March 22, 2021
3 min read
Today marks the inaugural celebration of World Coma Day, a daylong, online event organized by the Neurocritical Care Society designed to raise awareness of coma as a clinical event that can be treated and cured.
The first-ever World Coma Day also aims to engage caregivers in the research efforts, current and future, that focus on curing disorders of consciousness, according to a statement on the Neurocritical Care Society’s website. One recent example of such research, a cohort study, found that most individuals who became comatose following moderate or severe traumatic brain injury regained consciousness, including those who did so during rehabilitation.
Healio Neurology spoke with Claude Hemphill III, MD, MAS, professor of neurology at the University of California, San Francisco, Weill Institute for Neurosciences and past president of the Neurocritical Care Society, about the management of coma in clinical practice and the goals of World Coma Day.
Healio Neurology: What should clinicians know about coma as a treatable condition from which recovery is possible?
Hemphill: The history of coma care has unfortunately been filled with nihilism where medical providers have often assumed that a coma resulting from an acute brain injury such as trauma or stroke is the result of irreversible damage. But most clinicians who have been around for a while have had cases where they have been surprised that a patient recovered. These “surprises” should not really be surprises at all, but clear demonstration of two things, that patients may recover and that current approaches do not sufficiently inform which patients can and should recover, even with current medical care.
We need to focus on the difference between phenotype vs. endotype as part of the coma discussion. Regarding coma, when we say phenotype, we are referring to what somebody looks like, external characteristics. When describing the clinical entity of coma, that usually means lying in a bed with eyes closed and not purposely responding to the environment. Endotype relates to the underlying biological mechanism that explains why somebody might be in a coma. Using biomarkers to measure endotypes, we may be able to identify those patients with capacity to recover better and target intervention based on measures such as covert consciousness, cognitive motor dissociation (CMD) or other biomarkers. The first task of the Curing Coma Campaign scientific advisory council was to establish how endotypes and biomarkers need to be addressed to provide a roadmap for testing interventions to improve coma recovery.
Healio Neurology: Does this possibility of recovery vary depending on the cause of the coma?
Hemphill: Probably. Most of the focus until now has been on specific diseases and related manifestations: trauma causing coma or impaired consciousness, hemorrhagic stroke causing coma, cardiac arrest resulting in coma and so forth. But it may be that the underlying areas of structural brain injury, network circuits that relate to consciousness and electrical or metabolic aspects are more important than the individual issue that led to that problem. Understanding these may lead to treatments that can be applied based on the underlying biology of impaired consciousness and coma across many conditions. Additionally, because recovery may be rapid or, more often, may occur over months or even years, the trajectory of improvement and the interventions needed to support that may be different.
Healio Neurology: What are the goals of World Coma Day 2021?
Hemphill: The two big goals for the first World Coma Day are to raise awareness about the need for a unified, collaborative approach to improving the scientific understanding of coma and consciousness and to build the community of medical providers, researchers, patients and families, and advocates to make this happen.
Healio Neurology: How do these goals tie into the Curing Coma campaign?
Hemphill: The purpose of the Curing Coma Campaign is to create a platform to enable two interrelated goals. First, focus the science of acute disorders of consciousness on identifying and testing therapeutic interventions. Second, form an enduring community of medical providers, scientists and advocates to test and implement these advances. Fundamentally pushing the science forward will be key, but without an engaged community to implement new advances big and small, we don’t think we will achieve this grand challenge. We want everyone who takes care of patients with coma and disordered consciousness, or who studies ways to improve outcomes in these patients, or who has a family member or has been a patient with coma, or who wants to help this problem to realize that they are part of the Curing Coma Campaign.
Healio Neurology: What are the greatest unmet needs in coma research?
Hemphill: The first task of the Curing Coma Campaign scientific advisory council was to establish a set of scientific pillars upon which to address the unmet needs and provide a roadmap forward. This was published in 2020 and focuses on the three scientific pillars of endotyping, biomarkers and proof-of-concept clinical trials.
The Neurocritical Care Society and the National Institute of Neurological Disorders and Stroke cosponsored a symposium in September 2020 as a first step in the direction of developing a vision for advancing coma care and a second symposium is scheduled for May 2021 to continue to understand coma and coma recovery.