1
|
Liu X, Shi L, Li E, Jia S. Associations of hearing loss and structural changes in specific cortical regions: a Mendelian randomization study. Cereb Cortex 2024; 34:bhae084. [PMID: 38494888 DOI: 10.1093/cercor/bhae084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 03/19/2024] Open
Abstract
INTRODUCTION Previous studies have suggested a correlation between hearing loss (HL) and cortical alterations, but the specific brain regions that may be affected are unknown. METHODS Genome-wide association study (GWAS) data for 3 subtypes of HL phenotypes, sensorineural hearing loss (SNHL), conductive hearing loss, and mixed hearing loss, were selected as exposures, and GWAS data for brain structure-related traits were selected as outcomes. The inverse variance weighted method was used as the main estimation method. RESULTS Negative associations were identified between genetically predicted SNHL and brain morphometric indicators (cortical surface area, cortical thickness, or volume of subcortical structures) in specific brain regions, including the bankssts (β = -0.006 mm, P = 0.016), entorhinal cortex (β = -4.856 mm2, P = 0.029), and hippocampus (β = -24.819 cm3, P = 0.045), as well as in brain regions functionally associated with visual perception, including the pericalcarine (β = -10.009 cm3, P = 0.013). CONCLUSION Adaptive changes and functional remodeling of brain structures occur in patients with genetically predicted HL. Brain regions functionally associated with auditory perception, visual perception, and memory function are the main brain regions vulnerable in HL.
Collapse
Affiliation(s)
- Xiaoduo Liu
- Department of Neurology & Innovation Center for Neurological Disorders, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, 45 Changchun Street, Xicheng District, Beijing, 100053, China
| | - Lubo Shi
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, National Clinical Research Center for Digestive Diseases, Beijing Digestive Disease Center, 95 Yong'an Road, Xicheng District, Beijing, 100050, China
| | - Enze Li
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China
| | - Shuo Jia
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China
| |
Collapse
|
2
|
Habich A, Wahlund LO, Westman E, Dierks T, Ferreira D. (Dis-)Connected Dots in Dementia with Lewy Bodies-A Systematic Review of Connectivity Studies. Mov Disord 2023; 38:4-15. [PMID: 36253921 PMCID: PMC10092805 DOI: 10.1002/mds.29248] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/04/2022] [Accepted: 09/12/2022] [Indexed: 01/21/2023] Open
Abstract
Studies on dementia with Lewy bodies (DLB) have mainly focused on the degeneration of distinct cortical and subcortical regions related to the deposition of Lewy bodies. In view of the proposed trans-synaptic spread of the α-synuclein pathology, investigating the disease only in this segregated fashion would be detrimental to our understanding of its progression. In this systematic review, we summarize findings on structural and functional brain connectivity in DLB, as connectivity measures may offer better insights on how the brain is affected by the spread of the pathology. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched Web of Science, PubMed, and SCOPUS for relevant articles published up to November 1, 2021. Of 1215 identified records, we selected and systematically reviewed 53 articles that compared connectivity features between patients with DLB and healthy controls. Structural and functional magnetic resonance imaging, positron emission tomography, single-positron emission computer tomography, and electroencephalography assessments of patients revealed widespread abnormalities within and across brain networks in DLB. Frontoparietal, default mode, and visual networks and their connections to other brain regions featured the most consistent disruptions, which were also associated with core clinical features and cognitive impairments. Furthermore, graph theoretical measures revealed disease-related decreases in local and global network efficiency. This systematic review shows that structural and functional connectivity characteristics in DLB may be particularly valuable at early stages, before overt brain atrophy can be observed. This knowledge may help improve the diagnosis and prognosis in DLB as well as pinpoint targets for future disease-modifying treatments. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Annegret Habich
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Lars-Olof Wahlund
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Eric Westman
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroimaging, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Thomas Dierks
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Daniel Ferreira
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
3
|
Montaser-Kouhsari L, Young CB, Poston KL. Neuroimaging approaches to cognition in Parkinson's disease. PROGRESS IN BRAIN RESEARCH 2022; 269:257-286. [PMID: 35248197 DOI: 10.1016/bs.pbr.2022.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
While direct visualization of Lewy body accumulation within the brain is not yet possible in living Parkinson's disease patients, brain imaging studies offer insights into how the buildup of Lewy body pathology impacts different regions of the brain. Unlike biological biomarkers and purely behavioral research, these brain imaging studies therefore offer a unique opportunity to relate brain localization to cognitive function and dysfunction in living patients. Magnetic resonance imaging studies can reveal physical changes in brain structure as they relate to different cognitive domains and task specific impairments. Functional imaging studies use a combination of task and resting state magnetic resonance imaging, as well as positron emission tomography and single photon emission computed tomography, and can be used to determine changes in blood flow, neuronal activation and neurochemical changes in the brain associated with PD cognition and cognitive impairments. Other unique advantages to brain imaging studies are the ability to monitor changes in brain structure and function longitudinally as patients progress and the ability to study changes in brain function when patients are exposed to different pharmacological manipulations. This is particularly true when assessing the effects of dopaminergic replacement therapy on cognitive function in Parkinson's disease patients. Together, this chapter will describe imaging studies that have helped identify structural and functional brain changes associated with cognition, cognitive impairment, and dementia in Parkinson's disease.
Collapse
Affiliation(s)
- Leila Montaser-Kouhsari
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States
| | - Christina B Young
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States
| | - Kathleen L Poston
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States; Department of Neurosurgery, Stanford University, Stanford, CA, United States.
| |
Collapse
|
4
|
Sun M, Bao W, Huang C, Xia Z, Zhang C, Wang G, Wang R, Li J, Roux S, Li Q, Zou D, Ma K, Bao X. A Novel Probiotic Formula, BIOCG, Protects Against Alzheimer's-Related Cognitive Deficits via Regulation of Dendritic Spine Dynamics. Curr Alzheimer Res 2021; 18:558-572. [PMID: 34674621 DOI: 10.2174/1567205018666211022091110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 06/27/2021] [Accepted: 08/23/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND The brain-gut-microbiome axis has emerged as an important pathway through which perturbations in the gut and/or microbial microenvironment can impact neurological function. Such alterations have been implicated in a variety of neuropsychiatric disorders, includ- ing depression, anxiety, and Alzheimer's Disease (AD) and the use of probiotics as therapy for th- ese diseases remains promising. However, the mechanisms underlying the gut microenvironment's influence on disease pathogenesis and therapy remain unclear. OBJECTIVE The objective of this study is to investigate the effect of a novel probiotic formula, BIOCG, on cognitive function and pathobiological mechanisms, including amyloid processing and dendritic spine dynamics, in a mouse model of AD. METHODS BIOCG was administered for 3 months to 3xTg or 3xTg; Thy1-YFP AD mice and func- tional outcomes were assessed via behavioral testing and electrophysiology. Mechanisms relevant to AD pathogenesis including dendritic spine morphology and turnover, Amyloid Precursor Pro- tein (APP) processing and microglial phenotype were also evaluated. Finally, we sequenced fecal samples following probiotic treatment to assess the impact on gut microbial composition and corre- late the changes with the above described measures. RESULTS Mice treated with BIOCG demonstrated preserved cognitive abilities and stronger Long- Term Potentiation (LTP), spontaneous Excitatory Postsynaptic Currents (sEPSC), and glutamate-in- duced LTPs, indicative of functional and electrophysiological effects. Moreover, we observed atten- uated AD pathogenesis, including reduced Amyloid Beta (Aβ) burden, as well as more mature den- dritic spines in the BIOCG-treated. Our finding of changes in microglial number and phenotype in the treatment group suggests that this formulation may mediate its effects via attenuation of neu- roinflammation. Sequencing data confirmed that the gut microbiome in treated mice was more varied and harbored a greater proportion of "beneficial" bacteria. CONCLUSION Overall, our results indicate that treatment with BIOCG enhances microbial diversity and, through gut-brain axis interactions, attenuates neuroinflammation to produce histologic and functional improvement in AD pathogenesis.
Collapse
Affiliation(s)
- Miao Sun
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu. China
| | - Wenchenyang Bao
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu. China
| | - Chengyu Huang
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu. China
| | - Ziyue Xia
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu. China
| | - Changliang Zhang
- Jiangsu Biodep Biotechnology, 6-C2 Dongsheng West Road, Jiangyin 214400, Jiangsu. China
| | - Guangxian Wang
- Jiangsu Biodep Biotechnology, 6-C2 Dongsheng West Road, Jiangyin 214400, Jiangsu. China
| | - Runxin Wang
- Jiangsu Biodep Biotechnology, 6-C2 Dongsheng West Road, Jiangyin 214400, Jiangsu. China
| | - Jiangyu Li
- Admera Health, South Plainfield, NJ07080. United States
| | - Shaun Roux
- Probiotics Australia, 24-30 Blanck Street, Ormeau, QLD, 4208. Australia
| | - Qian Li
- Department of biology, College of Staten Island, Staten Island, NY 10314 . United States
| | - Dongmei Zou
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu. China
| | - Kai Ma
- Jiangsu Biodep Biotechnology, 6-C2 Dongsheng West Road, Jiangyin 214400, Jiangsu. China
| | - Xiaofeng Bao
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu. China
| |
Collapse
|
5
|
Mangalore S, Mukku SSR, Vankayalapati S, Sivakumar PT, Varghese M. Shape Profile of Corpus Callosum As a Signature to Phenotype Different Dementia. J Neurosci Rural Pract 2020; 12:185-192. [PMID: 33531781 PMCID: PMC7846348 DOI: 10.1055/s-0040-1716805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Background Phenotyping dementia is always a complex task for a clinician. There is a need for more practical biomarkers to aid clinicians. Objective The aim of the study is to investigate the shape profile of corpus callosum (CC) in different phenotypes of dementia. Materials and Methods Our study included patients who underwent neuroimaging in our facility as a part of clinical evaluation for dementia referred from Geriatric Clinic (2017-2018). We have analyzed the shape of CC and interpreted the finding using a seven-segment division. Results The sample included MPRAGE images of Alzheimer' dementia (AD) ( n = 24), posterior cortical atrophy- Alzheimer' dementia (PCA-AD) ( n = 7), behavioral variant of frontotemporal dementia (Bv-FTD) ( n = 17), semantic variant frontotemporal dementia (Sv-FTD) ( n = 11), progressive nonfluent aphasia (PNFA) ( n = 4), Parkinson's disease dementia (PDD) ( n = 5), diffuse Lewy body dementia ( n = 7), progressive supranuclear palsy (PSP) ( n = 3), and corticobasal degeneration (CBD) ( n = 3). We found in posterior dementias such as AD and PCA-AD that there was predominant atrophy of splenium of CC. In Bv-FTD, the genu and anterior half of the body of CC was atrophied, whereas in PNFA, PSP, PDD, and CBD there was atrophy of the body of CC giving a dumbbell like profile. Conclusion Our study findings were in agreement with the anatomical cortical regions involved in different phenotypes of dementia. Our preliminary study highlighted potential usefulness of CC in the clinical setting for phenotyping dementia in addition to clinical history and robust biomarkers.
Collapse
Affiliation(s)
- Sandhya Mangalore
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Shiva Shanker Reddy Mukku
- Geriatric Clinic and Services, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Sriharish Vankayalapati
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Palanimuthu Thangaraju Sivakumar
- Geriatric Clinic and Services, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Mathew Varghese
- Geriatric Clinic and Services, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, India
| |
Collapse
|
6
|
Donaghy PC, Firbank M, Petrides G, Lloyd J, Barnett N, Olsen K, Thomas AJ, O'Brien JT. Diffusion imaging in dementia with Lewy bodies: Associations with amyloid burden, atrophy, vascular factors and clinical features. Parkinsonism Relat Disord 2020; 78:109-115. [PMID: 32814228 DOI: 10.1016/j.parkreldis.2020.07.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 07/03/2020] [Accepted: 07/25/2020] [Indexed: 01/08/2023]
Abstract
INTRODUCTION White matter disruption in dementia has been linked to a variety of factors including vascular disease and cortical pathology. We aimed to examine the relationship between white matter changes on diffusion tensor imaging (DTI) in DLB and factors including vascular disease, structural atrophy and amyloid burden. METHODS Participants with DLB (n = 29), Alzheimer's disease (AD, n = 17) and healthy controls (n = 20) had clinical and neuropsychological assessments followed by structural and diffusion tensor 3T MRI and 18F-Florbetapir PET-CT imaging. Voxelwise statistical analysis of white matter fractional anisotropy (FA) and mean diffusivity (MD) was carried out using Tract-Based Spatial Statistics with family-wise error correction (p < 0.05). RESULTS DLB and AD groups demonstrated widespread increased MD and decreased FA when compared with controls. There were no differences between the DLB and AD groups. In DLB, increased MD and decreased FA correlated with decreased grey matter and hippocampal volumes as well as vascular disease. There was no correlation with cortical florbetapir SUVR. The relationship between DTI changes and grey matter/hippocampal volumes remained after including Cumulative Illness Rating Scale-Geriatric vascular score as a covariate. CONCLUSIONS Widespread disruption of white matter tracts is present in DLB and is associated with vascular disease, reduced hippocampal volume and reduced grey matter volume, but not with cortical amyloid deposition. The mechanism behind the correlation observed between hippocampal volume and white matter tract disruption should be investigated in future cohorts using tau imaging, as hippocampal atrophy has been shown to correlate with tau deposition in DLB.
Collapse
Affiliation(s)
- Paul C Donaghy
- Translational and Clinical Research Institute, Newcastle University, UK.
| | - Michael Firbank
- Translational and Clinical Research Institute, Newcastle University, UK
| | - George Petrides
- Nuclear Medicine Department, Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - Jim Lloyd
- Nuclear Medicine Department, Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - Nicola Barnett
- Translational and Clinical Research Institute, Newcastle University, UK
| | - Kirsty Olsen
- Translational and Clinical Research Institute, Newcastle University, UK
| | - Alan J Thomas
- Translational and Clinical Research Institute, Newcastle University, UK
| | | |
Collapse
|
7
|
Grosu AL, Frings L, Bentsalo I, Oehlke O, Brenner F, Bilger A, Fennell JT, Rothe T, Schneider-Fuchs S, Graf E, Schmoor C, Beck J, Becker G, Bock M, Egger K, Urbach H, Lahmann C, Popp I. Whole-brain irradiation with hippocampal sparing and dose escalation on metastases: neurocognitive testing and biological imaging (HIPPORAD) - a phase II prospective randomized multicenter trial (NOA-14, ARO 2015-3, DKTK-ROG). BMC Cancer 2020; 20:532. [PMID: 32513138 PMCID: PMC7281918 DOI: 10.1186/s12885-020-07011-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/27/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Whole brain radiation therapy (WBRT) is the standard therapy for multiple brain metastases. However, WBRT has a poor local tumor control and is associated with a decline in neurocognitive function (NCF). Aim of this trial is to assess the efficacy and safety of a new treatment method, the WBRT with hippocampus avoidance (HA) combined with the simultaneous integrated boost (SIB) on metastases/resection cavities (HA-WBRT+SIB). METHODS This is a prospective, randomized, two-arm phase II multicenter trial comparing the impact of HA on NCF after HA-WBRT+SIB versus WBRT+SIB in patients with multiple brain metastases. The study design is double-blinded. One hundred thirty two patients are to be randomized with a 1:1 allocation ratio. Patients between 18 and 80 years old are recruited, with at least 4 brain metastases of solid tumors and at least one, but not exceeding 10 metastases ≥5 mm. Patients must be in good physical condition and have no metastases/resection cavities in or within 7 mm of the hippocampus. Patients with dementia, meningeal disease, cerebral lymphomas, germ cell tumors, or small cell carcinomas are excluded. Previous irradiation and resection of metastases, as well as the number and size of metastases to be boosted have to comply with certain restrictions. Patients are randomized between the two treatment arms: HA-WBRT+SIB and WBRT+SIB. WBRT is to be performed with 30 Gy in 12 daily fractions and the SIB with 51 Gy/42 Gy in 12 daily fractions on 95% of volume for metastases/resection cavities. In the experimental arm, the dose to the hippocampi is restricted to 9 Gy in 98% of the volume and 17Gy in 2% of the volume. NCF testing is scheduled before WBRT, after 3 (primary endpoint), 9, 18 months and yearly thereafter. Clinical and imaging follow-ups are performed 6 and 12 weeks after WBRT, after 3, 9, 18 months and yearly thereafter. DISCUSSION This is a protocol of a randomized phase II trial designed to test a new strategy of WBRT for preventing cognitive decline and increasing tumor control in patients with multiple brain metastases. TRIAL REGISTRATION The HIPPORAD trial is registered with the German Clinical Trials Registry (DRKS00004598, registered 2 June 2016).
Collapse
Affiliation(s)
- Anca-Ligia Grosu
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
- German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lars Frings
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
- Present affiliation: Department of Nuclear Medicine, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Iryna Bentsalo
- Department of Psychosomatic Medicine and Psychotherapy, Faculty of Medicine, Medical Center - University of Freiburg, Hauptstraße 8, 79104, Freiburg, Germany
| | - Oliver Oehlke
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
- Present affiliation: Department of Radiation Oncology, Kliniken Maria Hilf GmbH Mönchengladbach, Mönchengladbach, Germany
| | - Franziska Brenner
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
- Present affiliation: Department of Radiation Oncology, Ortenau-Klinikum Offenburg-Gengenbach, Offenburg, Germany
| | - Angelika Bilger
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
| | - Jamina Tara Fennell
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
| | - Thomas Rothe
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
| | - Sabine Schneider-Fuchs
- Clinical Trials Unit, Faculty of Medicine, Medical Center - University of Freiburg, Elsässer Straße 2, 79110, Freiburg, Germany
| | - Erika Graf
- Institute of Medical Biometry and Statistics, Faculty of Medicine, Medical Center - University of Freiburg, Stefan-Meier-Str. 26, 79104, Freiburg, Germany
| | - Claudia Schmoor
- Clinical Trials Unit, Faculty of Medicine, Medical Center - University of Freiburg, Elsässer Straße 2, 79110, Freiburg, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Faculty of Medicine, Medical Center - University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - Gerhild Becker
- Department of Palliative Care, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany
| | - Michael Bock
- German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Physics, Department of Radiology, Faculty of Medicine, Medical Center - University of Freiburg, Killian Str. 5a, 79106, Freiburg, Germany
| | - Karl Egger
- Department of Neuroradiology, Faculty of Medicine, Medical Center - University of Freiburg, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Horst Urbach
- Department of Neuroradiology, Faculty of Medicine, Medical Center - University of Freiburg, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Claas Lahmann
- Department of Psychosomatic Medicine and Psychotherapy, Faculty of Medicine, Medical Center - University of Freiburg, Hauptstraße 8, 79104, Freiburg, Germany
| | - Ilinca Popp
- Department of Radiation Oncology, Faculty of Medicine, Medical Center - University of Freiburg, Robert-Koch-Str. 3, 79106, Freiburg, Germany.
| |
Collapse
|
8
|
PD and DLB: Brain imaging in Parkinson's disease and dementia with Lewy bodies. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:167-185. [DOI: 10.1016/bs.pmbts.2019.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
9
|
Blamire AM. MR approaches in neurodegenerative disorders. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 108:1-16. [PMID: 30538047 DOI: 10.1016/j.pnmrs.2018.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/22/2018] [Accepted: 11/01/2018] [Indexed: 06/09/2023]
Abstract
Neurodegenerative disease is the umbrella term which refers to a range of clinical conditions causing degeneration of neurons within the central nervous system leading to loss of brain function and eventual death. The most prevalent of these is Alzheimer's disease (AD), which affects approximately 50 million people worldwide and is predicted to reach 75 million by 2030. Neurodegenerative diseases can only be fully diagnosed at post mortem by neuropathological assessment of the type and distribution of protein deposits which characterise each different condition, but there is a clear role for imaging technologies in aiding patient diagnoses in life. Magnetic resonance imaging (MRI) and spectroscopy (MRS) techniques have been applied to study these conditions for many years. In this review, we consider the range of MR-based measurements and describe the findings in AD, but also contrast these with the second most common dementia, dementia with Lewy bodies (DLB). The most definitive observation is the major structural brain changes seen in AD using conventional T1-weighted (T1w) MRI, where medial temporal lobe structures are notably atrophied in most symptomatic patients with AD, but often preserved in DLB. Indeed these findings are sufficiently robust to have been incorporated into clinical diagnostic criteria. Diffusion tensor imaging (DTI) reveals widespread changes in tissue microstructure, with increased mean diffusivity and decreased fractional anisotropy reflecting the degeneration of the white matter structures. There are suggestions that there are subtle differences between AD and DLB populations. At the metabolic level, atrophy-corrected MRS demonstrates reduced density of healthy neurons in brain areas with altered perfusion and in regions known to show higher deposits of pathogenic proteins. As studies have moved from patients with advanced disease and clear dysfunction to patients with earlier presentation such as with mild cognitive impairment (MCI), which in some represents the first signs of their ensuing dementia, the ability of MRI to detect differences has been weaker and further work is still required, ideally in much larger cohorts than previously studied. The vast majority of imaging research in dementia populations has been univariate with respect to the MR-derived parameters considered. To date, none of these measurements has uniquely replicated the patterns of tissue involvement seen by neuropathology, and the ability of MR techniques to deliver a non-invasive diagnosis eludes us. Future opportunities may lie in combining MR and nuclear medicine approaches (position emission tomography, PET) to provide a more complete view of structural and metabolic changes. Such developments will require multi-variate analyses, possibly combined with artificial intelligence or deep learning algorithms, to enhance our ability to combine the array of image-derived information, genetic, gender and lifestyle factors.
Collapse
Affiliation(s)
- Andrew M Blamire
- Institute of Cellular Medicine and Centre for In Vivo Imaging, Newcastle University, UK.
| |
Collapse
|
10
|
|
11
|
Oppedal K, Engan K, Eftestøl T, Beyer M, Aarsland D. Classifying Alzheimer's disease, Lewy body dementia, and normal controls using 3D texture analysis in magnetic resonance images. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2016.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
12
|
Nedelska Z, Schwarz CG, Boeve BF, Lowe VJ, Reid RI, Przybelski SA, Lesnick TG, Gunter JL, Senjem ML, Ferman TJ, Smith GE, Geda YE, Knopman DS, Petersen RC, Jack CR, Kantarci K. White matter integrity in dementia with Lewy bodies: a voxel-based analysis of diffusion tensor imaging. Neurobiol Aging 2015; 36:2010-7. [PMID: 25863527 PMCID: PMC4433563 DOI: 10.1016/j.neurobiolaging.2015.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 11/21/2022]
Abstract
Many patients with dementia with Lewy bodies (DLB) have overlapping Alzheimer's disease (AD)-related pathology, which may contribute to white matter (WM) diffusivity alterations on diffusion tensor imaging (DTI). Consecutive patients with DLB (n = 30), age- and sex-matched AD patients (n = 30), and cognitively normal controls (n = 60) were recruited. All subjects underwent DTI, 18F 2-fluoro-deoxy-d-glucose, and (11)C Pittsburgh compound B positron emission tomography scans. DLB patients had reduced fractional anisotropy (FA) in the parietooccipital WM but not elsewhere compared with cognitively normal controls, and elevated FA in parahippocampal WM compared with AD patients, which persisted after controlling for β-amyloid load in DLB. The pattern of WM FA alterations on DTI was consistent with the more diffuse posterior parietal and occipital glucose hypometabolism of 2-fluoro-deoxy-d-glucose positron emission tomography in the cortex. DLB is characterized by a loss of parietooccipital WM integrity, independent of concomitant AD-related β-amyloid load. Cortical glucose hypometabolism accompanies WM FA alterations with a concordant pattern of gray and WM involvement in the parietooccipital lobes in DLB.
Collapse
Affiliation(s)
- Zuzana Nedelska
- Department of Radiology, Mayo Clinic, Rochester, MN, USA; Department of Neurology, Charles University in Prague, 2nd Faculty of Medicine and Motol University Hospital, Prague, The Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Brno, The Czech Republic
| | | | | | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Robert I Reid
- Department of Information Technology, Mayo Clinic, Rochester, MN, USA
| | | | - Timothy G Lesnick
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Jeffrey L Gunter
- Department of Information Technology, Mayo Clinic, Rochester, MN, USA
| | - Matthew L Senjem
- Department of Information Technology, Mayo Clinic, Rochester, MN, USA
| | - Tanis J Ferman
- Department of Psychiatry and Psychology, Mayo Clinic, Jacksonville, FL, USA
| | - Glenn E Smith
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
| | - Yonas E Geda
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, The Czech Republic; Department of Psychiatry and Psychology, Mayo Clinic, Scottsdale, AZ, USA; Department of Neurology, Mayo Clinic, Scottsdale, AZ, USA
| | | | | | | | - Kejal Kantarci
- Department of Radiology, Mayo Clinic, Rochester, MN, USA.
| |
Collapse
|
13
|
Classifying dementia using local binary patterns from different regions in magnetic resonance images. Int J Biomed Imaging 2015; 2015:572567. [PMID: 25873943 PMCID: PMC4385607 DOI: 10.1155/2015/572567] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/26/2015] [Accepted: 03/02/2015] [Indexed: 01/10/2023] Open
Abstract
Dementia is an evolving challenge in society, and no disease-modifying treatment exists. Diagnosis can be demanding and MR imaging may aid as a noninvasive method to increase prediction accuracy. We explored the use of 2D local binary pattern (LBP) extracted from FLAIR and T1 MR images of the brain combined with a Random Forest classifier in an attempt to discern patients with Alzheimer's disease (AD), Lewy body dementia (LBD), and normal controls (NC). Analysis was conducted in areas with white matter lesions (WML) and all of white matter (WM). Results from 10-fold nested cross validation are reported as mean accuracy, precision, and recall with standard deviation in brackets. The best result we achieved was in the two-class problem NC versus AD + LBD with total accuracy of 0.98 (0.04). In the three-class problem AD versus LBD versus NC and the two-class problem AD versus LBD, we achieved 0.87 (0.08) and 0.74 (0.16), respectively. The performance using 3DT1 images was notably better than when using FLAIR images. The results from the WM region gave similar results as in the WML region. Our study demonstrates that LBP texture analysis in brain MR images can be successfully used for computer based dementia diagnosis.
Collapse
|
14
|
Oishi K, Lyketsos CG. Alzheimer's disease and the fornix. Front Aging Neurosci 2014; 6:241. [PMID: 25309426 PMCID: PMC4161001 DOI: 10.3389/fnagi.2014.00241] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/22/2014] [Indexed: 11/27/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of neurodegenerative dementia. Researchers have long been focused on the cortical pathology of AD, since the most important pathologic features are the senile plaques found in the cortex, and the neurofibrillary tangles and neuronal loss that begin in the entorhinal cortex and the hippocampus. In addition to these gray matter (GM) structures, histopathological studies indicate that the white matter (WM) is also a good target for both the early diagnosis of AD and for monitoring disease progression. The fornix is a WM bundle that constitutes a core element of the limbic circuits, and is one of the most important anatomical structures related to memory. Functional and anatomical features of the fornix have naturally captured researchers’ attention as possible diagnostic and prognostic markers of AD. Indeed, neurodegeneration of the fornix has been histologically observed in AD, and growing evidence indicates that the alterations seen in the fornix are potentially a good marker to predict future conversion from mild cognitive impairment (MCI) to AD, and even from cognitively normal individuals to AD. The degree of alteration is correlated with the degree of memory impairment, indicating the potential for the use of the fornix as a functional marker. Moreover, there have been attempts to stimulate the fornix using deep brain stimulation (DBS) to augment cognitive function in AD, and ongoing research has suggested positive effects of DBS on brain glucose metabolism in AD patients. On the other hand, disease specificity for fornix degeneration, methodologies to evaluate fornix degeneration, and the clinical significance of the fornix DBS, especially for the long-term impact on the quality of life, are mostly unknown and need to be elucidated.
Collapse
Affiliation(s)
- Kenichi Oishi
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University Baltimore, MD, USA
| | - Constantine G Lyketsos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Bayview and Johns Hopkins Medicine Baltimore, MD, USA
| |
Collapse
|
15
|
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.
Collapse
|
16
|
Nemmi F, Saint-Aubert L, Adel D, Salabert AS, Pariente J, Barbeau EJ, Payoux P, Péran P. Insight on AV-45 binding in white and grey matter from histogram analysis: a study on early Alzheimer's disease patients and healthy subjects. Eur J Nucl Med Mol Imaging 2014; 41:1408-18. [PMID: 24573658 PMCID: PMC5101350 DOI: 10.1007/s00259-014-2728-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 02/07/2014] [Indexed: 01/21/2023]
Abstract
PURPOSE AV-45 amyloid biomarker is known to show uptake in white matter in patients with Alzheimer's disease (AD), but also in the healthy population. This binding, thought to be of a non-specific lipophilic nature, has not yet been investigated. The aim of this study was to determine the differential pattern of AV-45 binding in white matter in healthy and pathological populations. METHODS We recruited 24 patients presenting with AD at an early stage and 17 matched, healthy subjects. We used an optimized positron emission tomography-magnetic resonance imaging (PET-MRI) registration method and an approach based on an intensity histogram using several indices. We compared the results of the intensity histogram analyses with a more canonical approach based on target-to-cerebellum Standard Uptake Value (SUVr) in white and grey matter using MANOVA and discriminant analyses. A cluster analysis on white and grey matter histograms was also performed. RESULTS White matter histogram analysis revealed significant differences between AD and healthy subjects, which were not revealed by SUVr analysis. However, white matter histograms were not decisive to discriminate groups, and indices based on grey matter only showed better discriminative power than SUVr. The cluster analysis divided our sample into two clusters, showing different uptakes in grey, but also in white matter. CONCLUSION These results demonstrate that AV-45 binding in white matter conveys subtle information not detectable using the SUVr approach. Although it is not more efficient than standard SUVr in discriminating AD patients from healthy subjects, this information could reveal white matter modifications.
Collapse
Affiliation(s)
- Federico Nemmi
- Inserm, imagerie cérébrale et handicaps neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse, Place du Dr. Baylac, CHU Purpan, Pavillon Baudot, 31059, Toulouse cedex 9, France,
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Baron CA, Beaulieu C. Acquisition strategy to reduce cerebrospinal fluid partial volume effects for improved DTI tractography. Magn Reson Med 2014; 73:1075-84. [PMID: 24723303 DOI: 10.1002/mrm.25226] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/25/2014] [Accepted: 02/26/2014] [Indexed: 11/11/2022]
Abstract
PURPOSE An acquisition method that does not increase scan time or specific absorption rate is investigated for reducing the deleterious effects of cerebrospinal fluid (CSF) partial volume effects on diffusion tensor imaging (DTI) tractography. It is based on using a shorter repetition time (TR) by means of slice acquisition re-ordering to reduce the signal of long T1 CSF and a non-zero minimum diffusion weighting (b-value) to attenuate rapidly diffusing CSF signal with respect to brain tissue. METHODS A target reduction of the CSF/brain signal ratio from 3.5 to 0.8 required a TR of 2.5 s and minimum b-value of 425 s/mm(2) . This was evaluated at 4.7 Tesla in eight healthy young adults for tractography of the fornix, which has considerable CSF contamination and is difficult to track from standard DTI. RESULTS This method effectively reduced CSF signal relative to brain and yielded more robust tractography, increased tract volume, increased fractional anisotropy, and decreased mean diffusivity in the fornix relative to standard DTI. CONCLUSION CSF partial volume effects in DTI can be mitigated in acquisition through reduced TR and non-zero minimum diffusion weighting. The lack of RF absorption rate or scan time increases is attractive over other CSF suppression methods such as inversion recovery.
Collapse
Affiliation(s)
- Corey A Baron
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | | |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Degnan AJ, Levy LM. Neuroimaging of rapidly progressive dementias, part 1: neurodegenerative etiologies. AJNR Am J Neuroradiol 2014; 35:418-23. [PMID: 23436051 PMCID: PMC7964711 DOI: 10.3174/ajnr.a3454] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Most dementias begin insidiously, developing slowly and generally occurring in the elderly age group. The so-called rapidly progressive dementias constitute a different, diverse collection of conditions, many of which are reversible or treatable. For this reason, prompt identification and assessment of acute and subacute forms of dementia are critical to effective treatment. Numerous other entities within this category of presenile rapid-onset dementias are untreatable such as the prion-related diseases. Neuroimaging aids in the diagnosis and evaluation of many of these rapidly progressive dementias, which include myriad conditions ranging from variations of more common neurodegenerative dementias, such as Alzheimer disease, dementia with Lewy bodies, and frontotemporal dementia; infectious-related dementias such as acquired immune deficiency syndrome dementia; autoimmune and malignancy-related conditions; to toxic and metabolic forms of encephalopathy. This first of a 2-part review will specifically address the ability of MR imaging and ancillary neuroimaging strategies to support the diagnostic evaluation of rapidly progressive dementias due to neurodegenerative causes.
Collapse
Affiliation(s)
- A J Degnan
- From the University of Pittsburgh Medical Center (A.J.D.), Pittsburgh, Pennsylvania
| | | |
Collapse
|
20
|
Pelletier A, Periot O, Dilharreguy B, Hiba B, Bordessoules M, Pérès K, Amieva H, Dartigues JF, Allard M, Catheline G. Structural hippocampal network alterations during healthy aging: a multi-modal MRI study. Front Aging Neurosci 2013; 5:84. [PMID: 24367331 PMCID: PMC3852215 DOI: 10.3389/fnagi.2013.00084] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 11/16/2013] [Indexed: 11/13/2022] Open
Abstract
While hippocampal atrophy has been described during healthy aging, few studies have examined its relationship with the integrity of White Matter (WM) connecting tracts of the limbic system. This investigation examined WM structural damage specifically related to hippocampal atrophy in healthy aging subjects (n = 129), using morphological MRI to assess hippocampal volume and Diffusion Tensor Imaging (DTI) to assess WM integrity. Subjects with Mild Cognitive Impairment (MCI) or dementia were excluded from the analysis. In our sample, increasing age was significantly associated with reduced hippocampal volume and reduced Fractional Anisotropy (FA) at the level of the fornix and the cingulum bundle. The findings also demonstrate that hippocampal atrophy was specifically associated with reduced FA of the fornix bundle, but it was not related to alteration of the cingulum bundle. Our results indicate that the relationship between hippocampal atrophy and fornix FA values is not due to an independent effect of age on both structures. A recursive regression procedure was applied to evaluate sequential relationships between the alterations of these two brain structures. When both hippocampal atrophy and fornix FA values were included in the same model to predict age, fornix FA values remained significant whereas hippocampal atrophy was no longer significantly associated with age. According to this latter finding, hippocampal atrophy in healthy aging could be mediated by a loss of fornix connections. Structural alterations of this part of the limbic system, which have been associated with neurodegeneration in Alzheimer's disease, result at least in part from the aging process.
Collapse
Affiliation(s)
- Amandine Pelletier
- University of Bordeaux, INCIA, UMR 5287 Talence, France ; CNRS, INCIA, UMR 5287 Talence, France ; EPHE Bordeaux, France
| | - Olivier Periot
- University of Bordeaux, INCIA, UMR 5287 Talence, France ; CNRS, INCIA, UMR 5287 Talence, France ; CHU de Bordeaux, Service de Médecine Nucléaire Bordeaux, France
| | - Bixente Dilharreguy
- University of Bordeaux, INCIA, UMR 5287 Talence, France ; CNRS, INCIA, UMR 5287 Talence, France
| | | | - Martine Bordessoules
- University of Bordeaux, INCIA, UMR 5287 Talence, France ; CNRS, INCIA, UMR 5287 Talence, France ; CHU de Bordeaux, Service de Médecine Nucléaire Bordeaux, France
| | - Karine Pérès
- Université de Bordeaux, ISPED, Centre ISPED, INSERM U 897 Bordeaux, France
| | - Hélène Amieva
- Université de Bordeaux, ISPED, Centre ISPED, INSERM U 897 Bordeaux, France
| | | | - Michèle Allard
- University of Bordeaux, INCIA, UMR 5287 Talence, France ; CNRS, INCIA, UMR 5287 Talence, France ; EPHE Bordeaux, France ; CHU de Bordeaux, Service de Médecine Nucléaire Bordeaux, France
| | - Gwénaëlle Catheline
- University of Bordeaux, INCIA, UMR 5287 Talence, France ; CNRS, INCIA, UMR 5287 Talence, France ; EPHE Bordeaux, France
| |
Collapse
|
21
|
Cochrane CJ, Ebmeier KP. Diffusion tensor imaging in parkinsonian syndromes: a systematic review and meta-analysis. Neurology 2013; 80:857-64. [PMID: 23439701 DOI: 10.1212/wnl.0b013e318284070c] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES We performed a systematic review to assess alterations in measures of diffusion tensor imaging (DTI) in parkinsonian syndromes, exploring the potential role of DTI in diagnosis and as a candidate biomarker. METHODS We searched EMBASE and Medline databases for DTI studies comparing parkinsonian syndromes or related dementias with controls or another defined parkinsonian syndrome. Key details for each study regarding participants, imaging methods, and results were extracted. Estimates were pooled, where appropriate, by random-effects meta-analysis. RESULTS Of 333 results, we identified 43 studies suitable for inclusion (958 patients, 764 controls). DTI measures detected alterations in all parkinsonian syndromes, with distribution varying differentially with disease type. Nine studies were included in a meta-analysis of the substantia nigra in Parkinson disease. A notable effect size was found for lowered fractional anisotropy in the substantia nigra for patients with Parkinson disease vs controls (-0.639, 95% confidence interval -0.860 to -0.417, p < 0.0001). CONCLUSION DTI may be a promising biomarker in parkinsonian syndromes and have a future role in differential diagnosis. Larger cohort studies are required to investigate some encouraging preliminary findings. Given the complexity of the parkinsonian syndromes, it is likely that any potential DTI biomarker would be used in combination with other relevant biomarkers.
Collapse
Affiliation(s)
- Claire J Cochrane
- Division of Clinical Neurology and Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, UK.
| | | |
Collapse
|
22
|
Mielke MM. Focusing on the fornix: can fornix diffusion tensor imaging measures be used to predict Alzheimer’s disease? Neurodegener Dis Manag 2012. [DOI: 10.2217/nmt.12.60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Michelle M Mielke
- Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905, USA
| |
Collapse
|
23
|
Frederiksen KS, Waldemar G. Corpus callosum in aging and neurodegenerative diseases. Neurodegener Dis Manag 2012. [DOI: 10.2217/nmt.12.52] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
SUMMARY The corpus callosum (CC) is a major white matter bundle that connects primarily homologous areas of the cortex. The structure may be involved in interhemispheric communication and enable the lateralization of certain cerebral functions. Despite its possible role as the main conduit for interhemispheric communication, interest from researchers has, at times, been sparse. Renewed interest has led to research that has shown that the CC may play a role in both cognitive aging and neurodegenerative diseases including Alzheimer´s disease and frontotemporal dementia. Studies employing structural MRI and diffusion-weighted MRI have found distinct subregional patterns of callosal atrophy in aging, Alzheimer´s disease and frontotemporal dementia. Furthermore, imaging studies may help to elucidate the underlying pathological mechanisms of callosal atrophy. The present review aims to provide an overview of the current knowledge of the structure and function of the CC and its role in aging and neurodegenerative disease.
Collapse
Affiliation(s)
- Kristian Steen Frederiksen
- Memory Disorders Research Group, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Gunhild Waldemar
- Memory Disorders Research Group, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| |
Collapse
|
24
|
Abstract
Dementia with Lewy bodies (DLB) is a relative newcomer to the field of late-life dementia. Although a diversity of imaging methodologies is now available for the study of dementia, these have been applied most often to Alzheimer's disease (AD). Studies on DLB, although fewer, have yielded fascinating and important insights into the underlying pathophysiology of this condition and allowed clinical differentiation of DLB from other dementias. Imaging research on DLB has had significant ramifications in terms of raising the profile of DLB and helping define it as a distinctive and separate disease entity from AD.
Collapse
Affiliation(s)
- John-Paul Taylor
- Institute for Ageing and Health, Wolfson Research Centre, Campus for Aging and Vitality, Newcastle University, Newcastle Upon Tyne, NE4 5PL, UK.
| | | |
Collapse
|