title: The role of the corpus callosum in seizure spread: MRI lesion mapping in oligodendrogliomas.
abstract: BACKGROUND
  Some patients with oligodendrogliomas have generalized tonic-clonic seizures (GTCS) while others have only partial seizures (PS). We investigated the relationship between tumour localization and seizure generalization using quantitative lesion mapping on magnetic resonance images.
  
  
  METHODS
  Twenty one patients with histologically proven oligodendrogliomas and GTCS (n=11) or PS (n=10) were studied. Data were acquired on a 3 Tesla MRI System. We performed lesion mapping techniques to compare the spatial distribution of oligodendrogliomas between patient groups, and quantitatively determined the extent to which lesions intersected each probabilistic regions-of-interest, including the cerebral lobes, thalamus, striatum, and genu of the corpus callosum.
  
  
  RESULTS
  In patients experiencing GTCS, the greatest lesion load was observed in mesial frontal regions, including cortex connected to the genu. In contrast, the greatest lesion load in patients experiencing PS was observed more caudo-laterally in orbitofrontal and temporal lobes, but typically sparing cortex connected to the genu. The number of lesion intersections with genu region of interest was significantly greater in patients experiencing GTCS relative to patients with PS (p=0.03). There were no significant differences between patient groups with respect to lesion intersection with the individual cerebral lobes, thalamus and striatum, or with respect to overall oligodendroglioma size.
  
  
  CONCLUSIONS
  Our data suggest that the genu of the corpus callosum may be a major pathway for seizure generalization in patients with oligodendrogliomas.
authors.affiliation: Department of Neurology, The Walton Centre NHS Foundation Trust, Liverpool, UK. Electronic address: udo.wieshmann@thewaltoncentre.nhs.uk.
authors.forename: U C
authors.initials: UC
authors.lastname: Wieshmann
authors.affiliation: Department of Neuropathology,The Walton Centre NHS Foundation Trust, Liverpool, UK.
authors.forename: K
authors.initials: K
authors.lastname: Milinis
authors.affiliation: Department of Neurology, The Walton Centre NHS Foundation Trust, Liverpool, UK.
authors.forename: J
authors.initials: J
authors.lastname: Paniker
authors.affiliation: Department of Radiology, The Walton Centre NHS Foundation Trust, Liverpool, UK.
authors.forename: K
authors.initials: K
authors.lastname: Das
authors.affiliation: Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Liverpool, UK.
authors.forename: M D
authors.initials: MD
authors.lastname: Jenkinson
authors.affiliation: Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Liverpool, UK.
authors.forename: A
authors.initials: A
authors.lastname: Brodbelt
authors.affiliation: Department of Neuropathology,The Walton Centre NHS Foundation Trust, Liverpool, UK.
authors.forename: D
authors.initials: D
authors.lastname: Crooks
authors.affiliation: Department of Radiology, The Walton Centre NHS Foundation Trust, Liverpool, UK; Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
authors.forename: S S
authors.initials: SS
authors.lastname: Keller
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000473:pathology*; D003337:Corpus Callosum / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000473:pathology*; D012640:Seizures / Q000473:pathology*
keywords: Epilepsy; Genu of the corpus callosum; Lesion-mapping; Oligodendroglioma; Secondary generalization