Well before popular media began reporting on chronic traumatic encephalopathy in professional athletes, Cleveland Clinic Lou Ruvo Center for Brain Health was working on Diagnose CTE, a study that aims to detect underlying changes in the brain during life.

Chronic traumatic encephalopathy (CTE) is the term for the brain changes neuropathologists can see in individuals who have been exposed to repetitive head trauma. Those with CTE have deposits of tau protein in the brain’s frontal lobes and basal ganglia, the regions that govern behavior, emotion and executive function.

Currently, CTE can be diagnosed only after death, which presents a challenge for physicians evaluating brain health in athletes in a clinical setting. Recently, a panel of experts developed clinical criteria based on the symptoms that people who had CTE at autopsy were known to experience during life. This constellation of symptoms in the living is known as traumatic encephalopathy syndrome (TES).

A road map for evaluating brain changes
Physician-scientists from the Lou Ruvo Center for Brain Health, in collaboration with Boston University, the Mayo Clinic and New York University, contributed to the 2021 publication in the peer-reviewed journal Neurology of these first consensus criteria on TES.

“Thanks to a group of researchers across multiple institutions, we can now diagnose and study people with behavioral and cognitive changes after repetitive head impact,” says Lou Ruvo Center for Brain Health neuropsychiatrist Aaron Ritter, MD. “Now we can look more closely at the biological changes that might be underlying CTE. This is a big step for the field, and will hopefully allow us to better understand brain trauma in living patients.”

Based on the newly established criteria, to be diagnosed with TES, an individual must have:

• Significant exposure to repetitive head trauma (such as more than five seasons playing football or multiple blast injuries during military service), and
• Progressive changes in memory, or
• Behavioral dysregulation, such as explosive temper or irrational actions

An urgent public health issue
Researchers believe that repetitive injuries start a cascade of changes in the brain, leading to the slow, progressive destruction of brain tissue and associated changes in cognitive function, mood and behavior. When these changes become severe enough, they may lead to dementia.

Dr. Ritter says the TES consensus criteria will assist in differentiating CTE from similar disorders such as Alzheimer’s disease, as well as in clarifying the causes and specific risk and resilience factors for developing this neurodegenerative disease.

Researchers recognize CTE as a pending public health concern, given the prevalence of contact sports participation among today’s youth as well as the risk to soldiers exposed to blast injuries and to others who might experience repetitive head trauma, such as victims of domestic violence.

“Despite the excitement in the science community around consensus diagnostic criteria for TES, we still need further research,” says Dr. Ritter. “Ultimately, our goal, and the aim of the Diagnose CTE study, is to move CTE from being a purely pathological diagnosis to something we can see, treat or prevent during life, and to do everything we can to make sports as safe as possible.”

Photo: Lou Ruvo Center for Brain Health neuropsychiatrist Aaron Ritter, MD, Courtesy of Cleveland Clinic