Finally, we validate the whole methodology by obtaining brain source images of IEDs and compare them with those obtained at different time frames during the seizure onset. In this video, we introduce the procedures to acquire multichannel EEG from Wistar rats with focal cortical dysplasia, and describe the steps both to define the volume conductor model from the MRI atlas and to uniquely determine the IEDs. To overcome this issue, we combine a patented-technology to obtain 32-channel EEG recordings from rodents 2 and an MRI probabilistic atlas for brain anatomical structures in Wistar rats to perform brain source imaging. However, it is challenging to record multichannel EEG and to perform brain source imaging in such a small animal. Rats have been commonly used in preclinical studies of epilepsy 1 hence, there exist a large variety of models for focal epilepsy in this particular species. Preclinical models are very useful to find correlates between IED locations and the actual regions underlying seizure initiation in focal epilepsy. This methodology relies on the assumption that seizures originate from the same regions of the brain from which interictal epileptiform discharges (IEDs) emerge. Electroencephalogram (EEG) has been traditionally used to determine which brain regions are the most likely candidates for resection in patients with focal epilepsy.

Labchart reader video