title: EEG Derived Brain Activity Reflects Treatment Response from Vagus Nerve Stimulation in Patients with Epilepsy.
abstract: The mechanism of action of vagus nerve stimulation (VNS) is yet to be elucidated. To that end, the effects of VNS on the brain of epileptic patients were studied. Both when VNS was switched "On" and "Off", the brain activity of responders (R, seizure frequency reduction of over 50%) was compared to the brain activity of nonresponders (NR, seizure frequency reduction of less than 50%). Using EEG recordings, a significant increase in P300 amplitude for R and a significant decrease in P300 amplitude for NR were found. We found biomarkers for checking the efficacy of VNS with accuracy up to 94%. The results show that P300 features recorded in nonmidline electrodes are better P300 biomarkers for VNS efficacy than P300 features recorded in midline electrodes. Using source localization and connectivity analyses, the activity of the limbic system, insula and orbitofrontal cortex was found to be dependent on VNS switched "On" versus "Off" or patient group (R versus NR). The results suggest an important role for these areas in the mechanism of action of VNS, although a larger patient study should be done to confirm the findings.
authors.affiliation: * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.|† iMinds Medical IT Department, Ghent University, Ghent, Belgium.
authors.forename: Simon
authors.initials: S
authors.lastname: Wostyn
authors.affiliation: * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.|† iMinds Medical IT Department, Ghent University, Ghent, Belgium.
authors.forename: Willeke
authors.initials: W
authors.lastname: Staljanssens
authors.affiliation: ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium.
authors.forename: Leen
authors.initials: L
authors.lastname: De Taeye
authors.affiliation: * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.
authors.forename: Gregor
authors.initials: G
authors.lastname: Strobbe
authors.affiliation: ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Gadeyne
authors.affiliation: § Department of Neurosurgery, Ghent University Hospital, Ghent, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Van Roost
authors.affiliation: ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium.
authors.forename: Robrecht
authors.initials: R
authors.lastname: Raedt
authors.affiliation: ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium.
authors.forename: Kristl
authors.initials: K
authors.lastname: Vonck
authors.affiliation: * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.|† iMinds Medical IT Department, Ghent University, Ghent, Belgium.|¶ Functional Brain Mapping lab, University of Geneva, Geneva, Switzerland.
authors.forename: Pieter
authors.initials: P
authors.lastname: van Mierlo
mesh_terms: D000161:Acoustic Stimulation; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004569:Electroencephalography; D004827:Epilepsy / Q000000981:diagnostic imaging* / Q000628:therapy*; D005072:Evoked Potentials, Auditory; D006801:Humans; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology; D009483:Neuropsychological Tests; D012815:Signal Processing, Computer-Assisted; D016896:Treatment Outcome; D014630:Vagus Nerve / Q000503:physiopathology; D055536:Vagus Nerve Stimulation / Q000379:methods; D014741:Video Recording
keywords: Epilepsy; P300; VNS; betweenness centrality; electrical source imaging; functional directed connectivity