title: Structural changes in the temporal lobe and piriform cortex in frontal lobe epilepsy.
abstract: BACKGROUND
  Neuronal networks involved in seizure generation, maintenance and spread of epileptic activity comprise cortico-subcortical circuits. Although epileptic foci vary in location across focal epilepsy syndromes, there is evidence for common structures in the epileptogenic networks. We recently reported evidence from functional neuroimaging for a unique area in the piriform cortex, common to focal epilepsies in humans, which might play a role in modulating seizure activity. In this study, we aimed to identify common areas of structural abnormalities in patients with frontal lobe epilepsy (FLE).
  
  
  METHODS
  T1-weighted MRI scans of 43 FLE patients and 25 healthy controls were analysed using voxel based morphometry. Differences in regional grey matter volume were examined across the whole brain, and correlated with age at epilepsy onset, duration and frequency of seizures.
  
  
  RESULTS
  We detected areas of increased grey matter volume in the piriform cortex, amygdala and parahippocampal gyrus bilaterally, as well as left mid temporal gyrus of patients relative to controls, which did not correlate with any of the clinical variables tested. No common areas of atrophy were detected across the FLE group.
  
  
  CONCLUSIONS
  Structural abnormalities within the piriform cortex and adjacent structures of patients with FLE provide further evidence for the involvement of this area in the epileptogenic network of focal epilepsies. Lack of correlation with duration or age of onset of epilepsy suggests that this area of abnormality is not a consequence of seizure activity.
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK; Neurology Department, Hospital Universitario Vall d'Hebron, Universitat Autonoma de Barcelona, Paseo Vall d'Hebron, 119, 08035 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Centeno
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK; Epilepsy Centre, Department of Neurology, University of Munich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Vollmar
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK.
authors.forename: J
authors.initials: J
authors.lastname: Stretton
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK.
authors.forename: M R
authors.initials: MR
authors.lastname: Symms
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Thompson
authors.affiliation: Department of Clinical Neuroscience, Institute of Psychiatry, King's College, De Crespigny Park, London SE5 8AF, UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Richardson
authors.affiliation: Department of Clinical Neuroscience, Institute of Psychiatry, King's College, De Crespigny Park, London SE5 8AF, UK.
authors.forename: J
authors.initials: J
authors.lastname: O'Muircheartaigh
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Duncan
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, NSE MRI Unit, National Society for Epilepsy, Chalfont St Peter SL9 0RJ, UK. Electronic address: m.koepp@ucl.ac.uk.
authors.forename: M J
authors.initials: MJ
authors.lastname: Koepp
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000679:Amygdala / Q000473:pathology; D017034:Epilepsy, Frontal Lobe / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D036421:Nerve Fibers, Unmyelinated / Q000473:pathology; D009929:Organ Size; D020534:Parahippocampal Gyrus / Q000473:pathology; D066195:Piriform Cortex / Q000473:pathology*; D013702:Temporal Lobe / Q000473:pathology*; D055815:Young Adult
keywords: Frontal lobe epilepsy; MRI; Piriform cortex; Voxel based morphometry
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