Wednesday, January 24, 2018 Study: Concussions Aren't the Link to CTE New research on chronic traumatic encephalopathy (CTE) concludes that it's not concussions that cause the condition, but repeated traumatic brain injuries (TBIs)—the kind experienced by more people than just those involved in contact sports. Authors of the study also call for more clarity when it comes to concussion—which they describe as a syndrome—versus TBI, a tissue-damaging event that can happen with or without concussion. The study, published in the journal Brain, is based on head trauma experiments on mice, as well as an analysis of several brains of teenagers who had experienced head injuries. Researchers were looking for the presence of CTE or an abnormal accumulation of tau protein, a marker for CTE and Alzheimer's disease. They found those indicators even in brains that had not experienced concussions, leading researchers to conclude that it is repeated TBIs that can cause CTE. The results grabbed the attention of national news outlets, including CNN, National Public Radio, and The Washington Post. "The results may explain why approximately 20% of athletes with CTE never suffered a diagnosed concussion," Lee Goldstein, MD, PhD, 1 of the study's authors, told The Washington Post. "There are many vulnerable populations at greatly increased risk of repetitive head injury," Goldstein said in the Post interview. "It's a big problem for the [National Football League], a bigger problem for amateur athletes, and even larger problem still for the public." The study also aims to separate the concept of concussion as a neurological syndrome from TBI as an event that causes damage to tissue. In his Post interview, Goldstein explained that "If you don't have a concussion, you can absolutely have brain injury and the reverse is true." "Collectively, these results raise concern that repetitive neurotrauma, independent of concussion, may induce early CTE brain pathologies, even in teenagers and young adults," authors write in the study. "Cumulative exposure to such injuries may also increase risk for other tau protein neurodegenerative diseases, including Alzheimer’s disease…. These considerations are important not only for understanding and differentiating concussion, TBI, and CTE, but also to inform clinical practice, return-to-play protocols, and public health policy." For more information on the role of the physical therapist and physical therapist assistant in TBI and concussion, visit APTA's Concussion and Traumatic Brain Injury webpage.