title: Residual alterations of brain electrical activity in clinically asymptomatic concussed individuals: an EEG study.
abstract: OBJECTIVE
  To examine the neural substrates underlying performance on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and HeadRehab Virtual Reality (VR) balance and spatial modules in a concussed and control group.
  
  
  METHODS
  Thirteen controls and seven concussed participants were fitted with a Geodesic 128-channel EEG cap and completed three assessments: EEG baseline, ImPACT testing, and VR balance and spatial modules. Concussed participants completed were tested within 8 (5 ± 1) days after injury.
  
  
  RESULTS
  EEG power was significantly (p < .05) decreased in the concussed group over all testing modalities. EEG coherence was significantly (p < .05) increased in the concussed group during EEG baseline and ImPACT. For VR testing, two conditions showed significant (p < .05) increases in EEG coherence between ROIs, while two different conditions showed significant (p < .05) decreases in coherence levels.
  
  
  CONCLUSIONS
  Concussed participants passed all clinical concussion testing tools, but showed pathophysiological dysfunction when evaluating EEG variables.
  
  
  CONCLUSIONS
  Concussed participants are able to compensate and achieve normal functioning due to recruiting additional brain networks. This allows concussed participants to pass clinical tests while still displaying electrophysiological deficits and clinicians must consider this information when making return-to-play decisions.
authors.affiliation: Penn State University, Department of Kinesiology, 276 Recreation Building, University Park, PA 16802, USA; Penn State Center for Sport Concussion Research and Services, 19 Recreation Building, University Park, PA 16802, USA.
authors.forename: E F
authors.initials: EF
authors.lastname: Teel
authors.affiliation: Penn State University, Department of Psychology, 140 Moore Building, University Park, PA 16802, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Ray
authors.affiliation: Penn State University, Department of Engineering Science and Mechanics, 212 Earth-Engineering Sciences Building, University Park, PA 16802, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Geronimo
authors.affiliation: Penn State University, Department of Kinesiology, 276 Recreation Building, University Park, PA 16802, USA; Penn State Center for Sport Concussion Research and Services, 19 Recreation Building, University Park, PA 16802, USA. Electronic address: sms18@psu.edu.
authors.forename: S M
authors.initials: SM
authors.lastname: Slobounov
mesh_terms: D001265:Athletic Injuries / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D001924:Brain Concussion / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D004856:Postural Balance / Q000502:physiology; D065854:Spatial Navigation / Q000502:physiology*; D014584:User-Computer Interface; D055815:Young Adult
keywords: Coherence; Concussion; EEG; ImPACT; Power; Virtual Reality (VR)