title: Whole-brain MRI phenotyping in dysplasia-related frontal lobe epilepsy.
abstract: OBJECTIVE
  To perform whole-brain morphometry in patients with frontal lobe epilepsy and evaluate the utility of group-level patterns for individualized diagnosis and prognosis.
  
  
  METHODS
  We compared MRI-based cortical thickness and folding complexity between 2 frontal lobe epilepsy cohorts with histologically verified focal cortical dysplasia (FCD) (13 type I; 28 type II) and 41 closely matched controls. Pattern learning algorithms evaluated the utility of group-level findings to predict histologic FCD subtype, the side of the seizure focus, and postsurgical seizure outcome in single individuals.
  
  
  RESULTS
  Relative to controls, FCD type I displayed multilobar cortical thinning that was most marked in ipsilateral frontal cortices. Conversely, type II showed thickening in temporal and postcentral cortices. Cortical folding also diverged, with increased complexity in prefrontal cortices in type I and decreases in type II. Group-level findings successfully guided automated FCD subtype classification (type I: 100%; type II: 96%), seizure focus lateralization (type I: 92%; type II: 86%), and outcome prediction (type I: 92%; type II: 82%).
  
  
  CONCLUSIONS
  FCD subtypes relate to diverse whole-brain structural phenotypes. While cortical thickening in type II may indicate delayed pruning, a thin cortex in type I likely results from combined effects of seizure excitotoxicity and the primary malformation. Group-level patterns have a high translational value in guiding individualized diagnostics.
authors.affiliation: From the Neuroimaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
authors.forename: Seok-Jun
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: From the Neuroimaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
authors.forename: Boris C
authors.initials: BC
authors.lastname: Bernhardt
authors.affiliation: From the Neuroimaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
authors.forename: Dewi S
authors.initials: DS
authors.lastname: Schrader
authors.affiliation: From the Neuroimaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
authors.forename: Neda
authors.initials: N
authors.lastname: Bernasconi
authors.affiliation: From the Neuroimaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada. andrea@bic.mni.mcgill.ca.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bernasconi
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D015331:Cohort Studies; D017034:Epilepsy, Frontal Lobe / Q000145:classification / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D000069550:Machine Learning; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000145:classification / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D009929:Organ Size; D010641:Phenotype