Spatio-temporal spike dynamics predict surgical outcome in adult focal epilepsy

Clin Neurophysiol. 2022 Feb:134:88-99. doi: 10.1016/j.clinph.2021.10.023. Epub 2021 Dec 16.


Objective: We hypothesized that spatio-temporal dynamics of interictal spikes reflect the extent and stability of epileptic sources and determine surgical outcome.

Methods: We studied 30 consecutive patients (14 good outcome). Spikes were detected in prolonged stereo-electroencephalography recordings. We quantified the spatio-temporal dynamics of spikes using the variance of the spike rate, line length and skewness of the spike distribution, and related these features to outcome. We built a logistic regression model, and compared its performance to traditional markers.

Results: Good outcome patients had more dominant and stable sources than poor outcome patients as expressed by a higher variance of spike rates, a lower variance of line length, and a lower variance of positive skewness (ps < 0.05). The outcome was correctly predicted in 80% of patients. This was better or non-inferior to predictions based on a focal lesion (p = 0.016), focal seizure-onset zone, or complete resection (ps > 0.05). In the five patients where traditional markers failed, spike distribution predicted the outcome correctly. The best results were achieved by 18-h periods or longer.

Conclusions: Analysis of spike dynamics shows that surgery outcome depends on strong, single and stable sources.

Significance: Our quantitative method has the potential to be a reliable predictor of surgical outcome.

Keywords: Intracranial EEG; Spike dynamics; Surgical outcomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain / physiopathology*
  • Brain / surgery
  • Brain Mapping
  • Brain Waves / physiology*
  • Drug Resistant Epilepsy / physiopathology*
  • Drug Resistant Epilepsy / surgery
  • Electroencephalography
  • Epilepsies, Partial / physiopathology*
  • Epilepsies, Partial / surgery
  • Female
  • Humans
  • Male
  • Middle Aged
  • Models, Neurological
  • Neurosurgical Procedures
  • Prognosis
  • Treatment Outcome
  • Young Adult

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