Abstract:
HTML
Purpose: The objective of this project is to develop a comprehensive, quantitative and reproducible fMRI protocol to evaluate language and memory lateralisation in patients with temporal lobe epilepsy (TLE) using Wada test results as a reference. The language paradigms are designed to identify both expressive and receptive brain regions. The protocols for memory assessment are created to preferentially activate the left and right medial temporal lobes.
Methods and Materials: fMRI was performed for 8 healthy right-handed subjects using a 1.5T GE (Milwaukee, USA) LX/Nvi System. Blood oxygenation level-dependent contrast T2W* echo planar MR (TR 3s; TE 40ms; FOV 24 cm, slice thickness 5 mm, 22 slices) were acquired encompassing the whole cerebrum. T1W 3D inversion recovery prepared gradient echo image was also acquired. Instructions and stimuli were presented using a computer controlled projection system running EPrime software. Six two-condition box-car paradigms were employed: (i) Verbal category fluency task, (ii) Rhyming task, (iii) Sentence comprehension task, (iv) Complex scenes task, (v) Pattern memory task, (vi) Word-association and memory task The order of the paradigms was counterbalanced. Relevant behavioural data were acquired during paradigms. Post-scan memory tests were performed for (iv), (v) and (vi). Data were analysed with SPM99 software, particularly single subject (p<0.001) and group conjunction (p<0.05) analyses.
Results: Behavioural data revealed that all subjects were able to perform all tasks successfully. Preliminary group data analysis revealed that all three of the language paradigms resulted in activation of the left inferior frontal gyrus (IFG) (Broca's) and for the Sentence comprehension task significant activation was also detected in right IFG. The Rhyming and Sentence comprehension task additionally activated the superior temporal gyrus (STG). The Complex scene and Pattern memory paradigms produced significant bilateral parahippocampal activation. The Pattern memory task additionally activated bilateral middle frontal gyrus. The Word-association memory task resulted in significant left IFG, SMA, right cerebellum, and left parahippocampal activity.
Conclusion: The paradigms we have developed have the potential to yield activation in the desired brain structures with TLE patients. We are currently applying this protocol in patients with temporal lobe epilepsy for whom we have already obtained detailed measurements of brain structure, including hippocampal volumes and T2 relaxation time.
Questions about this event email: nasuda@hotmail.com
Danchaivijitr MD, N,
An fMRI Protocol to Evaluate Both Language and Memory for Presurgical Evaluation in Temporal lobeEpilepsy. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3101422.html
