title: Metabolic activity in external and internal awareness networks in severely brain-damaged patients.
abstract: 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.
  
  
  METHODS
  Prospective [18F]-fluorodeoxyglucose-positron emission tomography and Coma Recovery Scale-Revised assessments in a university hospital setting.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Coma Science Group, Cyclotron Research Centre and Neurology Department, University and University Hospital of Liège, 4000 Liège, Belgium.
authors.forename: Aurore
authors.initials: A
authors.lastname: Thibaut
authors.forename: Marie-Aurélie
authors.initials: MA
authors.lastname: Bruno
authors.forename: Camille
authors.initials: C
authors.lastname: Chatelle
authors.forename: Olivia
authors.initials: O
authors.lastname: Gosseries
authors.forename: Audrey
authors.initials: A
authors.lastname: Vanhaudenhuyse
authors.forename: Athena
authors.initials: A
authors.lastname: Demertzi
authors.forename: Caroline
authors.initials: C
authors.lastname: Schnakers
authors.forename: Marie
authors.initials: M
authors.lastname: Thonnard
authors.forename: Vanessa
authors.initials: V
authors.lastname: Charland-Verville
authors.forename: Claire
authors.initials: C
authors.lastname: Bernard
authors.forename: Mohammed
authors.initials: M
authors.lastname: Bahri
authors.forename: Christophe
authors.initials: C
authors.lastname: Phillips
authors.forename: Mélanie
authors.initials: M
authors.lastname: Boly
authors.forename: Roland
authors.initials: R
authors.lastname: Hustinx
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001364:Awareness; D001921:Brain / Q000378:metabolism*; D001930:Brain Injuries / Q000534:rehabilitation*; D003128:Coma / Q000534:rehabilitation*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D018458:Persistent Vegetative State / Q000534:rehabilitation*; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18