Affiliation:
1. Comprehensive Epilepsy Center Northwestern Memorial Hospital Chicago Illinois USA
2. Department of Neurology, Feinberg School of Medicine Northwestern University Chicago Illinois USA
3. Department of Medicine, School of Health Sciences Democritus University of Thrace Alexandroupoli Greece
4. Medical School National and Kapodistrian University of Athens Athens Greece
Abstract
AbstractBackground and PurposeThis work investigates verbal memory functional MRI (fMRI) versus language fMRI in terms of lateralization, and assesses the validity of performing word recognition during the functional scan.MethodsThirty patients with a diagnosis of epilepsy underwent verbal memory, visuospatial memory, and language fMRI. We used word encoding, word recognition, image encoding, and image recognition memory tasks, and semantic description, reading comprehension, and listening comprehension language tasks. We used three common lateralization metrics: network spatial distribution, maximum statistical value, and laterality index (LI).ResultsLateralization of signal spatial distribution resulted in poor similarity between verbal memory and language fMRI tasks. Signal maximum lateralization showed significant (>.8) but not perfect (1) similarity. Word encoding LI showed significant correlation only with listening comprehension LI (p = .016). Word recognition LI was significantly correlated with expressive language semantic description LI (p = .024) and receptive language reading and listening comprehension LIs (p = .015 and p = .019, respectively). There was no correlation between LIs of the visuospatial tasks and LIs of the language tasks.ConclusionsOur results support the association between language and verbal memory lateralization, optimally determined by LI quantification, and the introduction of quantitative means for language fMRI interpretation in clinical settings where verbal memory lateralization is imperative.
Subject
Neurology (clinical),Radiology, Nuclear Medicine and imaging