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Lateralized interictal epileptiform discharges during rapid eye movement sleep correlate with epileptogenic

Ayako Ochi1, Ryan Hung, Shelly Weiss

  • 1Division of Neurology, The Hospital for Sick Children, Toronto, ON, Canada. ayako.ochi@sickkids.ca

Epilepsia
|August 2, 2011
PubMed

Insights

Rapid eye movement (REM) sleep provokes the most lateralized interictal epileptiform discharges (IEDs) in children with tuberous sclerosis complex (TSC) epilepsy. REM-IED lateralization accurately predicts surgical candidacy and seizure control outcomes.

Area of Science:

  • Neurology
  • Epileptology
  • Pediatric Neurology

Background:

  • Tuberous sclerosis complex (TSC) is a genetic disorder that can cause intractable epilepsy in children.
  • Identifying the epileptogenic zone is crucial for surgical treatment of refractory epilepsy.
  • Interictal epileptiform discharges (IEDs) are EEG abnormalities that can help localize seizure onset.

Purpose of the Study:

  • To assess the lateralization of IEDs during rapid eye movement (REM) sleep compared to non-REM (NR) sleep and wakefulness (W) in children with TSC.
  • To determine the epileptogenicity of REM-IEDs and their concordance with ictal EEG, clinical semiology, and MRI findings.
  • To evaluate the utility of REM-IED lateralization in identifying surgical candidacy and predicting seizure control in TSC-associated epilepsy.

Main Methods:

  • Retrospective study of 23 children with TSC undergoing prolonged scalp video-EEG and MRI.
  • Analysis of at least 100 IEDs during REM, NR, and W to determine lateralization (right/left/generalized).
  • Comparison of IED lateralization with ictal EEG, clinical semiology, and MRI-based tuber location.

Main Results:

  • REM-IEDs showed higher lateralization (96%) compared to W-IEDs (83%) and NR-IEDs (70%).
  • Lateralization of REM-IEDs demonstrated strong concordance with ictal EEG (93%) and surgical hemisphere (100%).
  • Patients with REM-IED lateralization concordant with surgical hemisphere had a 69% seizure control rate after resective surgery.

Conclusions:

  • REM sleep significantly enhances the lateralization of IEDs in children with TSC-related epilepsy.
  • REM-IED lateralization is a reliable marker for identifying the epileptogenic zone and guiding surgical decisions.
  • Utilizing REM sleep for IED analysis improves the localization accuracy for resective epilepsy surgery in TSC.
Abstract

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