CTE Study

Boston University Study Provides First Window into Cognitive Impairments People Experience from Autopsy-Proven CTE

Researchers at Boston University have completed the largest study to date characterizing the cognitive symptoms of NFL players with confirmed chronic traumatic encephalopathy (CTE) who underwent neuropsychological tests while they were alive. CTE is the neurodegenerative disease linked to repeated head impacts that cannot yet be diagnosed accurately during life in part because its specific symptoms need to be determined.

This has important implications for former players seeking diagnosis and potential compensation through the NFL Concussion Settlement.

Michael Alosco, PhD

The study examined 33 NFL players who were diagnosed with CTE at autopsy and completed the NFL Concussion Settlement’s testing program known as the baseline assessment program (BAP). Their average age at the time of testing was 63, and their average age of death was 65. As part of the BAP, players completed a standardized paper-and-pencil neuropsychological test battery. The families of the 33 participants who donated their brains also provided the participant’s BAP assessment records. The researchers used this objective battery to complete the largest study to date linking cognitive test performance during life with CTE confirmed after death. The study provides important information on the type of thinking skills believed to be most impacted by CTE.

This is the largest study of its kind to directly link the amount of CTE pathology found at autopsy with objective cognitive testing during life.

Anna Aaronson

The results were published in JAMA Network Open.

Memory problems were the most common finding, affecting 63% of participants with autopsy-confirmed CTE, particularly short-term memory. More advanced CTE was associated with worse memory performance. Researchers also found impairments in executive function (52%), language (41%), and attention (26%). Because CTE can currently only be definitively diagnosed after death, identifying the pattern of cognitive changes associated with the disease is an important step toward improving diagnosis during life.

“This is the largest study of its kind to directly link the amount of CTE pathology found at autopsy with objective cognitive testing during life,” said Anna Aaronson, lead author and a PhD student at the Boston University CTE Center. “These findings provide an important roadmap for recognizing CTE in living patients.”

Researchers also identified potential limitations related to the NFL Concussion Settlement’s testing program, which is a program that can help players receive financial compensation for cognitive decline. Many players who showed measurable cognitive impairment on standardized testing, and were ultimately confirmed to have CTE at autopsy, did not meet the settlement’s criteria for cognitive impairment. Seven participants had advanced CTE (stage 3 or 4). Six showed measurable cognitive impairment on testing, yet all seven received the BAP’s lowest impairment rating (Level 0). Differences between the settlement’s scoring rules and clinical standards typically used to diagnose cognitive disorders may contribute to suboptimal identification of former players deserving of support.

“The BAP’s diagnostic criteria might miss cases of cognitive impairment that are objectively measurable and associated with confirmed CTE pathology,” said Michael Alosco, PhD, co-director of clinical research at the BU CTE Center. “This has important implications for former players seeking diagnosis and potential compensation through the NFL Concussion Settlement.”