Though we have made progress in recognizing what does not cause autism, little is currently known about what does cause most cases of autism. It is known that there is no single cause of the condition. In general, it is accepted that autism is related to structural differences in the brain, though not much is understood about the specific differences. Research suggests that autism may be caused by “a combination of genetic or nongenetic, or environmental, influencers.” And, while certain environmental factors are thought to increase risk, this is certainly not the same thing as directly causing autism. It’s well known that all of these factors affect brain development and communication between different regions of the brain, but the specific mechanisms are not as well-understood.
Using MRI scans to understand autism in the brain
Researchers are beginning to understand more about the biological differences in people with autism. A study published in Radiology details the findings of advanced brain scans performed on people with autism, as well as their family members who do not have autism and a control group. Magnetic resonance imaging scans, or MRI scans, produce very detailed images of the brain. These scans are used to diagnose a variety of conditions, as well as plan or assess treatments. However, the scans can have other purposes. In the case of this study, the radiologists performed the scans in order to closely examine the structures of the brains of the people involved. This was “the first major study of its kind.”
One of the understood genetic components of autism is that some people with autism have “abnormalities at a specific site on the 16th chromosome.” Both deletion or duplication of a piece of the chromosome at this site are related to autism. For this study, the researchers conducted MRI scans of 79 deletion carriers, ranging in age from 1 to 48, and 79 duplication carriers, ranging in age from 1 to 63. They also examined 64 family members of the carriers who do not have any chromosomal abnormalities, and 109 people in a control group. In addition to the scans, “participants completed a battery of cognitive and behavioral tests.”
Traits of chromosome duplication or deletion
There’s certain structural differences often associated with the chromosomal duplication or deletion. People with the deletion tend to have brain overgrowth, which is associated with developmental delays and increased risk of developing obesity. The opposite is typically associated with a chromosomal duplication. People with a duplication are born with smaller brains, and often have a lower than average body weight in addition to developmental delays also seen with chromosomal deletion.
These qualities were confirmed in this study. The MRI scans showed “striking differences” between the brain structures of those who were carriers for the duplication and deletions and non-carriers.
However, not everyone who is a carrier for the duplication or deletion has these results. Some people can be carriers for the chromosomal abnormality and still not have any structural abnormalities in the brain. This caveat was key to the researcher’s findings that brain structure certainly plays a role in behavioral outcomes. They found that the results from the cognitive assessment for carriers of the deletion whose scans showed radiological abnormalities “indicated worse daily living, communication and social skills” compared to people that are carriers for the deletion, but showed no radiological abnormalities. For the duplication carriers group, radiological abnormalities were associated with “decreased full-scale and verbal IQ scores, compared to duplication carriers without [the abnormalities].”
Therefore, the abnormal structure of the brain is the factor that is associated with cognitive and behavioral difficulties, not simply being a carrier for the chromosomal abnormality.
What do these findings mean?
This information helps researchers get one step closer to identifying the causes of autism. Additionally, it means that brain scans may eventually be able to be used to identify autism in the future. It could also help identify autism earlier in life, which means that people could begin receiving treatment earlier and hopefully have better long-term outcomes.
Early treatment is key for many people living with autism, although the exact treatment varies to fit the individual’s needs. Most therapies involve a combination of social skills training, speech language therapy, and occupational therapy. Some people also find alternative approaches, such as music therapy, helpful for things such as social interaction and communication. It’s ideal for parents, teachers, and therapists to all work together to develop an integrative therapy plan to best suit a child’s needs.
For many people, the earlier therapy can begin, the better. Early intervention is likely to increase success with social skills and daily function throughout the life of someone with autism. Because it can make such a lasting impact to start early, diagnosis via the MRI or other imaging techniques could help people identify their autism and begin therapy as early as possible, rather than waiting until later in life to be diagnosed with autism.
It’s also important to note that treatment doesn’t necessarily stop as children with autism grow up and enter adulthood. Though some adults develop skills and coping strategies over their lifetime and no longer need treatment for their autism, others certainly do. Again, it’s highly variable based on the individual person. Sometimes it isn’t necessarily treatment that someone needs, but assistance to make daily tasks doable without extreme discomfort. For example, given the sensory differences many people with autism experience, they may need a special room to work in the office where they can control the lighting or noise level. Others with more serious cognitive difficulties may need caretakers to assist them at home once they are no longer living with their parents or childhood caretaker.
Autism affects every person differently, but proper therapy and tools to succeed are important for everyone. Developments such as those made by the radiologists are a step in the right direction to identify the problem early and make sure that everyone is getting the help they need.