Epileptogenic Network Visualisation With Advanced MRI

Epileptogenic Network Visualisation With Advanced MRI

The goal of this clinical trial is to improve non-invasive identification of epileptogenic networks in drug-resistant epileptic patient.

The investigators aim to compare epileptogenic network identification with stereo-EEG (used as glod standard) with the identification of the same network using advanced MRI (rs-fMRI, microstructural analysis of white matter, ...). The main goals are to:

1. Compare the accuracy of network identification.
2. Analyse the effect of the MRI sequences on candidates selection and target identification.

Participants will already have been selected for stereoEEG and will undergo a supplementary MRI (about 1h) with the additional MRI sequences. Follow-up MRI are scheduled for patient undergoing a second, therapeutic epileptic surgery.

Patient identified for SEEG will undergo, prior to the implantation procedure an MRI with the following sequences:

• 3D T1
• rsfMRI
• multishell diffusion

The rsfMRI will be post-processed to delineate the epileptogenic networks based on an Independant Component Analysis (ICA) methods. Once the epileptogenic network(s) has/have been identified, connexion between the different regions will be identified through post-processing of the diffusion using a MSMT-CSD algorithm. Finally, the identified tract between the different region will be quantitatively analysed using different algorithms (NODDI, DIAMOND, MF) to better grasp there integrity.

In a follow-up study, the patients that will later on benefit from a resection or disconnection (i.e. curative surgery) will also have an identical MRI 3 months after the said procedure to evaluate the evolution on the network(s) based on the same criteria.

Inclusion Criteria:

• Patient suffering from drug-resistant epilepsy
• Patient already selected for SEEG implantation as part of their epileptic networks

Exclusion Criteria:

• Patient excluded from SEEG (pregnant women, children too young for the procedure, patient unable to undergo the procedure)
• Contra-indication for MRI