Sports-related Brain Injuries: Connecting Pathology to Diagnosis

James Pan, BS; Ian D. Connolly, MS; Sean Dangelmajer, BA; James Kintzing, BS; Allen L. Ho, MD; Gerald Grant, MD


Neurosurg Focus. 2016;40(4):e14 

In This Article

Abstract and Introduction


Brain injuries are becoming increasingly common in athletes and represent an important diagnostic challenge. Early detection and management of brain injuries in sports are of utmost importance in preventing chronic neurological and psychiatric decline. These types of injuries incurred during sports are referred to as mild traumatic brain injuries, which represent a heterogeneous spectrum of disease. The most dramatic manifestation of chronic mild traumatic brain injuries is termed chronic traumatic encephalopathy, which is associated with profound neuropsychiatric deficits. Because chronic traumatic encephalopathy can only be diagnosed by postmortem examination, new diagnostic methodologies are needed for early detection and amelioration of disease burden. This review examines the pathology driving changes in athletes participating in high-impact sports and how this understanding can lead to innovations in neuroimaging and biomarker discovery.


Many sports-related brain injuries involve mild traumatic brain injuries (mTBIs), which result from physical blows to the head sustained over a period of time. Sports associated with an increased risk of head injury include American football, ice hockey, soccer, rugby, the martial arts, boxing, and bicycling.[21,90] These injuries are often unrecognized, undiagnosed, or underreported, which reflects the fact that this is a growing medical concern, often labeled a "silent epidemic."[8,66] Chronic exposure to mild brain injuries can result in long-term neurological consequences and represents a spectrum of disorders. The most remarkable outcome of mTBI is termed chronic traumatic encephalopathy (CTE), a clinical syndrome that is associated with neurodegeneration and behavioral, cognitive, and/or motor deficits. Although this disease has distinct pathological features, CTE is considered a diagnosis of exclusion because only postmortem biopsies can confirm the diagnosis. Therefore, new diagnostic methods need to be developed to: 1) inform patients of a definitive diagnosis, 2) better understand the epidemiology and risk factors of the disease, and 3) implement intervention programs to prevent any potential long-term complications. This review examines how understanding the pathology and molecular changes associated with repeated head trauma can lead to the discovery of novel imaging techniques and biomarkers.