Review Article | Published:

Disorders of consciousness after acquired brain injury: the state of the science

Nature Reviews Neurology volume 10, pages 99114 (2014) | Download Citation

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Abstract

The concept of consciousness continues to defy definition and elude the grasp of philosophical and scientific efforts to formulate a testable construct that maps to human experience. Severe acquired brain injury results in the dissolution of consciousness, providing a natural model from which key insights about consciousness may be drawn. In the clinical setting, neurologists and neurorehabilitation specialists are called on to discern the level of consciousness in patients who are unable to communicate through word or gesture, and to project outcomes and recommend approaches to treatment. Standards of care are not available to guide clinical decision-making for this population, often leading to inconsistent, inaccurate and inappropriate care. In this Review, we describe the state of the science with regard to clinical management of patients with prolonged disorders of consciousness. We review consciousness-altering pathophysiological mechanisms, specific clinical syndromes, and novel diagnostic and prognostic applications of advanced neuroimaging and electrophysiological procedures. We conclude with a provocative discussion of bioethical and medicolegal issues that are unique to this population and have a profound impact on care, as well as raising questions of broad societal interest.

Key points

  • Disorders of consciousness (DOC) arise from direct perturbations of neural systems that regulate arousal and awareness, and indirectly from disruptions in the connections between these systems

  • Distinct clinical syndromes have been identified, but behavioural features often fluctuate and cross diagnostic borders within individual patients, probably reflecting aberrant dynamic changes in corticothalamic neuronal activity

  • Novel applications of functional neuroimaging and electrophysiological techniques have been employed to detect covert signs of conscious awareness, improve outcome prediction, and establish brain–computer interfaces to augment communication ability

  • Recent empirical evidence suggests that treatment interventions aimed at neuromodulation can accelerate recovery and enhance outcome during both the acute and chronic phases

  • A paradigm shift should change the pervasive nihilism that continues to complicate patient management, family adjustment, medicolegal issues and healthcare policy in relation to DOC

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Acknowledgements

This work was supported by the National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems (H133A120085), James S. McDonnell Foundation, Belgian Funds for Scientific Research (FRS), European Commission, European Space Agency, Wallonia–Brussels Federation Concerted Research Action, Mind Science Foundation and Belgian InterUniversity Attraction Pole.

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Affiliations

  1. Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, 300 First Avenue, Charlestown, Boston, MA 02129, USA.

    • Joseph T. Giacino
  2. Division of Medical Ethics, Weill Cornell Medical College, 435 East 70th Street, Suite 4-J, New York, NY 10021, USA.

    • Joseph J. Fins
  3. Coma Science Group, Cyclotron Research Centre and Neurology Department, University and University Hospital of Liège, Sart Tilman B30, 4000 Liège, Belgium.

    • Steven Laureys
  4. Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.

    • Nicholas D. Schiff

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Contributions

All four authors researched data for the article, made substantial contributions to discussions of the content, wrote the article, and reviewed and/or edited the manuscript before submission.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Joseph T. Giacino.

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DOI

https://doi.org/10.1038/nrneurol.2013.279

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