title: Abnormal Profiles of Local Functional Connectivity Proximal to Focal Cortical Dysplasias.
abstract: BACKGROUND
  Focal cortical dysplasia (FCD) is a congenital malformation of cortical development that often leads to medically refractory epilepsy. Focal resection can be an effective treatment, but is challenging as the surgically relevant abnormality may exceed the MR-visible lesion. The aim of the current study is to develop methodology to characterize the profile of functional connectivity around FCDs using resting-state functional MRI and in the individual patient. The detection of aberrant connectivity may provide a means to more completely delineate the clinically relevant lesion.
  
  
  METHODS
  Fifteen FCD patients (age, mean±SD: 31±11 years; 11 males) and 16 matched healthy controls (35±9 years; 7 males) underwent structural and functional imaging at 3 Tesla. The cortical surface was reconstructed from the T1-weighted scan and the registered functional MRI data was spatially normalized to a common anatomical standard space employing the gyral pattern. Seed-based functional connectivity was determined in all subjects for all dysplasia locations. A single patient was excluded based on an aberrant FCD seed time series. Functional connectivity as a function of geodesic distance (along the cortical surface) was compared between the individual patients and the homotopic normative connectivity profiles derived from the controls.
  
  
  RESULTS
  In 12/14 patients, aberrant profiles of functional connectivity were found, which demonstrated both hyper- and hypoconnectivity as well as combinations. Abnormal functional connectivity was typically found (also) beyond the lesion visible on structural MRI, while functional connectivity profiles not related to a lesion appeared normal in patients.
  
  
  CONCLUSIONS
  This novel functional MRI technique has potential for delineating functionally aberrant from normal cortex beyond the structural lesion in FCD, which remains to be confirmed in future research.
authors.affiliation: Epilepsy center Kempenhaeghe, Heeze, the Netherlands.|Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands.|Department of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: René M H
authors.initials: RM
authors.lastname: Besseling
authors.affiliation: Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands.|Department of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Jacobus F A
authors.initials: JF
authors.lastname: Jansen
authors.affiliation: Epilepsy center Kempenhaeghe, Heeze, the Netherlands.
authors.forename: Anton J A
authors.initials: AJ
authors.lastname: de Louw
authors.affiliation: Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands.|Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Mariëlle C G
authors.initials: MC
authors.lastname: Vlooswijk
authors.affiliation: Department of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: M Christianne
authors.initials: MC
authors.lastname: Hoeberigs
authors.affiliation: Epilepsy center Kempenhaeghe, Heeze, the Netherlands.|Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Albert P
authors.initials: AP
authors.lastname: Aldenkamp
authors.affiliation: Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands.|Department of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Walter H
authors.initials: WH
authors.lastname: Backes
authors.affiliation: Epilepsy center Kempenhaeghe, Heeze, the Netherlands.|Research School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands.|Department of Radiology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Paul A M
authors.identifier: http://orcid.org/0000-0003-0961-4300
authors.initials: PA
authors.lastname: Hofman
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology; D001931:Brain Mapping; D016022:Case-Control Studies; D063132:Connectome; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D054220:Malformations of Cortical Development / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012146:Rest; D055815:Young Adult