# Multimodal approach to characterize surgically removed epileptogenic zone from patients with focal drug‐resistant epilepsy: From operating room to wet lab

## TL;DR

A new protocol for studying brain tissue from epilepsy surgery helps understand how epilepsy develops and could improve diagnosis and treatment.

## Contribution

A systematic protocol for multimodal analysis of resected epileptogenic tissue to identify therapeutic targets and improve patient care.

## Key findings

- A protocol was developed to preserve and analyze resected tissue using imaging, electrophysiology, and molecular biology.
- The protocol enables co-registration of multimodal data with in vivo MRI to map epileptogenic zones.
- The approach allows for identifying structural, functional, and molecular characteristics of epileptogenic tissue.

## Abstract

We have established a comprehensive sample handling protocol designed for the multiscale assessment of epileptogenic tissue. This protocol aims to identify novel therapeutic targets and enhance the diagnosis and stratification of patients with drug‐resistant epilepsy, thereby optimizing their treatment with anti‐seizure medications and surgical interventions.

Patients with drug‐resistant focal epilepsy, recommended for surgical treatment, are recruited after detailed multidisciplinary preoperative evaluation at the Epilepsy Center at Kuopio University Hospital in Finland. A day before the resective surgery, patients undergo magnetic resonance imaging (MRI) including advanced methodologies. During the surgery, each piece of resected tissue is placed under oxygenation on ice‐cold artificial cerebral spinal fluid solution. The pieces are then immediately transported to the laboratory, assessed by a neuropathologist, and sliced for both clinical diagnosis and research. Two adjacent slices are provided for research and are sent to the University of Eastern Finland.

The developed sample handling protocol provides the opportunity for detailed characterization of the tissue from the same patient using emerging imaging, electrophysiology, and molecular biology technologies. We have optimized the conditions for preserving the resected tissue alive for electrophysiological measurements and simultaneously making possible ex vivo studies including multi‐omics acquisition, electron microscopy, histology, and MRI. Our protocol enables the mapping of functional readouts to structural and molecular alterations in human tissue. Our goal is to integrate multimodal data and co‐register the resected tissues within the whole brain's in vivo MRI space. This approach aims to enhance the characterization and localization of epileptogenic zones and refine surgical treatment targets by identifying abnormalities in global connectivity and structural patterns.

We have successfully developed a systematic protocol for the collection and analysis of multimodal data. This protocol aims to elucidate the structural, functional, and molecular characteristics that render tissue epileptogenic, thereby enhancing the diagnosis and subsequent care of patients with epilepsy.

We developed a new protocol for collecting and studying brain tissue removed during epilepsy surgery. By keeping the tissue alive and analyzing it with multiple techniques—such as imaging, electrophysiology, and molecular biology—we can better understand how epilepsy develops. This approach will help doctors identify treatment targets more precisely and improve diagnosis and care for people with drug‐resistant epilepsy.