Cerebral palsy (CP) is a group of permanent movement disorders that manifest in early childhood. These disorders affect a person’s ability to control body movement and maintain posture and balance. While the symptoms may become more noticeable over time, the underlying brain damage does not worsen. This article explores the various causes and factors that contribute to the development of cerebral palsy.
Causes During Pregnancy
Issues with brain formation can lead to CP, including abnormal brain development caused by genetic mutations or chromosomal abnormalities. Inherited genetic causes may play a role in up to 25% of cases.
Maternal infections during pregnancy can also impact fetal brain development. Viruses like rubella (German measles), cytomegalovirus (CMV), and the Zika virus, along with parasitic infections such as toxoplasmosis, increase the likelihood of CP. These infections can trigger inflammation that damages the developing brain. Chorioamnionitis, an infection of the fetal membranes, is also associated with an increased risk.
Certain maternal health conditions can affect the fetus and contribute to cerebral palsy. Severe thyroid problems, preeclampsia (high blood pressure during pregnancy), and uncontrolled diabetes can all impact fetal development. Mothers with chronic conditions, particularly autoimmune disorders, may also have an increased risk.
A stroke occurring in the developing fetus can interrupt blood supply to the brain, causing damage that leads to cerebral palsy. Fetal strokes are among the more common known causes of CP in infants born at term or near term. These strokes can be ischemic, resulting from blood clots blocking arteries, or hemorrhagic, caused by trauma damaging blood vessels in the brain. Exposure to certain toxins or specific medications during pregnancy may also increase the risk.
Causes During Birth
Events around the time of birth can also contribute to cerebral palsy. Oxygen deprivation, or asphyxia, to the baby’s brain during a difficult or prolonged labor and delivery can cause damage. While historically considered a major cause, birth asphyxia now accounts for a smaller percentage of all cerebral palsy cases.
Complications during labor and delivery, such as placental abruption or umbilical cord issues, can also lead to brain injury by disrupting oxygen flow. These events can result in conditions like hypoxic-ischemic encephalopathy (HIE), a specific type of brain damage caused by insufficient oxygen. Premature birth itself is a significant risk factor, with the risk increasing the earlier a baby is born.
Untreated, severe jaundice, a condition where bilirubin levels become excessively high, can lead to brain damage known as kernicterus. Bilirubin is a byproduct of red blood cell breakdown, and if the baby’s liver cannot process it effectively, it can accumulate and become toxic to brain tissue. Kernicterus is a rare but serious consequence, causing permanent neurological damage and cerebral palsy.
Causes After Birth
Cerebral palsy can also develop after a baby is born within the first few years of life. Severe infections like bacterial meningitis or viral encephalitis can cause inflammation and damage to the brain and spinal cord. These infections can lead to permanent neurological disabilities, including cerebral palsy, if not diagnosed and treated promptly.
Traumatic head injuries from accidents or child abuse, such as shaken baby syndrome, are another cause of acquired cerebral palsy. Shaken baby syndrome occurs when a baby is violently shaken, causing the fragile brain to move back and forth within the skull, leading to bruising, swelling, and bleeding. These injuries can result in irreversible brain damage and lifelong disabilities.
A stroke can occur in infants or young children, interrupting blood supply to parts of the brain and causing damage. Pediatric strokes are a leading cause of brain damage that can result in cerebral palsy, especially hemiplegic cerebral palsy, which affects one side of the body. While the exact cause is often unknown, risk factors include heart conditions and blood disorders.
In extreme cases, severe dehydration or malnutrition can impact brain health and development. Such conditions may contribute to the development of cerebral palsy.
When the Cause Remains Unknown
Despite thorough medical investigation, a specific cause for cerebral palsy cannot be identified in a significant number of cases. These are often referred to as idiopathic cases, meaning the origin is unknown.
The brain’s development is an intricate process, and subtle issues or a combination of various factors may contribute to cerebral palsy without a single, identifiable cause. These complex interactions between genetic predispositions and environmental influences are not always readily apparent. Ongoing research efforts continue to explore these unknown etiologies, aiming to uncover more precise explanations for these cases.