Related Experiment Video
Updated: Jul 28, 2026
Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping
Published on: June 26, 2012
Intracranial EEG analysis in tumor-related epilepsy: Evidence of distant epileptic abnormalities
S Mittal1, D Barkmeier2, J Hua3
1Department of Neurosurgery, Wayne State University, Detroit, MI, USA; Department of Oncology, Wayne State University, Detroit, MI, USA; Comprehensive Epilepsy Center, Detroit Medical Center, Wayne State University, Detroit, MI, USA; Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA.
Objective:
In patients with tumor-related epilepsy (TRE), surgery traditionally focuses on tumor resection; but identification and removal of associated epileptogenic zone may improve seizure outcome. Here, we study spatial relationship of tumor and seizure onset and early spread zone (SOSz). We also perform quantitative analysis of interictal epileptiform activities in patients with both TRE and non-lesional epilepsy in order to better understand the electrophysiological basis of epileptogenesis.
Methods:
Twenty-five patients (11 with TRE and 14 with non-lesional epilepsy) underwent staged surgery using intracranial electrodes. Tumors were outlined on MRI and images were coregistered with post-implantation CT images. For each electrode, distance to the nearest tumor margin was measured. Electrodes were categorized based on distance from tumor and involvement in seizure. Quantitative EEG analysis studying frequency, amplitude, power, duration and slope of interictal spikes was performed.
Results:
At least part of the SOSz was located beyond 1.5 cm from the tumor margin in 10/11 patients. Interictally, spike frequency and power were higher in the SOSz and spikes near tumor were smaller and less sharp. Interestingly, peritumoral electrodes had the highest spike frequencies and sharpest spikes, indicating greatest degree of epileptic synchrony. A complete resection of the SOSz resulted in excellent seizure outcome.
Conclusions:
Seizure onset and early spread often involves brain areas distant from the tumor.
Significance:
Utilization of epilepsy surgery approach for TRE may provide better seizure outcome and study of the intracranial EEG may provide insight into pathophysiology of TRE.
Insights
Surgery for tumor-related epilepsy (TRE) should target the seizure onset zone (SOSz), not just the tumor. The SOSz is often distant from the tumor, and its complete resection improves seizure outcomes.
Area of Science:
- Neurosurgery
- Epileptology
- Neuroimaging
Background:
- Tumor-related epilepsy (TRE) surgery traditionally focuses on tumor resection.
- Identifying and removing the epileptogenic zone is crucial for seizure control.
Purpose of the Study:
- To investigate the spatial relationship between tumors and the seizure onset zone (SOSz) in TRE.
- To analyze interictal epileptiform activities in TRE and non-lesional epilepsy.
Main Methods:
- Coregistration of MRI tumor imaging with post-implantation CT scans.
- Measurement of electrode distance to tumor margins.
- Quantitative EEG analysis of interictal spikes.
Main Results:
- The SOSz was frequently located beyond 1.5 cm from the tumor margin in TRE patients.
- Interictal spikes were more frequent and powerful in the SOSz, with distinct characteristics near the tumor.
- Peritumoral electrodes showed the highest spike frequency and sharpness, indicating high epileptic synchrony.
Conclusions:
- Seizure onset and spread often involve brain areas distant from the tumor.
- Epilepsy surgery techniques targeting the SOSz may improve outcomes for TRE.
- Intracranial EEG analysis offers insights into TRE pathophysiology.
More Related Videos
12:10Performing Behavioral Tasks in Subjects with Intracranial Electrodes
Published on: October 2, 2014
09:00Investigating the Function of Deep Cortical and Subcortical Structures Using Stereotactic Electroencephalography: Lessons from the Anterior Cingulate Cortex
Published on: April 15, 2015
