title: Detection of Intracranial Signatures of Interictal Epileptiform Discharges from Concurrent Scalp EEG.
abstract: Interictal epileptiform discharges (IEDs) are transient neural electrical activities that occur in the brain of patients with epilepsy. A problem with the inspection of IEDs from the scalp electroencephalogram (sEEG) is that for a subset of epileptic patients, there are no visually discernible IEDs on the scalp, rendering the above procedures ineffective, both for detection purposes and algorithm evaluation. On the other hand, intracranially placed electrodes yield a much higher incidence of visible IEDs as compared to concurrent scalp electrodes. In this work, we utilize concurrent scalp and intracranial EEG (iEEG) from a group of temporal lobe epilepsy (TLE) patients with low number of scalp-visible IEDs. The aim is to determine whether by considering the timing information of the IEDs from iEEG, the resulting concurrent sEEG contains enough information for the IEDs to be reliably distinguished from non-IED segments. We develop an automatic detection algorithm which is tested in a leave-subject-out fashion, where each test subject's detection algorithm is based on the other patients' data. The algorithm obtained a [Formula: see text] accuracy in recognizing scalp IED from non-IED segments with [Formula: see text] accuracy when trained and tested on the same subject. Also, it was able to identify nonscalp-visible IED events for most patients with a low number of false positive detections. Our results represent a proof of concept that IED information for TLE patients is contained in scalp EEG even if they are not visually identifiable and also that between subject differences in the IED topology and shape are small enough such that a generic algorithm can be used.
authors.affiliation: 1 Department of Computer Science, University of Surrey, UK.
authors.forename: Loukianos
authors.initials: L
authors.lastname: Spyrou
authors.affiliation: 2 Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, UK.|3 Department of Clinical Neurophysiology, King's College Hospital NHS FT, London, UK.|4 Department of Clinical Neurophysiology, Ashford and St Peter's Hospital NHS FT, Chertsey, UK.|5 Departamento de Fisiología, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Martín-Lopez
authors.affiliation: 2 Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, UK.|3 Department of Clinical Neurophysiology, King's College Hospital NHS FT, London, UK.|5 Departamento de Fisiología, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Valentín
authors.affiliation: 2 Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, UK.|3 Department of Clinical Neurophysiology, King's College Hospital NHS FT, London, UK.|6 Comprehensive Epilepsy Center Neuroscience Institute, Academic Health Systems, Hamad Medical Corporation, Doha, Qatar.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Alarcón
authors.affiliation: 1 Department of Computer Science, University of Surrey, UK.
authors.forename: Saeid
authors.initials: S
authors.lastname: Sanei
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D010363:Pattern Recognition, Automated / Q000379:methods*; D012372:ROC Curve; D012535:Scalp; D013686:Telemetry; D058067:Wavelet Analysis; D055815:Young Adult
keywords: Epileptic discharge detection; IED; clinical diagnosis; intracranial and scalp EEG