Abstract Details

Title Epileptic Networks in Temporal Lobe Epilepsy by Functional and Structural Images

Topic Epilepsy/Clinical Neurophysiology (EEG)

Presentation(s) S28 - (-)

Poster/Presentation
Number 001

Objective

Background Temporal lobe epilepsy (TLE) has varied underlying pathologies which may imply different neural networks.

Design/Methods We analyzed 25 patients (12 TLE-NL and 13 TLE-HS) with EEG-correlated functional MRI (EEG-fMRI) and Voxel-Based Morphometry (VBM). Images were acquired on 3T-MR scanner. EEG was recorded with 64 MR compatible electrodes. Time of interictal EEG epileptiform discharges (IEDs) was used to assess the positive (posBOLD) and negative (negBOLD) BOLD responses. Group analysis of BOLD maps were performed with HRF peak at zero (early response) and +5 seconds (late response) after IEDs with SPM8 software (one sample T-Test, P<0.001 uncorrected). VBM analysis was performed with VBM8/SPM8 (two-sample T-Test, P<0.05 FWE-corrected).

Results PosBOLD maps in TLE-HS showed early hemodynamic abnormalities in ipsilateral temporal lobe, insula and contralateral precentral gyrus, and late abnormalities in ipsilateral putamen, bilateral anterior cingulum, insula, and temporal lobes. In TLE-NL posBOLD maps showed diffuse early abnormalities, most significant in ipsilateral medial frontal gyrus and late abnormalities in ipsilateral insula and superior temporal gyrus. In both groups, early and late negBOLD were observed in brain areas compatible with default mode network (DMN). In TLE-HS and TLE-NL groups VBM analysis showed significant gray matter atrophy that did not overlap with functional maps.

Conclusions Activations of functional networks related to IEDs differ between TLE-HS and TLE-NL. Suppression of DMN during IEDs is observed in both TLE groups. Subtle gray matter atrophy does not overlap with functional networks what may indicate that the structures involved in these interictal networks do not sustain significant loss of volume. The importance of these findings extends beyond the definition of the irritative zone in individuals with refractory TLE and may direct future investigations about their interictal dysfunctions and response to treatments.

Authors/Disclosures
Ana C. Coan, MD (Unicamp) PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
Clarissa L. Yasuda, MD, PhD (University of Campinas)	Prof. Yasuda has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for LIBBS. Prof. Yasuda has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for ABBOTT. Prof. Yasuda has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for LIBBS.
	No disclosure on file
Galina Vorobeychik, MD, FRCPC, FAAN (Fraser Health MS Clinic)	Dr. Vorobeychik has nothing to disclose.
Fernando Cendes, MD, PhD, FAAN (Departamento de Neurologia; FCM; UNICAMP)	Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for UCB Pharma. Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for UCB Biopharma. Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for United Medical – Brazil. Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Zodiac Pharma . Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Eurofarma – Brazil . Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Epilepsia. Dr. Cendes has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Frontiers in Neurology - Epilepsy. The institution of Dr. Cendes has received research support from São Paulo Research Foundation - FAPESP. The institution of Dr. Cendes has received research support from Conselho Nacional de Desenvolvimento Científico e Tecnológico - Brazil . The institution of Dr. Cendes has received research support from NIH.

��ɫ��

��ɫ��