Over recent years, great strides have been made in improving emergency, acute rehabilitation, and community care. We have furthered our understanding of the pathophysiology of traumatic brain injury (TBI). Neuroimaging capability has advanced our capacity to determine the brain's response to therapies. The available pharmaceutical agents have broadened. Studies in stroke point to motor recovery in chronic stroke. However, our patients with residual impairments teach us that we are only partly down this road of optimizing care. Thankfully, we often observe "remarkable recoveries" both early after injury and as time passes after injury. It is unclear who will recover and what is attributable to such changes. It is also not clear how to best promote such gains. There is a pressing need to determine effective methods to promote recovery after TBI.
Animal research is providing a wealth of information and potentially beneficial and detrimental therapies about TBI. Unfortunately, for many reasons, the translation to clinical care has lagged behind. With such concurrent problems as substance abuse, comorbid conditions, and prior injuries, the human body and its environment is clearly more complex than that for the research animal. There is a need for more funds to be dedicated to clinical research, and for more clinicians to undertake quality research in this arena. There is need for effective application of what we are learning in the basic sciences to the clinical care of people with brain injury.
The purpose of this special issue is to summarize four areas of basic science research with direct implications to the care of TBI: Diffuse axonal injury, neuroplasticity, neuropharmacology, and neural growth factors and transplantation. These summaries review what we have learned over the years, new research directions, relevant clinical research, and clinical care implications. Each article provides thought-provoking perspectives with clinical relevance, expanding our beliefs and encouraging new approaches.
Dr. Smith and colleagues review one of the most fundamental pathophysiologic issues of TBI: diffuse axonal injury (DAI). The evolution of this problem over time after injury is discussed, along with its implications for recovery. Evidence for a potential link with Alzheimer's disease is outlined. And DAI is discussed in light of injury severity with a stimulating discussion of mild TBI and the concept of a "DAI syndrome" is introduced.
Drs. Stein and Hoffman provide a thorough overview of neuroplasticity. This is such a topic of interest that the literature has exploded in this arena and the term has many interpretations. These authors review the many aspects of this topic, including current theories and methods, and discuss emerging findings of neurosteroid use in TBI.
Animal research has shown noradrenergic agents to augment recovery when combined with the appropriate environment/therapy experience, whereas a noradrenergic agonist has a detrimental impact on recovery. This research and the studies in this area are reviewed by Dr. Phillips and colleagues in light of the alteration in neurotransmitters that accompanies TBI. This important topic has direct implications to the daily clinical care of individuals with TBI. There is obvious relevance in applying this knowledge to promote more optimal recovery. This research also points to important considerations in the management of problems caused by the injury such as sleep disturbance, agitation, depression, spasticity, and hypertension.
Dr. Lu and colleagues update us on the progress made in research on neural growth factors and cell transplantation. They review the effects of these agents from the biochemical, cellular, and tissue levels. This rapidly growing and complex area of research is one of the many areas holding promise to further the recoveries from TBI. This article sheds light on the alphabet soup of growth factors and the potential role rehabilitation in augmenting outcomes.
My appreciation goes out to the authors who have helped bring this important basic science research into the realm of clinical rehabilitation, challenging each of us to ponder what we have learned and where we can go to further the lives of those affected by TBI.