Acute Coma and Disorders of Consciousness

Hans A. Püttgen, MD

Romergryko G. Geocadin, MD

No clinical question more directly addresses the human condition than whether an unresponsive patient can again act independently, find enjoyment in life, or appreciate and return the love of those who care for him or her. Many areas of medicine confront us with our mortality, but treating a patient in coma demands that we consider carefully what it means to be alive, and that we make the uncomfortable admission that our answers to this question may lack precision and objectivity, may depend heavily on cultural factors, and may change with context. We must further admit that our understanding of disturbances in consciousness remains far from comprehensive.

As physicians must acknowledge the patient's agency as an essential guiding principle, care of an unresponsive patient becomes an ethically precarious endeavor. In such a scenario, guiding the patient's designated agents through the process of informed medical decision making becomes the central role for the treating physician. Such guidance depends on a careful synthesis of a variety of information. The physician must provide an assessment of the patient's true level of consciousness, the pathophysiologic etiology, and based on these, a notion of prognosis. Meeting this responsibility imposes a particular ethical imperative on advancing our knowledge of coma.

Any modern discourse on the comatose patient will eventually direct a neurologist's thoughts to his or her copy of Plum and Posner's Diagnosis of Stupor and Coma that sits dog-eared and coffee-stained among the other classic texts of neurology education. These texts serve not as mere references, but as challenges to master current canon and find areas for refinement and contribution. The principle challenge in treatment of comatose patients is to move beyond a paradigm of diagnosis followed by supportive care to an emphasis on strategies directed specifically toward return of consciousness and meaningful life.

The modern approach for coma after ventricular fibrillation or ventricular tachycardia cardiac arrest exemplifies such an emphasis. Therapeutic hypothermia entered the standard of care not because of an improvement in overall survival, but because of an effect on awakening from coma and improving the chances of returning to a productive life. At the same time, evidence has mounted to show that this therapy has upset previous conclusions regarding estimation of prognosis, bringing to the forefront a need for new research in this area and to redefine a new paradigm of care.

In this issue of Seminars in Neurology, we are truly appreciative of the contributions from renowned scientists and clinicians, which provide a survey of the changing field of coma in the context of present-day practice. Authors have volunteered to approach the subject from examination to localization leading to discussion of the pertinent neuroanatomy. Neuroanatomy in turn leads to discussion of imaging and electrophysiology techniques that provide insight not only into the nature of the injury but into its effect as well. Management of disturbances of consciousness is described from the immediate and acute to the early initiation of rehabilitation and tools for ongoing assessment are reviewed, and end of life issues and ethical dilemmas are approached with current practice insights.

A comatose patient demands that the neurologist performs at the height of his or her skill. The neurologist must form an assessment that integrates physical examination methods developed in the 19th century and the very latest in imaging techniques. Interventions must be guided by a detailed understanding of pathophysiology and the latest monitoring technology. Discussion with the patient's health care agent will involve the most complicated concepts in medical ethics, an estimate of prognosis based on incomplete information, and particular sensitivity toward the patient's cultural background. Though daunting, this care pushes us to the edge of our confidence best suited to innovation and discovery. We hope not only to provide the readers of this issue with an appreciation of the advances in this field, but also the realization of the immensity of the problem that is yet to be addressed. We further hope that each reader, as a clinician and possible investigator, has a chance to advance the field even more.

In developing this issue of Seminars in Neurology, we honor the many comatose patients and their families everywhere who stimulated us with the real-world clinical challenges and gave us the humility of how little we actually know and inspiration to do better and passion to push the boundaries of what is known. We give thanks to our families (Kate, Atticus, and August–HAP; Effie, Sofia, and Ginno–RGG), who have been supportive as we regularly fade from their midst and get into the NCCU to provide the clinical care and the laboratories to wrestle with the research questions. Lastly, we would like to dedicate this issue of Seminars in Neurology to Dr. Justin MacArthur, who mentored us, supported us, and believed in us.