Association between executive dysfunction and hippocampal volume in Alzheimer's disease

ABSTRACTBackground: Some previous research has hypothesized that executive dysfunction in patients with early Alzheimer's disease (AD) occurs as a result of a disconnection between different cerebral areas. The aim of the present study was to evaluate how the hippocampal volume influences executive function as a non-memory cognitive function.Methods: From 157 consecutive patients with AD or amnestic mild cognitive impairment (A-MCI), we recruited 107 subjects who had a global Clinical Dementia Rating (CDR) of 0.5 or 1.0 and whose degree of hippocampal atrophy had been measured using magnetic resonance imaging (MRI); the severity of atrophy was assessed using the voxel-based specific regional analysis for Alzheimer's disease (VSRAD) system. We divided the subjects into three groups: mild atrophy, 0 < Z-score < 1.0 (N = 21); moderate atrophy, 1.0 ≤ Z-score < 2.0 (N = 46); or severe atrophy, 2.0 ≤ Z-score < 4.0 (N = 40) according to the Z-score and compared the Frontal Assessment Battery (FAB) and its subtest scores between each atrophy group.Results: The results demonstrated that age, sex ratio, duration of illness, education years, MMSE score, Behave-AD score, and proportion of atrophy area in total brain (%) were not significantly different among the three groups. Only the go/no-go score among the six subtests was significantly lower for increasing atrophy severity (P < 0.05). Furthermore, hippocampal atrophy significantly influenced the go/no-go score independently of interactions from whether the diagnosis was early AD or A-MCI (P < 0.05).Conclusion: These results support a significant association between hippocampal atrophy and executive dysfunction as a non-memory cognitive impairment in patients with early AD and A-MCI.

Download Full-text

Altered Volume and Structural Connectivity of the Hippocampus in Alzheimer’s Disease and Amnestic Mild Cognitive Impairment

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.705030 ◽

2021 ◽

Vol 13 ◽

Author(s):

Feng Feng ◽

Weijie Huang ◽

Qingqing Meng ◽

Weijun Hao ◽

Hongxiang Yao ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Diffusion Tensor ◽

Structural Connectivity ◽

Hippocampal Volume ◽

Brain Regions ◽

Amnestic Mild Cognitive Impairment ◽

Hippocampal Atrophy

Background: Hippocampal atrophy is a characteristic of Alzheimer’s disease (AD). However, alterations in structural connectivity (number of connecting fibers) between the hippocampus and whole brain regions due to hippocampal atrophy remain largely unknown in AD and its prodromal stage, amnestic mild cognitive impairment (aMCI).Methods: We collected high-resolution structural MRI (sMRI) and diffusion tensor imaging (DTI) data from 36 AD patients, 30 aMCI patients, and 41 normal control (NC) subjects. First, the volume and structural connectivity of the bilateral hippocampi were compared among the three groups. Second, correlations between volume and structural connectivity in the ipsilateral hippocampus were further analyzed. Finally, classification ability by hippocampal volume, its structural connectivity, and their combination were evaluated.Results: Although the volume and structural connectivity of the bilateral hippocampi were decreased in patients with AD and aMCI, only hippocampal volume correlated with neuropsychological test scores. However, positive correlations between hippocampal volume and ipsilateral structural connectivity were displayed in patients with AD and aMCI. Furthermore, classification accuracy (ACC) was higher in AD vs. aMCI and aMCI vs. NC by the combination of hippocampal volume and structural connectivity than by a single parameter. The highest values of the area under the receiver operating characteristic (ROC) curve (AUC) in every two groups were all obtained by combining hippocampal volume and structural connectivity.Conclusions: Our results showed that the combination of hippocampal volume and structural connectivity (number of connecting fibers) is a new perspective for the discrimination of AD and aMCI.

Download Full-text

Executive dysfunction and periventricular diffusion tensor changes in amnesic mild cognitive impairment and early Alzheimer's disease

Human Brain Mapping ◽

10.1002/hbm.20810 ◽

2009 ◽

Vol 30 (11) ◽

pp. 3826-3836 ◽

Cited By ~ 55

Author(s):

Ta-Fu Chen ◽

Ya-Fang Chen ◽

Ting-Wen Cheng ◽

Mau-Sun Hua ◽

Hon-Man Liu ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Diffusion Tensor ◽

Executive Dysfunction ◽

Early Alzheimer’S Disease ◽

Amnesic Mild Cognitive Impairment

Download Full-text

Neurodegeneration and Astrogliosis in the Human ca1 Hippocampal Subfield Are Related to hsp90ab1 and bag3 in Alzheimer’s Disease

International Journal of Molecular Sciences ◽

10.3390/ijms23010165 ◽

2021 ◽

Vol 23 (1) ◽

pp. 165

Author(s):

Melania Gonzalez-Rodriguez ◽

Sandra Villar-Conde ◽

Veronica Astillero-Lopez ◽

Patricia Villanueva-Anguita ◽

Isabel Ubeda-Banon ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurodegenerative Disorder ◽

Amyloid Β ◽

Executive Dysfunction ◽

Hippocampal Volume ◽

P Value ◽

Hippocampal Atrophy ◽

Amyloid Β Peptide ◽

Ms Analysis

Alzheimer’s disease (AD), the most prevalent neurodegenerative disorder, is characterized by executive dysfunction and memory impairment mediated by the accumulation of extracellular amyloid-β peptide (Aβ) and intracellular hyperphosphorylated tau protein. The hippocampus (HIPP) is essential for memory formation and is involved in early stages of disease. In fact, hippocampal atrophy is used as an early biomarker of neuronal injury and to evaluate disease progression. It is not yet well-understood whether changes in hippocampal volume are due to neuronal or glial loss. The aim of the study was to assess hippocampal atrophy and/or gliosis using unbiased stereological quantification and to obtain hippocampal proteomic profiles related to neurodegeneration and gliosis. Hippocampal volume measurement, stereological quantification of NeuN-, Iba-1- and GFAP-positive cells, and sequential window acquisition of all theoretical mass spectrometry (SWATH-MS) analysis were performed in AD and non-AD cases. Reduced hippocampal volume was identified using the Cavalieri probe, particularly in the CA1 region, where it correlated with neuronal loss and astrogliosis. A total of 102 downregulated and 47 upregulated proteins were identified in the SWATH-MS analysis after restrictive filtering based on an FC >1.5 and p value < 0.01. The Hsp90 family of chaperones, particularly BAG3 and HSP90AB1, are closely related to astrocytes, indicating a possible role in degrading Aβ and tau through chaperone-mediated autophagy.

Download Full-text