Global breakdown in resting state networks fMRI connectivity in patients with disorders of consciousness

Patients with disorders of consciousness (DOC: brain death, coma, vegetative/unresponsive, minimally conscious state) show reduced resting state fMRI connectivity in a default mode network as a function of the level of consciousness.1, 2 Here, we aimed to assess resting state fMRI connectivity in multiple cerebral networks. We further aimed to correlate clinical ͞pain͟scales scores (i.e., Nociception Coma Scale, NCS3) with the functional integrity of the pain-related salience network4 because the issue of pain in DOC is of particular ethical interest.5Methods: 300 fMRI resting state scans were obtained in 28 patients (11 minimally conscious, 12 "vegetative͟/unresponsive, 5 coma) and 22 controls. Seven seed regions were used to identify functional connectivity in the default mode, left and right frontoparietal, salience, sensorimotor, auditory, and visual networks. For salience network, a regression analysis was performed with patients’NCS total score. Results: A group-level correlation between resting state functional connectivity and the level of consciousness was identified for all studied networks. Additionally, patients’ NCS scores showed a positive correlation with functional connectivity in the salience network’s anterior cingulate cortex (ACC). Conclusions: We observed group-level functional connectivity decreases in both primary (visual, auditory) and higher-order associative networks (default mode, right and left fronto-parietal, salience, sensorimotor) possibly accounting for patients diminished consciousness capacities.6 The observed positive correlation between the NCS scores and ACC salience network activity reflects nociception-related processes in these patients measured in the absence of an external stimulus. Our results emphasize the clinical importance of multiple fMRI resting state networks to consciousness. References 1. Boly M, et al. (2009). Hum Brain Mapp 30:2393-2400.2. Vanhaudenhuyse A, et al. (2009). Brain 133:161-171. 3. Schnakers C, et al. (2010). Pain 148:215-219.4. Ploner M, et al. (2010). Proc Natl Acad Sci U S A 107:355-360.5. Demertzi A, et al. (2012). Neuroethics:1-14.6. Baars B, et al. (2003). Trends Neurosci 26:671-675. Preference: Talk Track: Clinical