Has Brain Imaging Worked in Any Other Disorder?
The ability to image the structure and function of a brain has existed for decades. Although all of the brain imaging techniques are now being used to study autism, this has not always been the case. One other brain-based disorder has been more extensively scrutinized, and thus more progress has been made; this is Alzheimer’s disease (AD). Here, we look at progress made in AD as it is likely to be instructive about the possible progress of similar studies in autism in the next decade.
Early intervention by brain-based biomarkers
AD is the most common form of dementia (a serious loss of skills or knowledge) worldwide. AD is incurable, gets worse over time, and is eventually terminal. Brain imaging studies have clearly shown that the hippocampus (an area of the brain) is likely to cause the behavioral effects in AD. These studies have also found that there is a period of time (called the pre-symptomatic stage) that lasts for years before there is noticeable memory loss. Looking at the hippocampus of patients in the pre-symptomatic stage has uncovered clear changes in brain structure and function that can be detected using brain imaging methods. In the best cases, these studies have essentially resulted in brain-based signatures (or biomarkers) that can be detected before a patient has any symptoms. Similar to early therapy for autism, there are clinical methods that can be used for AD, and these have a stronger effect if used earlier. Currently, there are formal proposals to incorporate brain imaging studies as part of the diagnosis of AD, including in early diagnosis.
AD has a strong genetic component, meaning that it can be inherited through families. However, researchers have found that there is clearly an environmental effect as well. That is, there are certain conditions (such as the presence of a particular toxin) that can intensify the memory loss for some individuals. Researchers have tried to find a link between a certain genetic background and susceptibility to a toxin. However, recent work in the AD field has found that brain imaging studies can be effectively used to predict which environmental factors a particular person would be more susceptible to. Practically speaking, this means that an individual with AD can use the results of their own brain imaging studies to identify which toxins they should try to avoid. Although it is not yet clear whether the same type of “toxin-avoidance” suggestion could be made for autism in the future, it is clear that brain imaging studies have the potential to provide individualized information to a patient.