Traumatic Brain Injury

Geoffrey Ling, MD, PhD, FAAN, FANA

I have the honor of prefacing this issue of Seminars in Neurology that is focused on traumatic brain injury (TBI). Traumatic brain injury has afflicted humans since the advent of man. Despite this, only recently has it reached prominence among medical professionals and the lay public. This interest is largely due to the recognition that TBI was prevalent among service members deployed to the wars in Iraq and Afghanistan. Within this same time frame, professional athletics also noted that TBI was common among players—both active and retired. With this attention has come a call for action to develop effective prevention strategies and clinically meaningful therapies, including a cure.

In this issue of Seminars in Neurology, TBI is discussed broadly from basic mechanisms to clinical care. The first set of articles reviews TBI mechanisms and neuropathology. The opening article focuses on the biophysical mechanisms leading to TBI. Traumatic brain injury is a result of physics exceeding the capacity of biology to resist. For this reason, it is appropriate that this is how the TBI topic is introduced. The authors are engineers who have done critical work studying TBI physics, especially as it pertains to explosive blast injury. The fact that they are not biologists speaks to the multidisciplinary approach that must be taken if this condition is to be fully understood and overcome. The next article is on the cellular and biochemical mechanisms that result in TBI neuropathology and consequent neurologic deficits. Neuropathology follows. Depending on the type of TBI suffered, brain pathology may be vastly different. Clearly TBI is a heterogeneous condition. One very important emerging neuropathological finding is chronic traumatic encephalopathy. The next series of articles is on the clinical management of TBI victims. It begins with mild TBI or concussion. This is a rapidly developing area of neurologic care. As the authors discuss, these patients must be treated with best medical practices that are evidence based and delivered by expert clinicians. Following this contribution is an article focused on moderate to severe TBI, which has previously resulted in universally poor clinical outcomes. However, following the introduction and adoption of clinical practice guidelines, clinical outcome has significantly improved. These guidelines are updated regularly with medical advances. Epilepsy is a common complication of TBI, but fortunately can be controlled. Under appropriate circumstances, neurosurgical intervention can lead to dramatic improvement in survival and neurologic state. For TBI patients who have survived the subacute period, rehabilitation is critical for optimal outcome. Rehabilitation and chronic medical management of TBI survivors can result in highly functional lives. Neuropsychiatric consequences of TBI and how best to manage them needs to be part of every comprehensive TBI discussion. Finally, what is the potential of research in finding an effective neuro rescue or neuroprotection medication? This quest for a neuroprotective agent that is effective in humans has a history of disappointment, yet holds the greatest potential for improving patients' lives; the final article describes leading candidates presently under investigation.

It is our hope that this TBI issue will provide the reader with a better understanding of TBI mechanisms, and how to properly and effectively medically manage this affliction and provide hope to patients that meaningful medications are on the horizon. The most important lesson from these discussions is the realization that TBI is a treatable condition and if treated properly, meaningful recovery is very possible.