title: Altered brain activation during cognitive control in patients with moderate to severe traumatic brain injury.
abstract: BACKGROUND
  Persistent deficits in cognitive control have been documented following traumatic brain injury (TBI) but are inconsistently related to the presence and location of focal lesions.
  
  
  OBJECTIVE
  Functional magnetic resonance imaging (fMRI) was used to examine brain activation during a cognitive control task in patients with moderate to severe TBI or orthopedic injury (OI).
  
  
  METHODS
  Fourteen TBI patients and 10 OI patients underwent fMRI at 3 months postinjury using a stimulus-response compatibility task in which response accuracy and reaction time were measured. Performance between the groups was equated by individually adjusting the amount of training. Groups did not differ in age, gender, or education.
  
  
  RESULTS
  Brain activation during stimulus-response incompatibility was greater in TBI patients than in OI patients within the cingulate, medial frontal, middle frontal, and superior frontal gyri. However, the positive regression of activation with response accuracy during stimulus-response incompatibility indicated a stronger relationship for OI patients than the TBI group within the anterior cingulate gyrus, medial frontal, and parietal regions, as well as deep brain structures (eg, brainstem). The number of focal lesions within either the whole brain or within prefrontal areas was not related to brain activation, but there was a relationship between activation and TBI severity.
  
  
  CONCLUSIONS
  These findings suggest that neural networks mediating cognitive control are altered after moderate to severe TBI, possibly as a result of diffuse axonal injury, and that the typical relationship of brain activation to performance is disrupted.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX 77030, USA. scheibel@bcm.tmc.edu
authors.forename: Randall S
authors.initials: RS
authors.lastname: Scheibel
authors.forename: Mary R
authors.initials: MR
authors.lastname: Newsome
authors.forename: Joel L
authors.initials: JL
authors.lastname: Steinberg
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Pearson
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Rauch
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.forename: Maya
authors.initials: M
authors.lastname: Troyanskaya
authors.forename: Rajkumar G
authors.initials: RG
authors.lastname: Sharma
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Levin
mesh_terms: D000293:Adolescent; D000328:Adult; D001930:Brain Injuries / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology*; D005260:Female; D015600:Glasgow Coma Scale; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D013647:Task Performance and Analysis