05/12/2020
By Katharine Webster

Each year in the United States, more than 2.5 million people are diagnosed with traumatic brain injuries (TBIs), yet there’s no clear agreement on how to evaluate or treat those injuries.

Psychology Prof. Stephen Balsis is part of a research team that is working to change that. With a $3.74 million grant from the National Institutes of Health, the researchers are trying to better understand the relationship between physical changes caused by TBIs and the ability to perform routine tasks, also known as “functional ability.”

Currently, TBI diagnosis is primarily based on symptoms, sometimes followed by testing, including brain scans and blood tests. Through their research, Balsis and the other scientists hope to establish and refine systematic standards for diagnosing different degrees and subtypes of TBIs based on biological markers, not just symptoms. That will also allow them and future researchers to better measure patient outcomes.

“We know that TBIs can lead to changes in the brain, changes in mood and changes in functioning,” Balsis says. “With better criteria for categorizing them, we can measure with more precision the effectiveness of treatments. We can also gain a better understanding of the disease itself, including how physical changes correspond to the patient’s subjective experience.”

Under the grant, which is led by Assoc. Prof. Lindsay Nelson, a neuropsychologist at the Medical College of Wisconsin, Balsis is analyzing existing data from a drug trial on TBI patients as well as new data that the research team is collecting at several hospitals, including blood samples, genetic information and results of neuroimaging tests. Patients will be followed for a year and also asked to self-report their symptoms.

Once the diagnostic criteria are refined, that should allow other researchers looking at potential treatments to evaluate whether a specific drug or other intervention can help patients with different types of TBIs and more or less severe injuries.

Balsis says that after the initial analysis is complete, the research group will try to figure out why some people with similar types and levels of injury exhibit fewer symptoms or recover more quickly and completely. One possibility is “cognitive reserve,” the brain’s capacity to find alternate neurological pathways around damaged areas. Cognitive reserve is generally greater in people whose brains are better developed, whether through greater intellectual ability, activity or both.

“The hypothesis that greater cognitive reserve leads to better functioning is supported at least partially in Alzheimer’s disease,” Balsis says. “Physical exercise can be very helpful as well. It might also just be the brains you had at the beginning – a lot of it seems to be genetic.”

The research into TBIs is a new area for Balsis, a geriatric psychologist whose specialty is applying advanced statistical analysis to complex and variable data. But it’s a good fit, because Balsis has spent more than a decade researching Alzheimer’s disease, beginning when he was a Ph.D. student at Washington University in St. Louis.

The symptoms of Alzheimer’s are similar to the type of dementia found in people with advanced chronic traumatic encephalopathy (CTE), a progressive disease involving permanent brain changes caused by repeated impacts to the head.

Research on TBIs and CTE has grown in recent years, driven by concern about blast injuries suffered by members of the military and the long-term effects on athletes competing in sports that involve frequent hits to the head, such as football, soccer and boxing.

The more head impacts a person sustains – whether or not those impacts result in concussion – the more likely that person is to develop CTE, a slow-moving but relentless deterioration of the brain marked by symptoms including memory loss, confusion, poor judgment, tremors similar to those found in Parkinson’s disease, erratic and aggressive behavior, depression and suicide.

CTE symptoms can emerge years or decades after the last injury and they worsen over time, ultimately resulting in dementia.

Currently, CTE cannot be definitively diagnosed until after death, through an autopsy. Thus, it’s vitally important to better understand, diagnose and treat traumatic brain injuries that could lead to CTE, Balsis says.

TBIs themselves are underdiagnosed, especially when no immediate or obvious symptoms result. That doesn’t mean there’s no underlying and permanent damage, though, he says.

“CTE will often develop over the course of many, many years, so it’s going to take a lot of effort from the government and a lot of researchers over many years to understand it. And it would be nice if the incidence of traumatic brain injuries decreased over that period,” Balsis says.