title: The MR detection of neuronal depolarization during 3-Hz spike-and-wave complexes in generalized epilepsy.
abstract: Previously, an analysis of activations observed in a patient with idiopathic generalized epilepsy using electroencephalogram-correlated functional magnetic resonance imaging (MRI) during runs of 3-Hz generalized spike-wave discharge (GSWD) was presented by Salek-Haddadi. Time-locked, bilateral, thalamic blood oxygenation level-dependent increases were reported to be accompanied by widespread, symmetric, cortical deactivation with a frontal maximum. In light of recent investigations into MRI detection of the magnetic field perturbations caused by neuronal current loops during depolarization, we revisited the analysis of the data of Salek-Haddadi as a preliminary search for a neuroelectric signal. We modeled the MRI response as the sum of a fast signal and a slower signal and demonstrated significant MRI activity at a time scale of the order of 30 ms associated with GSWDs. Further work is necessary before firm conclusions may be drawn about the nature of this signal.
authors.affiliation: Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL Queen Square, London WC1N 3BG, UK. a.liston@ion.ucl.ac.uk
authors.forename: Adam D
authors.initials: AD
authors.lastname: Liston
authors.forename: Afraim
authors.initials: A
authors.lastname: Salek-Haddadi
authors.forename: Stefan J
authors.initials: SJ
authors.lastname: Kiebel
authors.forename: Khalid
authors.initials: K
authors.lastname: Hamandi
authors.forename: Robert
authors.initials: R
authors.lastname: Turner
authors.forename: Louis
authors.initials: L
authors.lastname: Lemieux
mesh_terms: D002540:Cerebral Cortex / Q000503:physiopathology*; D017352:Echo-Planar Imaging / Q000379:methods; D004569:Electroencephalography; D004829:Epilepsy, Generalized / Q000503:physiopathology*; D005071:Evoked Potentials / Q000502:physiology; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009474:Neurons / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D013788:Thalamus / Q000503:physiopathology
chemical_list: D010100:Oxygen