Structural Underpinnings of Cerebral Perfusion Abnormalities in Drug-resistant Temporal Lobe Epilepsy
Abstract number :
1.264
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2022
Submission ID :
2204332
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:24 AM
Authors :
Alexander Ngo, BS – McGill University; Sara Larivière, MSc – McGill University; Jessica Royer, PsyD – McGill University; Raúl Rodríguez-Cruces, MBBS PhD – McGill University; Ke Xie, MSc – McGill University; Hans Auer, BSc – McGill University; Jordan deKraker, PhD – McGill University; Shahin Tavakol, MSc – McGill University; Reinder Vos de Wael, PhD – McGill University; Qiongling Li, PhD – Beijing Normal University; Jack Lam, MD – McGill University; Andrea Bernasconi, MD – McGill University; Neda Ladbon-Bernasconi, MD, PhD – McGill University; Birgit Frauscher, MD, PhD – McGill University; Boris Bernhardt, PhD – McGill University
Rationale: Neuroimaging has been among the prevailing methods to study brain network alterations in health and disease. In temporal lobe epilepsy (TLE), the most common drug-resistant epilepsy in adults, extensive magnetic resonance imaging (MRI) analyses have provided in vivo evidence of structural alterations across multiple cortical and subcortical regions and connections.1,2 However, despite the critical role of the vascular system in maintaining whole-brain structure, their relationship has yet to be considered in TLE. Here, we mapped perfusion alterations in TLE and healthy controls using arterial spin labelling (ASL) MRI, and assessed associations to grey and white matter changes in the disease.
Methods: Participants: We analyzed multimodal MRI data (T1-weighted MRI, ASL MRI, and diffusion MRI) in 21 adults with drug-resistant unilateral TLE (11 males; mean±SD age: 35.9±10.7 years; mean±SD duration: 34.7±9.3 years; 13 left-sided focus) and 38 age and sex-matched healthy controls (19 males, mean±SD age: 34.7±9.3 years).
Cerebral perfusion: Based on ASL, we generated cortex- and subcortex-wide maps of cerebral perfusion. We compared patients with TLE to controls using surface-based linear models, while controlling for age and sex. Findings were corrected for multiple comparisons at a family-wise error (FWE) rate of p< 0.05.
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Relation to grey and white matter brain organization: We measured subject-specific cortical thickness and subcortical volume maps in all subjects. Superficial white matter was further examined by sampling diffusion tensor-derived fractional anisotropy and mean diffusivity along superficial white matter surfaces running 2mm below the grey-white matter interface. We utilized surface-based linear models to derive patient-control differences in grey and white matter measures. To assess the structural underpinnings of perfusion shifts, the perfusion analyses were repeated while controlling for morphology and superficial white matter.
Results: Compared to controls, individuals with TLE demonstrated marked cerebral blood flow reductions in ipsilateral temporal lobe, inferior parietal lobule and visual cortex (pFWE< 0.05; Figure 1B). Moreover, patients showed significant grey matter atrophy in ipsilateral frontocentral cortices as well as superficial white matter changes in bilateral temporolimbic, prefrontal, hippocampal and caudate regions, with stronger effects on the ipsilateral side (pFWE< 0.05; Figure 2A). Significant hypoperfusion patterns in temporo-parieto-occipital cortices weakened after correcting for MRI-derived structural alterations, suggesting a mediatory effect of grey and white matter integrity on cerebral blood flow reductions in TLE (pFWE< 0.05; Figure 2B).
Neuro Imaging