Is there anybody in there? Detecting awareness in disorders of consciousness

Abstract

The bedside detection of awareness in disorders of consciousness (DOC) caused by acquired brain injury is not an easy task. For this reason, differential diagnosis using neuroimaging and electrophysiological tools in search for objective markers of consciousness is being employed. However, such tools cannot be considered as diagnostic per se, but as assistants to the clinical evaluation, which, at present, remains the gold standard. Regarding therapeutic management in DOC, no evidence-based recommendations can be made in favor of a specific treatment. The present review summarizes clinical and paraclinical studies that have been conducted with neuroimaging and electrophysiological techniques in search of residual awareness in DOC. We discuss the medical, scientific and ethical implications that derive from these studies and we argue that, in the future, the role of neuroimaging and electrophysiology will be important not only for the diagnosis and prognosis of DOC but also in establishing communication with these challenging patients.

Keywords::

• assessment
• brain–computer interface
• brain death
• coma
• communication
• deep brain stimulation
• default mode network
• disorder of consciousness
• electrophysiology
• functional neuroimaging
• minimally conscious state
• neurorehabilitation
• vegetative state

Financial & conflicts of interest disclosure

This research was funded by the Belgian National Funds for Scientific Research (FNRS), the European Commission, the James McDonnell Foundation, the Mind Science Foundation, the French Speaking Community Concerted Research Action (ARC), the Fondation Médicale Reine Elisabeth and the University of Liège.

Athena Demertzi is funded by the DISCOS Marie-Curie Research Training Network, Audrey Vanhaudenhuyse and Pierre Boveroux are funded by ARC 06/11-340, Melanie Boly and Marie-Aurelie Bruno are research fellows at the FNRS, Pierre Maquet is research director and Steven Laureys senior research associate at the FNRS. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.