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Onoda K, Yada N, Ozasa K, Hara S, Yamamoto Y, Kitagaki H, Yamaguchi S. Can a Resting-State Functional Connectivity Index Identify Patients with Alzheimer's Disease and Mild Cognitive Impairment Across Multiple Sites? Brain Connect 2017; 7:391-400. [PMID: 28666395 DOI: 10.1089/brain.2017.0507] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Resting-state functional connectivity is one promising biomarker for Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, it is still not known how accurately network analysis identifies AD and MCI across multiple sites. In this study, we examined whether resting-state functional connectivity data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) could identify patients with AD and MCI at our site. We implemented an index based on the functional connectivity frequency distribution and compared performance for AD and MCI identification with multivoxel pattern analysis. The multivoxel pattern analysis using a connectivity map of the default mode network showed good performance, with an accuracy of 81.9% for AD and MCI identification within the ADNI, but the classification model obtained from the ADNI failed to classify AD, MCI, and healthy elderly adults from our site, with an accuracy of only 43.1%. In contrast, a functional connectivity index of the medial temporal lobe based on the frequency distribution showed moderate performance, with an accuracy of 76.5-80.3% for AD identification within the ADNI. The performance of this index was similar for our data, with an accuracy of 73.9-82.6%. The frequency distribution-based index of functional connectivity could be a good biomarker for AD across multiple sites.
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Affiliation(s)
- Keiichi Onoda
- Department of Neurology, Shimane University, Izumo, Japan
| | - Nobuhiro Yada
- Department of Radiology, Shimane University, Izumo, Japan
| | - Kentaro Ozasa
- Department of Radiology, Shimane University, Izumo, Japan
| | - Shinji Hara
- Department of Radiology, Shimane University, Izumo, Japan
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52
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Local-to-remote cortical connectivity in amnestic mild cognitive impairment. Neurobiol Aging 2017; 56:138-149. [DOI: 10.1016/j.neurobiolaging.2017.04.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 04/02/2017] [Accepted: 04/18/2017] [Indexed: 11/23/2022]
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53
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Onofrj M, Carrozzino D, D’Amico A, Di Giacomo R, Delli Pizzi S, Thomas A, Onofrj V, Taylor JP, Bonanni L. Psychosis in parkinsonism: an unorthodox approach. Neuropsychiatr Dis Treat 2017; 13:1313-1330. [PMID: 28553118 PMCID: PMC5439966 DOI: 10.2147/ndt.s116116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Psychosis in Parkinson's disease (PD) is currently considered as the occurrence of hallucinations and delusions. The historical meaning of the term psychosis was, however, broader, encompassing a disorganization of both consciousness and personality, including behavior abnormalities, such as impulsive overactivity and catatonia, in complete definitions by the International Classification of Diseases-10 (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Our review is aimed at reminding that complex psychotic symptoms, including impulsive overactivity and somatoform disorders (the last being a recent controversial entity in PD), were carefully described in postencephalitic parkinsonism (PEP), many decades before dopaminergic treatment era, and are now described in other parkinsonisms than PD. Eminent neuropsychiatrists of the past century speculated that studying psychosis in PEP might highlight its mechanisms in other conditions. Yet, functional assessments were unavailable at the time. Therefore, the second part of our article reviews the studies of neural correlates of psychosis in parkinsonisms, by taking into account both theories on the narrative functions of the default mode network (DMN) and hypotheses on DMN modulation.
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Affiliation(s)
- Marco Onofrj
- Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara
- CE.S.I. University Foundation
| | - Danilo Carrozzino
- Department of Psychological, Health, and Territorial Sciences, University “G. d’Annunzio” of Chieti-Pescara, Chieti, Italy
- Psychiatric Research Unit, Psychiatric Centre North Zealand, Copenhagen University Hospital, Hillerød, Denmark
| | - Aurelio D’Amico
- Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara
- CE.S.I. University Foundation
| | - Roberta Di Giacomo
- Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara
- CE.S.I. University Foundation
| | - Stefano Delli Pizzi
- Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara
| | - Astrid Thomas
- Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara
- CE.S.I. University Foundation
| | - Valeria Onofrj
- Department of Bioimaging, University Cattolica del Sacro Cuore, Rome, Italy
| | - John-Paul Taylor
- Institute of Neuroscience, Campus for Ageing and Vitality Newcastle University Newcastle upon Tyne, Newcastle upon Tyne, UK
| | - Laura Bonanni
- Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara
- CE.S.I. University Foundation
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Pievani M, Pini L, Ferrari C, Pizzini FB, Boscolo Galazzo I, Cobelli C, Cotelli M, Manenti R, Frisoni GB. Coordinate-Based Meta-Analysis of the Default Mode and Salience Network for Target Identification in Non-Invasive Brain Stimulation of Alzheimer’s Disease and Behavioral Variant Frontotemporal Dementia Networks. J Alzheimers Dis 2017; 57:825-843. [DOI: 10.3233/jad-161105] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Michela Pievani
- Laboratory Alzheimer’s Neuroimaging and Epidemiology, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
| | - Lorenzo Pini
- Laboratory Alzheimer’s Neuroimaging and Epidemiology, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Clarissa Ferrari
- Statistics Service, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
| | - Francesca B. Pizzini
- Neuroradiology, Department of Diagnostics and Pathology, Verona University Hospital, Verona, Italy
| | | | - Chiara Cobelli
- Neuropsychology Unit, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
| | - Maria Cotelli
- Neuropsychology Unit, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
| | - Rosa Manenti
- Neuropsychology Unit, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
| | - Giovanni B. Frisoni
- Laboratory Alzheimer’s Neuroimaging and Epidemiology, IRCCS Centro San Giovanni di Dio – Fatebenefratelli, Brescia, Italy
- University Hospitals and University of Geneva, Geneva, Switzerland
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55
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Caminiti SP, Tettamanti M, Sala A, Presotto L, Iannaccone S, Cappa SF, Magnani G, Perani D. Metabolic connectomics targeting brain pathology in dementia with Lewy bodies. J Cereb Blood Flow Metab 2017; 37:1311-1325. [PMID: 27306756 PMCID: PMC5453453 DOI: 10.1177/0271678x16654497] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/24/2016] [Accepted: 05/17/2016] [Indexed: 12/21/2022]
Abstract
Dementia with Lewy bodies is characterized by α-synuclein accumulation and degeneration of dopaminergic and cholinergic pathways. To gain an overview of brain systems affected by neurodegeneration, we characterized the [18F]FDG-PET metabolic connectivity in 42 dementia with Lewy bodies patients, as compared to 42 healthy controls, using sparse inverse covariance estimation method and graph theory. We performed whole-brain and anatomically driven analyses, targeting cholinergic and dopaminergic pathways, and the α-synuclein spreading. The first revealed substantial alterations in connectivity indexes, brain modularity, and hubs configuration. Namely, decreases in local metabolic connectivity within occipital cortex, thalamus, and cerebellum, and increases within frontal, temporal, parietal, and basal ganglia regions. There were also long-range disconnections among these brain regions, all supporting a disruption of the functional hierarchy characterizing the normal brain. The anatomically driven analysis revealed alterations within brain structures early affected by α-synuclein pathology, supporting Braak's early pathological staging in dementia with Lewy bodies. The dopaminergic striato-cortical pathway was severely affected, as well as the cholinergic networks, with an extensive decrease in connectivity in Ch1-Ch2, Ch5-Ch6 networks, and the lateral Ch4 capsular network significantly towards the occipital cortex. These altered patterns of metabolic connectivity unveil a new in vivo scenario for dementia with Lewy bodies underlying pathology in terms of changes in whole-brain metabolic connectivity, spreading of α-synuclein, and neurotransmission impairment.
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Affiliation(s)
- Silvia P Caminiti
- Vita-Salute San Raffaele University, Faculty of Medicine and Surgery, Milan, Italy
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Marco Tettamanti
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy
| | - Arianna Sala
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Luca Presotto
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Sandro Iannaccone
- Neurological Rehabilitation Department, San Raffaele Hospital, Milan, Italy
| | - Stefano F Cappa
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- IUSS Pavia, Piazza della Vittoria, Pavia, Italy
| | | | - Daniela Perani
- Vita-Salute San Raffaele University, Faculty of Medicine and Surgery, Milan, Italy
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy
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Takamura T, Hanakawa T. Clinical utility of resting-state functional connectivity magnetic resonance imaging for mood and cognitive disorders. J Neural Transm (Vienna) 2017; 124:821-839. [PMID: 28337552 DOI: 10.1007/s00702-017-1710-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/14/2017] [Indexed: 12/15/2022]
Abstract
Although functional magnetic resonance imaging (fMRI) has long been used to assess task-related brain activity in neuropsychiatric disorders, it has not yet become a widely available clinical tool. Resting-state fMRI (rs-fMRI) has been the subject of recent attention in the fields of basic and clinical neuroimaging research. This method enables investigation of the functional organization of the brain and alterations of resting-state networks (RSNs) in patients with neuropsychiatric disorders. Rs-fMRI does not require participants to perform a demanding task, in contrast to task fMRI, which often requires participants to follow complex instructions. Rs-fMRI has a number of advantages over task fMRI for application with neuropsychiatric patients, for example, although applications of task fMR to participants for healthy are easy. However, it is difficult to apply these applications to patients with psychiatric and neurological disorders, because they may have difficulty in performing demanding cognitive task. Here, we review the basic methodology and analysis techniques relevant to clinical studies, and the clinical applications of the technique for examining neuropsychiatric disorders, focusing on mood disorders (major depressive disorder and bipolar disorder) and dementia (Alzheimer's disease and mild cognitive impairment).
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Affiliation(s)
- T Takamura
- Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - T Hanakawa
- Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
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57
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Kobeleva X, Firbank M, Peraza L, Gallagher P, Thomas A, Burn DJ, O'Brien J, Taylor JP. Divergent functional connectivity during attentional processing in Lewy body dementia and Alzheimer's disease. Cortex 2017; 92:8-18. [PMID: 28391039 PMCID: PMC5480774 DOI: 10.1016/j.cortex.2017.02.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 02/03/2017] [Accepted: 02/21/2017] [Indexed: 12/14/2022]
Abstract
Attention and executive dysfunction are features of Lewy body dementia (LBD) but their neuroanatomical basis is poorly understood. To investigate underlying dysfunctional attention-executive network (EXEC) interactions, we examined functional connectivity (FC) in 30 patients with LBD, 20 patients with Alzheimer's disease (AD), and 21 healthy controls during an event-related functional magnetic resonance imaging (fMRI) experiment. Participants performed a modified Attention Network Test (ANT), where they were instructed to press a button in response to the majority direction of arrows, which were either all pointing in the same direction or with one pointing in the opposite direction. Network activations during both target conditions and a baseline condition (no target) were derived by (ICA) Independent Component Analysis, and interactions between these networks were examined using the beta series correlations approach. Our study revealed that FC of ventral and dorsal attention networks DAN was reduced in LBD during all conditions, although most prominently during incongruent trials. These alterations in connectivity might be driven by a failure of engagement of ventral attention networks, and consequent over-reliance on the DAN. In contrast, when comparing AD patients with the other groups, we found hyperconnectivity between the posterior part of the default mode network (DMN) and the DAN in all conditions, particularly during incongruent trials. This might be attributable to either a compensatory effect to overcome DMN dysfunction, or be arising as a result of a disturbed transition of the DMN from rest to task. Our results demonstrate that dementia syndromes can be characterized both by hyper- and hypoconnectivity of distinct brain networks, depending on the interplay between task demand and available cognitive resources. However these are dependent upon the underlying pathology, which needs to be taken into account when developing specific cognitive therapies for LBD as compared to Alzheimer's.
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Affiliation(s)
- Xenia Kobeleva
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK; Department of Neurology and Neurophysiology, Medical School Hannover, Hannover, Germany; University Hospital Bonn, Clinic for Neurology, Bonn, Germany.
| | - Michael Firbank
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
| | - Luis Peraza
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK
| | - Peter Gallagher
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK
| | - Alan Thomas
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK
| | - David J Burn
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
| | - John O'Brien
- Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, UK.
| | - John-Paul Taylor
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
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58
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Differential diagnosis between patients with probable Alzheimer's disease, Parkinson's disease dementia, or dementia with Lewy bodies and frontotemporal dementia, behavioral variant, using quantitative electroencephalographic features. J Neural Transm (Vienna) 2017; 124:569-581. [PMID: 28243755 PMCID: PMC5399050 DOI: 10.1007/s00702-017-1699-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 02/14/2017] [Indexed: 12/29/2022]
Abstract
The objective of this work was to develop and evaluate a classifier for differentiating probable Alzheimer’s disease (AD) from Parkinson’s disease dementia (PDD) or dementia with Lewy bodies (DLB) and from frontotemporal dementia, behavioral variant (bvFTD) based on quantitative electroencephalography (QEEG). We compared 25 QEEG features in 61 dementia patients (20 patients with probable AD, 20 patients with PDD or probable DLB (DLBPD), and 21 patients with bvFTD). Support vector machine classifiers were trained to distinguish among the three groups. Out of the 25 features, 23 turned out to be significantly different between AD and DLBPD, 17 for AD versus bvFTD, and 12 for bvFTD versus DLBPD. Using leave-one-out cross validation, the classification achieved an accuracy, sensitivity, and specificity of 100% using only the QEEG features Granger causality and the ratio of theta and beta1 band powers. These results indicate that classifiers trained with selected QEEG features can provide a valuable input in distinguishing among AD, DLB or PDD, and bvFTD patients. In this study with 61 patients, no misclassifications occurred. Therefore, further studies should investigate the potential of this method to be applied not only on group level but also in diagnostic support for individual subjects.
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Fujimoto H, Matsuoka T, Kato Y, Shibata K, Nakamura K, Yamada K, Narumoto J. Brain regions associated with anosognosia for memory disturbance in Alzheimer's disease: a magnetic resonance imaging study. Neuropsychiatr Dis Treat 2017; 13:1753-1759. [PMID: 28740390 PMCID: PMC5505610 DOI: 10.2147/ndt.s139177] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Patients with Alzheimer's disease (AD) are frequently unaware of their cognitive symptoms and medical diagnosis. The term "anosognosia" is used to indicate a general lack of awareness of one's disease or disorder. The neural substrate underlying anosognosia in AD is unclear. Since anosognosia for memory disturbance might be an initial sign of AD, it is important to determine the neural correlates. This study was designed to investigate the characteristics and neural correlates of anosognosia for memory disturbance in patients with mild AD. METHODS The subjects were 49 patients with mild AD who participated in a retrospective cross-sectional study. None of the patients had been treated with cholinesterase inhibitors, memantine, or psychotropic drugs. All patients underwent magnetic resonance imaging (MRI). Anosognosia for memory disturbance was assessed based on the discrepancy between questionnaire scores of patients and their caregivers. Structural MRI data were analyzed to explore the association between anosognosia and brain atrophy, using a voxel-based approach. Statistical parametric mapping software was used to explore neural correlations. In image analysis, multiple regression analysis was performed to examine the relationship between anosognosia score and regional gray matter volume. Age, years of education, and total intracranial volume were entered as covariates. RESULTS The anosognosia score for memory disturbance was significantly negatively correlated with gray matter volume in the left superior frontal gyrus. CONCLUSION The left superior frontal gyrus was involved in anosognosia for memory disturbance, while the medial temporal lobe, which is usually damaged in mild AD, was not associated with anosognosia. The left superior frontal gyrus might be an important region for anosognosia in mild AD.
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Affiliation(s)
- Hiroshi Fujimoto
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Teruyuki Matsuoka
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yuka Kato
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Keisuke Shibata
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kaeko Nakamura
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kei Yamada
- Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Jin Narumoto
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
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Onofrj V, Delli Pizzi S, Franciotti R, Taylor JP, Perfetti B, Caulo M, Onofrj M, Bonanni L. Medio-dorsal thalamus and confabulations: Evidence from a clinical case and combined MRI/DTI study. Neuroimage Clin 2016; 12:776-784. [PMID: 27812504 PMCID: PMC5079356 DOI: 10.1016/j.nicl.2016.10.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/06/2016] [Accepted: 10/11/2016] [Indexed: 11/30/2022]
Abstract
The Medio-Dorsal Nuclei (MDN) including the thalamic magnocellular and parvocellular thalamic regions has been implicated in verbal memory function. In a 77 year old lady, with a prior history of a clinically silent infarct of the left MDN, we observed the acute onset of spontaneous confabulations when an isolated new infarct occurred in the right MDN. The patient and five age-matched healthy subjects underwent Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI). The thalamic lesions were localized by overlapping Morel Thalamic Atlas with structural MRI data. DTI was used to assess: i) white matter alterations (Fractional Anisotropy, FA) within fibers connecting the ischemic areas to cortex; ii) the micro-structural damage (Mean Diffusivity) within the thalamic sub-regions defined by their structural connectivity to the Anterior Cingulate Cortex (ACC) and to the temporal lobes. These target regions were chosen because their damage is considered associated with the appearance of confabulations. Thalamic lesions were localized within the parvocellular regions of the right and left MDNs. The structural connectivity study showed that the fiber tracts, connecting the bilaterally damaged thalamic regions with the frontal cortex, corresponded to the anterior thalamic radiations (ATR). FA within these tracts was significantly lower in the patient as compared to controls. Mean diffusivity within the MDNs projecting to Broadman area (BA) 24, BA25 and BA32 of ACC was significantly higher in the patient than in control group. Mean diffusivity values within the MDN projecting to temporal lobes in contrast were not different between patient and controls. Our findings suggest the involvement of bilateral MDNs projections to ACC in the genesis of confabulations and help provide clarity to the longstanding debate on the origin of confabulations.
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Key Words
- ACC, Anterior Cingulate Cortex
- ACoA, Anterior communicating artery
- AN, Anterior thalamic nuclei
- ATR, Anterior thalamic radiations
- Amnesia
- BA, Broadman area
- BEDPOSTX, Bayesian Estimation of Diffusion Parameters obtained using Sampling
- BET, Brain Extraction Tool
- CSF, cerebrospinal fluid
- Confabulation
- DTI, Diffusion Tensor Imaging
- DWI-SE, Diffusion Weighted Image Spin-Echo
- FA, Fractional Anisotropy
- FAST, FMRIB's Automated Segmentation Tool
- FIRST, FMRIB's Integrated Registration and Segmentation Tool
- FLIRT, FMRIB's Linear Image Registration Tool
- FNIRT, FMRIB's Non-Linear Registration Tools
- KS, Korsakoff Syndrome
- MDN, Medio-dorsal thalamic nuclei
- MNI, Montreal Neurological Institute (MNI)
- MRI, Magnetic Resonance Imaging
- Medio-dorsal thalamic region
- SUSAN, Smallest Univalue Segment Assimilating Nucleus
- TE, Echo time
- TR, Repetition time
- W TFE, Weighted Turbo Field-Echo W TFE
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Affiliation(s)
- Valeria Onofrj
- Radiology Department, Policlinico Agostino Gemelli, Largo Agostino Gemelli 7, 00137 Roma, Italy
| | - Stefano Delli Pizzi
- Department of Neuroscience Imaging, and Clinical Sciences, University G. D’Annunzio, Via Vestini, 66103 Chieti Scalo, Italy
| | - Raffaella Franciotti
- Department of Neuroscience Imaging, and Clinical Sciences, University G. D’Annunzio, Via Vestini, 66103 Chieti Scalo, Italy
| | - John-Paul Taylor
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Bernardo Perfetti
- Parkinson's Disease and Movement Disorder Unit, “Fondazione Ospedale San Camillo” - I.R.C.C.S., Venice-Lido, Italy
| | - Massimo Caulo
- Department of Neuroscience Imaging, and Clinical Sciences, University G. D’Annunzio, Via Vestini, 66103 Chieti Scalo, Italy
| | - Marco Onofrj
- Department of Neuroscience Imaging, and Clinical Sciences, University G. D’Annunzio, Via Vestini, 66103 Chieti Scalo, Italy
| | - Laura Bonanni
- Department of Neuroscience Imaging, and Clinical Sciences, University G. D’Annunzio, Via Vestini, 66103 Chieti Scalo, Italy
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61
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Khazaee A, Ebrahimzadeh A, Babajani-Feremi A. Classification of patients with MCI and AD from healthy controls using directed graph measures of resting-state fMRI. Behav Brain Res 2016; 322:339-350. [PMID: 27345822 DOI: 10.1016/j.bbr.2016.06.043] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 01/03/2023]
Abstract
Brain network alterations in patients with Alzheimer's disease (AD) has been the subject of much investigation, but the biological mechanisms underlying these alterations remain poorly understood. Here, we aim to identify the changes in brain networks in patients with AD and mild cognitive impairment (MCI), and provide an accurate algorithm for classification of these patients from healthy control subjects (HC) by using a graph theoretical approach and advanced machine learning methods. Multivariate Granger causality analysis was performed on resting-state functional magnetic resonance imaging (rs-fMRI) data of 34 AD, 89 MCI, and 45 HC to calculate various directed graph measures. The graph measures were used as the original feature set for the machine learning algorithm. Filter and wrapper feature selection methods were applied to the original feature set to select an optimal subset of features. An accuracy of 93.3% was achieved for classification of AD, MCI, and HC using the optimal features and the naïve Bayes classifier. We also performed a hub node analysis and found that the number of hubs in HC, MCI, and AD were 12, 10, and 9, respectively, suggesting that patients with AD experience disturbance of critical communication areas in their brain network as AD progresses. The findings of this study provide insight into the neurophysiological mechanisms underlying MCI and AD. The proposed classification method highlights the potential of directed graph measures of rs-fMRI data for identification of the early stage of AD.
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Affiliation(s)
- Ali Khazaee
- Department of Electrical Engineering, University of Bojnord, Bojnord, Iran
| | - Ata Ebrahimzadeh
- Department of Electrical Engineering, Babol University of Technology, Babol, Iran
| | - Abbas Babajani-Feremi
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center, Memphis, TN, USA; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
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Delli Pizzi S, Franciotti R, Bubbico G, Thomas A, Onofrj M, Bonanni L. Atrophy of hippocampal subfields and adjacent extrahippocampal structures in dementia with Lewy bodies and Alzheimer's disease. Neurobiol Aging 2016; 40:103-109. [DOI: 10.1016/j.neurobiolaging.2016.01.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Revised: 01/12/2016] [Accepted: 01/15/2016] [Indexed: 10/22/2022]
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EEG-directed connectivity from posterior brain regions is decreased in dementia with Lewy bodies: a comparison with Alzheimer's disease and controls. Neurobiol Aging 2016; 41:122-129. [PMID: 27103525 DOI: 10.1016/j.neurobiolaging.2016.02.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 11/22/2022]
Abstract
Directed information flow between brain regions might be disrupted in dementia with Lewy bodies (DLB) and relate to the clinical syndrome of DLB. To investigate this hypothesis, resting-state electroencephalography recordings were obtained in patients with probable DLB and Alzheimer's disease (AD), and controls (N = 66 per group, matched for age and gender). Phase transfer entropy was used to measure directed connectivity in the groups for the theta, alpha, and beta frequency band. A posterior-to-anterior phase transfer entropy gradient, with occipital channels driving the frontal channels, was found in controls in all frequency bands. This posterior-to-anterior gradient was largely lost in DLB in the alpha band (p < 0.05). In the beta band, posterior brain regions were less driving in information flow in AD than in DLB and controls. In conclusion, the common posterior-to-anterior pattern of directed connectivity in controls is disturbed in DLB patients in the alpha band, and in AD patients in the beta band. Disrupted alpha band-directed connectivity may underlie the clinical syndrome of DLB and differentiate between DLB and AD.
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Firbank M, Kobeleva X, Cherry G, Killen A, Gallagher P, Burn DJ, Thomas AJ, O'Brien JT, Taylor JP. Neural correlates of attention-executive dysfunction in lewy body dementia and Alzheimer's disease. Hum Brain Mapp 2015; 37:1254-70. [PMID: 26705763 PMCID: PMC4784171 DOI: 10.1002/hbm.23100] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/18/2015] [Accepted: 12/13/2015] [Indexed: 12/12/2022] Open
Abstract
Attentional and executive dysfunction contribute to cognitive impairment in both Lewy body dementia and Alzheimer's disease. Using functional MRI, we examined the neural correlates of three components of attention (alerting, orienting, and executive/conflict function) in 23 patients with Alzheimer's disease, 32 patients with Lewy body dementia (19 with dementia with Lewy bodies and 13 with Parkinson's disease with dementia), and 23 healthy controls using a modified Attention Network Test. Although the functional MRI demonstrated a similar fronto-parieto-occipital network activation in all groups, Alzheimer's disease and Lewy body dementia patients had greater activation of this network for incongruent and more difficult trials, which were also accompanied by slower reaction times. There was no recruitment of additional brain regions or, conversely, regional deficits in brain activation. The default mode network, however, displayed diverging activity patterns in the dementia groups. The Alzheimer's disease group had limited task related deactivations of the default mode network, whereas patients with Lewy body dementia showed heightened deactivation to all trials, which might be an attempt to allocate neural resources to impaired attentional networks. We posit that, despite a common endpoint of attention-executive disturbances in both dementias, the pathophysiological basis of these is very different between these diseases.
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Affiliation(s)
- Michael Firbank
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom
| | - Xenia Kobeleva
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.,Department of Neurology and Neurophysiology, Medical School Hannover, Carl-Neuberg-Straße 1, Hannover, 30625, Germany
| | - George Cherry
- School of Medical Science, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, United Kingdom
| | - Alison Killen
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom
| | - Peter Gallagher
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom
| | - David J Burn
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom
| | - Alan J Thomas
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom
| | - John T O'Brien
- Department of Psychiatry, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0SP, United Kingdom
| | - John-Paul Taylor
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom
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Benito-León J, Louis ED, Romero JP, Hernández-Tamames JA, Manzanedo E, Álvarez-Linera J, Bermejo-Pareja F, Posada I, Rocon E. Altered Functional Connectivity in Essential Tremor: A Resting-State fMRI Study. Medicine (Baltimore) 2015; 94:e1936. [PMID: 26656325 PMCID: PMC5008470 DOI: 10.1097/md.0000000000001936] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Essential tremor (ET) has been associated with a spectrum of clinical features, with both motor and nonmotor elements, including cognitive deficits. We employed resting-state functional magnetic resonance imaging (fMRI) to assess whether brain networks that might be involved in the pathogenesis of nonmotor manifestations associated with ET are altered, and the relationship between abnormal connectivity and ET severity and neuropsychological function.Resting-state fMRI data in 23 ET patients (12 women and 11 men) and 22 healthy controls (HC) (12 women and 10 men) were analyzed using independent component analysis, in combination with a "dual-regression" technique, to identify the group differences of resting-state networks (RSNs) (default mode network [DMN] and executive, frontoparietal, sensorimotor, cerebellar, auditory/language, and visual networks). All participants underwent a neuropsychological and neuroimaging session, where resting-state data were collected.Relative to HC, ET patients showed increased connectivity in RSNs involved in cognitive processes (DMN and frontoparietal networks) and decreased connectivity in the cerebellum and visual networks. Changes in network integrity were associated not only with ET severity (DMN) and ET duration (DMN and left frontoparietal network), but also with cognitive ability. Moreover, in at least 3 networks (DMN and frontoparietal networks), increased connectivity was associated with worse performance on different cognitive domains (attention, executive function, visuospatial ability, verbal memory, visual memory, and language) and depressive symptoms. Further, in the visual network, decreased connectivity was associated with worse performance on visuospatial ability.ET was associated with abnormal brain connectivity in major RSNs that might be involved in both motor and nonmotor symptoms. Our findings underscore the importance of examining RSNs in this population as a biomarker of disease.
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Affiliation(s)
- Julián Benito-León
- From the Department of Neurology, University Hospital "12 de Octubre", Madrid (JB-L, FB-P, IP); Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) (JB-L, FB-P); Department of Medicine, Complutense University, Madrid, Spain (JB-L, FB-P, IP); Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA (EDL); Faculty of Biosanitary Sciences, Francisco de Vitoria University, Pozuelo de Alarcón (JPR); Neuroimaging Laboratory, Center for Biomedical Technology, Rey Juan Carlos University, Móstoles (JAH-T, EM); Department of Radiology, Hospital Ruber International, Madrid (JA-L); and Neural and Cognitive Engineering group, CAR, UPM-CSIC, CSIC, La Poveda - Arganda del Rey, Spain (ER)
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Delli Pizzi S, Franciotti R, Taylor JP, Esposito R, Tartaro A, Thomas A, Onofrj M, Bonanni L. Structural Connectivity is Differently Altered in Dementia with Lewy Body and Alzheimer's Disease. Front Aging Neurosci 2015; 7:208. [PMID: 26578952 PMCID: PMC4629464 DOI: 10.3389/fnagi.2015.00208] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 10/16/2015] [Indexed: 12/31/2022] Open
Abstract
The structural connectivity within cortical areas and between cortical and subcortical structures was investigated in dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD). We hypothesized that white matter (WM) tracts, which are linked to visual, attentional, and mnemonic functions, would be differentially and selectively affected in DLB as compared to AD and age-matched control subjects. Structural tensor imaging and diffusion tensor imaging (DTI) were performed on 14 DLB patients, 14 AD patients, and 15 controls. DTI metrics related to WM damage were assessed within tracts reconstructed by FreeSurfer’s TRActs Constrained by UnderLying Anatomy pipeline. Correlation analysis between WM and gray matter (GM) metrics was performed to assess whether the structural connectivity alteration in AD and DLB could be secondary to GM neuronal loss or a consequence of direct WM injury. Anterior thalamic radiation (ATR) and cingulum-cingulate gyrus were altered in DLB, whereas cingulum-angular bundle (CAB) was disrupted in AD. In DLB patients, secondary axonal degeneration within ATR was found in relation to microstructural damage within medio-dorsal thalamus, whereas axonal degeneration within CAB was related to precuneus thinning. WM alteration within the uncinate fasciculus was present in both groups of patients and was related to frontal and to temporal thinning in DLB and AD, respectively. We found structural connectivity alterations within fronto-thalamic and fronto-parietal (precuneus) network in DLB whereas, in contrast, disruption of structural connectivity of mnemonic pathways was present in AD. Furthermore, the high correlation between GM and WM metrics suggests that the structural connectivity alteration in DLB could be linked to GM neuronal loss rather than by direct WM injury. Thus, this finding supports the key role of cortical and subcortical atrophy in DLB.
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Affiliation(s)
- Stefano Delli Pizzi
- Department of Neuroscience, Imaging and Clinical Sciences, Aging Research Centre (CeSI), G. d'Annunzio University , Chieti , Italy ; Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
| | - Raffaella Franciotti
- Department of Neuroscience, Imaging and Clinical Sciences, Aging Research Centre (CeSI), G. d'Annunzio University , Chieti , Italy ; Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
| | - John-Paul Taylor
- Institute for Ageing and Health, Newcastle University , Newcastle upon Tyne , UK
| | - Roberto Esposito
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
| | - Armando Tartaro
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
| | - Astrid Thomas
- Department of Neuroscience, Imaging and Clinical Sciences, Aging Research Centre (CeSI), G. d'Annunzio University , Chieti , Italy ; Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
| | - Marco Onofrj
- Department of Neuroscience, Imaging and Clinical Sciences, Aging Research Centre (CeSI), G. d'Annunzio University , Chieti , Italy ; Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
| | - Laura Bonanni
- Department of Neuroscience, Imaging and Clinical Sciences, Aging Research Centre (CeSI), G. d'Annunzio University , Chieti , Italy ; Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies (ITAB), G. d'Annunzio University , Chieti , Italy
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Peraza LR, Colloby SJ, Firbank MJ, Greasy GS, McKeith IG, Kaiser M, O'Brien J, Taylor J. Resting state in Parkinson's disease dementia and dementia with Lewy bodies: commonalities and differences. Int J Geriatr Psychiatry 2015; 30:1135-46. [PMID: 26270627 PMCID: PMC4737212 DOI: 10.1002/gps.4342] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 07/13/2015] [Accepted: 07/14/2015] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) are two dementias with overlapping phenotypes. Clinically, these are differentiated by the one-year precedence rule between the onset of dementia with respect to Parkinsonism. In this report we aimed to find differences between DLB and PDD in functional connectivity (FC) using resting state functional magnetic resonance imaging, which we hypothesised would reflect the underlying pathological differences between DLB and PDD. METHODS The study cohort comprised of 18 patients with DLB, 12 with PDD and 17 healthy control (HC) groups. Eight cortical and four subcortical seeds were chosen, and time series extracted to estimate correlation maps. We also implemented a voxel-based morphometry (VBM) analysis to assess regional grey matter differences. FC analysis was corrected for age, sex and regional grey matter differences. RESULTS The FC analysis showed greater alterations in DLB than in PDD for seeds placed within the fronto-parietal network (FPN), whilst in contrast, for the supplementary motor area seed FC alterations were more apparent in PDD than in DLB. However, when comparing DLB and PDD, no significant differences were found. In addition, VBM analysis revealed greater atrophy in PDD than HC and DLB in the bilateral motor cortices and precuneus respectively. CONCLUSIONS PDD and DLB demonstrate similar FC alterations in the brain. However, attention- and motor-related seeds revealed subtle differences between both conditions when compared with HC, which may relate to the neuropathology and chronological precedence of core symptoms in the Lewy body dementias.
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Affiliation(s)
- Luis R. Peraza
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK,Institute of Ageing, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - Sean J. Colloby
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - Michael J. Firbank
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - G. Shirmin Greasy
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - Ian G. McKeith
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - Marcus Kaiser
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK,Interdisciplinary Computing and Complex BioSystems (ICOS) Research Group, School of Computing ScienceNewcastle UniversityNewcastle upon TyneUK
| | - John O'Brien
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK,Department of Psychiatry, Cambridge Biomedical CampusUniversity of Cambridge School of Clinical MedicineCambridgeUK
| | - John‐Paul Taylor
- Institute of Neuroscience, Campus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
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van Dellen E, de Waal H, van der Flier WM, Lemstra AW, Slooter AJ, Smits LL, van Straaten EC, Stam CJ, Scheltens P. Loss of EEGNetwork Efficiency Is Related to Cognitive Impairment in Dementia With Lewy Bodies. Mov Disord 2015; 30:1785-93. [DOI: 10.1002/mds.26309] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 05/14/2015] [Accepted: 05/22/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Edwin van Dellen
- Alzheimer Center and Department of Neurology; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
- Department of Clinical Neurophysiology and MEG Center; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
- Department of Intensive Care Medicine; Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
- Department of Psychiatry; Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
| | - Hanneke de Waal
- Alzheimer Center and Department of Neurology; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
| | - Wiesje M. van der Flier
- Alzheimer Center and Department of Neurology; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
- Department of Epidemiology and Biostatistics; VU University Medical Center; Amsterdam The Netherlands
| | - Afina W. Lemstra
- Alzheimer Center and Department of Neurology; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
| | - Arjen J.C. Slooter
- Department of Intensive Care Medicine; Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
| | - Lieke L. Smits
- Alzheimer Center and Department of Neurology; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
| | - Elisabeth C.W. van Straaten
- Department of Clinical Neurophysiology and MEG Center; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
| | - Cornelis J. Stam
- Department of Clinical Neurophysiology and MEG Center; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
| | - Philip Scheltens
- Alzheimer Center and Department of Neurology; Neuroscience Campus Amsterdam; VU University Medical Center; Amsterdam The Netherlands
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Franciotti R, Delli Pizzi S, Perfetti B, Tartaro A, Bonanni L, Thomas A, Weis L, Biundo R, Antonini A, Onofrj M. Default mode network links to visual hallucinations: A comparison between Parkinson's disease and multiple system atrophy. Mov Disord 2015; 30:1237-47. [PMID: 26094856 DOI: 10.1002/mds.26285] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 05/06/2015] [Accepted: 05/06/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Studying default mode network activity or connectivity in different parkinsonisms, with or without visual hallucinations, could highlight its roles in clinical phenotypes' expression. Multiple system atrophy is the archetype of parkinsonism without visual hallucinations, variably appearing instead in Parkinson's disease (PD). We aimed to evaluate default mode network functions in multiple system atrophy in comparison with PD. METHODS Functional magnetic resonance imaging evaluated default mode network activity and connectivity in 15 multiple system atrophy patients, 15 healthy controls, 15 early PD patients matched for disease duration, 30 severe PD patients (15 with and 15 without visual hallucinations), matched with multiple system atrophy for disease severity. Cortical thickness and neuropsychological evaluations were also performed. RESULTS Multiple system atrophy had reduced default mode network activity compared with controls and PD with hallucinations, and no differences with PD (early or severe) without hallucinations. In PD with visual hallucinations, activity and connectivity was preserved compared with controls and higher than in other groups. In early PD, connectivity was lower than in controls but higher than in multiple system atrophy and severe PD without hallucinations. Cortical thickness was reduced in severe PD, with and without hallucinations, and correlated only with disease duration. Higher anxiety scores were found in patients without hallucinations. CONCLUSIONS Default mode network activity and connectivity was higher in PD with visual hallucinations and reduced in multiple system atrophy and PD without visual hallucinations. Cortical thickness comparisons suggest that functional, rather than structural, changes underlie the activity and connectivity differences.
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Affiliation(s)
- Raffaella Franciotti
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy.,ITAB, "G. d'Annunzio" University Foundation, Chieti, Italy
| | - Stefano Delli Pizzi
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy.,ITAB, "G. d'Annunzio" University Foundation, Chieti, Italy
| | - Bernardo Perfetti
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy
| | - Armando Tartaro
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy.,ITAB, "G. d'Annunzio" University Foundation, Chieti, Italy
| | - Laura Bonanni
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy
| | - Astrid Thomas
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy
| | - Luca Weis
- Department for Parkinson's Disease, "Fondazione Ospedale San Camillo", I.R.C.C.S, Venice, Italy
| | - Roberta Biundo
- Department for Parkinson's Disease, "Fondazione Ospedale San Camillo", I.R.C.C.S, Venice, Italy
| | - Angelo Antonini
- Department for Parkinson's Disease, "Fondazione Ospedale San Camillo", I.R.C.C.S, Venice, Italy
| | - Marco Onofrj
- Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University and Aging Research Centre, Ce.S.I., "G. d'Annunzio" University Foundation, Chieti, Italy
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Falasca NW, D'Ascenzo S, Di Domenico A, Onofrj M, Tommasi L, Laeng B, Franciotti R. Hemispheric lateralization in top-down attention during spatial relation processing: a Granger causal model approach. Eur J Neurosci 2015; 41:914-24. [PMID: 25704649 DOI: 10.1111/ejn.12846] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 12/16/2014] [Accepted: 12/31/2014] [Indexed: 11/29/2022]
Abstract
Magnetoencephalography was recorded during a matching-to-sample plus cueing paradigm, in which participants judged the occurrence of changes in either categorical (CAT) or coordinate (COO) spatial relations. Previously, parietal and frontal lobes were identified as key areas in processing spatial relations and it was shown that each hemisphere was differently involved and modulated by the scope of the attention window (e.g. a large and small cue). In this study, Granger analysis highlighted the patterns of causality among involved brain areas--the direction of information transfer ran from the frontal to the visual cortex in the right hemisphere, whereas it ran in the opposite direction in the left side. Thus, the right frontal area seems to exert top-down influence, supporting the idea that, in this task, top-down signals are selectively related to the right side. Additionally, for CAT change preceded by a small cue, the right frontal gyrus was not involved in the information transfer, indicating a selective specialization of the left hemisphere for this condition. The present findings strengthen the conclusion of the presence of a remarkable hemispheric specialization for spatial relation processing and illustrate the complex interactions between the lateralized parts of the neural network. Moreover, they illustrate how focusing attention over large or small regions of the visual field engages these lateralized networks differently, particularly in the frontal regions of each hemisphere, consistent with the theory that spatial relation judgements require a fronto-parietal network in the left hemisphere for categorical relations and on the right hemisphere for coordinate spatial processing.
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Affiliation(s)
- N W Falasca
- BIND - Behavioral Imaging and Neural Dynamics Center, University of Chieti-Pescara, Chieti, Italy
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Lowther ER, O'Brien JT, Firbank MJ, Blamire AM. Lewy body compared with Alzheimer dementia is associated with decreased functional connectivity in resting state networks. Psychiatry Res 2014; 223:192-201. [PMID: 25035300 DOI: 10.1016/j.pscychresns.2014.06.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 05/23/2014] [Accepted: 06/19/2014] [Indexed: 10/25/2022]
Abstract
Resting state functional magnetic resonance imaging (fMRI) was used to measure whole brain functional connectivity within specific networks hypothesised to be more affected in dementia with Lewy bodies (DLB) (a disease characterised by prominent attentional deficits, spontaneous motor features of parkinsonism and depression) than in Alzheimer׳s disease (AD) and controls. This study involved 68 subjects (15 DLB, 13 AD and 40 controls) who were scanned using resting state BOLD (blood-oxygen-level-dependent) fMRI on a 3T MRI scanner. Functional connectivity was measured using a model-free independent component analysis approach that consisted of temporally concatenating the resting state fMRI data of all study subjects and investigating group differences using a back-reconstruction procedure. Resting state functional connectivity was affected in the default mode, salience, executive and basal ganglia networks in DLB subjects compared with AD and controls. Functional connectivity was lower in DLB compared with AD and controls in these networks, except for the basal ganglia network, where connectivity was greater in DLB. No resting state networks showed less connectivity in AD compared with DLB or controls. Our results suggest that functional connectivity of resting state networks can identify differences between DLB and AD subjects that may help to explain why DLB subjects have more frequent attentional deficits, parkinsonian symptoms, and depression than those with AD.
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Affiliation(s)
- Eva R Lowther
- Institute for Ageing and Health and Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom
| | - John T O'Brien
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom; Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
| | - Michael J Firbank
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew M Blamire
- Institute for Cellular Medicine and Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom.
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Delli Pizzi S, Franciotti R, Taylor JP, Thomas A, Tartaro A, Onofrj M, Bonanni L. Thalamic Involvement in Fluctuating Cognition in Dementia with Lewy Bodies: Magnetic Resonance Evidences. Cereb Cortex 2014; 25:3682-9. [PMID: 25260701 PMCID: PMC4585510 DOI: 10.1093/cercor/bhu220] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dementia with Lewy bodies (DLB) is characterized by fluctuation in cognition and attention. Thalamocortical connectivity and integrity of thalami are central to attentional function. We hypothesize that DLB patients with marked and frequent fluctuating cognition (flCog) have a loss of thalamocortical connectivity, an intrinsic disruption to thalamic structure and imbalances in thalamic neurotransmitter levels. To test this, magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and proton MR spectroscopy on thalami were performed on 16 DLB, 16 Alzheimer's disease (AD) and 13 healthy subjects. MRI and DTI were combined to subdivide thalami according to their cortical connectivity and to investigate microstructural changes in connectivity-defined thalamic regions. Compared with controls, lower N-acetyl-aspartate/total creatine (NAA/tCr) and higher total choline/total creatine (tCho/tCr) values were observed within thalami of DLB patients. tCho/tCr increase was found within right thalamus of DLB patients as compared with AD. This increase correlated with severity and frequency of flCog. As compared with controls, DLB patients showed bilateral damage within thalamic regions projecting to prefrontal and parieto-occipital cortices, whereas AD patients showed bilateral alteration within thalamic region projecting to temporal cortex. We posit that microstructural thalamic damage and cholinergic imbalance may be central to the etiology of flCog in DLB.
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Affiliation(s)
- Stefano Delli Pizzi
- Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and Institute for Advanced Biomedical Technologies (ITAB), "G. d'Annunzio" University, Chieti, Italy
| | - Raffaella Franciotti
- Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and Institute for Advanced Biomedical Technologies (ITAB), "G. d'Annunzio" University, Chieti, Italy
| | - John-Paul Taylor
- Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Astrid Thomas
- Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and
| | - Armando Tartaro
- Department of Neuroscience, Imaging and Clinical Sciences Institute for Advanced Biomedical Technologies (ITAB), "G. d'Annunzio" University, Chieti, Italy
| | - Marco Onofrj
- Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and
| | - Laura Bonanni
- Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and
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Disruption of Resting Functional Connectivity in Alzheimer’s Patients and At-Risk Subjects. Curr Neurol Neurosci Rep 2014; 14:491. [DOI: 10.1007/s11910-014-0491-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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74
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Relevance of subcortical visual pathways disruption to visual symptoms in dementia with Lewy bodies. Cortex 2014; 59:12-21. [PMID: 25113955 DOI: 10.1016/j.cortex.2014.07.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/14/2014] [Accepted: 07/10/2014] [Indexed: 11/21/2022]
Abstract
Visual hallucinations represent a core diagnostic criterion for dementia with Lewy bodies (DLB). We hypothesized that thalamic regions, which are critically involved in the modulation of visual transmission, may be differentially disrupted in DLB as compared to Alzheimer's Disease (AD) and that these deficits could relate to visual dysfunction in DLB patients. Magnetic Resonance and Diffusion Tensor Imaging (DTI) were performed with a 3 T scanner on a sample population of 15 DLB patients, 15 AD patients and 13 healthy volunteers. Regional thalamic micro-structural changes were assessed by parcelling the thalamus based on its connectivity to cortex and to amygdala and by measuring the mean diffusivity (MD) in each connectivity-defined sub-region. Micro-structural grey matter damage associated to higher MD values was found bilaterally in DLB compared to controls in the sub-regions projecting from thalamus to prefrontal and parieto-occipital cortices. Right thalamic sub-region projecting to amygdala and left thalamic sub-region projecting to motor cortex were also affected in DLB compared to controls. Higher MD values were found bilaterally in AD compared to controls in the thalamic sub-regions projecting to temporal cortex. Specific comparison between the two forms of dementia found differences: the sub-regions which project from thalamus to parieto-occipital cortex and to amygdala showed higher MD values in DLB compared to AD patients. In DLB patients, correlation analysis showed a significant correlation between NPI hallucinations item scores and MD values in the right thalamic sub-regions projecting to parietal and occipital cortices. The present study demonstrates how thalamic connectivity alterations between higher and lower visual areas may be relevant in explaining visual hallucinations in DLB.
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75
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Mulert C. Simultaneous EEG and fMRI: towards the characterization of structure and dynamics of brain networks. DIALOGUES IN CLINICAL NEUROSCIENCE 2014. [PMID: 24174908 PMCID: PMC3811108 DOI: 10.31887/dcns.2013.15.3/cmulert] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Progress in the understanding of normal and disturbed brain function is critically dependent on the methodological approach that is applied. Both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are extremely efficient methods for the assessment of human brain function. The specific appeal of the combination is related to the fact that both methods are complementary in terms of basic aspects: EEG is a direct measurement of neural mass activity and provides high temporal resolution. FMRI is an indirect measurement of neural activity and based on hemodynamic changes, and offers high spatial resolution. Both methods are very sensitive to changes of synaptic activity, suggesting that with simultaneous EEG and fMRI the same neural events can be characterized with both high temporal and spatial resolution. Since neural oscillations that can be assessed with EEG are a key mechanism for multi-site communication in the brain, EEG-fMRI can offer new insights into the connectivity mechanisms of brain networks.
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Affiliation(s)
- Christoph Mulert
- University Medical Center Hamburg-Eppendorf, Department of Psychiatry and Psychotherapy, Psychiatry Neuroimaging Branch, Hamburg, Germany
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76
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Mak E, Su L, Williams GB, O'Brien JT. Neuroimaging characteristics of dementia with Lewy bodies. ALZHEIMERS RESEARCH & THERAPY 2014; 6:18. [PMID: 25031634 PMCID: PMC4055038 DOI: 10.1186/alzrt248] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review summarises the findings and applications from neuroimaging studies in dementia with Lewy bodies (DLB), highlighting key differences between DLB and other subtypes of dementia. We also discuss the increasingly important role of imaging biomarkers in differential diagnosis and outline promising areas for future research in DLB. DLB shares common clinical, neuropsychological and pathological features with Parkinson’s disease dementia and other dementia subtypes, such as Alzheimer’s disease. Despite the development of consensus diagnostic criteria, the sensitivity for differential diagnosis of DLB in clinical practice remains low and many DLB patients will be misdiagnosed. The importance of developing accurate imaging markers in dementia is highlighted by the potential for treatments targeting specific molecular abnormalities as well as the responsiveness to cholinesterase inhibitors and marked neuroleptic sensitivity of DLB. We review various brain imaging techniques that have been applied to investigate DLB, including the characteristic nigrostriatal degeneration in DLB using positron emission tomography (PET) and single-photon emission computed tomography (SPECT) tracers. Dopamine transporter loss has proven to reliably differentiate DLB from other dementias and has been incorporated into the revised clinical diagnostic criteria for DLB. To date, this remains the 'gold standard' for diagnostic imaging of DLB. Regional cerebral blood flow, 18 F-fluorodeoxygluclose-PET and SPECT have also identified marked deficits in the occipital regions with relative sparing of the medial temporal lobe when compared to Alzheimer’s disease. In addition, structural, diffusion, and functional magnetic resonance imaging techniques have shown alterations in structure, white matter integrity, and functional activity in DLB. We argue that the multimodal identification of DLB-specific biomarkers has the potential to improve ante-mortem diagnosis and contribute to our understanding of the pathological background of DLB and its progression.
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Affiliation(s)
- Elijah Mak
- Department of Psychiatry, University of Cambridge School of Clinical Medicine, Box 189, Level E4 Cambridge Biomedical Campus, Cambridge CB2 0SP, UK
| | - Li Su
- Department of Psychiatry, University of Cambridge School of Clinical Medicine, Box 189, Level E4 Cambridge Biomedical Campus, Cambridge CB2 0SP, UK
| | | | - John T O'Brien
- Department of Psychiatry, University of Cambridge School of Clinical Medicine, Box 189, Level E4 Cambridge Biomedical Campus, Cambridge CB2 0SP, UK
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77
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fMRI resting state networks and their association with cognitive fluctuations in dementia with Lewy bodies. NEUROIMAGE-CLINICAL 2014; 4:558-65. [PMID: 24818081 PMCID: PMC3984441 DOI: 10.1016/j.nicl.2014.03.013] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 03/27/2014] [Accepted: 03/27/2014] [Indexed: 11/26/2022]
Abstract
Cognitive fluctuations are a core symptom in dementia with Lewy bodies (DLB) and may relate to pathological alterations in distributed brain networks. To test this we analysed resting state fMRI changes in a cohort of fluctuating DLB patients (n = 16) compared with age matched controls (n = 17) with the aim of finding functional connectivity (FC) differences between these two groups and whether these associate with cognitive fluctuations in DLB. Resting state networks (RSNs) were estimated using independent component analysis and FC between the RSN maps and the entirety of the brain was assessed using dual regression. The default mode network (DMN) appeared unaffected in DLB compared to controls but significant cluster differences between DLB and controls were found for the left fronto-parietal, temporal, and sensory–motor networks. Desynchronization of a number of cortical and subcortical areas related to the left fronto-parietal network was associated with the severity and frequency of cognitive fluctuations. Our findings provide empirical evidence for the potential role of attention–executive networks in the aetiology of this core symptom in DLB. We report resting state network (RSN) alterations in dementia with Lewy bodies (DLB). The default mode network was intact in DLB compared to healthy controls (HC). Fronto-parietal, temporal, and sensory–motor RSNs showed differences (DLB < HC). The left fronto-parietal network (FPN) correlated with cognitive fluctuations in DLB. The FPN therefore may be a potential marker for cognitive fluctuations in DLB.
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78
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Wojtowicz M, Mazerolle EL, Bhan V, Fisk JD. Altered functional connectivity and performance variability in relapsing-remitting multiple sclerosis. Mult Scler 2014; 20:1453-63. [PMID: 24619937 DOI: 10.1177/1352458514524997] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Patients with multiple sclerosis (MS) demonstrate slower and more variable performance on attention and information processing speed tasks. Greater variability in cognitive task performance has been shown to be an important predictor of neurologic status and provides a unique measure of cognitive performance in MS patients. OBJECTIVES This study investigated alterations in resting-state functional connectivity associated with within-person performance variability in MS patients. METHODS Relapsing-remitting MS patients and matched healthy controls completed structural MRI and resting-state fMRI (rsfMRI) scans, as well as tests of information processing speed. Performance variability was calculated from reaction time tests of processing speed. rsfMRI connectivity was investigated within regions associated with the default mode network (DMN). Relations between performance variability and functional connectivity in the DMN within MS patients were evaluated. RESULTS MS patients demonstrated greater reaction time performance variability compared to healthy controls (p<0.05). For MS patients, more stable performance on a complex processing speed task was associated with greater resting-state connectivity between the ventral medial prefrontal cortex and the frontal pole. CONCLUSIONS Among MS patients, greater functional connectivity between medial prefrontal and frontal pole regions appears to facilitate performance stability on complex speed-dependent information processing tasks.
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Affiliation(s)
| | - Erin L Mazerolle
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Canada
| | - Virender Bhan
- Department of Medicine, Dalhousie University, Canada
| | - John D Fisk
- Department of Psychology and Neuroscience, Dalhousie University, Canada Department of Medicine, Dalhousie University, Canada Psychology, QEII Health Sciences Centre, Canada Department of Psychiatry, Dalhousie University, Canada
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79
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Poza J, Gómez C, García M, Corralejo R, Fernández A, Hornero R. Analysis of neural dynamics in mild cognitive impairment and Alzheimer's disease using wavelet turbulence. J Neural Eng 2014; 11:026010. [PMID: 24608272 DOI: 10.1088/1741-2560/11/2/026010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Current diagnostic guidelines encourage further research for the development of novel Alzheimer's disease (AD) biomarkers, especially in its prodromal form (i.e. mild cognitive impairment, MCI). Magnetoencephalography (MEG) can provide essential information about AD brain dynamics; however, only a few studies have addressed the characterization of MEG in incipient AD. APPROACH We analyzed MEG rhythms from 36 AD patients, 18 MCI subjects and 27 controls, introducing a new wavelet-based parameter to quantify their dynamical properties: the wavelet turbulence. MAIN RESULTS Our results suggest that AD progression elicits statistically significant regional-dependent patterns of abnormalities in the neural activity (p < 0.05), including a progressive loss of irregularity, variability, symmetry and Gaussianity. Furthermore, the highest accuracies to discriminate AD and MCI subjects from controls were 79.4% and 68.9%, whereas, in the three-class setting, the accuracy reached 67.9%. SIGNIFICANCE Our findings provide an original description of several dynamical properties of neural activity in early AD and offer preliminary evidence that the proposed methodology is a promising tool for assessing brain changes at different stages of dementia.
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Affiliation(s)
- Jesús Poza
- Biomedical Engineering Group, Department TSCIT, ETS. Ingenieros de Telecomunicación, University of Valladolid, Valladolid, Spain. IMUVA, Instituto de Investigación en Matemáticas, University of Valladolid, Valladolid, Spain. INCYL, Instituto de Neurociencias de Castilla y León, Salamanca, Spain
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80
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Structural alteration of the dorsal visual network in DLB patients with visual hallucinations: a cortical thickness MRI study. PLoS One 2014; 9:e86624. [PMID: 24466177 PMCID: PMC3900597 DOI: 10.1371/journal.pone.0086624] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/15/2013] [Indexed: 11/19/2022] Open
Abstract
Visual hallucinations (VH) represent one of the core features in discriminating dementia with Lewy bodies (DLB) from Alzheimer’s Disease (AD). Previous studies reported that in DLB patients functional alterations of the parieto-occipital regions were correlated with the presence of VH. The aim of our study was to assess whether morphological changes in specific cortical regions of DLB could be related to the presence and severity of VH. We performed a cortical thickness analysis on magnetic resonance imaging data in a cohort including 18 DLB patients, 15 AD patients and 14 healthy control subjects. Relatively to DLB group, correlation analysis between the cortical thickness and the Neuropsychiatric Inventory (NPI) hallucination item scores was also performed. Cortical thickness was reduced bilaterally in DLB compared to controls in the pericalcarine and lingual gyri, cuneus, precuneus, superior parietal gyrus. Cortical thinning was found bilaterally in AD compared to controls in temporal cortex including the superior and middle temporal gyrus, part of inferior temporal cortex, temporal pole and insula. Inferior parietal and supramarginal gyri were also affected bilaterally in AD as compared to controls. The comparison between DLB and AD evidenced cortical thinning in DLB group in the right posterior regions including superior parietal gyrus, precuneus, cuneus, pericalcarine and lingual gyri. Furthermore, the correlation analysis between cortical thickness and NPI hallucination item scores showed that the structural alteration in the dorsal visual regions including superior parietal gyrus and precuneus closely correlated with the occurrence and severity of VH. We suggest that structural changes in key regions of the dorsal visual network may play a crucial role in the physiopathology of VH in DLB patients.
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81
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Taylor JP, Colloby SJ, McKeith IG, O'Brien JT. Covariant perfusion patterns provide clues to the origin of cognitive fluctuations and attentional dysfunction in dementia with Lewy bodies. Int Psychogeriatr 2013; 25:1917-28. [PMID: 24148774 PMCID: PMC3819183 DOI: 10.1017/s1041610213001488] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 07/24/2013] [Accepted: 07/24/2013] [Indexed: 01/19/2023]
Abstract
BACKGROUND Fluctuating cognition (FC), particularly in attention, is a core and defining symptom in dementia with Lewy bodies (DLB) but is seen much less frequently in Alzheimer's dementia (AD). However, its neurobiological origin is poorly understood. The aim of our study was therefore to characterize perfusion patterns in DLB patients that are associated with the severity and frequency of FC as measured both clinically and using objective neuropsychological assessments. METHODS Spatial covariance analyses were applied to data derived from single photon emission computed tomography (SPECT) HMPAO brain imaging in 19 DLB and 23 AD patients. Patients underwent clinical assessment of their FC and cognitive function as well as objective testing of their attention. RESULTS Covariant perfusion principal components (PCs) were not associated with either FC or cognitive or attentional measures in AD. However, in DLB patients, the second PC (defined as DLB-cognitive motor pattern, DLB-PCI2) which was characterized by bilateral relative increases in cerebellum, basal ganglia, and supplementary motor areas and widespread bilateral decreases in parietal regions, positively correlated with poorer cognitive function, increased FC and worse attentional function measured both clinically and neurophysiologically (p < 0.05) as well as with the severity of bradykinesia (p = 0.04). CONCLUSIONS FC in DLB appears distinct from those seen in AD, and likely to be driven by internal neurobiological perturbations in brain circuitry as evidenced using spatial covariance analyses of cerebral perfusion. FC and certain aspects of attentional dysfunction in DLB may, in part, depend upon both distributed motor and non-motor networks.
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Affiliation(s)
- John-Paul Taylor
- Institute for Ageing and Health, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Sean J. Colloby
- Institute for Ageing and Health, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Ian G. McKeith
- Institute for Ageing and Health, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - John T. O'Brien
- Institute for Ageing and Health, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne, UK
- Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, UK
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82
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Hsiao FJ, Chen WT, Wang YJ, Yan SH, Lin YY. Altered source-based EEG coherence of resting-state sensorimotor network in early-stage Alzheimer's disease compared to mild cognitive impairment. Neurosci Lett 2013; 558:47-52. [PMID: 24211686 DOI: 10.1016/j.neulet.2013.10.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 10/27/2013] [Accepted: 10/29/2013] [Indexed: 11/24/2022]
Abstract
Although the altered coherence between cortical areas in Alzheimer's disease (AD) has been widely studied, it remains unclear whether the source-based coherence measures within sensorimotor network show significant difference between mild cognitive impairment (MCI) and AD. In the present study, resting-state electroencephalographic signals were recorded from 21 MCI and 21 mild AD patients. The spectral power and coherence in the sensorimotor areas were analyzed using the minimum norm estimate (MNE) combined with fast Fourier transform and coherence analysis in delta (1-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (13-25 Hz), and gamma (25-40 Hz) bands. Our results indicated that source-based coherence in AD showed increased delta coherences between the bilateral precentral, left supplementary motor area (SMA) and right precentral, and left SMA and right postcentral areas. However, no significant difference of spectral powers was observed between AD and MCI. To conclude, the phenotype conversion from MCI to AD may be associated with an altered connectivity of the sensorimotor cortical network. This is a promising finding; however, further large-scale studies are needed.
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Affiliation(s)
- Fu-Jung Hsiao
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan; Department of Neurology, Taipei City Hospital, Taipei, Taiwan; Laboratory of Neurophysiology, Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan.
| | - Wei-Ta Chen
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yuh-Jen Wang
- Department of Neurology, Taipei City Hospital, Taipei, Taiwan
| | - Sui-Hing Yan
- Department of Neurology, Taipei City Hospital, Taipei, Taiwan
| | - Yung-Yang Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.
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83
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Cohort study of prevalence and phenomenology of tremor in dementia with Lewy bodies. J Neurol 2013; 260:1731-42. [PMID: 23400498 PMCID: PMC3705145 DOI: 10.1007/s00415-013-6853-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 01/21/2013] [Accepted: 01/22/2013] [Indexed: 10/27/2022]
Abstract
To study prevalence, specific patterns and response to treatment of tremor in dementia with Lewy bodies (DLB), in comparison with other tremulous disorders prevalence, qualitative and quantitative features of tremor were studied in an incident cohort of 67 dopaminergic treatment naive DLB, 111 Parkinson's Disease (PD) and 34 Essential Tremor (ET) patients. Tremulous DLB patients (tDLB) were compared with tremulous PD (tPD) and ET patients and followed for 2 years. Double blind placebo-controlled acute drug challenge with L-Dopa and alcohol was performed in all ET, 24 tDLB and 27 tPD. Effects of dopaminergic chronic treatment in all tDLB and tPD patients and primidone in 8 tDLB were also assessed. Tremor occurred in 44.76 % of DLB patients. The tDLB patients presented a complex pattern of mixed tremors, characterized by rest and postural/action tremor, including walking tremor and standing overflow in 50 % tDLB. Standing tremor with overflow was characteristic of tDLB (p < 0.001). Head tremor was more frequent in tDLB than tPD and ET (p = 0.001). The tDLB tremors were reduced by acute and chronic dopaminergic treatments (p < 0.01) but not by alcohol or primidone. Tremor occurs commonly in DLB patients with a complex mixed tremor pattern which shows a significant response to acute and chronic dopaminergic treatments. Recognizing that there is a clinical category of tremulous DLB may help the differential diagnosis of tremors.
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