Advances MEG in presurgical evaluation of drug resistant epilepsy at Aston University: from analysis strategies to neurophysiological biomarkers.
Stefano Seri, Andrew Lawley
A recent survey of European MEG centres confirmed that its acceptance as viable diagnostic tool still lags behind the evidence supporting its value as functional brain mapping tool (De Tiege X, et al., 2017). This somewhat maps the on-going gap between evidence of efficacy of surgical treatment as an option for drug-resistant epilepsy and its uptake worldwide. One of the main challenges our community faces if this gap is to be reduced is educational, to referring clinicians, trainees in neurology and clinical neurophysiology and scientists/technical staff. These include the understanding of the processes involved in reconstructing sources from scalp magnetic fields (Hall et al., 2018), recognition of artefacts in signal and source space (Bagic et al., 2020), interpretation of findings and reporting (Burgess R, 2020). In this presentation, based on the 20-year experience and over 100 patients per year investigated at the Aston University Wellcome MEG Laboratory, we aim to cover the main evidence supporting the use of MEG to localise the irritative zone, its spatial correlation with seizure-onset zone, its support in formulating localising/lateralising hypotheses on the spatial extent of the seizure-onset zone and guiding intracranial recording strategy (Agirre-Arrizubieta Z, 2014) and finally the role of MEG in detecting non-invasively pathological HFO (Foley et al., 2021). We will also present recent data from our group on the role of MEG in mapping eloquent cortex non-invasively (Foley, 2019; 2020), and its relationship with fMRI-base mapping and direct cortical stimulation.
1. Agirre-Arrizubieta Z, Thai NJ, Valentin A, Furlong PL, Seri S, Selway RP, Elwes RD, Alarcon G. The value of Magnetoencephalography to guide electrode implantation in epilepsy. Brain Topogr. 2014;27(1):197-207
2. Bagić, Anto I.*; Funke, Michael E.†; Kirsch, Heidi E.‡; Tenney, Jeffrey R.§; Zillgitt, Andrew J.‖; Burgess, Richard C. The 10 Common Evidence-Supported Indications for MEG in Epilepsy Surgery: An Illustrated Compendium, Journal of Clinical Neurophysiology: November 2020 - Volume 37 - Issue 6 - p 483-497 doi: 10.1097/WNP.0000000000000726
3. Burgess RC. MEG Reporting. J Clin Neurophysiol. 2020 Nov;37(6):545-553. doi: 10.1097/WNP.0000000000000700
4 De Tiege X, Lundqvist D, Beniczky S, Seri S, Paetau R. Current clinical magnetoencephalography practice across Europe: Are we closer to use MEG as an established clinical tool? Seizure. 2017;50:53-9
5. Foley E, Cross JH, Thai NJ, Walsh AR, Bill P, Furlong P, Wood AG, Cerquiglini A, Seri S. MEG Assessment of Expressive Language in Children Evaluated for Epilepsy Surgery. Brain Topogr. 2019;32(3):492-503.PMC6476853
6. Foley E, Quitadamo LR, Walsh AR, Bill P, Hillebrand A, Seri S. MEG detection of high frequency oscillations and intracranial-EEG validation in pediatric epilepsy surgery. Clin Neurophysiol. 2021;132(9):2136-45
7. Foley E, Wood AG, Furlong PL, Walsh AR, Kearney S, Bill P, Hillebrand A, Seri S. Mapping language networks and their association with verbal abilities in paediatric epilepsy using MEG and graph analysis. Neuroimage Clin. 2020;27:102265.PMC7226893
8. Hall MBH, Nissen IA, van Straaten ECW, Furlong PL, Witton C, Foley E, Seri S, Hillebrand A. An evaluation of kurtosis beamforming in magnetoencephalography to localize the epileptogenic zone in drug resistant epilepsy patients. Clin Neurophysiol. 2018;129(6):1221-9.PMC5953276