CIBM EEG HUG-UNIGE SECTION

Clinical and Translational Neuroimaging

Section Head : Prof. Serge Vulliémoz

The main research of the EEG Section focuses on EEG-based brain mapping methodology with applications to epilepsy and several other brain conditions. Our research methods include multimodal combinations of high-density EEG, simultaneous EEG-fMRI and simultaneous scalp, intracranial recordings with analyses based on source imaging and functional connectivity. Multimodal and multiscale recordings or post-processing combination allow to investigate complex relationships between single neurons and scalp signals, brain structure-function coupling and neuromodulation protocols using neurofeedback. We aim for invasive validations and integration into dedicated analysis and visualization platforms. These avenues offer new perspectives and challenges for understanding brain function as well as integration of these advances into clinical practice.

RESEARCH TOPICS

EEG-HUG-UNIGE

Electrical Neuroimaging Analysis and Software

Description: The estimation of the neuronal generators that underlie the scalp potential distribution measured with high-density EEG requires sophisticated head models based on individual MRI and source models that incorporate the properties of the generation and propagation of the electric field. The laboratory develops these models and implements them in the academic software CARTOOL developed by Denis Brunet. Patients with atypical anatomical configurations, such as skull openings, irregular brain tissue distributions, or pathological electromagnetic profiles like tumors or epileptic foci, could benefit from more advanced lead field models. Improved models are expected to provide more accurate source localization in both general cases and in specific conditions like epilepsy.

Investigators: Serge Vulliémoz (UNIGE), Denis Brunet (UNIGE)

Collaborator: Armen Bagdasarov (Duke University), Fiorenzo Artoni (UNIGE)

EEG-HUG-UNIGE

Multiscale Brain Dynamics and methodological validation

Description: This project leverages simultaneous intracranial EEG (iEEG) and high-density EEG (hdEEG) recordings to refine electrical brain source imaging and deepen our understanding of both physiological and pathological brain dynamics. iEEG serves as a gold standard for validating the accuracy of hdEEG source imaging, while the broader spatial coverage of hdEEG allows us to explore how pathological elements identified in iEEG impact brain function at the whole-brain level. This multiscale approach offers insights with wide-reaching applications across neurological research, extending beyond epilepsy. 

Investigators: Serge Vulliémoz (UNIGE), Nicolas Roehri (UNIGE)

Collaborators: Andrea Pigorini (University of Milan), Ezequiel Mikulan (University of Milan), Christian Bénar (Aix-Marseille University), Maria Chondrou (UNIGE)

EEG-HUG-UNIGE

Source imaging, connectivity and epilepsy surgery

Description: EEG is a critical tool in epilepsy diagnosis and treatment. However, current EEG-based source imaging methods face significant challenges and are not yet easily adaptable for routine clinical use. This project aims to enhance EEG source imaging using quantitative EEG, connectivity analysis and machine leaning, with the ultimate goal of predicting surgical outcomes of patients. 

Investigators: Nicolas Roehri (UNIGE), Serge Vulliémoz (UNIGE), Isotta Rigoni (UNIGE)

Collaborators: Margitta Seeck (HUG), Pierre Mégevand (HUG), Christian Korff (HUG), Laurent Spinelli (HUG), Karl Schaller (HUG), Juanli Zhang (UNIGE), Stanislas Lagarde (Aix-Marseille University)

EEG networks of cognition in epilepsy

Description: Memory issues are a major concern for people living with epilepsy, second only to seizures. The exact cause of these impairments remains unclear—whether they result from epileptic activity disrupting memory consolidation during sleep, dysfunction of sleep-related networks, or the underlying lesion itself. The lab focuses on studying EEG functional networks to explore these cognitive impairments, with a particular emphasis on understanding how sleep networks involved in memory consolidation may be affected and how they can help predict memory decline, even in the context of epilepsy surgery.

Investigators: Isotta Rigoni (UNIGE), Serge Vulliémoz (UNIGE)

Collaborators: Elena Pedrazzini (HUG), Virginie Sterpenich (UNIGE), Sophie Schwartz (UNIGE)

EEG-HUG-UNIGE

Investigation of sleep rhythms using iEEG

Description: This project uses intracranial EEG (iEEG) to investigate both pathological and physiological sleep rhythms. The aim is to gain a deeper understanding of memory consolidation processes, explore how epilepsy-related disruptions contribute to memory deficits, and examine the communication between different brain regions during sleep. By studying sleep dynamics with iEEG, this research seeks to provide insights into the mechanisms underlying memory and cognitive function, with potential implications for both epilepsy and broader neurological conditions.

Investigators: Nicolas Roehri (UNIGE), Serge Vulliémoz (UNIGE)

Collaborators: Isabelle Lambert (Aix-Marseille University), Laurent Sheybani (University College London)

EEG-HUG-UNIGE

Neurofeedback

Description: EEG-based neurofeedback is a powerful tool to alter ongoing brain dynamics and modulate the state of the brain. While traditionally EEG neurofeedback is based on controlling oscillations in certain frequencies, we are developing neurofeedback methods based on spatial features of high-density EEG (EEG microstates as well as connectivity dynamics) with the hypothesis that such features more directly allow to modulate large-scale network activity.

Investigators: Tomas Ros (UNIGE), Victor Férat (UNIGE), Serge Vulliémoz (UNIGE)

Collaborators: Adrian Guggisberg (UNIGE), Perroud Nader (UNIGE)

EEG-HUG-UNIGE

EEG Normative modelling

Description: Normative modeling for EEG involves creating a reference model of brain activity based on a large dataset of healthy individuals. This reference model then allows for the quantification of an individual’s EEG data as deviations from this norm. These deviations can serve as potential biomarkers for various brain disorders or conditions, offering insights into an individual’s brain health and aiding in personalized treatment approaches.

Investigators: Tomas Ros (UNIGE), Abele Michela (UNIGE), Serge Vulliémoz (UNIGE)

Collaborators: Thomas Wolfers (University of Tubingen), Seyed Kia (University of Tilburg)

Coupling of structural and functional networks

Description: Within the framework of the Sinergia project “Precision Mapping” (grant number 209470), the laboratory is combining high-density EEG and source-reconstruction techniques with 7 Tesla MRI to shed light on the structure-function interaction in the brain. The goal is to develop a high-fidelity connectome that represents the brain as a large-scale directed graph, capturing direction-specific electrical conductivity, axonal count, and other microstructural features, both within the white matter and across cortex-to-cortex connections. The multimodal imaging approach will allow to track the propagation of coherent neuronal electrical activity along the white matter axonal network and characterize the dynamic organization of neuronal assemblies and abnormal epileptic networks as a function of time, phase, frequency and space. Clinically, the lab examines how these structural and functional interactions evolve during epileptic activity, and whether they can constitute a biomarker to predict epilepsy surgical outcome.

Investigators: Serge Vulliémoz (UNIGE), Patric Hagmann (CHUV)

Collaborators: Emeline Mullier (UNIGE), Louise de Wouters (UNIGE), Dimitri Van De Ville (EPFL), Ileana Jelescu (CHUV), Olivier David (Marseille), Pieter van Mierlo (GENT)

EEG-HUG-UNIGE

Animal electrophysiology

Description: Animal models are fundamental to understand the neurophysiological mechanisms underlying large-scale brain networks measured by EEG. In an in-house collaboration, we exploit the kainate mouse model of temporal lobe epilepsy to study abnormal epileptic networks and probe connectivity measures. By integrating high-density scalp EEG with intracranial multi- and single-unit recordings in rodents, our laboratory contributes to the investigation of the mechanisms driving the development (epileptogenesis) and maintenance of both physiological and pathological whole-brain networks. Chemogenetics are also used to silence tactical nodes of the network (notably the epileptic focus or nodes strategic for cognitive processes) to simulate epilepsy surgery, with the final goal of extracting EEG biomarkers for the prediction of surgery outcomes, both in terms of seizure freedom and memory decline.

Investigators:  Charles Quairiaux (UNIGE), Serge Vulliémoz (UNIGE)

Collaborators: Isotta Rigoni (UNIGE)