Risk Factor Causal Pathways for Cerebral Palsy
This article has been fact checked by a Board Certified Pediatrician. Sources of information for the article are listed at the bottom.
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Cerebral palsy (CP) is a group of disorders that affect muscle tone, posture and movement that result from a variety of causes in the developing or infant brain. CP is not a progressive disease but its impact may change over time as the brain matures. A number of prenatal and perinatal risk factors are associated with an increased risk of CP.
A single risk factor is some condition or event that will increase the chances that a child will be diagnosed with cerebral palsy. Having more than one risk factor increases the chances even more, but a risk factor is never a guarantee that a child will have the condition and not having any known risk factors is also not a guarantee that a child will not have cerebral palsy.
More recent research into all the risk factors and potential causes of cerebral palsy has determined that a certain combination of risk factors, occurring in a particular order can correlate significantly with cerebral palsy. Researchers call this a causal pathway and the idea is that one risk factor may lead to another and another, ultimately resulting in cerebral palsy. Understanding these complex pathways could help researchers and doctors better figure out how to prevent cerebral palsy in children.
What is a Causal Pathway?
A causal pathway is something that researchers are just beginning to understand in terms of cerebral palsy. It is a complicated series of events that cause or accelerate damage to the developing brain and ultimately lead to a diagnosis of the condition. Diseases and conditions that don’t always have one definitive cause are often described as arising from a causal pathway. One event, condition, or a combination of events and conditions makes it more likely the child develops the condition known as cerebral palsy.
As an example, one of the biggest risk factors for cerebral palsy is a premature birth. Statistically, this is known to be a significant risk factor because a large percentage of children diagnosed with cerebral palsy were born prematurely. Higher rates of cerebral palsy are seen in premature babies compared to term babies. Premature birth does not cause cerebral palsy, but it is often associated with certain conditions common in premature infants such as bleeding on the brain and poor lung development.
An important concept of causal pathways is that risk factors are interconnected. Researchers are trying to figure out how one risk factor can cause conditions that magnify or lead to other risk factors. For instance, a risk factor for cerebral palsy is an abnormal presentation at the time of birth, such as breech position. If a baby is in the breech position, the doctor has to decide how to proceed safely. The breech position could lead to the doctor to choose to use forceps as opposed to performing a Cesarean section. The use of forceps to deliver the baby is another risk factor for cerebral palsy. One risk factor leads to another.
Examples of Cerebral Palsy Causal Pathways
Causal pathways that are associated with cerebral palsy can be very complicated because there are so many possibilities. One risk factor could be associated with a number of other risk factors and every individual and pregnancy presents new possibilities for risk factors and resulting pathways. This has made it difficult for experts to sort out the causes of cerebral palsy and how to prevent it.
An example of a causal pathway that ultimately leads to cerebral palsy might begin with a mother’s lifestyle and health choices, known risk factors for the condition. A mother may make the choice to ignore symptoms of an infection while pregnant. She finally gets treated, but only after developing a bad fever. The fever may trigger inflammation in the developing fetus and the production of proteins called cytokines. Cytokines circulating in the fetus can cause it to be less able to tolerate any deprivation of oxygen. During delivery, a minor complication, like the mother’s drop in blood pressure, could result in the baby temporarily lacking oxygen. In another baby this may not have any lasting effects, but in this particular child it may be enough to cause the damage that leads to cerebral palsy.
A Need to Understand Causal Pathways
Prior to the 1980’s cerebral palsy and its complications increased as survival for premature babies improved. In 1980 the rate of cerebral palsy was approximately 61 per 1000 live births among very low birth weight infants (<1500 grams). Improvements in prenatal care led to decreases in cerebral palsy to approximately 40 per 1000 live births in the same low weight category. Another study showed a decrease in cases of cerebral palsy from 155 per 1000 in the early 1990s to 16 per 1000 in the early 2000s. These improvements were seen despite overall decreased birth weight, more multiple births and increases in survival among premature infants. Among late preterm and term infants, the rate of cerebral palsy was unchanged and stable when comparing the 1980s to the early 2000s.
Cerebral palsy is multifactorial with most cases a result of factors that occur in the prenatal period. While prematurity is the most common risk factor, the following are also know risk factors for the development of cerebral palsy:
- Intrauterine growth restriction
- Intrauterine infection
- Abnormalities of the placenta
- Multiple pregnancy
- Bleeding before birth
According to researchers, the frequency of cerebral palsy has not gone down in recent years. Despite more and more research, an increased understanding of risk factors and what causes cerebral palsy, and ever-evolving medical technology, experts are failing to prevent cerebral palsy in many children. It has become clear that simply understanding individual risk factors is not enough.
Prevention of individual risk factors has failed to prevent cerebral palsy, but if there is a better understanding of the pathways that lead to it, preventative measures may be more effective. Researchers and doctors need to know how one risk factor leads to another, and how this complicated pathway comes together to create the conditions in the brain that cause cerebral palsy.
Implications for Prevention and Negligence
The growth in understanding of cerebral palsy causal pathways is important in better understanding how to prevent this common disability. But it also makes prevention more complicated and challenging. It may not be possible to prevent cerebral palsy by targeting one or two risk factors. It may require a fuller understanding of how one of these factors may lead a child down one of multiple possible pathways.
Because cerebral palsy may result from many different combinations of risk factors, it puts a lot more responsibility on parents. Long before you even conceive, it is important to understand the risk factors for cerebral palsy so that you can make all the best decisions to minimize the risk for your child.
This means that the role of good cerebral palsy lawyers becomes more important than ever before. If you find that your child has cerebral palsy and you believe that somewhere along the line your doctor made a mistake, you need this professional on your side more than ever before.