Mild Traumatic Brain Injury and Postconcussion Syndrome: The New Evidence Base for Diagnosis and Treatment

This book is a concise and accessible overview of the current state of knowledge about mild traumatic brain injury (MTBI). The target audience is clinicians and researchers in the fields of emergency medicine, neurology, neuropsychology, psychiatry, and rehabilitation medicine. It is not specifically tailored to the forensic practitioner, but contains useful information for forensic psychiatrists and psychologists.

The topic is timely, given the large number of military personnel and veterans who have sustained traumatic brain injuries in the conflicts in Iraq and Afghanistan. In response, the Department of Veterans Affairs has initiated a wide-ranging screening process to identify veterans with potential TBI and to develop protocols for their clinical management.

Each of the book's four sections contains three to seven chapters. In Part One, “The TBI Landscape,” author Michael McCrea sets the stage by discussing the epidemiology of traumatic brain injury, reviewing classification schemes for grading injury severity, and introducing recent research paradigms that have significantly advanced the understanding of MTBI. The study of sports injuries has provided an excellent real-life laboratory for the systematic study of MTBI, and the book's author has an active research program in this area.

Part Two, “Basic and Clinical Science of MTBI,” reviews the neuroscience of MTBI, providing an overview of the pathophysiology of this disease entity and examining the role of neuroimaging in research, diagnosis, and follow-up evaluation.

Parts Three and Four, totaling 14 chapters, offer a wealth of information about the diagnosis, management, and course of MTBI and postconcussion syndrome (PCS). Part Three, “The Natural History of MTBI,” contains a detailed description of early symptoms of MTBI, the time course of recovery, and long-term outcome. In Part Four, “Implications for Rethinking Postconcussion Syndrome,” the author lays out evidence for what is likely to be the most controversial assertion in the book: that PCS is a neuropsychological disorder, rather than a discrete neurological entity secondary to subtle organic damage.

One of the main thrusts of the book is distinguishing MTBI from moderate and severe traumatic brain injuries. The results of older studies were often confounded by the lumping together of injuries of various severities. Early on, the author states: “[T]he body of work on MTBI over the past decade suggests that MTBI may be a different animal altogether from moderate and severe TBI.” The difficulties inherent in classifying injuries as mild versus moderate and the limitations of existing classification systems are explored.

Once the groundwork has been laid in Parts One and Two, McCrea marshals evidence for the conclusion that MTBI is most commonly associated with complete functional recovery. For example, combined data from three prospective studies, conducted by his research group, of sports-related concussions in over 650 high school and college athletes indicate that only three percent of subjects had persistent signs or symptoms lasting more than one month after injury.

For the forensic audience, Parts Three and Four are likely to be the most interesting and relevant sections of the book. The author demonstrates in Part Three that persistent cognitive and psychiatric symptoms are very rare after mild TBI. In Part Four, he argues that PCS is not the direct result of a neurological insult consequent to MTBI. A significant amount of scientific evidence is cited in support of this contention.

PCS (which is found in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR)¹ in the Appendix describing criteria sets for further study under the section postconcussional disorder) is described by the author as “without question one of the most controversial concepts in the neurosciences.” In the final section of the book, the author contends that PCS is a “neuropsychological disorder” in which “the development and maintenance of [symptoms] are more directly the result of psychological, psychosocial, and other non-MTBI-specific factors.” One chapter is devoted to psychological theories of the origin of PCS, and the final two chapters review a multidisciplinary approach to the treatment and management of PCS based on its conceptualization as a neuropsychological disorder.

Although it is unlikely that this book will resolve the controversies surrounding PCS, there is much food for thought in the author's rigorous scientific examination of the syndrome. The text will be a welcome addition to the library of any forensic practitioner who evaluates individuals who report a history of MTBI or so-called PCS.

My only criticism is quite minor. The references are compiled at the end of each multichapter section and are numbered in the text. This arrangement yields four separate numbered listings of references, causing occasional difficulty in locating a particular citation quickly. Furthermore, when an article is cited in more than one section, it is separately listed in the reference list for each section where it appears, but with a different reference number. Either a single numbered reference list at the end of the book or non-numbered references listed at the end of each chapter would be easier to use. Perhaps the publisher will consider this in a second edition.

• American Academy of Psychiatry and the Law