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IC‐P‐035: BOLD SIGNAL VARIABILITY CHANGES IN THE DEFAULT MODE AND SALIENCE NETWORKS IN AMNESTIC MILD COGNITIVE IMPAIRMENT AND ALZHEIMER'S DISEASE AND THEIR ASSOCIATIONS WITH COGNITIVE DECLINE
Author(s) -
Zhang Liwen,
Zuo Xinian,
Ng Kwun Kei,
Xian Chong Joanna Su,
Shim Hee Youn,
Miin Yng,
Choo Boon Linn,
Chong Eddie,
Wong Zi Xuen,
Hilal Saima,
Venketasubramanian Narayanaswamy,
Tan Boon Yeow,
Chen Christopher,
Zhou Juan Helen
Publication year - 2019
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2019.06.4197
Subject(s) - default mode network , audiology , cognitive decline , psychology , resting state fmri , salience (neuroscience) , neuroscience , atrophy , cognition , dementia , medicine , disease
ability (p < 0.05). There was also a significant decrease (p < 0.05) in the SCD self-rating scale, the immediate and delayed test of Philadelphia verbal learning, while the remaining neuropsychological scales were within normal range. In the olfactory fMRI, activation in bilateral primary olfactory cortex was significantly reduced in SCD patients, including bilateral entorhinal cortex, amygdala, piriform cortex, anterior olfactory nucleus, and head of the hippocampus (Fig. 1). The resting-state functional connectivity with the bilateral primary olfactory cortex (POC) showed that the functional connections between the POC and frontal cortex and the default mode network (DMN) were significantly weakened in the SCD patients (Fig. 2 and 3, AlphaSim correction with voxel level p<0.01 and cluster level p<0.05). Conclusions: Olfactory identification were decreased significantly in SCD, although their neurocognitive scales appear to be normal. The olfactory fMRI also showed a significant degeneration in the SCD cohort in the POC, and the functional connectivity with the DMNwas also found to be significantly disrupted. Our data support the hypothesis that primary olfactory network is disrupted by AD at its earliest stage when cognitive declines are not yet detectable in SCD subjects. Olfactory fMRI may be an objective biomarkers for early detection of AD.