Frontiers in Human Neuroscience (Aug 2022)

What names for covert awareness? A systematic review

  • Caroline Schnakers,
  • Chase Bauer,
  • Rita Formisano,
  • Enrique Noé,
  • Roberto Llorens,
  • Roberto Llorens,
  • Nicolas Lejeune,
  • Nicolas Lejeune,
  • Michele Farisco,
  • Michele Farisco,
  • Liliana Teixeira,
  • Ann-Marie Morrissey,
  • Sabrina De Marco,
  • Vigneswaran Veeramuthu,
  • Kseniya Ilina,
  • Kseniya Ilina,
  • Brian L. Edlow,
  • Olivia Gosseries,
  • Olivia Gosseries,
  • Matteo Zandalasini,
  • Francesco De Bellis,
  • Aurore Thibaut,
  • Aurore Thibaut,
  • Anna Estraneo,
  • Anna Estraneo

DOI
https://doi.org/10.3389/fnhum.2022.971315
Journal volume & issue
Vol. 16

Abstract

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BackgroundWith the emergence of Brain Computer Interfaces (BCI), clinicians have been facing a new group of patients with severe acquired brain injury who are unable to show any behavioral sign of consciousness but respond to active neuroimaging or electrophysiological paradigms. However, even though well documented, there is still no consensus regarding the nomenclature for this clinical entity.ObjectivesThis systematic review aims to 1) identify the terms used to indicate the presence of this entity through the years, and 2) promote an informed discussion regarding the rationale for these names and the best candidates to name this fascinating disorder.MethodsThe Disorders of Consciousness Special Interest Group (DoC SIG) of the International Brain Injury Association (IBIA) launched a search on Pubmed and Google scholar following PRISMA guidelines to collect peer-reviewed articles and reviews on human adults (>18 years) published in English between 2006 and 2021.ResultsThe search launched in January 2021 identified 4,089 potentially relevant titles. After screening, 1,126 abstracts were found relevant. Finally, 161 manuscripts were included in our analyses. Only 58% of the manuscripts used a specific name to discuss this clinical entity, among which 32% used several names interchangeably throughout the text. We found 25 different names given to this entity. The five following names were the ones the most frequently used: covert awareness, cognitive motor dissociation, functional locked-in, non-behavioral MCS (MCS*) and higher-order cortex motor dissociation.ConclusionSince 2006, there has been no agreement regarding the taxonomy to use for unresponsive patients who are able to respond to active neuroimaging or electrophysiological paradigms. Developing a standard taxonomy is an important goal for future research studies and clinical translation. We recommend a Delphi study in order to build such a consensus.

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