title: Forward and inverse electroencephalographic modeling in health and in acute traumatic brain injury.
abstract: OBJECTIVE
  EEG source localization is demonstrated in three cases of acute traumatic brain injury (TBI) with progressive lesion loads using anatomically faithful models of the head which account for pathology.
  
  
  METHODS
  Multimodal magnetic resonance imaging (MRI) volumes were used to generate head models via the finite element method (FEM). A total of 25 tissue types-including 6 types accounting for pathology-were included. To determine the effects of TBI upon source localization accuracy, a minimum-norm operator was used to perform inverse localization and to determine the accuracy of the latter.
  
  
  RESULTS
  The importance of using a more comprehensive number of tissue types is confirmed in both health and in TBI. Pathology omission is found to cause substantial inaccuracies in EEG forward matrix calculations, with lead field sensitivity being underestimated by as much as ≈ 200% in (peri-) contusional regions when TBI-related changes are ignored. Failing to account for such conductivity changes is found to misestimate substantial localization error by up to 35 mm.
  
  
  CONCLUSIONS
  Changes in head conductivity profiles should be accounted for when performing EEG modeling in acute TBI.
  
  
  CONCLUSIONS
  Given the challenges of inverse localization in TBI, this framework can benefit neurotrauma patients by providing useful insights on pathophysiology.
authors.affiliation: Laboratory of Neuro Imaging, Department of Neurology, University of California, Los Angeles, CA 90095, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Irimia
authors.forename: S Y Matthew
authors.initials: SY
authors.lastname: Goh
authors.forename: Carinna M
authors.initials: CM
authors.lastname: Torgerson
authors.forename: Micah C
authors.initials: MC
authors.lastname: Chambers
authors.forename: Ron
authors.initials: R
authors.lastname: Kikinis
authors.forename: John D
authors.initials: JD
authors.lastname: Van Horn
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology* / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology; D001930:Brain Injuries / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D004569:Electroencephalography; D006257:Head / Q000033:anatomy & histology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D008959:Models, Neurological; D009929:Organ Size; D012016:Reference Values; D055815:Young Adult
keywords: Electroencephalography; Magnetic resonance imaging; Traumatic brain injury; finite element method