Article

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.

Langue : ANGLAIS