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Chen S, Xu W, Xue C, Hu G, Ma W, Qi W, Dong L, Lin X, Chen J. Voxelwise Meta-Analysis of Gray Matter Abnormalities in Mild Cognitive Impairment and Subjective Cognitive Decline Using Activation Likelihood Estimation. J Alzheimers Dis 2020; 77:1495-1512. [PMID: 32925061 DOI: 10.3233/jad-200659] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Background: Voxel-based morphometry studies have not yielded consistent results among patients with mild cognitive impairment (MCI) and subjective cognitive decline (SCD). Objective: Therefore, we aimed to conduct a meta-analysis of gray matter (GM) abnormalities acquired from these studies to determine their respective neuroanatomical changes. Methods: We systematically searched for voxel-based whole-brain morphometry studies that compared MCI or SCD subjects with healthy controls in PubMed, Web of Science, and EMBASE databases. We used the coordinate-based method of activation likelihood estimation to determine GM changes in SCD, MCI, and MCI sub-groups (amnestic MCI and non-amnestic MCI). Results: A total of 45 studies were included in our meta-analysis. In the MCI group, we found structural atrophy of the bilateral hippocampus, parahippocampal gyrus (PHG), amygdala, right lateral globus pallidus, right insula, and left middle temporal gyrus. The aMCI group exhibited GM atrophy in the bilateral hippocampus, PHG, and amygdala. The naMCI group presented with structural atrophy in the right putamen, right insula, right precentral gyrus, left medial/superior frontal gyrus, and left anterior cingulate. The right lingual gyrus, right cuneus, and left medial frontal gyrus were atrophic GM regions in the SCD group. Conclusion: Our meta-analysis identified unique patterns of neuroanatomical alternations in both the MCI and SCD group. Structural changes in SCD patients provide new evidence for the notion that subtle impairment of visual function, perception, and cognition may be related to early signs of cognitive impairment. In addition, our findings provide a foundation for future targeted interventions at different stages of preclinical Alzheimer’s disease.
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Affiliation(s)
- Shanshan Chen
- Department of Neurology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Wenwen Xu
- Department of Neurology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chen Xue
- Department of Radiology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Guanjie Hu
- Institute of Neuropsychiatry, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Wenying Ma
- Department of Neurology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Wenzhang Qi
- Department of Radiology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Lin Dong
- Department of Neurology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xingjian Lin
- Department of Neurology, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jiu Chen
- Institute of Neuropsychiatry, the Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, Jiangsu, China
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Manuello J, Nani A, Premi E, Borroni B, Costa T, Tatu K, Liloia D, Duca S, Cauda F. The Pathoconnectivity Profile of Alzheimer's Disease: A Morphometric Coalteration Network Analysis. Front Neurol 2018; 8:739. [PMID: 29472885 PMCID: PMC5810291 DOI: 10.3389/fneur.2017.00739] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/21/2017] [Indexed: 01/18/2023] Open
Abstract
Gray matter alterations are typical features of brain disorders. However, they do not impact on the brain randomly. Indeed, it has been suggested that neuropathological processes can selectively affect certain assemblies of neurons, which typically are at the center of crucial functional networks. Because of their topological centrality, these areas form a core set that is more likely to be affected by neuropathological processes. In order to identify and study the pattern formed by brain alterations in patients’ with Alzheimer’s disease (AD), we devised an innovative meta-analytic method for analyzing voxel-based morphometry data. This methodology enabled us to discover that in AD gray matter alterations do not occur randomly across the brain but, on the contrary, follow identifiable patterns of distribution. This alteration pattern exhibits a network-like structure composed of coaltered areas that can be defined as coatrophy network. Within the coatrophy network of AD, we were able to further identify a core subnetwork of coaltered areas that includes the left hippocampus, left and right amygdalae, right parahippocampal gyrus, and right temporal inferior gyrus. In virtue of their network centrality, these brain areas can be thought of as pathoconnectivity hubs.
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Affiliation(s)
- Jordi Manuello
- GCS-fMRI, Department of Psychology, Koelliker Hospital, University of Turin, Turin, Italy.,FOCUS Laboratory, Department of Psychology, University of Turin, Turin, Italy
| | - Andrea Nani
- GCS-fMRI, Department of Psychology, Koelliker Hospital, University of Turin, Turin, Italy.,FOCUS Laboratory, Department of Psychology, University of Turin, Turin, Italy.,Michael Trimble Neuropsychiatry Research Group, Birmingham and Solihull Mental Health NHS Foundation Trust, Birmingham, United Kingdom
| | - Enrico Premi
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Barbara Borroni
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Tommaso Costa
- GCS-fMRI, Department of Psychology, Koelliker Hospital, University of Turin, Turin, Italy.,FOCUS Laboratory, Department of Psychology, University of Turin, Turin, Italy
| | - Karina Tatu
- GCS-fMRI, Department of Psychology, Koelliker Hospital, University of Turin, Turin, Italy.,FOCUS Laboratory, Department of Psychology, University of Turin, Turin, Italy
| | - Donato Liloia
- FOCUS Laboratory, Department of Psychology, University of Turin, Turin, Italy
| | - Sergio Duca
- GCS-fMRI, Department of Psychology, Koelliker Hospital, University of Turin, Turin, Italy
| | - Franco Cauda
- GCS-fMRI, Department of Psychology, Koelliker Hospital, University of Turin, Turin, Italy.,FOCUS Laboratory, Department of Psychology, University of Turin, Turin, Italy
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3
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Gan CL, O'Sullivan MJ, Metzler-Baddeley C, Halpin S. Association of imaging abnormalities of the subcallosal septal area with Alzheimer's disease and mild cognitive impairment. Clin Radiol 2017; 72:915-922. [PMID: 28859851 PMCID: PMC5633012 DOI: 10.1016/j.crad.2017.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 12/30/2016] [Accepted: 04/12/2017] [Indexed: 11/16/2022]
Abstract
AIM To evaluate the use the distance between the adjacent septal nuclei as a surrogate marker of septal area atrophy seen in Alzheimer's disease (AD). MATERIALS & METHODS Interseptal distance (ISD) was measured, blind to clinical details, in 250 patients who underwent computed tomography (CT) of the brain at University Hospital of Wales. Clinical details including memory problem history were retrieved. An ISD cut-off value that discriminated those with and without memory symptoms was sought. ISD measurements were also made in 20 AD patients. To test both the method and the defined cut-off, measurements were then made in an independent cohort of 21 mild cognitive impairment (MCI) patients and 45 age-matched healthy controls, in a randomised and blinded fashion. RESULTS ISD measurement was achieved in all patients. In 28 patients with memory symptoms, the mean ISD was 5.9 mm compared with 2.3 mm in those without overt symptoms (p=0.001). The optimum ISD cut-off value was 4 mm (sensitivity 85.7% and specificity 85.8%). All AD patients had an ISD of >4 mm (mean ISD= 6.1 mm). The mean ISD for MCI patients was 3.84 mm compared with 2.18 mm in age-matched healthy controls (p=0.001). Using a 4 mm cut-off correctly categorised 10 mild cognitive impairment patients (47.6%) and 38 healthy controls (84.4%). CONCLUSION ISD is a simple and reliable surrogate measurement for septal area atrophy, applicable to CT and magnetic resonance imaging (MRI). It can be used to help select patients for further investigation.
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Affiliation(s)
- C L Gan
- Department of Neuroradiology, University Hospital of Wales, Cardiff, UK.
| | - M J O'Sullivan
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff, UK; Department of Clinical Neuroscience, Institute of Psychiatry, King's College London, London, UK
| | - C Metzler-Baddeley
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff, UK
| | - S Halpin
- Department of Neuroradiology, University Hospital of Wales, Cardiff, UK
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4
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Lajoie I, Nugent S, Debacker C, Dyson K, Tancredi FB, Badhwar A, Belleville S, Deschaintre Y, Bellec P, Doyon J, Bocti C, Gauthier S, Arnold D, Kergoat MJ, Chertkow H, Monchi O, Hoge RD. Application of calibrated fMRI in Alzheimer's disease. NEUROIMAGE-CLINICAL 2017; 15:348-358. [PMID: 28560160 PMCID: PMC5443910 DOI: 10.1016/j.nicl.2017.05.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/26/2017] [Accepted: 05/15/2017] [Indexed: 02/07/2023]
Abstract
Calibrated fMRI based on arterial spin-labeling (ASL) and blood oxygen-dependent contrast (BOLD), combined with periods of hypercapnia and hyperoxia, can provide information on cerebrovascular reactivity (CVR), resting blood flow (CBF), oxygen extraction fraction (OEF), and resting oxidative metabolism (CMRO2). Vascular and metabolic integrity are believed to be affected in Alzheimer's disease (AD), thus, the use of calibrated fMRI in AD may help understand the disease and monitor therapeutic responses in future clinical trials. In the present work, we applied a calibrated fMRI approach referred to as Quantitative O2 (QUO2) in a cohort of probable AD dementia and age-matched control participants. The resulting CBF, OEF and CMRO2 values fell within the range from previous studies using positron emission tomography (PET) with 15O labeling. Moreover, the typical parietotemporal pattern of hypoperfusion and hypometabolism in AD was observed, especially in the precuneus, a particularly vulnerable region. We detected no deficit in frontal CBF, nor in whole grey matter CVR, which supports the hypothesis that the effects observed were associated specifically with AD rather than generalized vascular disease. Some key pitfalls affecting both ASL and BOLD methods were encountered, such as prolonged arterial transit times (particularly in the occipital lobe), the presence of susceptibility artifacts obscuring medial temporal regions, and the challenges associated with the hypercapnic manipulation in AD patients and elderly participants. The present results are encouraging and demonstrate the promise of calibrated fMRI measurements as potential biomarkers in AD. Although CMRO2 can be imaged with 15O PET, the QUO2 method uses more widely available imaging infrastructure, avoids exposure to ionizing radiation, and integrates with other MRI-based measures of brain structure and function.
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Affiliation(s)
- Isabelle Lajoie
- Département de Pharmacologie et physiologie, Université de Montréal, Montreal, QC, Canada; Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada.
| | - Scott Nugent
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Clément Debacker
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Kenneth Dyson
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Physiology, McGill University, Montreal, QC, Canada
| | - Felipe B Tancredi
- Departamento de Radiologia, Centro de Pesquisa em Imagem, Hospital Israelita Albert Einstein, São Palo, SP, Brazil
| | - AmanPreet Badhwar
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Computer Science and Operations Research, Université de Montréal, Montreal, QC, Canada
| | - Sylvie Belleville
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Département de Psychologie, Université de Montréal, Montreal, QC, Canada
| | - Yan Deschaintre
- Département de Neurosciences, Université de Montréal, Montreal, QC, Canada; Service de neurologie, Département de Médecine, CHUM Notre-Dame, Montréal, QC, Canada
| | - Pierre Bellec
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Computer Science and Operations Research, Université de Montréal, Montreal, QC, Canada
| | - Julien Doyon
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Département de Psychologie, Université de Montréal, Montreal, QC, Canada
| | - Christian Bocti
- Division de Neurologie, Faculté de Médecine et des Sciences de la Santé & Research Centre on Aging, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Serge Gauthier
- McGill Center for Studies in Aging, Douglas Mental Health Research Institute, Montreal, QC, Canada
| | - Douglas Arnold
- Montreal Neurological Institute, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Marie-Jeanne Kergoat
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Département de Médecine, Université de Montréal, Montreal, QC, Canada
| | - Howard Chertkow
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada; Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Oury Monchi
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada; McGill Center for Studies in Aging, Douglas Mental Health Research Institute, Montreal, QC, Canada; Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Richard D Hoge
- Département de Pharmacologie et physiologie, Université de Montréal, Montreal, QC, Canada; Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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5
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Wang Z, Dai Z, Shu H, Liao X, Yue C, Liu D, Guo Q, He Y, Zhang Z. APOE Genotype Effects on Intrinsic Brain Network Connectivity in Patients with Amnestic Mild Cognitive Impairment. Sci Rep 2017; 7:397. [PMID: 28341847 PMCID: PMC5428452 DOI: 10.1038/s41598-017-00432-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 02/20/2017] [Indexed: 12/03/2022] Open
Abstract
Whether and how the apolipoprotein E (APOE) ε4 genotype specifically modulates brain network connectivity in patients with amnestic mild cognitive impairment (aMCI) remain largely unknown. Here, we employed resting-state (‘task-free’) functional MRI and network centrality approaches to investigate local (degree centrality, DC) and global (eigenvector centrality, EC) functional integrity in the whole-brain connectome in 156 older adults, including 66 aMCI patients (27 ε4-carriers and 39 non-carriers) and 90 healthy controls (45 ε4-carriers and 45 non-carriers). We observed diagnosis-by-genotype interactions on DC in the left superior/middle frontal gyrus, right middle temporal gyrus and cerebellum, with higher values in the ε4-carriers than non-carriers in the aMCI group. We further observed diagnosis-by-genotype interactions on EC, with higher values in the right middle temporal gyrus but lower values in the medial parts of default-mode network in the ε4-carriers than non-carriers in the aMCI group. Notably, these genotype differences in DC or EC were absent in the control group. Finally, the network connectivity DC values were negatively correlated with cognitive performance in the aMCI ε4-carriers. Our findings suggest that the APOE genotype selectively modulates the functional integration of brain networks in patients with aMCI, thus providing important insight into the gene-connectome interaction in this disease.
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Affiliation(s)
- Zan Wang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Zhengjia Dai
- Department of Psychology, Sun Yat-sen University, Guangzhou, 510006, China.,State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Hao Shu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Xuhong Liao
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Chunxian Yue
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Duan Liu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Qihao Guo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Yong He
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China.
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China.
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Papma JM, Smits M, de Groot M, Mattace Raso FU, van der Lugt A, Vrooman HA, Niessen WJ, Koudstaal PJ, van Swieten JC, van der Veen FM, Prins ND. The effect of hippocampal function, volume and connectivity on posterior cingulate cortex functioning during episodic memory fMRI in mild cognitive impairment. Eur Radiol 2017; 27:3716-3724. [PMID: 28289940 PMCID: PMC5544779 DOI: 10.1007/s00330-017-4768-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 01/10/2017] [Accepted: 02/01/2017] [Indexed: 11/30/2022]
Abstract
Objectives Diminished function of the posterior cingulate cortex (PCC) is a typical finding in early Alzheimer’s disease (AD). It is hypothesized that in early stage AD, PCC functioning relates to or reflects hippocampal dysfunction or atrophy. The aim of this study was to examine the relationship between hippocampus function, volume and structural connectivity, and PCC activation during an episodic memory task-related fMRI study in mild cognitive impairment (MCI). Method MCI patients (n = 27) underwent episodic memory task-related fMRI, 3D-T1w MRI, 2D T2-FLAIR MRI and diffusion tensor imaging. Stepwise linear regression analysis was performed to examine the relationship between PCC activation and hippocampal activation, hippocampal volume and diffusion measures within the cingulum along the hippocampus. Results We found a significant relationship between PCC and hippocampus activation during successful episodic memory encoding and correct recognition in MCI patients. We found no relationship between the PCC and structural hippocampal predictors. Conclusions Our results indicate a relationship between PCC and hippocampus activation during episodic memory engagement in MCI. This may suggest that during episodic memory, functional network deterioration is the most important predictor of PCC functioning in MCI. Key Points • PCC functioning during episodic memory relates to hippocampal functioning in MCI. • PCC functioning during episodic memory does not relate to hippocampal structure in MCI. • Functional network changes are an important predictor of PCC functioning in MCI. Electronic supplementary material The online version of this article (doi:10.1007/s00330-017-4768-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Janne M Papma
- Department of Neurology, Erasmus MC - University Medical Center Rotterdam, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
| | - Marion Smits
- Department of Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marius de Groot
- Department of Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Medical Informatics, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Francesco U Mattace Raso
- Department of Geriatrics, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Aad van der Lugt
- Department of Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Henri A Vrooman
- Department of Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Medical Informatics, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Wiro J Niessen
- Department of Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Medical Informatics, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands.,Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - Peter J Koudstaal
- Department of Neurology, Erasmus MC - University Medical Center Rotterdam, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
| | - John C van Swieten
- Department of Neurology, Erasmus MC - University Medical Center Rotterdam, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
| | | | - Niels D Prins
- Alzheimer Center, Department of Neurology, VU University Medical Center, Neuroscience Campus, Amsterdam, The Netherlands
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Wang P, Li J, Li HJ, Huo L, Li R. Mild Cognitive Impairment Is Not "Mild" at All in Altered Activation of Episodic Memory Brain Networks: Evidence from ALE Meta-Analysis. Front Aging Neurosci 2016; 8:260. [PMID: 27872591 PMCID: PMC5097923 DOI: 10.3389/fnagi.2016.00260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 10/19/2016] [Indexed: 12/18/2022] Open
Abstract
The present study conducted a quantitative meta-analysis aiming at assessing consensus across the functional neuroimaging studies of episodic memory in individuals with amnestic mild cognitive impairment (aMCI) and elucidating consistent activation patterns. An activation likelihood estimation (ALE) was conducted on the functional neuroimaging studies of episodic encoding and retrieval in aMCI individuals published up to March 31, 2015. Analyses covered 24 studies, which yielded 770 distinct foci. Compared to healthy controls, aMCI individuals showed statistically significant consistent activation differences in a widespread episodic memory network, not only in the bilateral medial temporal lobe and prefrontal cortex, but also in the angular gyrus, precunes, posterior cingulate cortex, and even certain more basic structures. The present ALE meta-analysis revealed that the abnormal patterns of widespread episodic memory network indicated that individuals with aMCI may not be completely "mild" in nature.
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Affiliation(s)
- Pengyun Wang
- Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of SciencesBeijing, China
| | - Juan Li
- Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of SciencesBeijing, China
| | - Hui-Jie Li
- Laboratory for Functional Connectome and Development, Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of SciencesBeijing, China
| | - Lijuan Huo
- Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
| | - Rui Li
- Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of SciencesBeijing, China
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8
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Alberdi A, Aztiria A, Basarab A. On the early diagnosis of Alzheimer's Disease from multimodal signals: A survey. Artif Intell Med 2016; 71:1-29. [PMID: 27506128 DOI: 10.1016/j.artmed.2016.06.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/23/2016] [Accepted: 06/07/2016] [Indexed: 11/15/2022]
Abstract
INTRODUCTION The number of Alzheimer's Disease (AD) patients is increasing with increased life expectancy and 115.4 million people are expected to be affected in 2050. Unfortunately, AD is commonly diagnosed too late, when irreversible damages have been caused in the patient. OBJECTIVE An automatic, continuous and unobtrusive early AD detection method would be required to improve patients' life quality and avoid big healthcare costs. Thus, the objective of this survey is to review the multimodal signals that could be used in the development of such a system, emphasizing on the accuracy that they have shown up to date for AD detection. Some useful tools and specific issues towards this goal will also have to be reviewed. METHODS An extensive literature review was performed following a specific search strategy, inclusion criteria, data extraction and quality assessment in the Inspec, Compendex and PubMed databases. RESULTS This work reviews the extensive list of psychological, physiological, behavioural and cognitive measurements that could be used for AD detection. The most promising measurements seem to be magnetic resonance imaging (MRI) for AD vs control (CTL) discrimination with an 98.95% accuracy, while electroencephalogram (EEG) shows the best results for mild cognitive impairment (MCI) vs CTL (97.88%) and MCI vs AD distinction (94.05%). Available physiological and behavioural AD datasets are listed, as well as medical imaging analysis steps and neuroimaging processing toolboxes. Some issues such as "label noise" and multi-site data are discussed. CONCLUSIONS The development of an unobtrusive and transparent AD detection system should be based on a multimodal system in order to take full advantage of all kinds of symptoms, detect even the smallest changes and combine them, so as to detect AD as early as possible. Such a multimodal system might probably be based on physiological monitoring of MRI or EEG, as well as behavioural measurements like the ones proposed along the article. The mentioned AD datasets and image processing toolboxes are available for their use towards this goal. Issues like "label noise" and multi-site neuroimaging incompatibilities may also have to be overcome, but methods for this purpose are already available.
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Affiliation(s)
- Ane Alberdi
- Mondragon University, Electronics and Computing Department, Goiru Kalea, 2, Arrasate 20500, Spain.
| | - Asier Aztiria
- Mondragon University, Electronics and Computing Department, Goiru Kalea, 2, Arrasate 20500, Spain.
| | - Adrian Basarab
- Université de Toulouse, Institut de Recherche en Informatique de Toulouse, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5505, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France.
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9
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Masdeu JC, Pascual B. Genetic and degenerative disorders primarily causing dementia. HANDBOOK OF CLINICAL NEUROLOGY 2016; 135:525-564. [PMID: 27432682 DOI: 10.1016/b978-0-444-53485-9.00026-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neuroimaging comprises a powerful set of instruments to diagnose the different causes of dementia, clarify their neurobiology, and monitor their treatment. Magnetic resonance imaging (MRI) depicts volume changes with neurodegeneration and inflammation, as well as abnormalities in functional and structural connectivity. MRI arterial spin labeling allows for the quantification of regional cerebral blood flow, characteristically altered in Alzheimer's disease, diffuse Lewy-body disease, and the frontotemporal dementias. Positron emission tomography allows for the determination of regional metabolism, with similar abnormalities as flow, and for the measurement of β-amyloid and abnormal tau deposition in the brain, as well as regional inflammation. These instruments allow for the quantification in vivo of most of the pathologic features observed in disorders causing dementia. Importantly, they allow for the longitudinal study of these abnormalities, having revealed, for instance, that the deposition of β-amyloid in the brain can antecede by decades the onset of dementia. Thus, a therapeutic window has been opened and the efficacy of immunotherapies directed at removing β-amyloid from the brain of asymptomatic individuals is currently being tested. Tau and inflammation imaging, still in their infancy, combined with genomics, should provide powerful insights into these disorders and facilitate their treatment.
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Affiliation(s)
- Joseph C Masdeu
- Department of Neurology, Houston Methodist Hospital, Houston, TX, USA.
| | - Belen Pascual
- Department of Neurology, Houston Methodist Hospital, Houston, TX, USA
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Turner BO, Marinsek N, Ryhal E, Miller MB. Hemispheric lateralization in reasoning. Ann N Y Acad Sci 2015; 1359:47-64. [PMID: 26426534 DOI: 10.1111/nyas.12940] [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: 03/26/2015] [Revised: 08/17/2015] [Accepted: 08/20/2015] [Indexed: 11/30/2022]
Abstract
A growing body of evidence suggests that reasoning in humans relies on a number of related processes whose neural loci are largely lateralized to one hemisphere or the other. A recent review of this evidence concluded that the patterns of lateralization observed are organized according to two complementary tendencies. The left hemisphere attempts to reduce uncertainty by drawing inferences or creating explanations, even at the cost of ignoring conflicting evidence or generating implausible explanations. Conversely, the right hemisphere aims to reduce conflict by rejecting or refining explanations that are no longer tenable in the face of new evidence. In healthy adults, the hemispheres work together to achieve a balance between certainty and consistency, and a wealth of neuropsychological research supports the notion that upsetting this balance results in various failures in reasoning, including delusions. However, support for this model from the neuroimaging literature is mixed. Here, we examine the evidence for this framework from multiple research domains, including an activation likelihood estimation analysis of functional magnetic resonance imaging studies of reasoning. Our results suggest a need to either revise this model as it applies to healthy adults or to develop better tools for assessing lateralization in these individuals.
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Affiliation(s)
- Benjamin O Turner
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, California
| | - Nicole Marinsek
- Dynamical Neuroscience, University of California Santa Barbara, Santa Barbara, California
| | - Emily Ryhal
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, California
| | - Michael B Miller
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, California
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11
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Chen J, Zhang Z, Li S. Can multi-modal neuroimaging evidence from hippocampus provide biomarkers for the progression of amnestic mild cognitive impairment? Neurosci Bull 2015; 31:128-40. [PMID: 25595368 DOI: 10.1007/s12264-014-1490-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 11/06/2014] [Indexed: 02/01/2023] Open
Abstract
Impaired structure and function of the hippocampus is a valuable predictor of progression from amnestic mild cognitive impairment (aMCI) to Alzheimer's disease (AD). As a part of the medial temporal lobe memory system, the hippocampus is one of the brain regions affected earliest by AD neuropathology, and shows progressive degeneration as aMCI progresses to AD. Currently, no validated biomarkers can precisely predict the conversion from aMCI to AD. Therefore, there is a great need of sensitive tools for the early detection of AD progression. In this review, we summarize the specific structural and functional changes in the hippocampus from recent aMCI studies using neurophysiological and neuroimaging data. We suggest that a combination of advanced multi-modal neuroimaging measures in discovering biomarkers will provide more precise and sensitive measures of hippocampal changes than using only one of them. These will potentially affect early diagnosis and disease-modifying treatments. We propose a new sequential and progressive framework in which the impairment spreads from the integrity of fibers to volume and then to function in hippocampal subregions. Meanwhile, this is likely to be accompanied by progressive impairment of behavioral and neuropsychological performance in the progression of aMCI to AD.
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Affiliation(s)
- Jiu Chen
- Department of Neurology, Affiliated ZhongDa Hospital, Neuropsychiatric Institute and Medical School of Southeast University, Nanjing, 210009, China
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12
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Relationship between amygdala volume and emotion recognition in adolescents at ultra-high risk for psychosis. Psychiatry Res 2014; 224:159-67. [PMID: 25456521 DOI: 10.1016/j.pscychresns.2014.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 06/23/2014] [Accepted: 10/03/2014] [Indexed: 11/23/2022]
Abstract
Amygdala volume has been proposed as a neural risk biomarker for psychotic illness, but findings in the ultra-high risk for psychosis (UHR) population have been somewhat inconsistent, which may be related to underlying social cognitive abilities. The current study investigated whether amygdala volumes were related to emotion-recognition impairments in UHR individuals, and whether volumes differed by sex. Secondary aims were to assess whether (a) emotion-recognition performance was associated with interhemispheric amygdala volume asymmetry and (b) amgydala volume and volume asymmetry acted as a mediator between emotion-recognition and outcome measures. The amygdala was manually delineated from magnetic resonance images for 39 UHR individuals who had also completed facial and prosody emotion-recognition tasks. Partial correlations were conducted to examine associations between amydgala volume/asymmetry and recognition of negative emotions. Mediation analyses were conducted using regression and bootstrapping techniques. Amygdala volume was positively correlated with sadness emotion recognition, in particular prosody, for females only. Left amygdala volume mediated the effect of sadness recognition on depressive symptoms, negative symptoms, overall psychopathology, and global functioning in females. Findings suggest a complex relationship between emotion recognition, the structure of the amygdala and illness outcome, where recognition of sadness appears to be the precipitator of this relationship in UHR females. Further research is needed to determine illness specificity and to confirm our sex- and emotion-specific results.
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Meusel LAC, Kansal N, Tchistiakova E, Yuen W, MacIntosh BJ, Greenwood CE, Anderson ND. A systematic review of type 2 diabetes mellitus and hypertension in imaging studies of cognitive aging: time to establish new norms. Front Aging Neurosci 2014; 6:148. [PMID: 25071557 PMCID: PMC4085499 DOI: 10.3389/fnagi.2014.00148] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 06/17/2014] [Indexed: 12/19/2022] Open
Abstract
The rising prevalence of type 2 diabetes (T2DM) and hypertension in older adults, and the deleterious effect of these conditions on cerebrovascular and brain health, is creating a growing discrepancy between the "typical" cognitive aging trajectory and a "healthy" cognitive aging trajectory. These changing health demographics make T2DM and hypertension important topics of study in their own right, and warrant attention from the perspective of cognitive aging neuroimaging research. Specifically, interpretation of individual or group differences in blood oxygenation level dependent magnetic resonance imaging (BOLD MRI) or positron emission tomography (PET H2O(15)) signals as reflective of differences in neural activation underlying a cognitive operation of interest requires assumptions of intact vascular health amongst the study participants. Without adequate screening, inclusion of individuals with T2DM or hypertension in "healthy" samples may introduce unwanted variability and bias to brain and/or cognitive measures, and increase potential for error. We conducted a systematic review of the cognitive aging neuroimaging literature to document the extent to which researchers account for these conditions. Of the 232 studies selected for review, few explicitly excluded individuals with T2DM (9%) or hypertension (13%). A large portion had exclusion criteria that made it difficult to determine whether T2DM or hypertension were excluded (44 and 37%), and many did not mention any selection criteria related to T2DM or hypertension (34 and 22%). Of all the surveyed studies, only 29% acknowledged or addressed the potential influence of intersubject vascular variability on the measured BOLD or PET signals. To reinforce the notion that individuals with T2DM and hypertension should not be overlooked as a potential source of bias, we also provide an overview of metabolic and vascular changes associated with T2DM and hypertension, as they relate to cerebrovascular and brain health.
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Affiliation(s)
| | - Nisha Kansal
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada
| | - Ekaterina Tchistiakova
- Sunnybrook Research Institute, Heart and Stroke Foundation Canadian Partnership for Stroke Recovery Toronto, ON, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - William Yuen
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Bradley J MacIntosh
- Sunnybrook Research Institute, Heart and Stroke Foundation Canadian Partnership for Stroke Recovery Toronto, ON, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Carol E Greenwood
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Nicole D Anderson
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Departments of Psychology and Psychiatry, University of Toronto Toronto, ON, Canada
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14
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Julayanont P, Brousseau M, Chertkow H, Phillips N, Nasreddine ZS. Montreal Cognitive Assessment Memory Index Score (MoCA-MIS) as a Predictor of Conversion from Mild Cognitive Impairment to Alzheimer's Disease. J Am Geriatr Soc 2014; 62:679-84. [DOI: 10.1111/jgs.12742] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Parunyou Julayanont
- Center for Diagnosis and Research on Alzheimer's Disease; Greenfield Park Quebec Canada
- Department of Internal Medicine; Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - Mélanie Brousseau
- Center for Diagnosis and Research on Alzheimer's Disease; Greenfield Park Quebec Canada
| | - Howard Chertkow
- Bloomfield Center for Research in Aging; Lady Davis Institute; General Hospital; Montreal Quebec Canada
- Department of Clinical Neurosciences and Division of Geriatric Medicine; Sir Mortimer B. Davis-Jewish General Hospital; McGill University; Montreal Quebec Canada
- Research Center; University Institute of Geriatrics; University of Montreal; Montreal Quebec Canada
| | - Natalie Phillips
- Bloomfield Center for Research in Aging; Lady Davis Institute; General Hospital; Montreal Quebec Canada
- Center for Research in Human Development; Department of Psychology; Concordia University; Montreal Quebec Canada
| | - Ziad S. Nasreddine
- Center for Diagnosis and Research on Alzheimer's Disease; Greenfield Park Quebec Canada
- Department of Clinical Neurosciences and Division of Geriatric Medicine; Sir Mortimer B. Davis-Jewish General Hospital; McGill University; Montreal Quebec Canada
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15
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Parahippocampal corpora amylacea and neuronal lipofuscin in human aging. Open Med (Wars) 2013. [DOI: 10.2478/s11536-013-0214-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe aim of this research was to quantify the number of corpora amylacea and lipofuscin-bearing neurons in the parahippocampal region of the brain. Right parahippocampal gyrus specimens of 30 cadavers were used as material for histological and morphometric analyses. A combined Alcian Blue and Periodic Acid-Schiff technique was used for identification and quantification of corpora amylacea and lipofuscin-bearing neurons. Immunohistochemistry was performed using S100 polyclonal, neuron-specific enolase and glial fibrillary acidic protein monoclonal antibodies for differentiation of corpora amylacea and other spherical inclusions of the aging brain. Cluster analysis of obtained data showed the presence of three age groups (median age: I = 41.5, II = 68, III = 71.5). The second group was characterized by a significantly higher numerical density of subcortical corpora amylacea and number of lipofuscin-bearing neurons than other two groups. Values of the latter cited parameters in the third group were insignificantly higher than the first younger group. Linear regression showed that number of parahippocampal lipofuscin-bearing neurons significantly predicts numerical density of subcortical corpora amylacea. The above results suggest that more numerous parahippocampal region corpora amylacea and lipofuscin-bearing neurons in some older cases might represent signs of its’ neurons quantitatively-altered metabolism.
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16
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Griffith HR, Okonkwo OC, Stewart CC, Stoeckel LE, den Hollander JA, Elgin JM, Harrell LE, Brockington JC, Clark DG, Ball KK, Owsley C, Marson DC, Wadley VG. Lower hippocampal volume predicts decrements in lane control among drivers with amnestic mild cognitive impairment. J Geriatr Psychiatry Neurol 2013; 26:259-66. [PMID: 24212246 PMCID: PMC4114386 DOI: 10.1177/0891988713509138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVES There are few methods to discern driving risks in patients with early dementia and mild cognitive impairment (MCI). We aimed to determine whether structural magnetic resonance imaging (MRI) of the hippocampus-a biomarker of probable Alzheimer pathology and a measure of disease severity in those affected--is linked to objective ratings of on-road driving performance in older adults with and without amnestic MCI. METHODS In all, 49 consensus-diagnosed participants from an Alzheimer's Disease Research Center (15 diagnosed with amnestic MCI and 34 demographically similar controls) underwent structural MRI and on-road driving assessments. RESULTS Mild atrophy of the left hippocampus was associated with less-than-optimal ratings in lane control but not with other discrete driving skills. Decrements in left hippocampal volume conferred higher risk for less-than-optimal lane control ratings in the patients with MCI (B = -1.63, standard error [SE] = .74, Wald = 4.85, P = .028), but not in controls (B = 0.13, SE = .415, Wald = 0.10, P = .752). The odds ratio and 95% confidence interval for below-optimal lane control in the MCI group was 4.41 (1.18-16.36), which was attenuated to 3.46 (0.88-13.60) after accounting for the contribution of left hippocampal volume. CONCLUSION These findings suggest that there may be a link between hippocampal atrophy and difficulties with lane control in persons with amnestic MCI. Further study appears warranted to better discern patterns of brain atrophy in MCI and Alzheimer disease and whether these could be early markers of clinically meaningful driving risk.
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Affiliation(s)
- H Randall Griffith
- Departments of Neurology, University of Alabama at Birmingham, AL,Departments of Psychology, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL
| | - Ozioma C Okonkwo
- Department of Medicine and Wisconsin Alzheimer's Disease Research Center, University of Wisconsin-Madison, Madison, WI
| | | | - Luke E Stoeckel
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | | | - Jennifer M Elgin
- Departments of Opthalmology, University of Alabama at Birmingham, AL,Edward R. Roybal Center for Translational Research on Aging and Mobility, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lindy E Harrell
- Departments of Neurology, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL,Birmingham Regional Veterans Affairs Medical Center, Birmingham, AL, USA
| | - John C Brockington
- Departments of Neurology, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL
| | - David G Clark
- Departments of Neurology, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL,Birmingham Regional Veterans Affairs Medical Center, Birmingham, AL, USA
| | - Karlene K Ball
- Departments of Psychology, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL,Edward R. Roybal Center for Translational Research on Aging and Mobility, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Cynthia Owsley
- Departments of Opthalmology, University of Alabama at Birmingham, AL,Edward R. Roybal Center for Translational Research on Aging and Mobility, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Daniel C Marson
- Departments of Neurology, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL
| | - Virginia G Wadley
- Departments of Medicine, University of Alabama at Birmingham, AL,Alzheimer's Disease Research Center, University of Alabama at Birmingham, AL,Edward R. Roybal Center for Translational Research on Aging and Mobility, University of Alabama at Birmingham, Birmingham, AL, USA
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Gawron N, Łojek E, Kijanowska-Haładyna B, Nestorowicz J, Harasim A, Pluta A, Sobańska M. Cognitive patterns of normal elderly subjects are consistent with frontal cortico-subcortical and fronto-parietal neuropsychological models of brain aging. APPLIED NEUROPSYCHOLOGY-ADULT 2013; 21:195-209. [PMID: 25084844 DOI: 10.1080/09084282.2013.789965] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Three neuropsychological theories have been developed according to a possible existence of a similar pattern of cognitive decline in elderly individuals and patients with brain damage. The respective neuropsychological theories attribute age-related deficits to: (a) dysfunction of the frontal lobes, (b) temporo-parietal dysfunction, or (c) decline of right-hemisphere functions. In the present study, we examined which of these theories best explains the cognitive patterns of normal elderly subjects older than 80 years of age (old elderly). Thirty normal old elderly subjects, 14 patients with subcortical vascular dementia, 14 with mild Alzheimer's disease, 15 with damage of the right hemisphere of the brain, and 20 young elderly controls participated. A test battery covering the main cognitive domains was administered to all participants. A hierarchical cluster analysis revealed five groups of individuals with different cognitive patterns across the whole sample. Old elderly subjects were assigned to four groups according to: (a) preserved overall cognitive performance, (b) processing speed decline, (c) attention decline, or (d) executive impairment. The results of the study are most congruent with models emphasizing frontal-lobe cortical-subcortical and fronto-parietal changes in old age. The results also indicate considerable heterogeneity in the cognitive patterns of normal old elderly adults.
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Affiliation(s)
- Natalia Gawron
- a Faculty of Psychology , University of Warsaw , Warsaw , Poland
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18
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Neurokinin3 receptor as a target to predict and improve learning and memory in the aged organism. Proc Natl Acad Sci U S A 2013; 110:15097-102. [PMID: 23983264 DOI: 10.1073/pnas.1306884110] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Impaired learning and memory performance is often found in aging as an early sign of dementia. It is associated with neuronal loss and reduced functioning of cholinergic networks. Here we present evidence that the neurokinin3 receptors (NK3-R) and their influence on acetylcholine (ACh) release may represent a crucial mechanism that underlies age-related deficits in learning and memory. Repeated pharmacological stimulation of NK3-R in aged rats was found to improve learning in the water maze and in object-place recognition. This treatment also enhanced in vivo acetylcholinergic activity in the frontal cortex, hippocampus, and amygdala but reduced NK3-R mRNA expression in the hippocampus. Furthermore, NK3-R agonism incurred a significantly higher increase in ACh levels in aged animals that showed superior learning than in those that were most deficient in learning. Our findings suggest that the induced activation of ACh, rather than basal ACh activity, is associated with superior learning in the aged. To test whether natural variation in NK3-R function also determines learning and memory performance in aged humans, we investigated 209 elderly patients with cognitive impairments. We found that of the 15 analyzed single single-nucleotide ploymorphism (SNPs) of the NK3-R-coding gene, TACR3, the rs2765 SNP predicted the degree of impairment of learning and memory in these patients. This relationship could be partially explained by a reduced right hippocampus volume in a subsample of 111 tested dementia patients. These data indicate the NK3-R as an important target to predict and improve learning and memory performance in the aged organism.
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Burhan AM, Bartha R, Bocti C, Borrie M, Laforce R, Rosa-Neto P, Soucy JP. Role of emerging neuroimaging modalities in patients with cognitive impairment: a review from the Canadian Consensus Conference on the Diagnosis and Treatment of Dementia 2012. ALZHEIMERS RESEARCH & THERAPY 2013; 5:S4. [PMID: 24565285 PMCID: PMC3981649 DOI: 10.1186/alzrt200] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Fourth Canadian Consensus Conference on the Diagnosis and Treatment of Dementia (CCCDTD4) was held 3 to 4 May 2012 in Montreal, Quebec, Canada. A group of neuroimaging experts were assigned the task of reviewing and summarizing the literature on clinical and research applications of different neuroimaging modalities in cognitive disorders. This paper summarizes the literature and recommendations made to the conference regarding the role of several emerging neuroimaging modalities in cognitive disorders. Functional magnetic resonance imaging (MRI), magnetic resonance spectroscopy, and diffusion tensor imaging are discussed in detail within this paper. Other emergent neuroimaging modalities such as positron emission tomography with novel ligands, high-field MRI, arterial spin labeling MRI and noncerebral blood flow single-photon emission computerized tomography are only discussed briefly. Neuroimaging modalities that were recommended at the CCCDTD4 for both clinical and research applications such as amyloid and flurodeoxyglucose positron emission tomography, computerized tomography and structural MRI are discussed in a separate paper by the same authors. A literature search was conducted using the PubMed database including articles in English that involved human subjects and covered the period from the last CCCDTD publication (CCCDTD3; January 2006) until April 2012. Search terms included the name of the specific modality, dementia, Alzheimer's disease, and mild cognitive impairment. A separate search used the same parameters but was restricted to review articles to identify recent evidence-based reviews. Case studies and small case series were not included. Papers representing current evidence were selected, reviewed, and summarized, and the results were presented at the CCCDTD4 meeting with recommendations regarding the utility of various neuroimaging modalities in cognitive disorders. The evidence was graded according to the Oxford Centre for Evidence Based Medicine guidelines. Due to the limitations of current evidence, the neuroimaging modalities discussed in this paper were not recommended for clinical investigation of patients presenting with cognitive impairment. However, in the research setting, each modality provides a unique contribution to the understanding of basic mechanisms and neuropathological markers of cognitive disorders, to the identification of markers for early detection and for the risk of conversion to dementia in the at-risk populations, to the differentiation between different types of cognitive disorders, and to the identification of treatment targets and indicators of treatment response. In conclusion, for all of the neuroimaging modalities discussed in this paper, further studies are needed to establish diagnostic utility such as validity, reliability, and predictive and prognostic value. More multicenter studies are therefore needed with standardized image acquisition, experimental protocols, definition of the clinical population studied, larger numbers of participants, and longer duration of follow-up to allow generalizability of the results to the individual patient.
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Maillet D, Rajah MN. Association between prefrontal activity and volume change in prefrontal and medial temporal lobes in aging and dementia: a review. Ageing Res Rev 2013. [PMID: 23183352 DOI: 10.1016/j.arr.2012.11.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Functional neuroimaging studies have consistently reported age-related changes in prefrontal cortex (PFC) activity during a variety of cognitive tasks, including episodic memory. These changes are often interpreted within the context of one of the following three neural models of age-related changes in brain function: dedifferentiation, neural inefficiency, and neural plasticity and compensation models. Distinguishing between these competing models has proven difficult when interpreting results using functional imaging data alone. In this paper we suggest that a more accurate interpretation of age-related changes in PFC activity requires consideration of age-related differences in gray matter volume (GMv) in PFC and the medial temporal lobes (MTL). We review fMRI studies of cognitive aging that have directly examined the relationship between PFC activity and both local (PFC) and distal (MTL) GMv in older versus younger adults. We also considered how structure-function relationships may be further modified in pathological aging (i.e. mild cognitive impairment (MCI) and Alzheimer's disease (AD)). We found that when task performance was matched between age-groups there was a negative association between regional PFC volume and activity in older adults. However, when older adults performed worse than young adults we observed a positive association between volume and activity in right lateral PFC. Additionally during memory tasks, several studies revealed that PFC activity is positively related to GM volume in MTL in healthy older adults, but negatively related in MCI and AD patients. We conclude that PFC activity is related to age-related changes in local and distal GM volume reductions and that consideration of these structural measures aids the interpretation of fMRI results. Furthermore, the study of structure-function relationships may provide important insights into the biological mechanisms underlying healthy versus pathological aging.
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Affiliation(s)
- David Maillet
- Department of Neuroscience, McGill University, Montreal, QC H3A 2T5, Canada
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Abstract
PURPOSE OF REVIEW In 2011, a new set of new guidelines for the research diagnosis of three stages of Alzheimer disease was promulgated by the US National Institute of Aging and the Alzheimer Association. For the first time, they include the diagnosis of presymptomatic Alzheimer disease, recognizing that the disease process begins years before cognitive impairment develops. Awareness of this fact has largely been driven by neuroimaging, and particularly by imaging amyloid β (abeta) deposition in the brain, a procedure approved by the US Food and Drug Administration for clinical use in April 2012. RECENT FINDINGS In Alzheimer disease, abeta deposition antecedes, probably by decades, the onset of cognitive impairment. In brain regions with greatest abeta deposition, synaptic dysfunction can be imaged beginning at preclinical stages. In regions that are not identical with the ones with greatest abeta deposition but heavily connected with them, regional atrophy and loss of white-matter anisotropy can be detected later in the course of the disease, near the time when mild cognitive impairment supervenes. Together with neuropsychological testing, imaging can improve the prediction of worsening to Alzheimer disease among patients with mild cognitive impairment. SUMMARY These findings have huge implications for research on therapeutic approaches to Alzheimer disease. For instance, while so far only patients with the clinical diagnosis have been treated with immunotherapy targeting abeta removal, a consensus is building that to be effective, this therapy should be given in the preclinical stages of the disease, which are assessed most advantageously by means of neuroimaging.
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