Focal ictal β discharge on scalp EEG predicts excellent outcome of frontal lobe epilepsy surgery

Gregory A. Worrell, Elson L. So, John Kazemi, Terence J. O'Brien, Russell K. Mosewich, Gregory D. Cascino, Frederic B. Meyer, W. Richard Marsh

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52 Citations (Scopus)


Purpose: To determine whether a focal β-frequency discharge at seizure onset on scalp EEG predicts outcome of frontal lobe epilepsy (FLE) surgery. Methods: We identified 54 consecutive patients with intractable FLE who underwent epilepsy surgery between December 1987 and December 1996. A blind review of EEGs and magnetic resonance images (MRIs) was performed. Lesional epilepsy is defined as presence of an underlying structural abnormality on MRI. Results: Overall, 28 (52%) patients were seizure free, with a mean follow-up of 46.5 months. Presence of a focal β-frequency discharge at seizure onset on scalp EEG predicted seizure-free outcome in lesional (p = 0.02) and nonlesional (p = 0.01) epilepsy patients. At least 90% of patients who had either lesional or nonlesional epilepsy were seizure free if scalp EEG revealed a focal β discharge at ictal onset. Moreover, logistic regression analysis showed that focal ictal β pattern and completeness of lesion resection were independently predictive of seizure-free outcome. Ictal onset with lateralized EEG activity of any kind and postresection electrocorticographic spikes did not predict surgical outcome (p > 0.05). Conclusions: Only about 25% of FLE surgical patients have a focal β-frequency discharge at seizure onset on scalp EEG. However, its presence is highly predictive of excellent postsurgical seizure control in either lesional or nonlesional FLE surgical patients.

Original languageEnglish
Pages (from-to)277-282
Number of pages6
Issue number3
Publication statusPublished - 9 Apr 2002
Externally publishedYes


  • EEG
  • Epilepsy
  • Epilepsy surgery
  • Frontal lobe epilepsy
  • Surgical outcome

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