Traumatic Brain Injury and Post-Concussive Syndrome

Head trauma is a common cause of morbidity and mortality. Approximately 2 million head injuries occur per year in the United States, and 25% of them require inpatient hospital treatment. A concussion is a head injury associated with a transient loss of consciousness. The neuropathological correlate of a concussion is diffuse axonal injury, i.e., a shearing force injury to longer axons of the cortex and subcortex of the brain. In other words, imagine a bowl of jello (i.e., the brain and skull) struck from the side—the jello will be subject to a variety of shock waves with different vectors changing its internal structure. This correlates with the effects of diffuse axonal injury in the brain. Approximately 50% of mild head injuries with or without loss of consciousness progress to the post-concussive syndrome. ¹