Metabolic activity in external and internal awareness networks in severely brain-damaged patients
Aurore Thibaut, Marie-Aurélie Bruno, Camille Chatelle, Olivia Gosseries, Audrey Vanhaudenhuyse, Athena Demertzi, Caroline Schnakers, Marie Thonnard, Vanessa Charland-Verville, Claire Bernard, Mohammed Bahri, Christophe Phillips, Mélanie Boly, Roland Hustinx, Steven Laureys
Objective: An extrinsic cerebral network (encompassing lateral frontoparietal cortices) related to external/sensory awareness and an intrinsic midline network related to internal/self-awareness have been identified recently. This study measured brain metabolism in both networks in patients with severe brain damage.
Design: Prospective [18F]-fluorodeoxyglucose-positron emission tomography and Coma Recovery Scale-Revised assessments in a university hospital setting.
Subjects: Healthy volunteers and patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS), minimally conscious state (MCS), emergence from MCS (EMCS), and locked-in syndrome (LIS).
Results: A total of 70 patients were included in the study: 24 VS/UWS, 28 MCS, 10 EMCS, 8 LIS and 39 age-matched controls. VS/UWS showed metabolic dysfunction in extrinsic and intrinsic networks and thalami. MCS showed dysfunction mostly in intrinsic network and thalami. EMCS showed impairment in posterior cingulate/retrosplenial cortices. LIS showed dysfunction only in infratentorial regions. Coma Recovery Scale-Revised total scores correlated with metabolic activity in both extrinsic and part of the intrinsic network and thalami.
Conclusion: Progressive recovery of extrinsic and intrinsic awareness network activity was observed in severely brain-damaged patients, ranging from VS/UWS, MCS, EMCS to LIS. The predominance of intrinsic network impairment in MCS could reflect altered internal/self-awareness in these patients, which is difficult to quantify at the bedside.
Do you want to comment on this paper? The comments will show up here and if appropriate the comments will also separately be forwarded to the authors.
You need to login/create an account to comment on articles. Click here to login/create an account