Stereo-Electroencephalography-Guided Radiofrequency Thermocoagulation Affects Brain Network Connectivity in Epilepsy Patients
Abstract number :
2.04
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2021
Submission ID :
1826240
Source :
www.aesnet.org
Presentation date :
12/9/2021 12:00:00 PM
Published date :
Nov 22, 2021, 06:53 AM
Authors :
Rutger Slegers, MD - Academic Centre for Epileptology Kempenhaeghe/MUMC+, Heeze, The Netherlands; Raf van Hoof – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Karolina Gasztych – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Danny Hilkman – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Vivianne van Kranen-Mastenbroek – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Jacobus Jansen – Department of Radiology and Nuclear Medicine – Maastricht University Medical Centre (MUMC+), The Netherlands; Paul Hofman – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Kim Rijkers – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Louis Wagner – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Albert Colon – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Olaf Schijns – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands; Simon Tousseyn – Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands
Rationale: Stereo-electroencephalography (SEEG) is an invasive diagnostic method to identify the epileptogenic zone (EZ) and network in drug-resistant epilepsy. In selected patients, SEEG-guided radiofrequency thermocoagulation (RFTC) can be employed therapeutically by lesioning of the EZ. Little is known on the effect of focal RFTC on distant large-scale brain network connectivity. This study investigates whether brain responses to repetitive electrical stimulation are affected by RFTC.
Methods: Patients who underwent SEEG-guided RFTC and 1Hz bipolar repetitive electrical stimulation for 30s (for eloquent cortex mapping and seizure provocation) before and immediately after RFTC were retrospectively selected from our SEEG cohort implanted between 2017-2020. Stimulations were performed on selected electrode channels deemed clinically relevant by the neurologist.
Measure of effective brain connectivity was expressed as root-mean-square (RMS) of the cortico-cortical evoked potentials (CCEPs) following stimulation. RMS was calculated in the 15 to 300ms interval after stimulation. Pre-stimulus period -200 to -15ms was used for baseline correction. RMS was compared across all channels (excluding artifactual and stimulated contact pairs) before and after RFTC using a T-test (Bonferroni corrected P< 0.05). As stimulation amplitude (range: 4-10mA) was kept identical, changes in RMS were attributed to RFTC treatment. Electrode contact pairs were categorized as both coagulated (C), hybrid (H) (one coagulated/one non-coagulated) or both non-coagulated (N). The data was divided in nine categories based on the stimulating and recording contact pair combinations (C-C, C-H, C-N, H-C, H-H, H-N, N-C, N-H, N-N). Number of CCEPs with significant changes in RMS was compared to the total number of analyzed CCEPs, per category and per patient.
Neurophysiology