Distinctive Resting State Network Disruptions Among Alzheimer’s Disease, Subcortical Vascular Dementia, and Mixed Dementia Patients

Article type: Research Article

Authors: Kim, Hee Jin^{a; b; 1} | Cha, Jungho^{c; 1} | Lee, Jong-Min^{c; *} | Shin, Ji Soo^d | Jung, Na-Yeon^{a; b; 3} | Kim, Yeo Jin^{a; b} | Choe, Yearn Seong^c | Lee, Kyung Han^e | Kim, Sung Tae^f | Kim, Jae Seung^g | Lee, Jae Hong^h | Na, Duk L.^{a; b; i} | Seo, Sang Won^{a; b; j; *}

Affiliations: [a] Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea | [b] Neuroscience Center, Samsung Medical Center, Seoul, Korea | [c] Department of Biomedical Engineering, Hanyang University, Seoul, Korea | [d] Pfizer Pharmaceuticals Korea Ltd., Seoul, Republic of Korea | [e] Department of Neurology, Pusan National University Hospital, Pusan National University, Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea | [f] Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea | [g] Department of Nuclear Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea | [h] Department of Neurology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea | [i] Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea | [j] Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University, Seoul, Korea

Correspondence: [*] Correspondence to: Sang Won Seo, MD, PhD, Department of Neurology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, South Korea. Tel.: +82 2 3410 1233; Fax: +82 2 3410 0052; E-mail: [email protected].

Correspondence: [*] Correspondence to: Jong-Min Lee, PhD, Department of Biomedical Engineering, Hanyang University, Sanhakgisulkwan 319, Wangsimni-ro Seongdong-gu, Seoul 133-791, Korea. Tel.: +82 2 2220 0685; Fax: +82 2 2296 5943; E-mail: [email protected].

Note: [1] These authors contributed equally to this work.

Abstract: Background:Recent advances in resting-state functional MRI have revealed altered functional networks in Alzheimer’s disease (AD), especially those of the default mode network (DMN) and central executive network (CEN). However, few studies have evaluated whether small vessel disease (SVD) or combined amyloid and SVD burdens affect the DMN or CEN. Objective:The aim of this study was to evaluate whether SVD or combined amyloid and SVD burdens affect the DMN or CEN. Methods:In this cross-sectional study, we investigated the resting-state functional connectivity within DMN and CEN in 37 Pittsburgh compound-B (PiB)(+) AD, 37 PiB(–) subcortical vascular dementia (SVaD), 13 mixed dementia patients, and 65 normal controls. Results:When the resting-state DMN of PiB(+) AD and PiB(–) SVaD patients were compared, the PiB(+) AD patients displayed lower functional connectivity in the inferior parietal lobule while the PiB(–) SVaD patients displayed lower functional connectivity in the medial frontal and superior frontal gyri. Compared to the PiB(–) SVaD or PiB(+) AD, the mixed dementia patients displayed lower functional connectivity within the DMN in the posterior cingulate gyrus. When the resting-state CEN connectivity of PiB(+) AD and PiB(–) SVaD patients were compared, the PiB(–) SVaD patients displayed lower functional connectivity in the anterior insular region. Compared to the PiB(–) SVaD or PiB(+) AD, the mixed dementia patients displayed lower functional connectivity within the CEN in the inferior frontal gyrus. Conclusions:Our findings suggest that in PiB(+) AD and PiB(–) SVaD, there is divergent disruptions in resting-state DMN and CEN. Furthermore, patients with combined amyloid and SVD burdens exhibited more disrupted resting-state DMN and CEN than patients with only amyloid or SVD burden.

Keywords: Alzheimer’s disease, amyloid, central executive network, default mode network, resting-state functional MRI, small vessel disease, subcortical vascular dementia,

DOI: 10.3233/JAD-150637

Journal: Journal of Alzheimer's Disease, vol. 50, no. 3, pp. 709-718, 2016