P1‐335: Functional Connectivity Patterns Across Cognitively‐defined Alzheimer's Disease Subtypes in the Alzheimer's Disease Neuroimaging Initiative
Year: 2019
Type: article
Abstract: We are interested in whether cognitively-defined subgroups of people with Alzheimer's disease (AD) have disrupted functional connectivity in networks that support the impaired cognitive domains. Using data from the AD Neuroimaging Initiative, we generated memory, executive, language, and visuospatial scores at AD diagnosis. We calculated differences between each domain score and cross-domain average to create AD subgroups: isolated single domain relative impairment (4 groups), no domain without a single distinct relative impairment, and multiple domains with more than one relative impairment. After preprocessing of 3T resting state and structural scans from people ≥65 years old at diagnosis we obtained images from four groups: AD-Executive (n=8), AD-Memory (n=9), AD-Visuospatial (n=7) and AD-No domain (n=14) (Table 1). We performed an independent component analysis using FSL Melodic (limited to 30 components) followed by dual regression to identify independent spatial network maps and time courses. We identified nine cognitive networks (Figure 1). We examined group differences between each subgroup and all other groups combined; however, due to the small sample size, none of the contrasts survived multiple comparison correction. Additionally, we computed Fisher z-transformed cross-correlation coefficients between all pairs of cognitive networks to study large-scale interactions. The correlation between the posterior default mode network and auditory network was nominally greater in the AD-Executive group compared to the AD-No domain group (Figure 2). Additionally, the correlation between the salience network and the anterior default mode network was greater in the AD-Memory group than in the AD-Executive and AD-No domain groups (Figure 3). Notably, we found no difference in functional connectivity patterns in the hypothesized networks (hippocampal, right/left executive and visual) between subgroups.
Source: Alzheimer s & Dementia
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2980849202