OBJECTIVE: To evaluate the possible role of the default mode network (DMN) in 
consciousness and assess the diagnostic or prognostic potential of DMN 
connectivity measures in the assessment of a patient group lacking cognitive 
awareness.
METHODS: DMN connectivity was established using independent component analysis 
of resting-state fMRI data in patients with reversible (n = 2) and irreversible 
(n = 11) coma following cardiac arrest and compared to healthy controls (n = 
12).
RESULTS: A present and intact DMN was observed in controls and those patients 
who subsequently regained consciousness, but was disrupted in all patients who 
failed to regain consciousness.
CONCLUSIONS: The results suggest that the DMN is necessary but not sufficient to 
support consciousness. Clinically, DMN connectivity may serve as an indicator of 
the extent of cortical disruption and predict reversible impairments in 
consciousness.