In order to better characterize residual cerebral activity following severe brain injury recent investigations of severely brain-injured persons using multi-modal neuroimaging techniques will be discussed. Combined evaluations of brain function with positron emission tomography, structural and functional magnetic resonance imaging, and electroencephalography or magnetoencephalography promise to provide greater insight into two parallel issues: 1) the underlying pathophysiological mechanisms separating different disorders of consciousness such as the vegetative state (VS) and minimally conscious state (MCS) and 2) assaying the integrity of functional cerebral networks in the severely brain-injured. The discussion will focus on comparisons of quantitative measurements in patients in the persistent vegetative state and MCS. The results of multi-modal imaging will be used to develop a model of the pathophysiologic basis of MCS and to suggest potential markers for identifying residual functional capacities in some patients.

Selected references:
Schiff ND, Ribary U, Moreno DR, Beattie B, Kronberg E, Blasberg R, Giacino J, McCagg C, Fins JJ, Llinas R, Plum F. Residual cerebral activity and behavioural fragments can remain in the persistently vegetative brain. Brain. 2002 Jun;125(Pt 6):1210-34
Schiff ND, Plum F. The role of arousal and "gating" systems in the neurology of impaired
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Schiff ND, Plum F. Cortical function in the persistent vegetative state. Trends Cogn Sci. 1999 Feb;3(2):43-44.