Year: 2019
Type: article
Study design: Observational Study
Abstract: Ab-CN to identify brain regions strongly connected to MTL seed regions. Thirdly, we analyzed altered connectivity patterns in Ab+ CN and Ab+ MCI by comparing them to Ab-CN. Results: Our seed-to-whole-brain analysis revealed that MTL subregions are connected to several neocortical regions within PM/AT systems. Ab+ CN mainly exhibited decreased FC between left PrC and medial prefrontal cortex (mPFC) (AT, Fig1A). Levels of CSF P-tau in Ab+ CN individuals correlated with decreases in FC both between left PrC and mPFC (AT, Fig1B), and between anterior HC and posterior cingulate cortex (PCC) (PM). While Ab+ MCI also showed reduced MTL-AT connectivity, they mostly exhibited connectivity reductions between the anterior HC and PCC (PM, Fig1C). In addition, MCI were characterized by significantly increased connectivity within the MTL (Fig1D). Reductions in FC with both PM and AT systems were associated with worse memory already in CN individuals, but also in MCI. Increased MTL connectivity found in MCI was also associated to worse memory. Conclusions: Our results suggest that Ab-related changes in MTL-AT connectivity precede those with PM regions and are already associated to memory impairment in CN individuals. MTL subregional analyses point to early involvement of PrC and the HC in line with neuropathological studies. During disease progression, MTL-PM connectivity is progressively reduced and results in increased connectivity within the MTL in the MCI stage.
Source: Alzheimer s & Dementia
Institution: Lund University
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2981075893