title: Functional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients.
abstract: Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this entity can be subcategorized into MCS- (i.e., patients only showing nonreflex behavior such as visual pursuit, localization of noxious stimulation and/or contingent behavior) and MCS+ (i.e., patients showing command following).Patterns of cerebral glucose metabolism were studied using [(18)F]-fluorodeoxyglucose-PET in 39 healthy volunteers (aged 46 ± 18 years) and 27 MCS patients of whom 13 were MCS- (aged 49 ± 19 years; 4 traumatic; 21 ± 23 months post injury) and 14 MCS+ (aged 43 ± 19 years; 5 traumatic; 19 ± 26 months post injury). Results were thresholded for significance at false discovery rate corrected p < 0.05.We observed a metabolic impairment in a bilateral subcortical (thalamus and caudate) and cortical (fronto-temporo-parietal) network in nontraumatic and traumatic MCS patients. Compared to MCS-, patients in MCS+ showed higher cerebral metabolism in left-sided cortical areas encompassing the language network, premotor, presupplementary motor, and sensorimotor cortices. A functional connectivity study showed that Broca's region was disconnected from the rest of the language network, mesiofrontal and cerebellar areas in MCS- as compared to MCS+ patients.The proposed subcategorization of MCS based on the presence or absence of command following showed a different functional neuroanatomy. MCS- is characterized by preserved right hemispheric cortical metabolism interpreted as evidence of residual sensory consciousness. MCS+ patients showed preserved metabolism and functional connectivity in language networks arguably reflecting some additional higher order or extended consciousness albeit devoid of clinical verbal or nonverbal expression.
authors.affiliation: Coma Science Group, Cyclotron Research Center, University of Liège, Sart-Tilman B30, 4000 Liège, Belgium. ma.bruno@ulg.ac.be
authors.forename: Marie-Aurélie
authors.initials: MA
authors.lastname: Bruno
authors.forename: Steve
authors.initials: S
authors.lastname: Majerus
authors.forename: Mélanie
authors.initials: M
authors.lastname: Boly
authors.forename: Audrey
authors.initials: A
authors.lastname: Vanhaudenhuyse
authors.forename: Caroline
authors.initials: C
authors.lastname: Schnakers
authors.forename: Olivia
authors.initials: O
authors.lastname: Gosseries
authors.forename: Pierre
authors.initials: P
authors.lastname: Boveroux
authors.forename: Murielle
authors.initials: M
authors.lastname: Kirsch
authors.forename: Athena
authors.initials: A
authors.lastname: Demertzi
authors.forename: Claire
authors.initials: C
authors.lastname: Bernard
authors.forename: Roland
authors.initials: R
authors.lastname: Hustinx
authors.forename: Gustave
authors.initials: G
authors.lastname: Moonen
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018458:Persistent Vegetative State / Q000000981:diagnostic imaging* / Q000473:pathology*; D049268:Positron-Emission Tomography / Q000379:methods; D055815:Young Adult
references.citation: Conscious Cogn. 2007 Sep;16(3):722-41; discussion 742-5
references.pmid: 17544299
references.citation: Trends Cogn Sci. 2008 Aug;12(8):314-21
references.pmid: 18606562
references.citation: Neuropsychologia. 2008 Feb 12;46(3):864-9
references.pmid: 18237752
references.citation: Ann N Y Acad Sci. 2003 Oct;1001:65-78
references.pmid: 14625356
references.citation: J Neurosci. 2003 Apr 15;23(8):3423-31
references.pmid: 12716950
references.citation: J Neurol. 2001 Sep;248(9):743-9
references.pmid: 11596777
references.citation: Neurology. 2002 Feb 12;58(3):349-53
references.pmid: 11839831
references.citation: Neurology. 2004 Sep 14;63(5):916-8
references.pmid: 15365150
references.citation: Arch Neurol. 2004 Feb;61(2):233-8
references.pmid: 14967772
references.citation: Brain. 2007 Oct;130(Pt 10):2494-507
references.pmid: 17827174
references.citation: Trends Cogn Sci. 2005 Dec;9(12):556-9
references.pmid: 16271507
references.citation: Neuroimage. 2003 Nov;20 Suppl 1:S89-100
references.pmid: 14597301
references.citation: Brain. 2000 Aug;123 ( Pt 8):1589-601
references.pmid: 10908189
references.citation: Neuroimage. 2006 May 1;30(4):1414-32
references.pmid: 16413796
references.citation: Neurology. 2010 Nov 23;75(21):1871-8
references.pmid: 20980667
references.citation: J Neurol Neurosurg Psychiatry. 2006 Jul;77(7):856-62
references.pmid: 16549415
references.citation: Neuroimage. 2002 Apr;15(4):870-8
references.pmid: 11906227
references.citation: Neuroimage. 1999 Apr;9(4):377-82
references.pmid: 10191166
references.citation: Proc Natl Acad Sci U S A. 1998 Feb 3;95(3):906-13
references.pmid: 9448258
references.citation: J Neurotrauma. 2010 Jan;27(1):35-49
references.pmid: 19715400
references.citation: Brain. 2000 Jul;123 ( Pt 7):1293-326
references.pmid: 10869045
references.citation: Science. 2011 May 13;332(6031):858-62
references.pmid: 21566197
references.citation: Prog Brain Res. 2009;177:49-61
references.pmid: 19818894
references.citation: Neuroimage. 2002 Oct;17(2):732-41
references.pmid: 12377148
references.citation: BMC Neurol. 2010 May 26;10:35
references.pmid: 20504324
references.citation: Brain. 2010 Jan;133(Pt 1):161-71
references.pmid: 20034928
references.citation: N Engl J Med. 2010 Feb 18;362(7):579-89
references.pmid: 20130250
references.citation: J Cogn Neurosci. 2010 May;22(5):888-902
references.pmid: 19320547
references.citation: J Neurosurg Anesthesiol. 1999 Jan;11(1):17-24
references.pmid: 9890381
references.citation: Neurology. 2005 Feb 22;64(4):700-6
references.pmid: 15728295
references.citation: Arch Phys Med Rehabil. 2004 Dec;85(12):2020-9
references.pmid: 15605342
references.citation: J Cogn Neurosci. 2004 May;16(4):621-36
references.pmid: 15165352
references.citation: Neurology. 2005 Feb 8;64(3):514-23
references.pmid: 15699384
references.citation: Lancet Neurol. 2008 Nov;7(11):1013-20
references.pmid: 18835749
references.citation: Nat Rev Neurosci. 2008 Dec;9(12):934-46
references.pmid: 19020512
references.citation: J Clin Invest. 2006 Jul;116(7):2005-11
references.pmid: 16823492
references.citation: Nat Rev Neurosci. 2007 May;8(5):393-402
references.pmid: 17431404
references.citation: Philos Trans R Soc Lond B Biol Sci. 1998 Nov 29;353(1377):1879-82
references.pmid: 9854259
references.citation: Neuroimage. 2005 Apr 15;25(3):661-7
references.pmid: 15808967
references.citation: J Neurol. 2011 Jul;258(7):1373-84
references.pmid: 21674197
references.citation: Brain Cogn. 2005 Mar;57(2):131-4
references.pmid: 15708203