A clinically applicable functional MRI memory paradigm for use with pediatric patients

• Published in: Epilepsy & behavior 2022-01, Vol.126, p.108461-108461, Article 108461
• Main Authors: Shurtleff, Hillary A., Poliakov, Andrew, Barry, Dwight, Wright, Jason N., Warner, Molly H., Novotny, Edward J., Marashly, Ahmad, Buckley, Robert, Goldstein, Hannah E., Hauptman, Jason S., Ojemann, Jeffrey G., Shaw, Dennis W.W.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Child; Epilepsy surgery; Epilepsy, Temporal Lobe; fMRI; Functional Laterality - physiology; Hippocampus; Humans; Magnetic Resonance Imaging; Memory, Episodic; Neuropsychological Tests; Retrospective Studies; Temporal Lobe; Temporal lobe epilepsy; Tumor; Young Adult
• ISSN: 1525-5050; 1525-5069
• DOI: 10.1016/j.yebeh.2021.108461

•A novel fMRI memory paradigm for use with clinically involved children is introduced.•Most pediatric epilepsy surgery patients could perform the tasks.•This novel paradigm activated mesial temporal structures on an individual basis.•Activation patterns differ for cases with left versus right pathology.•The paradigm helps assess mesial temporal structures for surgical workups. Clinically employable functional MRI (fMRI) memory paradigms are not yet established for pediatric patient epilepsy surgery workups. Seeking to establish such a paradigm, we evaluated the effectiveness of memory fMRI tasks we developed by quantifying individual activation in a clinical pediatric setting, analyzing patterns of activation relative to the side of temporal lobe (TL) pathology, and comparing fMRI and Wada test results. We retrospectively identified 72 patients aged 6.7–20.9 years with pathology (seizure focus and/or tumor) limited to the TL who had attempted memory and language fMRI tasks over a 9-year period as part of presurgical workups. Memory fMRI tasks required visualization of autobiographical memories in a block design alternating with covert counting. Language fMRI protocols involved verb and sentence generation. Scans were both qualitatively interpreted and quantitatively assessed for blood oxygenation level dependent (BOLD) signal change using region of interest (ROI) masks. We calculated the percentage of successfully scanned individual cases, compared 2 memory task activation masks in cases with left versus right TL pathology, and compared fMRI with Wada tests when available. Patients who had viable fMRI and Wada tests had generally concordant results. Of the 72 cases, 60 (83%), aged 7.6–20.9 years, successfully performed the memory fMRI tasks and 12 (17%) failed. Eleven of 12 unsuccessful scans were due to motion and/or inability to perform the tasks, and the success of a twelfth was indeterminate due to orthodontic metal artifact. Seven of the successful 60 cases had distorted anatomy that precluded employing predetermined masks for quantitative analysis. Successful fMRI memory studies showed bilateral mesial temporal activation and quantitatively demonstrated: (1) left activation (L-ACT) less than right activation (R-ACT) in cases with left temporal lobe (L-TL) pathology, (2) nonsignificant R-ACT less than L-ACT in cases with right temporal lobe (R-TL) pathology, and (3) lower L-ACT plus R-ACT activation for cases with L-TL versus R-TL pathology. Patients