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Increased brain rewiring in patients with mild cognitive impairment
Author(s) -
Li Yong,
ButzOstendorf Markus
Publication year - 2021
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 - 10.1002/alz.054121
Subject(s) - posterior cingulate , neuroscience , cognitive impairment , psychology , grey matter , cortex (anatomy) , cohort , cognition , audiology , medicine , cardiology , white matter , magnetic resonance imaging , radiology
Background Depending on disease progression, differentiation of patients with mild cognitive impairments from those with Alzheimer disease from structural MRI is often difficult as grey matter (GM) loss is not yet present in MCI patients. Therefore, we re‐assessed WM densities at the initial and changes between two measurements in 22 randomly chosen MCI patients from the ADNI3 cohort [Weiner MW et al. 2017] and compared them to 25 matched controls. Method We computed full brain probabilistic tractography by MrTrix3 [Tournier et al. 2019]. ROI to ROI connectivity (HCP MMP 1.0 brain atlas) was compared between groups for Superior Longitudinal Fasciculus (SLF) and Occipital Cortex networks in two longitudinal DTI scans with one year interval by the help of NICARA ( www.nicara.eu ) [Kopetzky, Butz‐Ostendorf, 2018]. Result Surprisingly, MCI patients showed an increase in brain connectivity of the SLF that was associated with an increased brain rewiring, which we did not observe in matched controls. By contrast, we did not find a similar pattern in WM connections of the visual cortex. This observation was seen in about 40% of MCI patients and did not correlate with age, nor with disease onset. Patients with increased connectivity did not show a decrease in MMSE scores over time whereas patients with a loss in connectivity were more likely to decrease in MMSE score. Conclusion This study is the first that reports a pronounced brain [Van Ooyen, Butz‐Ostendorf 2017 (eds)] rewiring in association with WM hyperconnectivity [Delli Puzzi et al. 2019] in MCI patients. Phases of pronounced brain rewiring could be an expression of a compensatory response aiming at functional reorganization of brain networks. Our findings point to the urgent need for including longitudinal DTI tractographies in routine brain scans and clinical trials.