A Verbal Memory fMRI Clinical Paradigm for Epilepsy Patients
Abstract number :
2.165
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2021
Submission ID :
1825844
Source :
www.aesnet.org
Presentation date :
12/5/2021 12:00:00 PM
Published date :
Nov 22, 2021, 06:50 AM
Authors :
Estefanía Conde-Blanco, MD, MSc - Hospital Clinic Barcelona; José Carlos Pariente, physicist - IDIBAPS; Emma Muñoz-Moreno, physicist - IDIBAPS; Saül Pascual-Diaz, Physicist - IDIBAPS; Teresa Boget, neuropsychologist - Hospital Clinic; Isabel Manzanares, nurse - Hospital Clinic Barcelona; Antonio Donaire, MD - Hospital clinic; María Centeno, MD - Hospital Clinic; Mar Carreño, MD - Hospital Clinic; Nuria Bargalló, MD - Hospital Clinic
Rationale: Functional MRI (fMRI) was introduced as a promising non-invasive tool for predicting postsurgical deficits in the presurgical evaluation of patients with pharmacoresistant temporal lobe epilepsy (TLE), but its predictive outcome power is very heterogeneous among centers. We aimed to assess fMRI validity predicting verbal memory lateralization with a clinical paradigm and compare results to neuropsychological scores.
Methods: fMRI protocol based on both encoding and retrieval phases aiming to achieve a sensitive laterality index of hippocampal involvement by using bootstrapping and an anterior-posterior index along the hippocampus. The verbal memory task was intended to be simple and reliable for assessing hippocampal function, therefore we used an adapted version of the Rey Auditory Verbal Learning Test. Depending on the task, a hippocampal or language ROI was included to focus on the area of interest.
Results: Fifty patients, 32 females, median age 31 years (IQR: 43-27), 40 of them with left TLE, and 22 healthy controls (HC) with no significant sex and age differences. In left TLE, verbal memory lateralization was rightward in 11 (32.35%) patients, 14 (41.18%) showed a leftward activation and 9 (26.47%) activation in both hippocampi while in right TLE only 1 (10%) patient activated bilaterally and in HC only 3 (13.6%). Verbal memory activation in right hippocampus was significantly higher in patients 272 (IQR 622) compared to HC 62.5 (IQR 376) [p=0.035]. Verbal memory activation in left hippocampus was not significantly different among HC, left TLE and right TLE [x2(2)=5.38, p=0.07]. These are preliminary results and validation to neuropsychology by ROC analysis is pending by the time of submission.
Conclusions: fMRI may be clinically relevant if we find a proper method for hippocampal activation. Left TLE show a higher tendency to bilateral activation, potentially secondary to reorganization in memory encoding processes.
Funding: Please list any funding that was received in support of this abstract.: No funding.
Neuro Imaging