Open Access Review

Improving the clinical assessment of consciousness with advances in electrophysiological and neuroimaging techniques

Jodie R Gawryluk12, Ryan CN D'Arcy123, John F Connolly4 and Donald F Weaver567*

Author Affiliations

1 Department of Psychology, Dalhousie University, Halifax, Canada

2 National Research Council, Institute for Biodiagnostics (Atlantic) Halifax, Canada

3 Department of Radiology, Dalhousie University, Halifax, Canada

4 Department of Linguistics & Languages, McMaster University, Hamilton, Canada

5 Queen Elizabeth II Health Sciences Centre (Neurology), Halifax, Canada

6 Department of Medicine (Neurology), Dalhousie University, Halifax, Canada

7 Department of Chemistry, Dalhousie University, Halifax, Canada

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BMC Neurology 2010, 10:11  doi:10.1186/1471-2377-10-11

Published: 29 January 2010


In clinical neurology, a comprehensive understanding of consciousness has been regarded as an abstract concept - best left to philosophers. However, times are changing and the need to clinically assess consciousness is increasingly becoming a real-world, practical challenge. Current methods for evaluating altered levels of consciousness are highly reliant on either behavioural measures or anatomical imaging. While these methods have some utility, estimates of misdiagnosis are worrisome (as high as 43%) - clearly this is a major clinical problem. The solution must involve objective, physiologically based measures that do not rely on behaviour. This paper reviews recent advances in physiologically based measures that enable better evaluation of consciousness states (coma, vegetative state, minimally conscious state, and locked in syndrome). Based on the evidence to-date, electroencephalographic and neuroimaging based assessments of consciousness provide valuable information for evaluation of residual function, formation of differential diagnoses, and estimation of prognosis.