Publications by authors named "Jawata Afnan"
Electro/Magneto-EncephaloGraphy (EEG/MEG) source imaging (EMSI) of epileptic activity from deep generators is often challenging due to the higher sensitivity of EEG/MEG to superficial regions and to the spatial configuration of subcortical structures. We previously demonstrated the ability of the coherent Maximum Entropy on the Mean (cMEM) method to accurately localize the superficial cortical generators and their spatial extent. Here, we propose a depth-weighted adaptation of cMEM to localize deep generators more accurately.
View Article and Find Full Text PDFObjective: The use of electrical source imaging (ESI) in assessing the source of interictal epileptic discharges (IEDs) is gaining increasing popularity in presurgical work-up of patients with drug-resistant focal epilepsy. While vigilance affects the ability to locate IEDs and identify the epileptogenic zone, we know little about its impact on ESI.
Methods: We studied overnight high-density electroencephalography recordings in focal drug-resistant epilepsy.
Article Synopsis
- MEG is a non-invasive tool used to estimate brain activity but its accuracy in identifying cortical sources is uncertain and needs validation.
- The study compared MEG source imaging with an iEEG atlas to assess resting state activity in healthy participants, using wavelet-based techniques and virtual iEEG potentials for quantitative analysis.
- Results showed that MEG performed better in lateral brain regions and highlighted overestimations in the alpha band, suggesting that while MEG provides valuable insights, its measurements may not always match those from more invasive iEEG techniques.
Background And Objectives: Accurate delineation of the seizure-onset zone (SOZ) in focal drug-resistant epilepsy often requires stereo-EEG (SEEG) recordings. Our aims were to propose a truly objective and quantitative comparison between EEG/magnetoencephalography (MEG) source imaging (EMSI), EEG/fMRI responses for similar spikes with primary irritative zone (PIZ) and SOZ defined by SEEG and to evaluate the value of EMSI and EEG/fMRI to predict postsurgical outcome.
Methods: We identified patients with drug-resistant epilepsy who underwent EEG/MEG, EEG/fMRI, and subsequent SEEG at the Epilepsy Service from the Montreal Neurological Institute and Hospital.