WEDNESDAY, May 20, 2026 (HealthDay News) -- Traumatic encephalopathy syndrome (TES) has poor performance for predicting chronic traumatic encephalopathy neuropathological change (CTE-NC), according to a study published online May 14 in Nature Medicine.John D. Arena, M.D., from the University of Pennsylvania in Philadelphia, and colleagues reviewed antemortem clinical records for 1,038 cases in a neurodegenerative brain bank to examine the diagnostic accuracy of TES criteria for predicting CTE-NC. In all cases, neuropathological evaluation for CTE-NC was then conducted.The researchers found that 25 cases (2.4 percent) met the criteria for TES diagnosis, six of which demonstrated CTE-NC (positive predictive value, 24.0 percent). CTE-NC was present in seven of the remaining 1,013 cases (0.69 percent). The diagnostic accuracy of TES for CTE-NC was due to exposure to repetitive head impacts as opposed to clinical features. No differences were seen in the prevalence of core or supportive clinical features of TES among CTE-NC cases versus a matched sample."Before we can responsibly diagnose CTE in living patients, we need a much clearer understanding of how the disease develops and which symptoms it truly causes," Arena said in a statement. "The necessary next step is prospective longitudinal research that follows people during life, carefully documents head injury exposures and symptoms, and then assesses for neuropathology after death."Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter