baby is still a fetus or during the birth process, whether the infant is born premature or full-term.
  3. Intraventricular hemorrhage. Sometimes called IVH for short, intraventricular hemorrhage is brain damage that occurs as a result of a brain hemorrhage, also known as a brain bleed. This hemorrhage is seen more frequently in babies born prematurely and can either involve the infant’s arteries (which are more difficult to control) or veins. The level of damage sustained from the bleeding is dependent on where in the brain the hemorrhage occurred and how severe it was.
  4. Periventricular leukomalacia. Periventricular leukomalacia (PVL) refers to damage to the white matter of the baby’s brain, causing the injured cells to die. This is the portion of the brain responsible for motor function, and results in movement-related issues.

The Role of Genetics in Cerebral Palsy

Many research studies have been conducted to determine whether genetics play a role in the development of cerebral palsy.

In one such 2017 study, researchers looked at 97 children from Ontario, Canada. They all had hemiplegic cerebral palsy, a form of cerebral palsy that only affects one side of the body. The children’s health records were studied, their parents were interviewed, and their DNA was extracted from saliva samples.

After studying all of the data, researchers revealed that 18.6 percent of the participants inherited rare copy number variants (CNVs) from one of their parents. These are structural alterations of typical genomes. An additional 7.2 percent had new variations associated with hemiplegic CP, both of which suggest that there is a genetic component to CP.

Impact of The Mother’s Health

Other studies have found that a mother’s health may have an impact on whether or not her child develops CP.

For instance, in a March 2017 study, researchers looked at 1,423,929 Swedish-born children, 3,029 of whom were diagnosed with cerebral palsy by the time they were 8 years old.

Based on the data collected, researchers concluded that maternal weight had an impact on the development of CP. Specifically, if the mother had a body mass index (BMI) over 25, which is classified as being overweight or obese, the babies had a higher rate of cerebral palsy compared to babies with mothers who had lower BMIs.

Other factors related to the mother’s health that could potentially impact whether or not her child will develop CP include:

  • If the mother develops German measles or chickenpox.
  • If the mother develops cytomegalovirus, a virus that creates flu-like symptoms, or the Zika virus.
  • If the mother has herpes or syphilis.
  • If the mother comes in contact with a parasite commonly found in cat feces or contaminated food (toxoplasmosis).

Other conditions related to the mother’s health that could cause cerebral palsy in the child include thyroid issues, intellectual disabilities, or if she has seizures.