Bridging Reduced Grip Strength and Altered Executive Function: Specific Brain White Matter Structural Changes in Patients with Alzheimer’s Disease

Abstract

Shan-Wen Liu,1 Xiao-Ting Ma,1 Shuai Yu,2 Xiao-Fen Weng,3 Meng Li,4 Jiangtao Zhu,4 Chun-Feng Liu,1 Hua Hu1 1Department of Neurology, the Second Affiliated Hospital of Soochow University, Suzhou, 215004, People’s Republic of China; 2Department of Neurology, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Suzhou, 215000, People’s Republic of China; 3Department of Geriatric Medicine, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Suzhou, 215000, People’s Republic of China; 4Department of Imaging, the Second Affiliated Hospital of Soochow University, Suzhou, 215004, People’s Republic of ChinaCorrespondence: Hua Hu, Department of Neurology, the Second Affiliated Hospital of Soochow University, 1055 San Xiang Road, Suzhou, Jiangsu Province, 215004, People’s Republic of China, Email [email protected]: To investigate the correlation between specific fiber tracts and grip strength and cognitive function in patients with Alzheimer’s disease (AD) by fixel-based analysis (FBA).Methods: AD patients were divided into AD with low grip strength (AD-LGS, n=29) and AD without low grip strength (AD-nLGS, n=25), along with 31 normal controls (NC). General data, neuropsychological tests, grip strength and cranial magnetic resonance imaging (MRI) scans were collected. FBA evaluated white matter (WM) fiber metrics, including fiber density (FD), fiber cross-sectional (FC), and fiber density and cross-sectional area (FDC). The mean fiber indicators of the fiber tracts of interest (TOI) were extracted in cerebral region of significant statistical differences in FBA to further compare the differences between groups and analyze the correlation between fiber properties and neuropsychological test scores.Results: Compared to AD-nLGS group, AD-LGS group showed significant reductions in FDC in several cerebral regions. In AD patients, FDC values of bilateral uncinate fasciculus and left superior longitudinal fasciculus were positively correlated with Clock Drawing Test scores, while FDC of splenium of corpus callosum, bilateral anterior cingulate tracts, forceps major, and bilateral inferior longitudinal fasciculus were positively correlated with the Executive Factor Score of Memory and Executive Screening scale scores.Conclusion: Reduced grip strength in AD patients is associated with extensive impairment of WM structural integrity. Changes in FDC of specific WM fiber tracts related to executive function play a significant mediating role in the reduction of grip strength in AD patients.Keywords: Alzheimer disease, grip strength, white matter, fixel-based analysis, cognition function

Keywords

• alzheimer disease；grip strength；white matter；fixel-based analysis；cognition function