Abstract
Cortico-cortical evoked potentials offer the possibility of understanding connectivity within seizure networks to improve diagnosis and more accurately identify candidates for seizure surgery. We sought to determine if cortico-cortical evoked potentials and post-stimulation oscillatory changes differ for sites of EARLY versus LATE ictal spread. 37 patients undergoing stereoelectroencephalography were tested using a cortico-cortical evoked potential paradigm. All electrodes were classified according to the speed of ictal spread. EARLY spread sites were matched to a LATE spread site equidistant from the onset zone. Root-mean-square was used to quantify evoked responses and post-stimulation gamma band power and coherence were extracted and compared. Sites of EARLY spread exhibited significantly greater evoked responses after stimulation across all patients (t(36) = 2.973, p= 0.004). Stimulation elicited enhanced gamma band activity at EARLY spread sites (t(36) = 2.61, p= 0.03, FDR corrected); this gamma band oscillation was highly coherent with the onset zone. Cortico-cortical evoked potentials and post-stimulation changes in gamma band activity differ between sites of EARLY versus LATE ictal spread. The oscillatory changes can help visualize connectivity within the seizure network.
Original language | English (US) |
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Pages (from-to) | 17-29 |
Number of pages | 13 |
Journal | Epilepsy Research |
Volume | 115 |
DOIs | |
State | Published - Sep 1 2015 |
Keywords
- Cortical stimulation
- Evoked potentials
- Seizure networks
- Stereoelectroencephalography
ASJC Scopus subject areas
- Clinical Neurology
- Neurology