Although the cause of autism remains a mystery, one theory is that early brain injury could result in the disorder. A few studies have indicated this could be the case although the results are still far from conclusive. More study is needed to determine whether there is a link, but it's helpful to understand the research that's been done so far.
Autism and Brain Injury Can Look Similar
Autism is a neurological disorder, which means it affects functioning in the brain. A person with ASD may have normal or above normal functioning is some areas and significant challenges in others. This is similar to brain injury, which sometimes affects parts of the brain while leaving other parts untouched. ASD is a developmental disability, which means it affects an individual during key areas of development. Brain injury can happen at any time in life.
Shared Characteristics and Treatment
A 2016 article in the journal Behavioral Neurology explored the many similarities between traumatic brain injury (TBI) and autism, including how the two disorders are treated. There are many symptoms common to both, including anxiety, learning challenges, executive functioning problems, and sensory processing difficulties. The treatments that work for one disorder can also help with the other. However, the article does not draw any causative connection between TBI and autism.
It's important to note this article found a few areas that TBI and autism did not have in common. This included one of the key diagnostic characteristics of autism, repetitive and restrictive behaviors. Those with TBI did not typically display this quality.
The Role of the Cerebellum
A review of the literature published in the journal Neuron in 2014 proposes pre-natal injury to a specific portion of the brain, the cerebellum, may be related to autism. The review underscores the role of the cerebellum, which is located in the back of the brain, in relation to sensory input, social interaction, and facial expression recognition. These are all related to characteristics of autism. Additionally, the researchers note the cerebellum may affect how other areas of the brain develop, resulting in a cascading effect of deficits in a variety of areas.
The researchers propose prenatal injury could occur as a result of maternal stress or autoimmune response and manifest itself later as ASD. They note more research is needed in this area.
Birth Complications and Autism
Another possible link between brain injury and ASD involves birth complications, especially oxygen deprivation or cerebral hypoxia. This is different from traumatic brain injury, which usually happens as the result of an accident or specific injury. Cerebral hypoxia can begin only five minutes after the loss of oxygen and can result in significant brain injury.
A 2017 study published in the American Journal of Perinatology found birth complications, including oxygen deprivation, were linked to a higher risk of a later ASD diagnosis. However, the study established a correlation and did not propose autism was caused by birth complications.
More Research Needed
Ultimately, brain injury and autism have many, but not all, characteristics in common. A possible link between the two still needs to be explored with more research. A prenatal injury to the cerebellum, a loss of oxygen during delivery, or another factor might be involved in the development of ASD. However, research has not proven that link yet.