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.
Keywords: 18F-FDDNP = 2-(1-{6-[(2-[fluorine-18]fluoroethyl)(methyl)amino]-2-naphthyl}-ethylidene)malononitrile; AD = Alzheimer's disease; APOE = apolipoprotein E; ASL = arterial spin labeling; BBB = blood-brain barrier; BOLD = blood oxygen level–dependent; CA = cornu ammonis; CTE = chronic traumatic encephalopathy; DTI = diffusion tensor imaging; FA = fractional anisotropy; GFAP = glial fibrillary acidic protein; GRE = gradient recall echo; MRS = MR spectroscopy; NFL = National Football League; NFT = neurofibrillary tangle; NINDS = National Institute of Neurological Disorders and Stroke; NSE = neuron-specific enolase; SWI = susceptibility-weighted imaging; TDP-43 = TAR DNA–binding protein 43; biomarkers; chronic traumatic encephalopathy; concussion; fMRI = functional MRI; imaging; mTBI = mild traumatic brain injury; miRNA = microRNA; neurodegeneration; p-tau = phosphorylated tau; sports; traumatic brain injury.