Cumulative effects of repetitive mild traumatic brain injury.

The majority of traumatic brain injuries (TBI) in the USA are mild in severity. Sports, particularly American football, and military experience are especially associated with repetitive, mild TBI (mTBI). The consequences of repetitive brain injury have garnered increasing scientific and public attention following reports of altered mood and behavior, as well as progressive neurological dysfunction many years after injury. This report provides an up-to-date review of the clinical, pathological, and pathophysiological changes associated with repetitive mTBI, and their potential for cumulative effects in certain individuals.