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Chen W, Deng S, Jiang H, Li H, Zhao Y, Yuan Y. Alterations of White Matter Connectivity in Adults with Essential Hypertension. Int J Gen Med 2024; 17:335-346. [PMID: 38314198 PMCID: PMC10838498 DOI: 10.2147/ijgm.s444384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/19/2024] [Indexed: 02/06/2024] Open
Abstract
Purpose To explore the topology of the white matter network in individuals with essential hypertension by graph theory. Patients and Methods T1-weighted image and diffusion tensor imaging (DTI) data from 43 patients diagnosed with essential hypertension (EHT) and 33 individuals with normotension (healthy controls, HCs) were incorporated in this cross-sectional study. Furthermore, structural networks were constructed by graph theory to calculate whole brain network characteristics and intracerebral node characteristics. Results Both EHT and HC groups displayed small-worldness in their structural networks. The area under the curve (AUC) of the small-worldness coefficient (σ) was higher in the EHT group compared to the HC group, whereas the AUC of assortativity was lower in the EHT group in contrast to the HC group. The nodal clustering coefficient (CP) and local efficiency (Eloc) of the EHT group decreased in the right dorsolateral superior frontal gyrus and the left medial superior frontal gyrus. These values increased in the left anterior cingulate and paracingulate gyrus. Furthermore, weight and body mass index (BMI) were positively correlated with σ. Conclusion The EHT group showed brain network separation and integration dysfunction. Weight and BMI were positively correlated with σ. The data acquired in this investigation implied that altered structural connectivity in the prefrontal region may be a potential neuroimaging marker in EHT patients.
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Affiliation(s)
- Weijie Chen
- Department of Cardiology, The Second School of Clinical Medicine, Southern Medical University, Guangdong, People's Republic of China
- Department of Cardiology, Dongguan Tung Wah Hospital, Guangdong, People's Republic of China
| | - Simin Deng
- Research Center, Dongguan Eighth People's Hospital, Guangdong, People's Republic of China
| | - Huali Jiang
- Department of Cardiology, Dongguan Tung Wah Hospital, Guangdong, People's Republic of China
| | - Heng Li
- Department of Cardiology, Dongguan Tung Wah Hospital, Guangdong, People's Republic of China
| | - Yu Zhao
- Department of Cardiology, Dongguan Tung Wah Hospital, Guangdong, People's Republic of China
| | - Yiqiang Yuan
- Department of Cardiology, The Second School of Clinical Medicine, Southern Medical University, The Seventh People's Hospital of Zhengzhou, Henan, People's Republic of China
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Roseborough AD, Saad L, Goodman M, Cipriano LE, Hachinski VC, Whitehead SN. White matter hyperintensities and longitudinal cognitive decline in cognitively normal populations and across diagnostic categories: A meta-analysis, systematic review, and recommendations for future study harmonization. Alzheimers Dement 2023; 19:194-207. [PMID: 35319162 DOI: 10.1002/alz.12642] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 01/18/2023]
Abstract
INTRODUCTION The primary aim of this paper is to improve the clinical interpretation of white matter hyperintensities (WMHs) and provide an overarching summary of methodological approaches, allowing researchers to design future studies targeting current knowledge gaps. METHODS A meta-analysis and systematic review was performed investigating associations between baseline WMHs and longitudinal cognitive outcomes in cognitively normal populations, and populations with mild cognitive impairment (MCI), Alzheimer's disease (AD), and stroke. RESULTS Baseline WMHs increase the risk of cognitive impairment and dementia across diagnostic categories and most consistently in MCI and post-stroke populations. Apolipoprotein E (APOE) genotype and domain-specific cognitive changes relating to strategic anatomical locations, such as frontal WMH and executive decline, represent important considerations. Meta-analysis reliability was assessed using multiple methods of estimation, and results suggest that heterogeneity in study design and reporting remains a significant barrier. DISCUSSION Recommendations and future directions for study of WMHs are provided to improve cross-study comparison and translation of research into consistent clinical interpretation.
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Affiliation(s)
- Austyn D Roseborough
- Vulnerable Brain Laboratory, Department of Anatomy and Cell Biology, The Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Lorenzo Saad
- Vulnerable Brain Laboratory, Department of Anatomy and Cell Biology, The Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Maren Goodman
- Western Libraries, The University of Western Ontario, London, Ontario, Canada
| | - Lauren E Cipriano
- Ivey Business School and Department of Epidemiology and Biostatistics, The University of Western Ontario, London, Ontario, Canada
| | - Vladimir C Hachinski
- Department of Clinical Neurological Sciences, The Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Shawn N Whitehead
- Vulnerable Brain Laboratory, Department of Anatomy and Cell Biology, The Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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Wang D, Xu C, Wang W, Lu H, Zhang J, Liang F, Li X. The Effect of APOE ɛ4 on the Functional Connectivity in Frontoparietal Network in Hypertensive Patients. Brain Sci 2022; 12:brainsci12050515. [PMID: 35624902 PMCID: PMC9138811 DOI: 10.3390/brainsci12050515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/06/2022] [Accepted: 04/15/2022] [Indexed: 02/01/2023] Open
Abstract
Allele 4 of the apolipoprotein E gene (APOE ε4) and hypertension are considered risk factors for Alzheimer’s Disease (AD). The detection of differences in cognitive function and brain networks between hypertensive patients who are APOE ε4 carriers and non-carriers may help in understanding how hypertension and risk genes cumulatively impair brain function, which could provide critical insights into the genetic mechanism by which hypertension serves as a potential risk factor for cognitive decline and even AD. Using behavioral data from 233 elderly hypertensive patients and neuroimaging data from 38 of them from Beijing, China; the study aimed to assess the effects of APOE ε4 on cognition and to explore related changes in functional connectivity. Cognitively, the patients with APOE ε4 showed decreased executive function, memory and language. In the MRI sub-cohort, the frontoparietal networks in the APOE ε4 carrier group exhibited an altered pattern, mainly in the left precentral regions, inferior frontal lobe and angular gyrus. More importantly, the decline of cognitive function was correlated with abnormal FC in the left precentral regions in APOE ε4 carriers. APOE ε4 aggravated the dysfunction in frontal and parietal regions in hypertensive patients. This highlights the importance of brain protection in hypertensive patients, especially those with a genetic risk of AD.
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Affiliation(s)
- Dandan Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; (D.W.); (C.X.); (W.W.); (H.L.)
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Center, Beijing Normal University, Beijing 100875, China
| | - Chang Xu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; (D.W.); (C.X.); (W.W.); (H.L.)
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Center, Beijing Normal University, Beijing 100875, China
| | - Wenxiao Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; (D.W.); (C.X.); (W.W.); (H.L.)
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Center, Beijing Normal University, Beijing 100875, China
| | - Hui Lu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; (D.W.); (C.X.); (W.W.); (H.L.)
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Center, Beijing Normal University, Beijing 100875, China
| | - Junying Zhang
- Institute of Basic Research in Clinical Medicine, China Academy of Traditional Chinese Medicine, Beijing 100700, China;
| | - Furu Liang
- Department of Neurology, Baotou Central Hospital, Baotou 014040, China;
| | - Xin Li
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; (D.W.); (C.X.); (W.W.); (H.L.)
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Center, Beijing Normal University, Beijing 100875, China
- Correspondence:
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Puzo C, Labriola C, Sugarman MA, Tripodis Y, Martin B, Palmisano JN, Steinberg EG, Stein TD, Kowall NW, McKee AC, Mez J, Killiany RJ, Stern RA, Alosco ML. Independent effects of white matter hyperintensities on cognitive, neuropsychiatric, and functional decline: a longitudinal investigation using the National Alzheimer's Coordinating Center Uniform Data Set. Alzheimers Res Ther 2019; 11:64. [PMID: 31351489 PMCID: PMC6661103 DOI: 10.1186/s13195-019-0521-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 07/14/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND Longitudinal investigations are needed to improve understanding of the contributions of cerebral small vessel disease to the clinical manifestation of Alzheimer's disease, particularly in the early disease stages. This study leveraged the National Alzheimer's Coordinating Center Uniform Data Set to longitudinally examine the association between white matter hyperintensities and neuropsychological, neuropsychiatric, and functional decline among participants with normal cognition. METHODS The sample included 465 participants from the National Alzheimer's Coordinating Center Uniform Data Set who had quantitated volume of white matter hyperintensities from fluid-attenuated inversion recovery MRI, had normal cognition at the time of their MRI, and were administered the National Alzheimer's Coordinating Center Uniform Data Set neuropsychological test battery within 1 year of study evaluation and had at least two post-MRI time points of clinical data. Neuropsychiatric status was assessed by the Geriatric Depression Scale-15 and Neuropsychiatric Inventory-Questionnaire. Clinical Dementia Rating Sum of Boxes defined functional status. For participants subsequently diagnosed with mild cognitive impairment (MCI) or dementia, their impairment must have been attributed to Alzheimer's disease (AD) to evaluate the relationships between WMH and the clinical presentation of AD. RESULTS Of the 465 participants, 56 converted to MCI or AD dementia (average follow-up = 5 years). Among the 465 participants, generalized estimating equations controlling for age, sex, race, education, APOE ε4, and total brain and hippocampal volume showed that higher baseline log-white matter hyperintensities predicted accelerated decline on the following neuropsychological tests in rank order of effect size: Trails B (p < 0.01), Digit Symbol Coding (p < 0.01), Logical Memory Immediate Recall (p = 0.02), Trail Making A (p < 0.01), and Semantic Fluency (p < 0.01). White matter hyperintensities predicted increases in Clinical Dementia Rating Sum of Boxes (p < 0.01) and Geriatric Depression Scale-15 scores (p = 0.01). Effect sizes were comparable to total brain and hippocampal volume. White matter hyperintensities did not predict diagnostic conversion. All effects also remained after including individuals with non-AD suspected etiologies for those who converted to MCI or dementia. CONCLUSIONS In this baseline cognitively normal sample, greater white matter hyperintensities were associated with accelerated cognitive, neuropsychiatric, and functional decline independent of traditional risk factors and MRI biomarkers for Alzheimer's disease.
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Affiliation(s)
- Christian Puzo
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
| | - Caroline Labriola
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
| | - Michael A Sugarman
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
| | - Yorghos Tripodis
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Brett Martin
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Biostatistics and Epidemiology Data Analytics Center, Boston University School of Public Health, Boston, MA, USA
| | - Joseph N Palmisano
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Biostatistics and Epidemiology Data Analytics Center, Boston University School of Public Health, Boston, MA, USA
| | - Eric G Steinberg
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
| | - Thor D Stein
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, USA
- VA Boston Healthcare System, U.S. Department of Veteran Affairs, Jamaica Plain, USA
| | - Neil W Kowall
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, USA
- VA Boston Healthcare System, U.S. Department of Veteran Affairs, Jamaica Plain, USA
| | - Ann C McKee
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, USA
- VA Boston Healthcare System, U.S. Department of Veteran Affairs, Jamaica Plain, USA
| | - Jesse Mez
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Ronald J Killiany
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, USA
- Center for Biomedical Imaging, Boston University School of Medicine, Boston, USA
| | - Robert A Stern
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Departments of Neurosurgery and Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Michael L Alosco
- Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, 72 E. Concord Street, Suite B7800, Boston, MA, 02118, USA.
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
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Ishibashi M, Kimura N, Aso Y, Matsubara E. Effects of white matter lesions on brain perfusion in patients with mild cognitive impairment. Clin Neurol Neurosurg 2018; 168:7-11. [PMID: 29499394 DOI: 10.1016/j.clineuro.2018.02.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/07/2018] [Accepted: 02/19/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To evaluate the effects of white matter lesions on regional cerebral blood flow in subjects with amnestic mild cognitive impairment. PATIENTS AND METHODS Seventy-five subjects with mild cognitive impairment (36 men and 39 women; mean age, 78.1 years) were included in the study. We used the Mini-Mental State Examination to assess cognitive function. All subjects underwent brain magnetic resonance imaging and 99mTc ethylcysteinate dimer single photon emission computed tomography. Subjects were stratified based on the presence or absence of white matter lesions on magnetic resonance imaging. Statistical parametric mapping of differences in regional cerebral blood flow between the two groups were assessed by voxel-by-voxel group analysis using SPM8. RESULTS Of all 75 subjects with mild cognitive impairment, 46 (61.3%) had mild to moderate white matter lesions. The prevalence of hypertension tended to be higher in subjects with white matter lesions than in those without white matter lesions. Mini-Mental State Examination scores were significantly lower in subjects with white matter lesions than in those without white matter lesions. Subjects with white matter lesions had decreased regional cerebral blood flow mainly in the frontal, parietal, and medial temporal lobes, as well as the putamen, compared to those without white matter lesions. CONCLUSION In subjects with mild cognitive impairment, white matter lesions were associated with cognitive impairment and mainly frontal lobe brain function.
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Affiliation(s)
- Masato Ishibashi
- Department of Neurology, Oita University, Faculty of Medicine, Japan
| | - Noriyuki Kimura
- Department of Neurology, Oita University, Faculty of Medicine, Japan.
| | - Yasuhiro Aso
- Department of Neurology, Oita University, Faculty of Medicine, Japan
| | - Etsuro Matsubara
- Department of Neurology, Oita University, Faculty of Medicine, Japan
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Vulnerability of the frontal and parietal regions in hypertensive patients during working memory task. J Hypertens 2017; 35:1044-1051. [PMID: 28118278 DOI: 10.1097/hjh.0000000000001250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Hypertension is related with cognitive decline in the elderly. The frontal-parietal executive system plays an important role in cognitive aging and is also vulnerable to damage in elderly patients with hypertension. Examination of the brain's functional characteristics in frontal-parietal regions of hypertension is likely to be important for understanding the neural mechanisms of hypertension's effect on cognitive aging. METHODS We address this issue by comparing hypertension and control-performers in a functional MRI study. Twenty-eight hypertensive patients and 32 elderly controls were tested with n-back task with two load levels. RESULTS The hypertensive patients exhibited worse executive and memory abilities than control subjects. The patterns of brain activation changed under different working memory loads in the hypertensive patients, who exhibited reduced activation only in the precentral gyrus under low loads and reduced activation in the middle frontal gyrus, left medial superior frontal gyrus and right precuneus under high loads. Thus, more regions of diminished activation were observed in the frontal and parietal regions with increasing task difficulty. More importantly, we found that lower activation in changed frontal and parietal regions was associated with worse cognitive function in high loads. CONCLUSION The results demonstrate the relationship between cognitive function and frontoparietal functional activation in hypertension and their relevance to cognitive aging risk. Our findings provide a better understanding of the mechanism of cognitive decline in hypertension and highlight the importance of brain protection in hypertension.
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Disrupted white matter structure underlies cognitive deficit in hypertensive patients. Eur Radiol 2015; 26:2899-907. [PMID: 26615558 DOI: 10.1007/s00330-015-4116-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/19/2015] [Accepted: 11/12/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Hypertension is considered a risk factor of cognitive impairments and could result in white matter changes. Current studies on hypertension-related white matter (WM) changes focus only on regional changes, and the information about global changes in WM structure network is limited. METHODS We assessed the cognitive function in 39 hypertensive patients and 37 healthy controls with a battery of neuropsychological tests. The WM structural networks were constructed by utilizing diffusion tensor tractography and calculated topological properties of the networks using a graph theoretical method. The direct and indirect correlations among cognitive impairments, brain WM network disruptions and hypertension were analyzed with structural equation modelling (SEM). RESULTS Hypertensive patients showed deficits in executive function, memory and attention compared with controls. An aberrant connectivity of WM networks was found in the hypertensive patients (P Eglob = 0.005, P Lp = 0.005), especially in the frontal and parietal regions. Importantly, SEM analysis showed that the decline of executive function resulted from aberrant WM networks in hypertensive patients (p = 0.3788, CFI = 0.99). CONCLUSIONS These results suggest that the cognitive decline in hypertensive patients was due to frontal and parietal WM disconnections. Our findings highlight the importance of brain protection in hypertension patients. KEY POINTS • Hypertension has a negative effect on the performance of the cognitive domains • Reduced efficiencies of white matter networks were shown in hypertension • Disrupted white matter networks are responsible for poor cognitive function in hypertension.
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Disrupted Frontoparietal Network Mediates White Matter Structure Dysfunction Associated with Cognitive Decline in Hypertension Patients. J Neurosci 2015; 35:10015-24. [PMID: 26157001 DOI: 10.1523/jneurosci.5113-14.2015] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Some previous reports have suggested that hypertension is a risk factor for dementia and cognitive impairments. Using behavioral data from 1007 elderly human subjects (405 hypertensive patients) of Han ethnicity from Beijing, China, the present study aimed to assess the effects of hypertension on cognitive performance and explore related neuronal changes via advanced resting-state functional magnetic resonance imaging and diffusion tensor imaging data from 84 of these subjects (44 hypertensive patients). Cognitively, we found that patients with hypertension showed decreased executive functions and attention compared with those with normotension in the large sample. In magnetic resonance imaging scan sample, using independent component analysis to examine the functional connectivity difference between the two groups, we found that the frontoparietal networks in the hypertensive group exhibited altered patterns compared with the control group, mainly in the inferior parietal lobe, left inferior frontal lobe, and precuneus. Using tract-based spatial statistics to investigate the between-group structural difference, we found that the hypertensive group showed significantly reduced integrity of white matter in the bilateral superior longitudinal fasciculus. Importantly, using the mediation analysis, we found that the functional connectivity of the frontoparietal networks mediates the impact of white matter on executive function in the hypertensive group. The results demonstrate that hypertension targets a specific pattern of cognitive decline, possibly due to deficits in the white matter and functional connectivity in frontal and parietal lobes. Our findings highlight the importance of brain protection in hypertension. SIGNIFICANCE STATEMENT Hypertension is a risk factor for cognitive decline and dementia. However, the neural mechanism underlying cognitive decline in hypertension is largely unknown. We studied the relationship among cognitive decline, brain functional, and structural changes in hypertensive patients via advanced resting-state functional magnetic resonance imaging and diffusion tensor imaging data in a Chinese cohort. Hypertensive patients showed executive dysfunction, along with disrupted functional connectivity in frontoparietal (FP) networks and reduced integrity of white matter in the bilateral superior longitudinal fasciculus. Importantly, the functional connectivity changes mediate the impact of white matter alterations on cognitive decline in the hypertensive group. Our findings provide a better understanding of the mechanism of cognitive decline in hypertension and highlight the importance of brain protection in hypertension.
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Abstract
BACKGROUND Cerebral white matter lesions (WML), evident on CT and MRI brain scans, are histopathologically heterogeneous but associated with vascular risk factors and thought mainly to indicate ischemic damage. There has been disagreement over their clinical prognostic value in predicting conversion from mild cognitive impairment (MCI) to dementia. METHODS We scrutinised and rated CT and MRI brain scans for degree of WML in a memory clinic cohort of 129 patients with at least 1 year of follow-up. We examined the relationship between WML severity and time until conversion to dementia for all MCI patients and for amnestic (aMCI) and non-amnestic (naMCI) subgroups separately. RESULTS Five-year outcome data were available for 87 (67%) of the 129 patients. The proportion of patients converting to dementia was 25% at 1 year and 76% at 5 years. Patients with aMCI converted to dementia significantly earlier than those with naMCI. WML severity was not associated with time to conversion to dementia for either MCI patients in general or aMCI patients in particular. Among naMCI patients, there was a tendency for those with a low degree of WML to survive without dementia for longer than those with a high degree of WML. However, this was not statistically significant. CONCLUSIONS MCI subtype is a significant independent predictor of conversion to dementia, with aMCI patients having higher risk than naMCI for conversion throughout the 5-year follow-up period. WML severity does not influence conversion to dementia for aMCI but might accelerate progression in naMCI.
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Jacobs HIL, Leritz EC, Williams VJ, Van Boxtel MPJ, van der Elst W, Jolles J, Verhey FRJ, McGlinchey RE, Milberg WP, Salat DH. Association between white matter microstructure, executive functions, and processing speed in older adults: the impact of vascular health. Hum Brain Mapp 2011; 34:77-95. [PMID: 21954054 DOI: 10.1002/hbm.21412] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 06/08/2011] [Accepted: 07/01/2011] [Indexed: 11/12/2022] Open
Abstract
Cerebral white matter damage is not only a commonly reported consequence of healthy aging, but is also associated with cognitive decline and dementia. The aetiology of this damage is unclear; however, individuals with hypertension have a greater burden of white matter signal abnormalities (WMSA) on MR imaging than those without hypertension. It is therefore possible that elevated blood pressure (BP) impacts white matter tissue structure which in turn has a negative impact on cognition. However, little information exists about whether vascular health indexed by BP mediates the relationship between cognition and white matter tissue structure. We used diffusion tensor imaging to examine the impact of vascular health on regional associations between white matter integrity and cognition in healthy older adults spanning the normotensive to moderate-severe hypertensive BP range (43-87 years; N = 128). We examined how white matter structure was associated with performance on tests of two cognitive domains, executive functioning (EF) and processing speed (PS), and how patterns of regional associations were modified by BP and WMSA. Multiple linear regression and structural equation models demonstrated associations between tissue structure, EF and PS in frontal, temporal, parietal, and occipital white matter regions. Radial diffusivity was more prominently associated with performance than axial diffusivity. BP only minimally influenced the relationship between white matter integrity, EF and PS. However, WMSA volume had a major impact on neurocognitive associations. This suggests that, although BP and WMSA are causally related, these differential metrics of vascular health may act via independent pathways to influence brain structure, EF and PS.
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Affiliation(s)
- Heidi I L Jacobs
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Alzheimer Center Limburg, University Maastricht, 6200 MD Maastricht, The Netherlands.
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Kovács KR, Szekeres CC, Bajkó Z, Csapó K, Molnár S, Oláh L, Magyar MT, Bereczki D, Kardos L, Soltész P, Bojtor AB, Csiba L. Cerebro- and cardiovascular reactivity and neuropsychological performance in hypertensive patients. J Neurol Sci 2010; 299:120-5. [PMID: 20800240 DOI: 10.1016/j.jns.2010.07.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 07/24/2010] [Indexed: 11/27/2022]
Abstract
BACKGROUND Hypertensive (HT) patients are at higher risk of cognitive decline than normotensive individuals, because high blood pressure is a risk factor for mild cognitive deterioration. In this study cardio- and cerebrovascular reactivity along with cognitive performance was assessed on newly diagnosed HT patients. METHODS Diagnosis of hypertension was based on international recommendations. None of the patients had diabetes, and all of them had normal cerebral CT scan. Eighty-one patients (43.5±10.2 years, male/female ratio: 42/39) were compared with 94 healthy controls (44±9.4 years, male/female ratio: 50/44). In both groups continuous, non-invasive and simultaneous monitoring of cerebral and cardiac hemodynamical parameters were recorded during head-up tilt table testing (HUTT). Reaction time, attention and memory skills, anxiety and depression rate were determined by neuropsychological tests. RESULTS During HUTT significant differences were found in certain cardiovascular parameters (blood pressure, total peripheral resistance index, stroke index), but no differences were detected in cerebral blood flow velocity. While there was no significant difference in reaction time between the two groups, tests estimating short-term memory (Digit Span Test) differed significantly. Moreover, sum of standardized test scores was significantly lower, while anxiety level was significantly increased in HT patients compared to controls. CONCLUSION Decrease in neuropsychological performance along with alterations of cardiovascular parameters is an early manifestation of hypertension. Aim for an early intervention and accurate treatment is crucial for preventing further impairments.
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Affiliation(s)
- Katalin Réka Kovács
- Department of Neurology, University of Debrecen Medical and Health Science Center, Debrecen, Hungary
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Hannesdottir K, Nitkunan A, Charlton RA, Barrick TR, MacGregor GA, Markus HS. Cognitive impairment and white matter damage in hypertension: a pilot study. Acta Neurol Scand 2009; 119:261-8. [PMID: 18798828 DOI: 10.1111/j.1600-0404.2008.01098.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Hypertension has been associated with impaired cognition. Diffusion tensor imaging (DTI) and magnetic resonance spectroscopy were applied to assess white matter abnormalities in treated vs untreated hypertension and if these correlated with neuropsychological performance. METHODS Subjects were 40 patients with medically treated hypertension (mean age 69.3 years), 10 patients with untreated hypertension (mean age 57.6 years) and 30 normotensive controls (mean age 68.2 years). Hypertension was defined as a previous diagnosis and taking hypertensive medication, or a resting blood pressure of >140/90 mmHg on the day of assessment. RESULTS Patients with treated hypertension performed worse on immediate (P = 0.037) as well as delayed memory tasks (P = 0.024) compared with normotensive controls. Cognitive performance was worse in untreated compared with treated hypertension on executive functions (P = 0.041) and psychomotor speed (P = 0.003). There was no significant correlation between cognition and any of the imaging parameters in treated hypertension. However, in untreated hypertension the results revealed a positive correlation between an executive functioning and attention composite score and DTI mean diffusivity values (P = 0.016) and between psychomotor speed and spectroscopy NAA/tCr levels (P = 0.015). CONCLUSIONS These results suggest there is cognitive impairment in hypertension. Treated hypertension was associated with deficits in memory while untreated hypertension revealed a more 'subcortical' pattern of cognitive impairment.
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Affiliation(s)
- K Hannesdottir
- Centre for Clinical Neuroscience, St Georges University of London, UK.
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