Abstracts

Rationale: Aim of this study was to determine the brain regions showing BOLD signal changes associated with inter-ictal EEG epileptic spikes and the relationship with the 3D source distribution of the focal EEG discharges in three patients with Landau Kleffner Syndrome (LKS) Methods: Three patients with LKS aged 8, 9 and 15 years were studied using simultaneous EEG-fMRI acquisition at rest and during the presentation of an auditory paradigm consisting of a tonal stimulus modulated in amplitude and frequency. EEG source analysis on the interictal EEG transients recorded from the 21 scalp locations of the international 10-20 system during the EEG-fMRI session was performed using the distributed linear local autoregressive average (LAURA) solution. Functional MRI data was analysed using SPM Results: In the three cases there was a good correspondence between hemodynamic changes and source localization. We have found a primary involvement of the superior temporal gyrus (STG) corresponding to primary auditory cortex. An increase in BOLD signal during interictal spikes was also seen in the lateral frontal cortex and the parieto-temporal junction Conclusions: Our findings suggest the anatomical and functional background of this epileptic syndrome could be related to a more widespread dysfunction than that previously hypothesized by MEG and EEG studies, involving more complex cortical networks. Source analyses from data acquired during the simultaneous EEG-fMRI seems to be applicable in spite of the electromagnetic noise and of the limited spatial sampling and could contribute to the comprehension of the complex relationships between bioelectric and hemodynamic changes related to interictal spikes