PhD Scientific Days 2025

Poster Session I. - Q: Neurosciences

Intracortical mechanisms of after-discharges elicited by intracranial 50 Hz stimulation of epileptic patients

Előadó neve

Dr. Szabó Johanna Petra

Neptun code

NA45EO

Előadó munkahelye

Semmelweis University Clinic for Neurosurgery and Neurointervention

Előadó telefonszáma

+36 704221437

Előadó e-mail címe

sz.johanna.petra@gmail.com

Az előadás címe

Intracortical mechanisms of after-discharges elicited by intracranial 50 Hz stimulation of epileptic patients

Szerző(k) neve és munkahelye

Johanna Petra Szabó¹, Boglárka Hajnal¹, Anna Sákovics¹, Loránd Erőss¹, Dániel Fabó²

1: Semmelweis University Clinic for Neurosurgery and Neurointervention
2: Semmelweis University Institute of Behavioural Sciences

Bemutatás módja

Poszter

Szekció

Poster Session I. - Q: Neurosciences

Language of the presentation

English

Preferred session

Neurosciences

Összefoglaló szövege

Rhythmic stimulation-induced discharges, known as after-discharges (AD), have long been correlated with epileptogenic processes. Nevertheless, the latent neuronal processes are still poorly understood.
Our goal was to delineate cortical domain-specific characteristics of polyspike burst type ADs derived from intracranial macro- and microelectrode recordings. Our study examines the data of 7 drug-resistant epileptic patients undergoing presurgical evaluation with subdural grid electrodes, presenting ADs after 50 Hz stimulation. Simultaneously, laminar multielectrode arrays (LME) were implanted in the hypothesized epileptogenic zone.
Recordings were evaluated during stimulation (n = 6) and ADs (n = 5). We examined 989 stimulation events along with 50 AD-series with overall 797 AD events. Stimulation elicited either increased (81/989), decreased (430/989) or no change (189/989) in multi-unit activity (MUA), depending on the localization of stimulated site relative to the LME. More pronounced change in MUA predicted AD appearance. Additionally, non AD-generating events showed higher MUA when stimulating an otherwise AD-producing site compared to regions where no ADs emerged.
ADs proved to be very localized, detectable changes were found on LME in 17/50 series. The initial AD spikes, associated with infragranular sinks and prominent MUA, were followed by an upper-middle layer wave gradually extending to deep layers.
In sum, stimulation induces excitation in cortical neurons, accompanied by pronounced surround inhibition. The magnitude of this effect is related to the cortical susceptibility to generate ADs. ADs engage cortical layers in a specific sequence. A better understanding of stimulation-dependent neural dynamics may shed light to epileptogenic process within the cortex.
Supported by the EKÖP-2024-205 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund.

University

Semmelweis University

Supervisor

dr. Dániel Fabó

Publication of my abstract

I give consent to the publication of my abstract on the website of the congress.

phd.section.field

in doctoral studies after complex exam (PhD)

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

7504

Start

16:48

End

16:54