Identifying seizures in MEG data:

Localization of MEG seizures onset

Valentina Gumenyuk, PhD* ; Oleg Korzyukov PhD*; Werner Doyle MD**,

Alyson Silverberg RN **, and Ole Jensen PhD ***

*MEG lab, Hudson Regional Hospital, NJ USA

** NYU Langone Medical Center, Department of Neurosurgery, NYC USA

*** Centre for Human Brain Health, University of Birmingham, UK

Magnetoencephalograpghy (MEG) has a strong clinical potential and valuable tool for specific brain surgery in epilepsy patients. Although, the MEG clinical exam is not designed for monitoring and collecting a seizure activity such as video EEG, however some patients may have seizures during the MEG study. The localization of seizure onset in the MEG data yields the clinical meaning of the MEG exam results at significant level and can change diagnostic prognosis and/or guide intervention. However, multiple approaches can be used for analyzing the MEG data in order to localize the focus of the seizures onset. The aim of this data analysis challenge promote the development of new ideas and tools for localizing the seizures onset in MEG data.

For Biomag 2018 meeting in Philadelphia, we propose MEG /EEG data analysis challenge of three epileptic patients who had MEG seizure. The proposed task for participants as followed: 1. The onset of the MEG seizure should be localized into patient's MRI. 2. The MRI (DICOM) should be used for calculating the patient's head model . 3. Results should be submitted on slides (3-5). Please include in presentation: your motivation for this challenge and details of the analysis in addition to the brain locations (mapped into patient's MRI) using either coordinates of Broadman atlas or Talairach atlas. Each patient's MEG data has MAXfilter option and RAW data option, so participants of challenge will have free choice to work with. The results of the challenge will be compared to clinical report of each patient and surgery outcomes of each patient after results submission. The winner will present results on Biomag 2018 (however we cannot cover any costs).

Data: The RAW data was acquired via 306-channel whole-head Elekta Triux magnetoencephalography machine and simultaneous EEG. The EEG was recorded using an EEG cap with 64 electrodes placed in a standard 10-20 system montage in addition to 4 EOG and 2 EKG electrodes. MEG and EEG data were recorded at a 2 kHz sample rate with an online filter band-pass of 0.03-660Hz. Maxfilter parameters were provided by the MEG manufacturer Elekta Neuromag.


Patient A was 10 yrs old boy. He had treatment resistant epilepsy with complex partial seizures (~ 20/30 seizures /day from age of 4 years. The MEG results was very helpful for this patient because the focal cortical dysplasia was identified in MEG data, the epileptic focus was matched with focal cortical dysplasia and successfully removed in the following brain surgery. Patient is seizure free now.

Patient B was 57 yrs old women. She had treatment resistant epilepsy, her MRI shows post-surgery resection of the right temporal lobe. She was admitted to the second surgery, however the MEG results did change the surgery prognosis for her, she still having seizures and taking medication to control her seizures.

Patient C was patient 25 yrs old female, with history of intractable epilepsy. Her MRI shows right parietal craniotomy. Her MEG results was helpful for identifying the epileptic focus for the second brain surgery. Patient is seizure free now.

The MEG and MRI data are accessible from the Open MEG Archives (OMEGA), a free and open data repository for shared MEG resources. Participants can download the files directly at this page: (Click the 'Download' link in the upper-right corner to download all the files.

Anatomical landmarks for co-registration of MRI & MEG can be found here:

Results of the the challenge consistent of summary images (pdf. or jpeg or .bmp format) with locations of the seizures onset for every patient should be provided to Valentina Gumenyuk at by August 1st, 2018.

CORRECT RESULTS derived from clinical reports and surgery outcomes will be available for review after submission of results.