title: An EEG-fMRI Study on the Termination of Generalized Spike-And-Wave Discharges in Absence Epilepsy.
abstract: BACKGROUND
  Different studies have investigated by means of EEG-fMRI coregistration the brain networks related to generalized spike-and-wave discharges (GSWD) in patients with idiopathic generalized epilepsy (IGE). These studies revealed a widespread GSWD-related neural network that involves the thalamus and regions of the default mode network. In this study we investigated which brain regions are critically involved in the termination of absence seizures (AS) in a group of IGE patients.
  
  
  METHODS
  Eighteen patients (6 male; mean age 25 years) with AS were included in the EEG-fMRI study. Functional data were acquired at 3T with continuous simultaneous video-EEG recording. Event-related analysis was performed with SPM8 software, using the following regressors: (1) GSWD onset and duration; (2) GSWD offset. Data were analyzed at single-subject and at group level with a second level random effect analysis.
  
  
  RESULTS
  A mean of 17 events for patient was recorded (mean duration of 4.2 sec). Group-level analysis related to GSWD onset respect to rest confirmed previous findings revealing thalamic activation and a precuneus/posterior cingulate deactivation. At GSWD termination we observed a decrease in BOLD signal over the bilateral dorsolateral frontal cortex respect to the baseline (and respect to GSWD onset). The contrast GSWD offset versus onset showed a BOLD signal increase over the precuneus-posterior cingulate region bilaterally. Parametric correlations between electro-clinical variables and BOLD signal at GSWD offset did not reveal significant effects.
  
  
  CONCLUSIONS
  The role of the decreased neural activity of lateral prefrontal cortex at GSWD termination deserve future investigations to ascertain if it has a role in promoting the discharge offset, as well as in the determination of the cognitive deficits often present in patients with AS. The increased BOLD signal at precuneal/posterior cingulate cortex might reflect the recovery of neural activity in regions that are "suspended" during spike and waves activity, as previously hypothesized.
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Benuzzi
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Ballotta
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Unit, NOCSAE Hospital-ASL, Modena, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Mirandola
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ruggieri
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Unit, NOCSAE Hospital-ASL, Modena, Italy.
authors.forename: Anna Elisabetta
authors.initials: AE
authors.lastname: Vaudano
authors.affiliation: Department of Psychology University of Bologna, Bologna, Italy.
authors.forename: Micaela
authors.initials: M
authors.lastname: Zucchelli
authors.affiliation: IIT, Genova, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ferrari
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Unit, NOCSAE Hospital-ASL, Modena, Italy.
authors.forename: Paolo Frigio
authors.initials: PF
authors.lastname: Nichelli
authors.affiliation: Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Unit, NOCSAE Hospital-ASL, Modena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Meletti
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D004569:Electroencephalography; D004832:Epilepsy, Absence / Q000175:diagnosis / Q000503:physiopathology*; D004829:Epilepsy, Generalized / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology; D009474:Neurons / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013788:Thalamus / Q000503:physiopathology; D014741:Video Recording; D055815:Young Adult