title: Neural Activity Elicited by a Cognitive Task can be Detected in Single-Trials with Simultaneous Intracerebral EEG-fMRI Recordings.
abstract: Recent studies have shown that it is feasible to record simultaneously intracerebral EEG (icEEG) and functional magnetic resonance imaging (fMRI) in patients with epilepsy. While it has mainly been used to explore the hemodynamic changes associated with epileptic spikes, this approach could also provide new insight into human cognition. However, the first step is to ensure that cognitive EEG components, that have lower amplitudes than epileptic spikes, can be appropriately detected under fMRI. We compared the high frequency activities (HFA, 50-150[Formula: see text]Hz) elicited by a reading task in icEEG-only and subsequent icEEG-fMRI in the same patients ([Formula: see text]), implanted with depth electrodes. Comparable responses were obtained, with 71% of the recording sites that responded during the icEEG-only session also responding during the icEEG-fMRI session. For all the remaining sites, nearby clusters (distant of 7[Formula: see text]mm or less) also demonstrated significant HFA increase during the icEEG-fMRI session. Significant HFA increases were also observable at the single-trial level in icEEG-fMRI recordings. Our results show that low-amplitude icEEG signal components such as cognitive-induced HFAs can be reliably recorded with simultaneous fMRI. This paves the way for the use of icEEG-fMRI to address various fundamental and clinical issues, notably the identification of the neural correlates of the BOLD signal.
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.|† Epilepsy Institute IDEE, Lyon, France.
authors.forename: Mani
authors.initials: M
authors.lastname: Saignavongs
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.|† Epilepsy Institute IDEE, Lyon, France.|‡ Department of Clinical Neurosciences, Centre Hospitalo-Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Carolina
authors.initials: C
authors.lastname: Ciumas
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Petton
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Bouet
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.|† Epilepsy Institute IDEE, Lyon, France.|§ Department of Functional Neurology and Epileptology, Hospices Civils de Lyon, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Boulogne
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.|† Epilepsy Institute IDEE, Lyon, France.|§ Department of Functional Neurology and Epileptology, Hospices Civils de Lyon, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Rheims
authors.affiliation: ¶ Developmental Imaging and Biophysics, UCL Institute of Child Health, University College London, UK.
authors.forename: David W
authors.initials: DW
authors.lastname: Carmichael
authors.affiliation: * Lyon Neuroscience Research Center, INSERM U1028 / CNRS UMR 5292 Lyon, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lachaux
authors.affiliation: † Epilepsy Institute IDEE, Lyon, France.|‡ Department of Clinical Neurosciences, Centre Hospitalo-Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ryvlin
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology* / Q000601:surgery; D001931:Brain Mapping / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003071:Cognition / Q000502:physiology; D000069279:Drug Resistant Epilepsy / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D000069280:Electrocorticography / Q000379:methods*; D004567:Electrodes, Implanted; D004828:Epilepsies, Partial / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D005260:Female; D065818:Gamma Rhythm / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D064847:Multimodal Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology; D011932:Reading; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D010100:Oxygen
keywords: Intracranial EEG; data quality; gamma activity; high frequency activity; simultaneous icEEG-fMRI