title: Features of scalp EEG in unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis: Determining factors and predictive value for epilepsy surgery.
abstract: OBJECTIVE
  To investigate determining factors of the ictal scalp EEG pattern at seizure onset and its predictive value for postsurgical outcome in people with unilateral MTLE due to hippocampal sclerosis (MTLE-HS).
  
  
  METHODS
  Review of consecutive people with chronic MTLE-HS undergoing presurgical video-EEG telemetry. Exclusion criteria were additional epileptogenic lesions or seizure generators or compromised EEG traces at seizure-onset. Mixed linear or logistic regression models were used.
  
  
  RESULTS
  Inclusion of 63 patients with 219 seizures with a favorable outcome (no seizures or auras only) in 43 patients at last follow-up. Rhythmic activity at seizure-onset (RA) had a frequency of 4.7±1.5/s (range 1-8/s), mostly localized in the anterior temporal region. Postsurgical seizure outcome was not associated with any clinical or electrophysiological feature. RA in the delta-band was more often observed with shorter epilepsy duration (p=0.002).
  
  
  CONCLUSIONS
  RA on scalp EEG gets faster with increasing epilepsy duration, possibly via time-dependent alterations of epileptogenic networks. Neither the frequency of RA nor other EEG-features appeared to predict postsurgical seizure outcome.
  
  
  CONCLUSIONS
  The results challenge the view that if patients with apparent MTLE display RA in the delta-band, seizure-onset in neocortical structures rather than in temporo-mesial tissue should be considered and further investigations should be prompted.
authors: Department of Epileptology, University Hospital of Bonn, Germany; Department of Neurology, University Hospital Cologne, Germany.
authors: Michael P
authors: MP
authors: Malter
authors: Department of Epileptology, University Hospital of Bonn, Germany.
authors: Christina
authors: C
authors: Bahrenberg
authors: Department of Neuropathology, University Hospital of Bonn, Germany.
authors: Pitt
authors: P
authors: Niehusmann
authors: Department of Epileptology, University Hospital of Bonn, Germany.
authors: Christian E
authors: CE
authors: Elger
authors: Department of Epileptology, University Hospital of Bonn, Germany. Electronic address: rainer.surges@ukb.uni-bonn.de.
authors: Rainer
authors: R
authors: Surges
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004569:Electroencephalography / Q000639:trends*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012535:Scalp / Q000503:physiopathology; D012598:Sclerosis; D016896:Treatment Outcome; D055815:Young Adult
keywords: Amygdalo-hippocampectomy; EEG; Epilepsy surgery; Hippocampal sclerosis