Scientists are advancing imaging and blood tests to definitively diagnose chronic traumatic encephalopathy (C. T. E.) in living patients, a breakthrough that could guide treatment for memory loss, mood swings, and erratic behavior.

Hundreds of cases, mostly professional football players, have been confirmed only post‑mortem, limiting therapeutic research. Recent studies suggest up to a quarter of N. F.

L. players—about 400 individuals—may develop C. T. E., raising urgency for early detection.

Researchers are focusing on PET scans and radiochemical tracers that can bind to C. T. E.’s unique tau protein clusters, distinguishing them from Alzheimer’s tau. Dr. Neil Vasdev’s team at the Brain Health Imaging Centre in Toronto demonstrated that tracer OXD‑2314 safely enters the brain and is now being tested in patients with tau accumulation.

Simultaneously, Dr. Julian Bailes in Evanston, Ill., is developing a biomarker for C. T. E. visible on PET scans, with a Phase 3 trial underway.

These tools could identify at‑risk groups—high‑school athletes, soccer players, military personnel—and assess treatment efficacy, offering new hope for patients currently diagnosed only after death.