Ictal and Pre-ictal Functional Near-infrared Spectroscopy Ccmbined with Video- or Stereo-eeg Monitoring
Abstract number :
3.573
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2024
Submission ID :
1101
Source :
www.aesnet.org
Presentation date :
12/9/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Netaniel Rein, MD – Hadassah Medical Center
Revital Shechter, PhD – Hulon Institute of Technology
Oshrit Arviv, PhD – Hebrew University of Jerusalem
Dana Ekstein, MD PhD – Hadassah Medical Center
Tal Benoliel, MD – Hadassah Medical Center
Diya Doufish, MD – Hadassah Medical Center
Naomi Froimovich, BS – Hadassah Medical Center
Yulia Katz, BS – Hadassah Medical Center
Guy Rosenthal, MD – Hadassah Medical Center
Sami Heymann, MD – Hadassah Medical Center
Zvi Israel, MD PhD – Hadassah Medical Center
Michal Balberg, PhD – Hulon Institute of Technology
Mordekhay Medvedovsky, MD PhD – Hadassah Medical Center
Rationale: Functional near-infrared spectroscopy (fNIRS) measures local changes in oxyhemoglobin (HbO2) and deoxyhemoglobin (HHb) concentrations to assess cerebral cortex activation using near infrared light. fNIRS has been used to detect, lateralize, and localize epileptic seizures and pre-ictal changes by measuring fluctuations in cerebral HbO2 and HHb levels. In the present study, in addition to combining fNIRS with scalp video EEG (VEEG), we also combined fNIRS with stereo-EEG (SEEG) to assess its feasibility of use, clinical contribution, and whether pre-ictal hemodynamic changes previously observed with fNIRS-VEEG may represent deep electrical activity revealed by SEEG.
Methods: Ten patients with epilepsy, admitted for either VEEG (3) or SEEG (7), after giving informed consent, were additionally connected to 6-32 channels of fNIRS monitoring. Seizure detection and timing of seizure onset were determined by an expert epileptologist using standard VEEG and SEEG, who was blinded to the data of the fNIRS. Variations in HHb and HbO2 as well as the weighted difference between them were plotted and visually examined for ictal and pre-ictal patterns.
Results: Patients were connected to the fNIRS in parallel with EEG monitoring for 3-48 hours. Seizures were detected in all 3 patients connected to both VEEG and fNIRS. Distinct alterations in HbO2 and HHb levels, including high-amplitude slow oscillations, were associated with seizures and visually identified. Two of these patients had variations in HHb and HbO2 that preceded the clinical and electrographic onset of seizures by over a minute in one case. Seizures were detected in 5 of 7 patients connected to SEEG and fNIRS. Here again, the variations preceded the clinical and electrographic onset of seizures in 2 patients. In the figure, the weighted difference between the concentration of HbO2 and HHb is presented as a function of time, relative to the electrographic seizure onset, identified by the depth electrode (time = 0). The data from the fNIRS channels, positioned around the depth electrodes, show a marked increase in amplitude of slow frequency oscillations that starts 100 seconds before seizure onset.
Conclusions: In this study, we demonstrated the feasibility of combined monitoring with SEEG and fNIRS, which may be used during selected periods of SEEG monitoring to assist in the characterization of the epileptic network. The detection of hemodynamic changes prior to clinical and electrographic seizure onset in VEEG, and even during SEEG in half of the patients, raises interesting questions regarding the pathophysiology of ictogenesis and will hopefully lead to further research and potential therapies, pending future studies.
Funding: This research was funded by the Israeli Innovation Authority, grants #77084 & 77092.
Neuro Imaging