Respiratory modulations of cortical excitabilityand interictal spike timing in focal epilepsy - a case report

Kluger, D. S.; Erdbruegger, T.; Stier, C.; Hoeltershinken, M. B.; Saltafossi, M.; Unnwongse, K.; Wehner, T.; Wellmer, J.; Gross, J.; Wolters, C. H.

doi:10.1101/2023.08.28.555061

bioRxiv · 10.1101/2023.08.28.555061

Respiratory modulations of cortical excitabilityand interictal spike timing in focal epilepsy - a case report

Kluger, D. S.·Erdbruegger, T.·Stier, C.·Hoeltershinken, M. B.·Saltafossi, M.·Unnwongse, K.·Wehner, T.·Wellmer, J.·Gross, J.·Wolters, C. H.

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Abstract

Brain activity in focal epilepsy is marked by a pronounced excitation-inhibition (E:I) imbalance and interictal epileptiform discharges (IEDs) observed in periods between recurrent seizures. As a marker of E:I balance, aperiodic neural activity and its underlying 1/f characteristic reflect the dynamic interplay of excitatory and inhibitory currents. Recent studies have independently assessed 1/f changes both in epilepsy and in the context of body-brain interactions in neurotypical individuals where the respiratory rhythm has emerged as a potential modulator of excitability states in the brain. Here, we investigate respiration phase-locked modulations of E:I balance and their involvement in the timing of spike discharges in a case report of a 25 year-old focal epilepsy patient using magnetoencephalography (MEG). We show that i) respiration differentially modulates E:I balance in focal epilepsy compared to N = 40 neurotypical controls and ii) IED timing depends on both excitability and respiratory states. These findings overall suggest an intricate interplay of respiration phase-locked changes in excitation and the consequential susceptibility for IED generation and we hope they will spark interest in subsequent work on body-brain coupling and E:I balance in epilepsy.

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Kluger, D. S., Erdbruegger, T., Stier, C., Hoeltershinken, M. B., Saltafossi, M., Unnwongse, K., Wehner, T., Wellmer, J., Gross, J., Wolters, C. H.. 2023-08-29. Respiratory modulations of cortical excitabilityand interictal spike timing in focal epilepsy - a case report. https://doi.org/10.1101/2023.08.28.555061

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