In the very first sentence, in the very first chapter of this very fine compilation (titled the Clinical Continuum of Care and Natural History), the editors who were also authors on this chapter mention simply that “systems of care for patients with traumatic brain injury (TBI) should account for the particular characteristics of this disorder.” As I was just sitting down to begin plowing through this huge volume that single sentence really struck me. In so many ways, the current systems of care for a disconcerting and far too large a fraction of patients fall well short of this simple heuristic, in large part, because there is a deceptively widespread ignorance within our healthcare system about traumatic brain injury. I find myself not infrequently amazed and at the same time troubled by the widespread ignorance, even within what are regarded as elite teaching institutions within the Boston “medical-industrial complex”—widely regarded as among, if not the, most elite training ground for physicians and other healthcare professionals in the world. Even in this milieu, I not infrequently encounter physicians, nurses, social workers, psychologists, and even neuropsychologists whose training in and sophistication about traumatic brain injury has been modest if not simply minimal and inadequate. I have been forced to the reluctant conclusion that medical school, graduate school, and nursing school curriculums do not adequately present the clinical neuroscience of head trauma for most healthcare professionals passing though their programs. Indeed, I believe that it is the exception rather than the rule that healthcare professionals of various disciplines emerge from their advanced training with anything more than a cursory review of closed head trauma, its symptoms, fundamental biology, spectrum of severity, natural course, treatment, rehabilitation, and so on. This unfortunately is consistent with other troubling evidence that it is actually in relationship with the more commonplace disorders in clinical neuroscience (such as depression, delirium, neurodegenerative disorders, and closed head injury) where clinicians are actually most poorly trained and most poorly equipped to function as effective professionals within the healthcare system.
One can only hope that this volume—reflecting contributions from many experts in relationship with the protean aspects of traumatic brain injury—helps reduce that ignorance, and the derivative mistakes, in terms of both diagnostic and treatment errors, that emerge directly as a result of that ignorance. Such mitigation cannot come too soon or too widely, particularly in the view of the enormous penetration of traumatic brain injury into our society as one of the most common types of neurological conditions, affecting perhaps as many 1.7 million individuals (roughly one half of 1% of the entire society) each year, and with perhaps as many as 3.2 million living with some degree of disability from TBI. More than 50,000 people a year die and more than 200,000 people a year are hospitalized in the context of head trauma. Tragically, TBI is commonly both more a younger and an older person's syndrome, with a disproportionate number of patients suffering from TBI either adolescent or early adults and then another large fraction reflecting a high penetration of TBI into an elderly cohort. A disproportionate number of TBI patients have had pre-existing difficulties such as substance abuse, learning disability, and various psychiatric and other behavioral disorders that place them at elevated risk for injury through multifactorial mechanisms. Additionally, and perhaps more widely appreciated, patients throughout the lifecycle suffering from TBI are more prone to develop various emotional and psychiatric disorders—most especially and paradigmatically depression—following head injury.
Chapters in this very fine compilation cover virtually every aspect of the syndrome that one would want reviewed, including overviews of clinical care, public health issues, and basic research (the first nine chapters), the basic biomechanics, pathophysiology and neurobiology of head trauma and recovery from head trauma (the next four chapters), neuroimaging and neurodiagnostic testing (three chapters), prognosis and outcome (four chapters), acute care including surgical management and acute rehab and nursing (six chapters), special brain injury populations such as the elderly, mild traumatic brain injury and its outcomes, including sports concussions (three chapters), assessment and rehabilitation of individuals with disorders of consciousness emerging from head trauma and military TBI (blast and penetrating missile wound). Then, there are five chapters on pediatric TBI, various neurological disorders including movement disorders, sleep disorders, and cranial nerve disorders, four chapters on sensory disorders associated with TBI including disorders of audition, smell, taste, and vestibular dysfunction, three chapters on motor and musculoskeletal disorders, four chapters covering autonomic, endocrine, gastrointestinal, and sexual dysfunctions following TBI, three chapters on posttraumatic pain disorders, three chapters on cognitive impairment, neuropsychological assessment, and cognitive rehab with TBI, three chapters on behavioral and emotional sequelae, three chapters on speech, language, and swallowing disorders, four chapters on functional mobility and ADLs including movement rehab, OT and PT, and assistive technology, five chapters on the neuropharmacology and alternative treatments of TBI, six chapters on psychosocial functioning, re-entry into the community, return to work, and recreation and leisure pursuits in TBI, and finally, four chapters on medicolegal and ethical issues. It is safe to say that the coverage is exceptionally comprehensive and leaves literally no stone unturned.
One of the intriguing and at the same time frustrating and troubling realities emerging from any review of this literature is that outside of prevention—which everyone agrees needs more emphasis—there are no clearly established neuroprotective interventions that successfully reduce the so-called secondary injury following the primary injury of the head trauma. Even though several neuroprotective treatments have been successful in animal models, they have all failed in phase 2 or 3 clinical trials. Additionally, aside from our having no clearly established or well-validated way to enhance neuroprotection, we also have no clearly validated mechanism to enhance neurorestoration—a separate issue from neuroprotection and coming at the tertiary (late) stage of the process (where the first stage would be the actual trauma, the second stage the so-called “secondary injury” cascades, and the third stage where various neurorestorative and neuroplastic compensatory mechanisms might be recruited and optimized. This obviously suggests that much more fundamental research is needed.
Obviously, in a volume of this size, one can always find a few things that one might question, but in general the level of excellence is uniformly high. One of the few differences that I might have with the editors might be around the relatively modest coverage afforded the syndrome of Chronic Traumatic Encephalopathy, which garners attention only in a subset of a few chapters and has no dedicated chapter which I believe it deserves. I also might place a slightly different emphasis on where future developments might most significantly improve the prognosis of unlucky individuals suffering from moderate to severe head trauma, where the editors appear to be very high on the neuroprosthetic frontier, and I might be more impressed with the possibility that future treatments will emphasize biology over technology and allow traumatized brains to better rewire themselves while limiting post-injury “neural casualties.” This capacity to limit the effects of so-called “secondary injury” damage will of course require better molecular ligands and biotechnologies for altering the complex cell signals promoting secondary injury, where a host of mechanisms ranging from posttraumatic cerebral ischemia, calcium channel dysfunction, disinhibited inflammation, mitochondrial failure, amino acid excitotoxicity, and several other factors driving over-recruitment of programmed cell death pathways serve to further the damage from the primary injury (associated with the acute physical trauma and the immediate contusion to cortex, brain parenchyma, and vascular and axonal shearing).
On this critically important subject, there is a very fine chapter on the biology of “secondary” brain injury in head trauma—chapter 12, and additional first-rate chapters on CNS plasticity and experimental therapeutic approaches for traumatic brain injury emphasizing what we know about a host of cutting-edge (or is it crumbling edge?) therapies and their implications for the broad therapeutic frontier of TBI. Another intriguing issue that emerges from a concerted review of the literature is that the mechanisms of secondary injury in head trauma overlap hugely with the fundamental mechanisms of aging itself, suggesting that future treatments for closed head trauma may benefit from the emerging fundamental science in relationship with the biology of aging (seeWatt, 2013, for detailed treatment). One of the challenges that has escaped current detailed understanding is how to minimize the destructive cascades of excitotoxicity, disinhibited inflammation and programmed cell death without interfering with downstream compensatory plasticity, a difficult challenge given how proinflammatory cytokines may mediate both negative sequelae from injury, as well as later promotion of compensatory neuroplasticity (chapters 12–14 and 72–76 address intriguing questions and clinical work in these critical areas). A deeper understanding of the mysteries of signal transduction and internal cellular regulation that govern cell fate after the “primary injury” and which determine the so-called “secondary injury” cascade—matters again intrinsically intertwined with the very biology of aging—may eventually provide therapeutic targets and modalities that might significantly improve outcome in moderate and severe head trauma and perhaps even improve recovery from milder TBI and concussion. In this critical sense, the biological puzzle boxes of head trauma and neurodegenerative disorders may have many rich points of intersection in terms of underlying mechanisms, even though their immediate contexts (acute physical trauma to the brain—often in a young person vs. changes in an aging brain) may appear to be radically disjunctive. This suggests that perhaps future breakthroughs in relationship with one set of disorders will help us in relation to the other set of problems.
Overall, this is a uniformly high-quality compilation, with many dozens of reference-grade articles and very few significant hiccups. It is admittedly a massive 1,500 page reference tome (and toting it around in your briefcase is not recommended unless you are looking for a real workout!), and predictably with a correspondingly hefty price tag, but for clinicians who work regularly with patients with TBI, Brain Injury Medicine really is a must have reference volume and should be on the desk of virtually every neuropsychologist and physician who regularly assesses patients suffering from the effects of closed head trauma and related conditions. The fact that the book is available both as a hard copy and as an e-book (making it easy to print out individual chapters, for example, in relationship with teaching a particular subtopic within the large territory of TBI) is a huge plus (and likely to be dearly appreciated by those teaching any aspect of the subject!). One suspects that this decision to make an e-book bundled in with the hard copy probably took some courage, at a time when intellectual property rights and their protection often times conflict with the need to make high-quality clinical neuroscience more readily available.
I recommend this book very highly to anyone in our discipline looking for a state-of-the-art summary of all the many dimensions to one of our most troubling public health problems. In the course of almost four decades in the mind/brain sciences, I have reviewed easily a dozen or more of these massive textbook compilations on various subjects in the neurosciences and I would have to place this volume at the top, as one of the very best on any subject. It took real courage from the editors and the publishers to bear the risks and challenges of creating this large a volume, to say nothing of the hard work and effort. Bravo to the editors and the many contributors for this absolutely first rate compilation!