PURPOSE: To determine the utility of functional magnetic resonance imaging (fMRI) in preoperative lateralization of memory function in patients with medial temporal lobe epilepsy (MTLE). METHODS: Nine patients with MTLE underwent standard preoperative assessment including video-EEG and intracarotid amytal testing (IAT). fMRI was performed while subjects encoded four types of stimuli (patterns, faces, scenes, and words). Activation maps were created for each subject representing areas more active for novel than for repeated stimuli. Regions of interest were drawn around the MTL in individual subjects, suprathreshold voxels were counted, and an asymmetry index was calculated. RESULTS: In eight of nine subjects, lateralization of memory encoding by fMRI was concordant with that obtained from the IAT. Group-level analysis demonstrated greater activation in the MTL contralateral to the seizure focus such that in the left MTLE group, verbal encoding engaged the right MTL, whereas in the right MTLE group, nonverbal encoding engaged the left MTL. CONCLUSIONS: fMRI is a valid tool for assessing of memory lateralization in patients with MTLE and may therefore allow noninvasive preoperative evaluation of memory lateralization. FMRI revealed that memory encoding may be reorganized to the contralateral MTL in patients with MTLE.
PURPOSE: To determine the utility of functional magnetic resonance imaging (fMRI) in preoperative lateralization of memory function in patients with medial temporal lobe epilepsy (MTLE). METHODS: Nine patients with MTLE underwent standard preoperative assessment including video-EEG and intracarotid amytal testing (IAT). fMRI was performed while subjects encoded four types of stimuli (patterns, faces, scenes, and words). Activation maps were created for each subject representing areas more active for novel than for repeated stimuli. Regions of interest were drawn around the MTL in individual subjects, suprathreshold voxels were counted, and an asymmetry index was calculated. RESULTS: In eight of nine subjects, lateralization of memory encoding by fMRI was concordant with that obtained from the IAT. Group-level analysis demonstrated greater activation in the MTL contralateral to the seizure focus such that in the left MTLE group, verbal encoding engaged the right MTL, whereas in the right MTLE group, nonverbal encoding engaged the left MTL. CONCLUSIONS: fMRI is a valid tool for assessing of memory lateralization in patients with MTLE and may therefore allow noninvasive preoperative evaluation of memory lateralization. FMRI revealed that memory encoding may be reorganized to the contralateral MTL in patients with MTLE.
Authors: Leigh N Sepeta; Madison M Berl; Marko Wilke; Xiaozhen You; Meera Mehta; Benjamin Xu; Sara Inati; Irene Dustin; Omar Khan; Alison Austermuehle; William H Theodore; William D Gaillard Journal: Epilepsia Date: 2015-12-23 Impact factor: 5.864
Authors: Greg S Harrington; Sarah Tomaszewski Farias; Michael H Buonocore; Andrew P Yonelinas Journal: Neuroradiology Date: 2006-05-09 Impact factor: 2.804
Authors: Franklin C Brown; Erin Tuttle; Michael Westerveld; F Richard Ferraro; Teresa Chmielowiec; Michelle Vandemore; Gina Gibson-Beverly; Lisa Bemus; Robert M Roth; Hal Blumenfeld; Dennis D Spencer; Susan S Spencer Journal: Epilepsy Behav Date: 2010-01-06 Impact factor: 2.937
Authors: H W Robert Powell; Mark P Richardson; Mark R Symms; Philip A Boulby; Pam J Thompson; John S Duncan; Matthias J Koepp Journal: Epilepsia Date: 2007-03-13 Impact factor: 5.864
Authors: Franklin C Brown; Michael Westerveld; John T Langfitt; Marla Hamberger; Hamada Hamid; Shlomo Shinnar; Michael R Sperling; Orrin Devinsky; William Barr; Joseph Tracy; David Masur; Carl W Bazil; Susan S Spencer Journal: Epilepsy Behav Date: 2013-11-26 Impact factor: 2.937
Authors: Cristina Bigras; Paula K Shear; Jennifer Vannest; Jane B Allendorfer; Jerzy P Szaflarski Journal: Epilepsy Behav Date: 2012-11-30 Impact factor: 2.937