title: Interhemispheric propagation of seizures in mesial temporal lobe epilepsy.
abstract: OBJECTIVE
  To investigate interhemispheric propagation of mesial temporal lobe epilepsy seizures in patients undergoing long-term video-EEG monitoring with combined scalp and foramen ovale electrodes.
  
  
  OBJECTIVE
  To reveal possible interhemispheric propagation patterns in mesial temporal lobe epilepsy, to improve presurgical evaluation of temporal epileptic patients.
  
  
  METHODS
  Sixty-five seizures from 20 patients were analyzed. We defined two contralateral seizure propagation patterns: Type I for those seizures that spread to the contralateral foramen ovale electrodes earlier than to the contralateral scalp electrodes, and type II for the opposite.
  
  
  METHODS
  Twenty drug resistant epileptic patients were investigated in frame of their presurgical evaluation.
  
  
  RESULTS
  The majority of seizures (80%) were classified as type I. Inter-foramen ovale electrode propagation time was significantly shorter for type I compared to type II seizures. Ninety percent of patients had either type I or type II seizures only. Patients with type I seizures significantly more often had mesiotemporal structural alterations evident on magnetic resonance imaging scans, and became more often seizure-free after surgery compared to patients with type II seizures whose surgical outcome was less favorable or surgery could not be indicated because of independent bilateral ictal seizure-onset.
  
  
  CONCLUSIONS
  The two types of contralateral propagation patterns we are describing seem to represent two subtypes of mesial temporal lobe epilepsy with different morphological and prognostic features. The predominance of type I over type II seizures together with shorter propagation times for type I seizures indicate a role of a more direct and dominant interhemispheric pathway in mesial temporal lobe epilepsy.
authors.affiliation: National Neuroscience Institute, Budapest, Hungary. eross@oiti.hu
authors.forename: Loránd
authors.initials: L
authors.lastname: Eross
authors.forename: László
authors.initials: L
authors.lastname: Entz
authors.forename: Dániel
authors.initials: D
authors.lastname: Fabó
authors.forename: Rita
authors.initials: R
authors.lastname: Jakus
authors.forename: Anna
authors.initials: A
authors.lastname: Szucs
authors.forename: György
authors.initials: G
authors.lastname: Rásonyi
authors.forename: Anna
authors.initials: A
authors.lastname: Kelemen
authors.forename: Gábor
authors.initials: G
authors.lastname: Barcs
authors.forename: Vera
authors.initials: V
authors.lastname: Juhos
authors.forename: Attila
authors.initials: A
authors.lastname: Balogh
authors.forename: Péter
authors.initials: P
authors.lastname: Barsi
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Clemens
authors.forename: Péter
authors.initials: P
authors.lastname: Halász
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012640:Seizures / Q000145:classification / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult