Association of cortical spreading depression and seizures in patients with medically intractable epilepsy

Objective: Monitoring of the ultra-low frequency potentials, particularly cortical spreading (CSD), is excluded in epilepsy monitoring due to technical barriers imposed by the scalp ultra-low quency electroencephalogram (EEG). As a result, clinical studies of CSD have been limited EEG. Therefore, the occurrence of CSD and its interaction with epileptiform field potentials (EFP) investigation in epilepsy monitoring. Methods: Using a novel AC/DC-EEG approach, the occurrence of DC potentials in patients with epilepsy presenting different symptoms of aura was investigated during long-term video-EEG ing. Results: Various forms of slow potentials, including simultaneous negative direct current (DC) and prolonged EFP, propagated negative DC potentials, and non-propagated single negative DC were recorded from the scalp of the epileptic patients. The propagated and single negative DC preceded the prolonged EFP with a time lag and seizure appeared at the final shoulder of some of the propagated negative DC potentials. The slow potential deflections had a high amplitude longed duration and propagated slowly through the brain. The high-frequency EEG was suppressed vicinity of the negative DC potential propagations. Conclusions: The study is the first to report the recording of the propagated and single negative DC potentials with EFP at the scalp of patients with intractable epilepsy. The negative DC potentials preceded the prolonged EFP and may trigger seizures. The propagated and single negative DC potentials may be considered as CSD. Significance: Recordings of CSD may serve as diagnostic and prognostic monitoring tools in epilepsy. (c) 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.