Schedule of Events | Symposia

The salience and frontoparietal networks in dementia with Lewy bodies: functional connectivity changes through disease progression

Poster Session D - Monday, March 31, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Vincent Gabriel¹ (vincent.gabriel125@gmail.com), Elena Chabran¹, Marion Sourty¹, Paulo Loureiro de Sousa¹, Anne Botzung², Olivier Bousiges¹, Frédéric Blanc²; ¹University of Strasbourg and CNRS, ICube Laboratory UMR-7357, IMIS Team, Strasbourg, France, ²University Hospital of Strasbourg, CM2R, Geriatric Day Hospital and Neuropsychological Unit, Strasbourg, France

Context: Previous resting-state fMRI studies in dementia with Lewy bodies (DLB) have described functional connectivity modifications in key brain networks related to cognition, attention, psychiatric and motor functions. However, little is known about the evolution of these changes as the disease progresses towards dementia. This study compares the functional connectivity of key neurodegenerative brain networks in DLB patients at different disease stages with healthy older controls (HC) and Alzheimer's disease (AD) patients. Methods: Seventy-seven DLB patients, including 55 DLB patients with mild cognitive impairment (MCI-DLB) and 22 DLB patients with dementia (d-DLB), along with 13 AD patients and 34 HC underwent a detailed clinical and neuropsychological evaluation and resting-state fMRI. ROI-to-ROI analyses were performed to assess within- and between-network functional connectivity differences across groups, using the CONN toolbox. Results: The DLB group showed significantly lower functional connectivity within the salience network (SN) compared with HC group, but did not significantly differ from the AD group. While no significant changes were found in the MCI-DLB subgroup, the DLB-d subgroup showed reduced functional connectivity within the SN and the FPN compared to both the HCS and AD groups. The DLB-d subgroup showed significantly lower functional connectivity within the FPN compared to the MCI-DLB subgroup. Conclusion: We identified intra-network changes involving the SN and the FPN in DLB patients, which appeared as trends at the prodromal stage and became significant at the dementia stage. These networks may play a key role in disease progression in DLB.

Topic Area: METHODS: Neuroimaging