Page 172 - MEGIN Book Of Abstracts - 2023

How cerebral cortex protects itself from interictal Keywords: alpha, beta, epilepsy, inhibition, interictal
spikes: The alpha/beta inhibition mechanism (2021) epileptiform discharges, magnetoencephalography, oscil-
lations
Pellegrino, Giovanni; Hedrich, Tanguy; Sziklas, Viviane;
Lina, Jean-Marc; Grova, Christophe; Kobayashi, Eliane Human brain mapping (2021), Vol. 42, No. 11 (34002916)
(6 citations)
Department of Neurology and Neurosurgery, Montreal
Neurological Institute, McGill University, Montreal, Quebec,
Canada; Department of Biomedical Engineering, Multimodal Neuromagnetic high frequency spikes are a new
Functional Imaging Lab, McGill University, Montreal, Quebec, and noninvasive biomarker for localization of
Canada; Centre De Recherches En Mathematiques, Montreal, epileptogenic zones (2021)
Quebec, Canada; Department of Physics and PERFORM Cen-
tre, Concordia University, Montreal, Quebec, Canada Xiang, Jing; Maue, Ellen; Tong, Han; Mangano,
Francesco T; Greiner, Hansel; Tenney, Jeffrey
ABSTRACT Interactions between interictal epileptiform
discharges (IEDs) and distant cortical regions subserve MEG Center, Cincinnati Children's Hospital Medical Center,
potential effects on cognition of patients with focal Cincinnati, OH, United States; Division of Neurology, Cin-
epilepsy. We hypothesize that "healthy" brain areas cinnati Children's Hospital Medical Center, Cincinnati, OH,
at a distance from the epileptic focus may respond to United States. Electronic address: [email protected];
the interference of IEDs by generating inhibitory alpha MEG Center, Cincinnati Children's Hospital Medical Center,
and beta oscillations. We predict that more prominent Cincinnati, OH, United States; Neuroscience Graduate Pro-
alpha-beta oscillations can be found in patients with gram, University of Cincinnati, Cincinnati, OH, United States;
less impaired neurocognitive profile. We performed Division of Neurosurgery, Cincinnati Children's Hospital Medi-
a source imaging magnetoencephalography study, cal Center, Cincinnati, OH, United States
including 41 focal epilepsy patients: 21 with frontal
lobe epilepsy (FLE) and 20 with mesial temporal lobe OBJECTIVE One barrier hindering high frequency brain
epilepsy. We investigated the effect of anterior (i.e., signals (HFBS, >80 Hz) from wide clinical applications is
frontal and temporal) IEDs on the oscillatory pattern that the brain generates both pathological and physi-
over posterior head regions. We compared cortical ological HFBS. This study was to find specific biomark-
oscillations (5-80 Hz) temporally linked to 3,749 IEDs ers for localizing epileptogenic zones (EZs).
(1,945 frontal and 1,803 temporal) versus an equal
number of IED-free segments. We correlated results METHODS Twenty three children with drug-resistant
from IED triggered oscillations to global neurocognitive epilepsy and age/sex matched healthy controls were
performance. Only frontal IEDs triggered alpha-beta os- studied with magnetoencephalography (MEG). High
cillations over posterior head regions. IEDs with higher frequency oscillations (HFOs, > 4 oscillatory waveforms)
amplitude triggered alpha-beta oscillations of higher and high frequency spikes (HFSs, > 1 spiky or sharp
magnitude. The intensity of posterior head region waveforms) in 80-250 Hz and 250-600 Hz bands were
alpha-beta oscillations significantly correlated with a blindly detected with an artificial intelligence method
better neuropsychological profile. Our study demon- and validated with visual inspection. The magnitude of
strated that cerebral cortex protects itself from IEDs HFOs and HFSs were quantified with spectral analyses.
with generation of inhibitory alpha-beta oscillations at Sources of HFSs and HFOs were localized and com-
distant cortical regions. The association of more promi- pared with clinical EZs determined by invasive record-
nent oscillations with a better cognitive status suggests ings and surgical outcomes.
that this mechanism might play a role in determining
the cognitive resilience in patients with FLE. RESULTS HFOs in 80-250 Hz and 250-600 Hz were iden-
tified in both epilepsy patients (18/23, 12/23, respec-

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