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Mohammadi S, Ghaderi S, Fatehi F. MRI biomarkers and neuropsychological assessments of hippocampal and parahippocampal regions affected by ALS: A systematic review. CNS Neurosci Ther 2024; 30:e14578. [PMID: 38334254 PMCID: PMC10853901 DOI: 10.1111/cns.14578] [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: 09/14/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND AND OBJECTIVE Amyotrophic lateral sclerosis (ALS) is a progressive motor and extra-motor neurodegenerative disease. This systematic review aimed to examine MRI biomarkers and neuropsychological assessments of the hippocampal and parahippocampal regions in patients with ALS. METHODS A systematic review was conducted in the Scopus and PubMed databases for studies published between January 2000 and July 2023. The inclusion criteria were (1) MRI studies to assess hippocampal and parahippocampal regions in ALS patients, and (2) studies reporting neuropsychological data in patients with ALS. RESULTS A total of 46 studies were included. Structural MRI revealed hippocampal atrophy, especially in ALS-FTD, involving specific subregions (CA1, dentate gyrus). Disease progression and genetic factors impacted atrophy patterns. Diffusion tensor imaging (DTI) showed increased mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and decreased fractional anisotropy (FA) in the hippocampal tracts and adjacent regions, indicating loss of neuronal and white matter integrity. Functional MRI (fMRI) revealed reduced functional connectivity (FC) between the hippocampus, parahippocampus, and other regions, suggesting disrupted networks. Perfusion MRI showed hypoperfusion in parahippocampal gyri. Magnetic resonance spectroscopy (MRS) found changes in the hippocampus, indicating neuronal loss. Neuropsychological tests showed associations between poorer memory and hippocampal atrophy or connectivity changes. CA1-2, dentate gyrus, and fimbria atrophy were correlated with worse memory. CONCLUSIONS The hippocampus and the connected regions are involved in ALS. Hippocampal atrophy disrupted connectivity and metabolite changes correlate with cognitive and functional decline. Specific subregions can be particularly affected. The hippocampus is a potential biomarker for disease monitoring and prognosis.
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Affiliation(s)
- Sana Mohammadi
- Neuromuscular Research Center, Department of Neurology, Shariati HospitalTehran University of Medical SciencesTehranIran
- Department of Medical Sciences, School of MedicineIran University of Medical SciencesTehranIran
| | - Sadegh Ghaderi
- Neuromuscular Research Center, Department of Neurology, Shariati HospitalTehran University of Medical SciencesTehranIran
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in MedicineTehran University of Medical SciencesTehranIran
| | - Farzad Fatehi
- Neuromuscular Research Center, Department of Neurology, Shariati HospitalTehran University of Medical SciencesTehranIran
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Vanherle L, Lidington D, Uhl FE, Steiner S, Vassallo S, Skoug C, Duarte JM, Ramu S, Uller L, Desjardins JF, Connelly KA, Bolz SS, Meissner A. Restoring myocardial infarction-induced long-term memory impairment by targeting the cystic fibrosis transmembrane regulator. EBioMedicine 2022; 86:104384. [PMID: 36462404 PMCID: PMC9718964 DOI: 10.1016/j.ebiom.2022.104384] [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] [Received: 08/08/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Cognitive impairment is a serious comorbidity in heart failure patients, but effective therapies are lacking. We investigated the mechanisms that alter hippocampal neurons following myocardial infarction (MI). METHODS MI was induced in male C57Bl/6 mice by left anterior descending coronary artery ligation. We utilised standard procedures to measure cystic fibrosis transmembrane regulator (CFTR) protein levels, inflammatory mediator expression, neuronal structure, and hippocampal memory. Using in vitro and in vivo approaches, we assessed the role of neuroinflammation in hippocampal neuron degradation and the therapeutic potential of CFTR correction as an intervention. FINDINGS Hippocampal dendrite length and spine density are reduced after MI, effects that associate with decreased neuronal CFTR expression and concomitant microglia activation and inflammatory cytokine expression. Conditioned medium from lipopolysaccharide-stimulated microglia (LCM) reduces neuronal cell CFTR protein expression and the mRNA expression of the synaptic regulator post-synaptic density protein 95 (PSD-95) in vitro. Blocking CFTR activity also down-regulates PSD-95 in neurons, indicating a relationship between CFTR expression and neuronal health. Pharmacologically correcting CFTR expression in vitro rescues the LCM-mediated down-regulation of PSD-95. In vivo, pharmacologically increasing hippocampal neuron CFTR expression improves MI-associated alterations in neuronal arborisation, spine density, and memory function, with a wide therapeutic time window. INTERPRETATION Our results indicate that CFTR therapeutics improve inflammation-induced alterations in hippocampal neuronal structure and attenuate memory dysfunction following MI. FUNDING Knut and Alice Wallenberg Foundation [F 2015/2112]; Swedish Research Council [VR; 2017-01243]; the German Research Foundation [DFG; ME 4667/2-1]; Hjärnfonden [FO2021-0112]; The Crafoord Foundation; Åke Wibergs Stiftelse [M19-0380], NMMP 2021 [V2021-2102]; the Albert Påhlsson Research Foundation; STINT [MG19-8469], Lund University; Canadian Institutes of Health Research [PJT-153269] and a Heart and Stroke Foundation of Ontario Mid-Career Investigator Award.
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Affiliation(s)
- Lotte Vanherle
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Darcy Lidington
- Department of Physiology, University of Toronto, Toronto, Canada
| | - Franziska E. Uhl
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Saskia Steiner
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Stefania Vassallo
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Cecilia Skoug
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Joao M.N. Duarte
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Sangeetha Ramu
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Lena Uller
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | | | - Kim A. Connelly
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital; Toronto, Ontario, Canada
| | | | - Anja Meissner
- Department of Experimental Medical Science, Lund University, Lund, Sweden,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden,Department of Physiology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany,German Centre for Neurodegenerative Diseases, Bonn, Germany,Corresponding author. Klinikgatan 32, Lund SE-22184, Sweden.
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Leaston J, Ferris CF, Kulkarni P, Chandramohan D, van de Ven AL, Qiao J, Timms L, Sepulcre J, El Fakhri G, Ma C, Normandin MD, Gharagouzloo C. Neurovascular imaging with QUTE-CE MRI in APOE4 rats reveals early vascular abnormalities. PLoS One 2021; 16:e0256749. [PMID: 34449808 PMCID: PMC8396782 DOI: 10.1371/journal.pone.0256749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/13/2021] [Indexed: 11/19/2022] Open
Abstract
Cerebrovascular abnormality is linked to Alzheimer's disease and related dementias (ADRDs). ApoE-Ɛ4 (APOE4) is known to play a critical role in neurovascular dysfunction, however current medical imaging technologies are limited in quantification. This cross-sectional study tested the feasibility of a recently established imaging modality, quantitative ultra-short time-to-echo contrast-enhanced magnetic resonance imaging (QUTE-CE MRI), to identify small vessel abnormality early in development of human APOE4 knock-in female rat (TGRA8960) animal model. At 8 months, 48.3% of the brain volume was found to have significant signal increase (75/173 anatomically segmented regions; q<0.05 for multiple comparisons). Notably, vascular abnormality was detected in the tri-synaptic circuit, cerebellum, and amygdala, all of which are known to functionally decline throughout AD pathology and have implications in learning and memory. The detected abnormality quantified with QUTE-CE MRI is likely a result of hyper-vascularization, but may also be partly, or wholly, due to contributions from blood-brain-barrier leakage. Further exploration with histological validation is warranted to verify the pathological cause. Regardless, these results indicate that QUTE-CE MRI can detect neurovascular dysfunction with high sensitivity with APOE4 and may be helpful to provide new insights into health and disease.
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Affiliation(s)
- Joshua Leaston
- Imaginostics, Inc., Cambridge, Massachusetts, United States of America
| | - Craig F. Ferris
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States of America
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
| | - Praveen Kulkarni
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States of America
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
| | | | - Anne L. van de Ven
- Department of Physics, Northeastern University, Boston, Massachusetts, United States of America
- Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts, United States of America
| | - Ju Qiao
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
- Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts, United States of America
| | - Liam Timms
- Department of Physics, Northeastern University, Boston, Massachusetts, United States of America
- Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts, United States of America
| | - Jorge Sepulcre
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Chao Ma
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marc D. Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Codi Gharagouzloo
- Imaginostics, Inc., Cambridge, Massachusetts, United States of America
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States of America
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
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Khlif MS, Bird LJ, Restrepo C, Khan W, Werden E, Egorova‐Brumley N, Brodtmann A. Hippocampal subfield volumes are associated with verbal memory after first-ever ischemic stroke. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12195. [PMID: 34136634 PMCID: PMC8197170 DOI: 10.1002/dad2.12195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Hippocampal subfield volumes are more closely associated with cognitive impairment than whole hippocampal volume in many diseases. Both memory and whole hippocampal volume decline after stroke. Understanding the subfields' temporal evolution could reveal valuable information about post-stroke memory. METHODS We sampled 120 participants (38 control, 82 stroke), with cognitive testing and 3T-MRI available at 3 months and 3 years, from the Cognition and Neocortical Volume after Stroke (CANVAS) study. Verbal memory was assessed using the Hopkins Verbal Learning Test-Revised. Subfields were delineated using FreeSurfer. We used partial Pearson's correlation to assess the associations between subfield volumes and verbal memory scores, adjusting for years of education, sex, and stroke side. RESULTS The left cornu ammonis areas 2/3 and hippocampal tail volumes were significantly associated with verbal memory 3-month post-stroke. At 3 years, the associations became stronger and involved more subfields. DISCUSSION Hippocampal subfield volumes may be a useful biomarker for post-stroke cognitive impairment.
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Affiliation(s)
- Mohamed Salah Khlif
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Laura J. Bird
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Carolina Restrepo
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Wasim Khan
- Department of NeuroscienceCentral Clinical SchoolMonash UniversityClaytonVictoriaAustralia
- Department of Neuroimaging Institute of PsychiatryPsychology, and Neuroscience (IoPPN), King's College LondonLondonUK
| | - Emilio Werden
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Natalia Egorova‐Brumley
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
- Melbourne School of Psychological SciencesUniversity of MelbourneParkvilleVictoriaAustralia
| | - Amy Brodtmann
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
- Department of NeurologyAustin HealthHeidelbergVictoriaAustralia
- Eastern Cognitive Disorders ClinicBox Hill HospitalMonash UniversityBox HillVictoriaAustralia
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Guo Y, Zou G, Qi K, Jin J, Yao L, Pan Y, Xiong W. Simvastatin impairs hippocampal synaptic plasticity and cognitive function in mice. Mol Brain 2021; 14:41. [PMID: 33627175 PMCID: PMC7905661 DOI: 10.1186/s13041-021-00758-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/19/2021] [Indexed: 12/11/2022] Open
Abstract
Lipophilic statins which are blood brain barrier (BBB) permeable are speculated to affect the cholesterol synthesis and neural functions in the central nervous system. However, whether these statins can affect cholesterol levels and synaptic plasticity in hippocampus and the in vivo consequence remain unclear. Here, we report that long-term subcutaneous treatments of simvastatin significantly impair mouse hippocampal synaptic plasticity, reflected by the attenuated long-term potentiation of field excitatory postsynaptic potentials. The simvastatin administration causes a deficiency in recognition and spatial memory but fails to affect motor ability and anxiety behaviors in the mice. Mass spectrometry imaging indicates a significant decrease in cholesterol intensity in hippocampus of the mice receiving chronic simvastatin treatments. Such effects of simvastatin are transient because drug discontinuation can restore the hippocampal cholesterol level and synaptic plasticity and the memory function. These findings may provide further clues to elucidate the mechanisms of neurological side effects, especially the brain cognitive function impairment, caused by long-term usage of BBB-permeable statins.
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Affiliation(s)
- Yujun Guo
- Department of Neurosurgery, Institute On Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Guichang Zou
- Department of Neurosurgery, Institute On Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Keke Qi
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, China
| | - Jin Jin
- Department of Neurosurgery, Institute On Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Lei Yao
- Department of Neurosurgery, Institute On Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Yang Pan
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, China
| | - Wei Xiong
- Department of Neurosurgery, Institute On Aging and Brain Disorders, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230026, China.
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100070, China.
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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Rheault F, De Benedictis A, Daducci A, Maffei C, Tax CMW, Romascano D, Caverzasi E, Morency FC, Corrivetti F, Pestilli F, Girard G, Theaud G, Zemmoura I, Hau J, Glavin K, Jordan KM, Pomiecko K, Chamberland M, Barakovic M, Goyette N, Poulin P, Chenot Q, Panesar SS, Sarubbo S, Petit L, Descoteaux M. Tractostorm: The what, why, and how of tractography dissection reproducibility. Hum Brain Mapp 2020; 41:1859-1874. [PMID: 31925871 PMCID: PMC7267902 DOI: 10.1002/hbm.24917] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/23/2019] [Accepted: 12/16/2019] [Indexed: 12/19/2022] Open
Abstract
Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called "virtual dissection." Human errors and personal decisions make these manual segmentations hard to reproduce, which have not yet been quantified by the dMRI community. It is our opinion that if the field of dMRI tractography wants to be taken seriously as a widespread clinical tool, it is imperative to harmonize WM bundle segmentations and develop protocols aimed to be used in clinical settings. The EADC-ADNI Harmonized Hippocampal Protocol achieved such standardization through a series of steps that must be reproduced for every WM bundle. This article is an observation of the problematic. A specific bundle segmentation protocol was used in order to provide a real-life example, but the contribution of this article is to discuss the need for reproducibility and standardized protocol, as for any measurement tool. This study required the participation of 11 experts and 13 nonexperts in neuroanatomy and "virtual dissection" across various laboratories and hospitals. Intra-rater agreement (Dice score) was approximately 0.77, while inter-rater was approximately 0.65. The protocol provided to participants was not necessarily optimal, but its design mimics, in essence, what will be required in future protocols. Reporting tractometry results such as average fractional anisotropy, volume or streamline count of a particular bundle without a sufficient reproducibility score could make the analysis and interpretations more difficult. Coordinated efforts by the diffusion MRI tractography community are needed to quantify and account for reproducibility of WM bundle extraction protocols in this era of open and collaborative science.
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Affiliation(s)
- Francois Rheault
- Sherbrooke Connectivity Imaging Laboratory (SCIL)Université de SherbrookeSherbrookeCanada
| | - Alessandro De Benedictis
- Neurosurgery Unit, Department of Neuroscience and NeurorehabilitationBambino Gesù Children's Hospital, IRCCSRomeItaly
| | | | - Chiara Maffei
- Athinoula A. Martinos Center for Biomedical ImagingMassachusetts General Hospital and Harvard Medical SchoolBostonMA
| | - Chantal M. W. Tax
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of PsychologyCardiff UniversityCardiffUK
| | - David Romascano
- Signal Processing Lab (LTS5)École Polytechnique Fédérale de LausanneLausanneSwitzerland
| | | | | | | | - Franco Pestilli
- Department of Psychological and Brain SciencesIndiana UniversityBloomingtonIN
| | - Gabriel Girard
- Signal Processing Lab (LTS5)École Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Guillaume Theaud
- Sherbrooke Connectivity Imaging Laboratory (SCIL)Université de SherbrookeSherbrookeCanada
| | | | - Janice Hau
- Brain Development Imaging Laboratories, Department of PsychologySan Diego State UniversitySan DiegoCAUSA
| | - Kelly Glavin
- Learning Research & Development Center (LRDC)University of PittsburghPittsburghPAUSA
| | | | - Kristofer Pomiecko
- Learning Research & Development Center (LRDC)University of PittsburghPittsburghPAUSA
| | - Maxime Chamberland
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of PsychologyCardiff UniversityCardiffUK
| | - Muhamed Barakovic
- Signal Processing Lab (LTS5)École Polytechnique Fédérale de LausanneLausanneSwitzerland
| | | | - Philippe Poulin
- Sherbrooke Connectivity Imaging Laboratory (SCIL)Université de SherbrookeSherbrookeCanada
| | | | | | - Silvio Sarubbo
- Division of Neurosurgery, Emergency Department, "S. Chiara" HospitalAzienda Provinciale per i Servizi Sanitari (APSS)TrentoItaly
| | - Laurent Petit
- Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives ‐ UMR 5293, CNRSCEA University of BordeauxBordeauxFrance
| | - Maxime Descoteaux
- Sherbrooke Connectivity Imaging Laboratory (SCIL)Université de SherbrookeSherbrookeCanada
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Broadhouse KM, Singh MF, Suo C, Gates N, Wen W, Brodaty H, Jain N, Wilson GC, Meiklejohn J, Singh N, Baune BT, Baker M, Foroughi N, Wang Y, Kochan N, Ashton K, Brown M, Li Z, Mavros Y, Sachdev PS, Valenzuela MJ. Hippocampal plasticity underpins long-term cognitive gains from resistance exercise in MCI. Neuroimage Clin 2020; 25:102182. [PMID: 31978826 PMCID: PMC6974789 DOI: 10.1016/j.nicl.2020.102182] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/13/2020] [Accepted: 01/13/2020] [Indexed: 01/15/2023]
Abstract
Dementia affects 47 million individuals worldwide, and assuming the status quo is projected to rise to 150 million by 2050. Prevention of age-related cognitive impairment in older persons with lifestyle interventions continues to garner evidence but whether this can combat underlying neurodegeneration is unknown. The Study of Mental Activity and Resistance Training (SMART) trial has previously reported within-training findings; the aim of this study was to investigate the long-term neurostructural and cognitive impact of resistance exercise in Mild Cognitive Impairment (MCI). For the first time we show that hippocampal subareas particularly susceptible to volume loss in Alzheimer's disease (AD) are protected by resistance exercise for up to one year after training. One hundred MCI participants were randomised to one of four training groups: (1) Combined high intensity progressive resistance and computerised cognitive training (PRT+CCT), (2) PRT+Sham CCT, (3) CCT+Sham PRT, (4) Sham physical+sham cognitive training (SHAM+SHAM). Physical, neuropsychological and MRI assessments were carried out at baseline, 6 months (directly after training) and 18 months from baseline (12 months after intervention cessation). Here we report neuro-structural and functional changes over the 18-month trial period and the association with global cognitive and executive function measures. PRT but not CCT or PRT+CCT led to global long-term cognitive improvements above SHAM intervention at 18-month follow-up. Furthermore, hippocampal subfields susceptible to atrophy in AD were protected by PRT revealing an elimination of long-term atrophy in the left subiculum, and attenuation of atrophy in left CA1 and dentate gyrus when compared to SHAM+SHAM (p = 0.023, p = 0.020 and p = 0.027). These neuroprotective effects mediated a significant portion of long-term cognitive benefits. By contrast, within-training posterior cingulate plasticity decayed after training cessation and was unrelated to long term cognitive benefits. Neither general physical activity levels nor fitness change over the 18-month period mediated hippocampal trajectory, demonstrating that enduring hippocampal subfield plasticity is not a simple reflection of post-training changes in fitness or physical activity participation. Notably, resting-state fMRI analysis revealed that both the hippocampus and posterior cingulate participate in a functional network that continued to be upregulated following intervention cessation. Multiple structural mechanisms may contribute to the long-term global cognitive benefit of resistance exercise, developing along different time courses but functionally linked. For the first time we show that 6 months of high intensity resistance exercise is capable of not only promoting better cognition in those with MCI, but also protecting AD-vulnerable hippocampal subfields from degeneration for at least 12 months post-intervention. These findings emphasise the therapeutic potential of resistance exercise; however, future work will need to establish just how long-lived these outcomes are and whether they are sufficient to delay dementia.
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Affiliation(s)
- Kathryn M Broadhouse
- Nola Thompson Centre for Advanced Imaging, Sunshine Coast Mind and Neuroscience Thompson Institute, University of the Sunshine Coast, QLD, Australia; Regenerative Neuroscience Group, Brain and Mind Centre and Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.
| | - Maria Fiatarone Singh
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences and Sydney Medical School, The University of Sydney, Lidcombe, NSW, Australia; Hebrew SeniorLife and Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA
| | - Chao Suo
- Regenerative Neuroscience Group, Brain and Mind Centre and Sydney Medical School, The University of Sydney, Sydney, NSW, Australia; School of Psychological Sciences and Monash Biomedical Imaging, Monash University, Melbourne, VIC, Australia
| | - Nicola Gates
- Regenerative Neuroscience Group, Brain and Mind Centre and Sydney Medical School, The University of Sydney, Sydney, NSW, Australia; School of Psychiatry, University of New South Wales, Sydney, NSW, Australia; Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Wei Wen
- School of Psychiatry, University of New South Wales, Sydney, NSW, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia
| | - Henry Brodaty
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia; Dementia Collaborative Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Nidhi Jain
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia
| | - Guy C Wilson
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia
| | - Jacinda Meiklejohn
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia
| | - Nalin Singh
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia
| | - Bernhard T Baune
- Department of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Michael Baker
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences and Sydney Medical School, The University of Sydney, Lidcombe, NSW, Australia; School of Exercise Science, Australian Catholic University, Strathfield, NSW, Australia
| | - Nasim Foroughi
- Clinical and Rehabilitation Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia
| | - Yi Wang
- Clinical and Rehabilitation Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia; Department of Medicine and the Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Nicole Kochan
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Kevin Ashton
- Biomedical Sciences, Faculty of Health Sciences and Medicine, Bond University, QLD, Australia
| | - Matt Brown
- Institute of Health and Biomedical Innovation, Queensland University of Technology, QLD, Australia; King's College London National Institutes of Health Biomedical Research Centre, UK
| | - Zhixiu Li
- Institute of Health and Biomedical Innovation, Queensland University of Technology, QLD, Australia
| | - Yorgi Mavros
- Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Faculty of Health Sciences and Sydney Medical School, The University of Sydney, Lidcombe, NSW, Australia
| | - Perminder S Sachdev
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Michael J Valenzuela
- Regenerative Neuroscience Group, Brain and Mind Centre and Sydney Medical School, The University of Sydney, Sydney, NSW, Australia; School of Medical Sciences, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
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Lowe AJ, Paquola C, Vos de Wael R, Girn M, Lariviere S, Tavakol S, Caldairou B, Royer J, Schrader DV, Bernasconi A, Bernasconi N, Spreng RN, Bernhardt BC. Targeting age-related differences in brain and cognition with multimodal imaging and connectome topography profiling. Hum Brain Mapp 2019; 40:5213-5230. [PMID: 31444896 PMCID: PMC6864903 DOI: 10.1002/hbm.24767] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/29/2019] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Aging is characterized by accumulation of structural and metabolic changes in the brain. Recent studies suggest transmodal brain networks are especially sensitive to aging, which, we hypothesize, may be due to their apical position in the cortical hierarchy. Studying an open‐access healthy cohort (n = 102, age range = 30–89 years) with MRI and Aβ PET data, we estimated age‐related cortical thinning, hippocampal atrophy and Aβ deposition. In addition to carrying out surface‐based morphological and metabolic mapping experiments, we stratified effects along neocortical and hippocampal resting‐state functional connectome gradients derived from independent datasets. The cortical gradient depicts an axis of functional differentiation from sensory‐motor regions to transmodal regions, whereas the hippocampal gradient recapitulates its long‐axis. While age‐related thinning and increased Aβ deposition occurred across the entire cortical topography, increased Aβ deposition was especially pronounced toward higher‐order transmodal regions. Age‐related atrophy was greater toward the posterior end of the hippocampal long‐axis. No significant effect of age on Aβ deposition in the hippocampus was observed. Imaging markers correlated with behavioral measures of fluid intelligence and episodic memory in a topography‐specific manner, confirmed using both univariate as well as multivariate analyses. Our results strengthen existing evidence of structural and metabolic change in the aging brain and support the use of connectivity gradients as a compact framework to analyze and conceptualize brain‐based biomarkers of aging.
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Affiliation(s)
- Alexander J Lowe
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Casey Paquola
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Reinder Vos de Wael
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Manesh Girn
- Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Sara Lariviere
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Shahin Tavakol
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Benoit Caldairou
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Jessica Royer
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Dewi V Schrader
- Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - R Nathan Spreng
- Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.,Department of Psychiatry and Psychology, McGill University, Montreal, Canada
| | - Boris C Bernhardt
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
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Impact of adrenal hormones, reproductive aging, and major depression on memory circuitry decline in early midlife. Brain Res 2019; 1721:146303. [PMID: 31279842 DOI: 10.1016/j.brainres.2019.146303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/12/2019] [Accepted: 06/18/2019] [Indexed: 11/24/2022]
Abstract
Dehydroepiandrosterone-sulfate (DHEAS) is an adrenal androgen that is, in part, aromatized to estradiol. It continues to be produced after menopause and provides estrogenicity after depletion of ovarian hormones. Estradiol depletion contributes to memory circuitry changes over menopause, including changes in hippocampal (HIPP) and dorsolateral- and ventrolateral-prefrontal cortex (DLPFC; VLPFC) function. Further, major depressive disorder (MDD) patients have, in general, lower levels of estradiol and lower DHEAS than healthy controls, thus potentially a higher risk of adverse menopausal outcomes. We investigated whether higher DHEAS levels after menopause is associated with better memory circuitry function, especially in women with MDD. 212 adults (ages 45-55, 50% women) underwent clinical and fMRI testing. Participants performed a working memory (WM) N-back task and an episodic memory verbal encoding (VE) task during fMRI scanning. DHEAS levels were significantly associated with memory circuitry function, specifically in MDD postmenopausal women. On the WM task, lower DHEAS levels were associated with increased HIPP activity. On the VE task, lower DHEAS levels were associated with decreased activity in the HIPP and VLPFC. In contrast, there was no association between DHEAS levels and memory circuitry function in MDD pre/perimenopausal women, men, and non-MDD participants regardless of sex and reproductive status. In fact, MDD postmenopausal women with higher levels of DHEAS were similar to MDD pre/perimenopausal women and men. Thus, memory circuitry deficits associated with MDD and a lower ability of the adrenal gland to produce DHEAS after menopause may contribute to a lower ability to maintain intact memory function with age.
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10
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Wolters FJ, Zonneveld HI, Hofman A, van der Lugt A, Koudstaal PJ, Vernooij MW, Ikram MA. Cerebral Perfusion and the Risk of Dementia: A Population-Based Study. Circulation 2017; 136:719-728. [PMID: 28588075 DOI: 10.1161/circulationaha.117.027448] [Citation(s) in RCA: 318] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 05/02/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Cerebral hypoperfusion has previously been associated with mild cognitive impairment and dementia in various cross-sectional studies, but whether hypoperfusion precedes neurodegeneration is unknown. We prospectively determined the association of cerebral perfusion with subsequent cognitive decline and development of dementia. METHODS Between 2005 and 2012, we measured cerebral blood flow by 2-dimensional phase-contrast magnetic resonance imaging in participants of the population-based Rotterdam Study without dementia. We determined the association of cerebral perfusion (mL/100mL/min) with risk of dementia (until 2015) using a Cox model, adjusting for age, sex, demographics, cardiovascular risk factors, and apolipoprotein E genotype. We repeated analyses for Alzheimer disease and accounting for stroke. We used linear regression to determine change in cognitive performance during 2 consecutive examination rounds in relation to perfusion. Finally, we investigated whether associations were modified by baseline severity of white matter hyperintensities. RESULTS Of 4759 participants (median age 61.3 years, 55.2% women) with a median follow-up of 6.9 years, 123 participants developed dementia (97 Alzheimer disease). Lower cerebral perfusion was associated with higher risk of dementia (adjusted hazard ratio, 1.31; 95% confidence interval per standard deviation decrease, 1.07-1.61), similar for Alzheimer disease only, and unaltered by accounting for stroke. Risk of dementia with hypoperfusion was higher with increasing severity of white matter hyperintensities (with severe white matter hyperintensities; hazard ratio, 1.54; 95% confidence interval, 1.11-2.14). At cognitive reexamination after on average 5.7 years, lower baseline perfusion was associated with accelerated decline in cognition (global cognition: β=-0.029, P=0.003), which was similar after excluding those with incident dementia, and again most profound in individuals with higher volume of white matter hyperintensities (P value for interaction=0.019). CONCLUSIONS Cerebral hypoperfusion is associated with accelerated cognitive decline and an increased risk of dementia in the general population.
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Affiliation(s)
- Frank J Wolters
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.)
| | - Hazel I Zonneveld
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.)
| | - Albert Hofman
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.)
| | - Aad van der Lugt
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.)
| | - Peter J Koudstaal
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.)
| | - Meike W Vernooij
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.)
| | - M Arfan Ikram
- From Department of Epidemiology (F.J.W., H.I.Z., A.H., M.W.V., M.A.I.), Department of Neurology (F.J.W., P.J.K., M.A.I.), Department of Radiology and Nuclear Medicine (H.I.Z., A.v.d.L., M.W.V., M.A.I.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (F.J.W., A.H.).
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Kazim SF, Chuang SC, Zhao W, Wong RKS, Bianchi R, Iqbal K. Early-Onset Network Hyperexcitability in Presymptomatic Alzheimer's Disease Transgenic Mice Is Suppressed by Passive Immunization with Anti-Human APP/Aβ Antibody and by mGluR5 Blockade. Front Aging Neurosci 2017; 9:71. [PMID: 28392767 PMCID: PMC5364175 DOI: 10.3389/fnagi.2017.00071] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 03/08/2017] [Indexed: 11/26/2022] Open
Abstract
Cortical and hippocampal network hyperexcitability appears to be an early event in Alzheimer’s disease (AD) pathogenesis, and may contribute to memory impairment. It remains unclear if network hyperexcitability precedes memory impairment in mouse models of AD and what are the underlying cellular mechanisms. We thus evaluated seizure susceptibility and hippocampal network hyperexcitability at ~3 weeks of age [prior to amyloid beta (Aβ) plaque deposition, neurofibrillary pathology, and cognitive impairment] in a triple transgenic mouse model of familial AD (3xTg-AD mouse) that harbors mutated human Aβ precursor protein (APP), tau and presenilin 1 (PS1) genes. Audiogenic seizures were elicited in a higher proportion of 3xTg-AD mice compared with wild type (WT) controls. Seizure susceptibility in 3xTg-AD mice was attenuated either by passive immunization with anti-human APP/Aβ antibody (6E10) or by blockade of metabotropic glutamate receptor 5 (mGluR5) with the selective antagonist, 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP). In in vitro hippocampal slices, suppression of synaptic inhibition with the GABAA receptor antagonist, bicuculline, induced prolonged epileptiform (>1.5 s in duration) ictal-like discharges in the CA3 neuronal network in the majority of the slices from 3xTg-AD mice. In contrast, only short epileptiform (<1.5 s in duration) interictal-like discharges were observed following bicuculline application in the CA3 region of WT slices. The ictal-like activity in CA3 region of the hippocampus was significantly reduced in the 6E10-immunized compared to the saline-treated 3xTg-AD mice. MPEP acutely suppressed the ictal-like discharges in 3xTg-AD slices. Remarkably, epileptiform discharge duration positively correlated with intraneuronal human (transgenic) APP/Aβ expression in the CA3 region of the hippocampus. Our data suggest that in a mouse model of familial AD, hypersynchronous network activity underlying seizure susceptibility precedes Aβ plaque pathology and memory impairment. This early-onset network hyperexcitability can be suppressed by passive immunization with an anti-human APP/Aβ antibody and by mGluR5 blockade in 3xTg-AD mice.
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Affiliation(s)
- Syed F Kazim
- Robert F. Furchgott Center for Neural and Behavioral Science and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical CenterBrooklyn, NY, USA; Department of Neurochemistry and SUNY Downstate/NYSIBR Center for Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR)Staten Island, NY, USA; Graduate Program in Neural and Behavioral Science, SUNY Downstate Medical CenterBrooklyn, NY, USA
| | - Shih-Chieh Chuang
- Robert F. Furchgott Center for Neural and Behavioral Science and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center Brooklyn, NY, USA
| | - Wangfa Zhao
- Robert F. Furchgott Center for Neural and Behavioral Science and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center Brooklyn, NY, USA
| | - Robert K S Wong
- Robert F. Furchgott Center for Neural and Behavioral Science and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center Brooklyn, NY, USA
| | - Riccardo Bianchi
- Robert F. Furchgott Center for Neural and Behavioral Science and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center Brooklyn, NY, USA
| | - Khalid Iqbal
- Department of Neurochemistry and SUNY Downstate/NYSIBR Center for Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR) Staten Island, NY, USA
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Geevarghese R, Lumsden DE, Costello A, Hulse N, Ayis S, Samuel M, Ashkan K. Verbal Memory Decline following DBS for Parkinson's Disease: Structural Volumetric MRI Relationships. PLoS One 2016; 11:e0160583. [PMID: 27557088 PMCID: PMC4996448 DOI: 10.1371/journal.pone.0160583] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/21/2016] [Indexed: 12/02/2022] Open
Abstract
Background Parkinson’s disease is a chronic degenerative movement disorder. The mainstay of treatment is medical. In certain patients Deep Brain Stimulation (DBS) may be offered. However, DBS has been associated with post-operative neuropsychology changes, especially in verbal memory. Objectives Firstly, to determine if pre-surgical thalamic and hippocampal volumes were related to verbal memory changes following DBS. Secondly, to determine if clinical factors such as age, duration of symptoms or motor severity (UPDRS Part III score) were related to verbal memory changes. Methods A consecutive group of 40 patients undergoing bilateral Subthalamic Nucleus (STN)-DBS for PD were selected. Brain MRI data was acquired, pre-processed and structural volumetric data was extracted using FSL. Verbal memory test scores for pre- and post-STN-DBS surgery were recorded. Linear regression was used to investigate the relationship between score change and structural volumetric data. Results A significant relationship was demonstrated between change in List Learning test score and thalamic (left, p = 0.02) and hippocampal (left, p = 0.02 and right p = 0.03) volumes. Duration of symptoms was also associated with List Learning score change (p = 0.02 to 0.03). Conclusion Verbal memory score changes appear to have a relationship to pre-surgical MRI structural volumetric data. The findings of this study provide a basis for further research into the use of pre-surgical MRI to counsel PD patients regarding post-surgical verbal memory changes.
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Affiliation(s)
- Ruben Geevarghese
- Department of Neurosurgery, King’s College Hospital NHS Foundation Trust, King’s Health Partners, London, United Kingdom
- Department of Neurosurgery, Charing Cross Hospital, London, United Kingdom
- * E-mail:
| | - Daniel E. Lumsden
- Complex Motor Disorders Service, Evelina Children’s Hospital, Guy’s & St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Angela Costello
- Department of Neuropsychology, King’s College Hospital NHS Foundation Trust, King’s Health Partners, London, United Kingdom
| | - Natasha Hulse
- Department of Neurology, King’s College Hospital NHS Foundation Trust, King’s Health Partners, London, United Kingdom
| | - Salma Ayis
- Department of Primary Care and Public Health Sciences, King’s College London, United Kingdom
| | - Michael Samuel
- Department of Neurology, King’s College Hospital NHS Foundation Trust, King’s Health Partners, London, United Kingdom
| | - Keyoumars Ashkan
- Department of Neurosurgery, King’s College Hospital NHS Foundation Trust, King’s Health Partners, London, United Kingdom
- Clinical Neurosciences, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom
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13
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Kazim SF, Iqbal K. Neurotrophic factor small-molecule mimetics mediated neuroregeneration and synaptic repair: emerging therapeutic modality for Alzheimer's disease. Mol Neurodegener 2016; 11:50. [PMID: 27400746 PMCID: PMC4940708 DOI: 10.1186/s13024-016-0119-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 07/02/2016] [Indexed: 11/10/2022] Open
Abstract
Alzheimer's disease (AD) is an incurable and debilitating chronic progressive neurodegenerative disorder which is the leading cause of dementia worldwide. AD is a heterogeneous and multifactorial disorder, histopathologically characterized by the presence of amyloid β (Aβ) plaques and neurofibrillary tangles composed of Aβ peptides and abnormally hyperphosphorylated tau protein, respectively. Independent of the various etiopathogenic mechanisms, neurodegeneration is a final common outcome of AD neuropathology. Synaptic loss is a better correlate of cognitive impairment in AD than Aβ or tau pathologies. Thus a highly promising therapeutic strategy for AD is to shift the balance from neurodegeneration to neuroregeneration and synaptic repair. Neurotrophic factors, by virtue of their neurogenic and neurotrophic activities, have potential for the treatment of AD. However, the clinical therapeutic usage of recombinant neurotrophic factors is limited because of the insurmountable hurdles of unfavorable pharmacokinetic properties, poor blood-brain barrier (BBB) permeability, and severe adverse effects. Neurotrophic factor small-molecule mimetics, in this context, represent a potential strategy to overcome these short comings, and have shown promise in preclinical studies. Neurotrophic factor small-molecule mimetics have been the focus of intense research in recent years for AD drug development. Here, we review the relevant literature regarding the therapeutic beneficial effect of neurotrophic factors in AD, and then discuss the recent status of research regarding the neurotrophic factor small-molecule mimetics as therapeutic candidates for AD. Lastly, we summarize the preclinical studies with a ciliary neurotrophic factor (CNTF) small-molecule peptide mimetic, Peptide 021 (P021). P021 is a neurogenic and neurotrophic compound which enhances dentate gyrus neurogenesis and memory processes via inhibiting leukemia inhibitory factor (LIF) signaling pathway and increasing brain-derived neurotrophic factor (BDNF) expression. It robustly inhibits tau abnormal hyperphosphorylation via increased BDNF mediated decrease in glycogen synthase kinase-3β (GSK-3β, major tau kinase) activity. P021 is a small molecular weight, BBB permeable compound with suitable pharmacokinetics for oral administration, and without adverse effects associated with native CNTF or BDNF molecule. P021 has shown beneficial therapeutic effect in several preclinical studies and has emerged as a highly promising compound for AD drug development.
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Affiliation(s)
- Syed Faraz Kazim
- />Department of Neurochemistry, and SUNY Downstate/NYSIBR Program in Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), 1050 Forest Hill Road, Staten Island, NY 10314 USA
- />Graduate Program in Neural and Behavioral Science, and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203 USA
| | - Khalid Iqbal
- />Department of Neurochemistry, and SUNY Downstate/NYSIBR Program in Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), 1050 Forest Hill Road, Staten Island, NY 10314 USA
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Montagne A, Pa J, Zlokovic BV. Vascular plasticity and cognition during normal aging and dementia. JAMA Neurol 2015; 72:495-6. [PMID: 25751405 DOI: 10.1001/jamaneurol.2014.4636] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Axel Montagne
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles
| | - Judy Pa
- Institute for Neuroimaging and Informatics, Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles
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15
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Catheline G, Amieva H, Dilharreguy B, Bernard C, Duperron MG, Helmer C, Dartigues JF, Allard M. Semantic retrieval over time in the aging brain: Structural evidence of hippocampal contribution. Hippocampus 2015; 25:1008-16. [PMID: 25614980 DOI: 10.1002/hipo.22423] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2015] [Indexed: 01/15/2023]
Abstract
This study investigates relationship between regional cerebral volumes and performances over time of a categorical fluency task, in a sample of older adults (n = 316). Using voxel-wise technique, the relationship between local grey matter volume and Isaacs Set Test (IST) scores at its early (first 15 sec) and late (last 15 sec) phase production was analyzed with a linear regression model adjusting for age, sex, educational level, ApoEɛ4 allele, handedness and Grey Matter atrophy. Lower early IST scores were associated with smaller volumes in bilateral inferior frontal gyri and in right thalamus, whereas lower late IST scores were associated to smaller left inferior parietal gyrus and left anterior hippocampus. An analysis based on automatic segmentation of hippocampus confirmed the latest relationship which cannot be attributed to the correlation of each variable with global cognitive impairment because it remained when MMSE was accounted for. We observed a switch from frontal to temporo-parietal regions as words retrieval become more difficult over time. Automatic speech production of the early phase of the category fluency task is dependent on executive networks integrity whereas controlled speech production of the late phase is dependent on memory networks integrity, including left hippocampus. These results are concordant with recent imaging studies expanding the implication of hippocampus to semantic memory performances and they underlie the need to consider verbal fluency task over time.
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Affiliation(s)
- Gwénaëlle Catheline
- Univ. Bordeaux, INCIA, UMR 5287, Talence, France.,CNRS, INCIA, UMR 5287, Talence, France.,EPHE, Paris, France
| | - Hélène Amieva
- ISPED, Université de Bordeaux, Bordeaux, France.,Centre de Recherche Inserm U897, Bordeaux, France
| | - Bixente Dilharreguy
- Univ. Bordeaux, INCIA, UMR 5287, Talence, France.,CNRS, INCIA, UMR 5287, Talence, France
| | | | | | - Catherine Helmer
- ISPED, Université de Bordeaux, Bordeaux, France.,Centre de Recherche Inserm U897, Bordeaux, France
| | - Jean-François Dartigues
- ISPED, Université de Bordeaux, Bordeaux, France.,Centre de Recherche Inserm U897, Bordeaux, France
| | - Michèle Allard
- Univ. Bordeaux, INCIA, UMR 5287, Talence, France.,CNRS, INCIA, UMR 5287, Talence, France.,EPHE, Paris, France.,Chu de Bordeaux, France
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16
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Price CC, Tanner JJ, Schmalfuss I, Garvan CW, Gearen P, Dickey D, Heilman K, McDonagh DL, Libon DJ, Leonard C, Bowers D, Monk TG. A pilot study evaluating presurgery neuroanatomical biomarkers for postoperative cognitive decline after total knee arthroplasty in older adults. Anesthesiology 2014; 120:601-13. [PMID: 24534857 DOI: 10.1097/aln.0000000000000080] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Total knee arthroplasty improves quality of life but is associated with postoperative cognitive dysfunction in older adults. This prospective longitudinal pilot study with a parallel control group tested the hypotheses that (1) nondemented adults would exhibit primary memory and executive difficulties after total knee arthroplasty, and (2) reduced preoperative hippocampus/entorhinal volume would predict postoperative memory change, whereas preoperative leukoaraiosis and lacunae volumes would predict postoperative executive dysfunction. METHODS Surgery (n = 40) and age-education-matched controls with osteoarthritis (n = 15) completed pre- and postoperative (3 weeks, 3 months, and 1 yr) memory and cognitive testing. Hypothesized brain regions of interest were measured in patients completing preoperative magnetic resonance scans (surgery, n = 31; control, n = 12). Analyses used reliable change methods to identify the frequency of cognitive change at each time point. RESULTS The incidence of postoperative memory difficulties was shown with delay test indices (i.e., story memory test: 3 weeks = 17%, 3 months = 25%, 1 yr = 9%). Postoperative executive difficulty with measures of inhibitory function (i.e., Stroop Color Word: 3 weeks = 21%, 3 months = 22%, 1 yr = 9%). Hierarchical regression analysis assessing the predictive interaction of group (surgery, control) and preoperative neuroanatomical structures on decline showed that greater preoperative volumes of leukoaraiosis/lacunae were significantly contributed to postoperative executive (inhibitory) declines. CONCLUSIONS This pilot study suggests that executive and memory declines occur in nondemented adults undergoing orthopedic surgery. Severity of preoperative cerebrovascular disease may be relevant for understanding executive decline, in particular.
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Affiliation(s)
- Catherine C Price
- From the Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida (C.C.P., J.J.T., D.D., and D.B.); Joint Appointment, Department of Anesthesiology, University of Florida, Gainesville, Florida (C.C.P.); Department of Radiology, University of Florida, Gainesville, Florida (I.S.); Department of Radiology, North Florida South Georgia Veteran Association, Gainesville, Florida (I.S.); Health Science Center, University of Florida, Gainesville, Florida (C.W.G.); Department of Orthopedic Surgery, University of Florida, Gainesville, Florida (P.G. and D.B.); Department of Neurology, University of Florida, Gainesville, Florida (K.H. and T.G.M.); Department of Anesthesiology, Duke University, Durham, North Carolina (D.L.M.); Department of Neurology, Drexel University, Philadelphia, Pennsylvania (D.J.L.); and Department of Neuroscience, University of Florida, Gainesville, Florida (C.L.)
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Maruszak A, Thuret S. Why looking at the whole hippocampus is not enough-a critical role for anteroposterior axis, subfield and activation analyses to enhance predictive value of hippocampal changes for Alzheimer's disease diagnosis. Front Cell Neurosci 2014; 8:95. [PMID: 24744700 PMCID: PMC3978283 DOI: 10.3389/fncel.2014.00095] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 03/13/2014] [Indexed: 01/06/2023] Open
Abstract
The hippocampus is one of the earliest affected brain regions in Alzheimer's disease (AD) and its dysfunction is believed to underlie the core feature of the disease-memory impairment. Given that hippocampal volume is one of the best AD biomarkers, our review focuses on distinct subfields within the hippocampus, pinpointing regions that might enhance the predictive value of current diagnostic methods. Our review presents how changes in hippocampal volume, shape, symmetry and activation are reflected by cognitive impairment and how they are linked with neurogenesis alterations. Moreover, we revisit the functional differentiation along the anteroposterior longitudinal axis of the hippocampus and discuss its relevance for AD diagnosis. Finally, we indicate that apart from hippocampal subfield volumetry, the characteristic pattern of hippocampal hyperactivation associated with seizures and neurogenesis changes is another promising candidate for an early AD biomarker that could become also a target for early interventions.
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Affiliation(s)
- Aleksandra Maruszak
- Centre for the Cellular Basis of Behaviour, Department of Neuroscience, Institute of Psychiatry, King’s College LondonLondon, UK
| | - Sandrine Thuret
- Centre for the Cellular Basis of Behaviour, Department of Neuroscience, Institute of Psychiatry, King’s College LondonLondon, UK
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Teipel S, Heinsen H, Amaro E, Grinberg LT, Krause B, Grothe M. Cholinergic basal forebrain atrophy predicts amyloid burden in Alzheimer's disease. Neurobiol Aging 2013; 35:482-91. [PMID: 24176625 DOI: 10.1016/j.neurobiolaging.2013.09.029] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/09/2013] [Accepted: 09/19/2013] [Indexed: 01/24/2023]
Abstract
We compared accuracy of hippocampus and basal forebrain cholinergic system (BFCS) atrophy to predict cortical amyloid burden in 179 cognitively normal subjects (CN), 269 subjects with early stages of mild cognitive impairment (MCI), 136 subjects with late stages of MCI, and 86 subjects with Alzheimer's disease (AD) dementia retrieved from the Alzheimer's Disease Neuroimaging Initiative database. Hippocampus and BFCS volumes were determined from structural magnetic resonance imaging scans at 3 Tesla, and cortical amyloid load from AV45 (florbetapir) positron emission tomography scans. In receiver operating characteristics analyses, BFCS volume provided significantly more accurate classification into amyloid-negative and -positive categories than hippocampus volume. In contrast, hippocampus volume more accurately identified the diagnostic categories of AD, late and early MCI, and CN compared with whole and anterior BFCS volume, whereas posterior BFCS and hippocampus volumes yielded similar diagnostic accuracy. In logistic regression analysis, hippocampus and posterior BFCS volumes contributed significantly to discriminate MCI and AD from CN, but only BFCS volume predicted amyloid status. Our findings suggest that BFCS atrophy is more closely associated with cortical amyloid burden than hippocampus atrophy in predementia AD.
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Affiliation(s)
- Stefan Teipel
- Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany; DZNE, German Center for Neurodegenerative Disorders, Rostock, Germany.
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Foss MP, Diniz PRB, Formigheri P, Salmon CEG, Speciali JG, Santos AC. Magnetic resonance imaging and neuropsychological testing in the spectrum of normal aging. Clinics (Sao Paulo) 2013; 68:1197-205. [PMID: 24141834 PMCID: PMC3782730 DOI: 10.6061/clinics/2013(09)04] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Revised: 01/15/2013] [Accepted: 04/16/2013] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE To understand the relationships between brain structures and function (behavior and cognition) in healthy aging. METHOD The study group was composed of 56 healthy elderly subjects who underwent neuropsychological assessment and quantitative magnetic resonance imaging. Cluster analysis classified the cohort into two groups, one (cluster 1) in which the magnetic resonance imaging metrics were more preserved (mean age: 66.4 years) and another (cluster 2) with less preserved markers of healthy brain tissue (mean age: 75.4 years). RESULTS The subjects in cluster 2 (older group) had worse indices of interference in the Stroop test compared with the subjects in cluster 1 (younger group). Therefore, a simple test such as the Stroop test could differentiate groups of younger and older subjects based on magnetic resonance imaging metrics. CONCLUSION These results are in agreement with the inhibitory control hypotheses regarding cognitive aging and may also be important in the interpretation of studies with other clinical groups, such as patients with dementia and mild cognitive impairment.
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Affiliation(s)
- Maria Paula Foss
- Neurosciences Program, Department of Neurosciences and Behavioral Sciences, Faculdade de Medicina de Ribeirão Preto, Hospital das Clínicas de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brazil
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Daulatzai MA. Neurotoxic Saboteurs: Straws that Break the Hippo’s (Hippocampus) Back Drive Cognitive Impairment and Alzheimer’s Disease. Neurotox Res 2013; 24:407-59. [DOI: 10.1007/s12640-013-9407-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/06/2013] [Accepted: 06/17/2013] [Indexed: 12/29/2022]
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21
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Bennett DA, Wilson RS, Arvanitakis Z, Boyle PA, de Toledo-Morrell L, Schneider JA. Selected findings from the Religious Orders Study and Rush Memory and Aging Project. J Alzheimers Dis 2013; 33 Suppl 1:S397-403. [PMID: 22647261 DOI: 10.3233/jad-2012-129007] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The Religious Orders Study and the Rush Memory and Aging Project are both cohort studies of aging and dementia that include organ donation at death. Together, more than 2,700 persons have agreed to annual clinical evaluation and brain donation at death. A subset of participants also participated in a substudy that included ante-mortem imaging. We highlight recent findings that have been highly cited over the past five years. The findings fall into three general categories. The first relates to the neuropathology of probable Alzheimer's disease, mild cognitive impairment, and those without dementia or mild cognitive impairment. The second relates to risk factors for Alzheimer's disease and neuropathology. The third are clinical and imaging studies of mild cognitive impairment. The findings illustrate the range of insights that can be gained into cognitive aging by incorporating neuropathologic indices into well designed, prospective cohort studies.
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Affiliation(s)
- David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA. David A
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22
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Vuoksimaa E, Panizzon MS, Chen CH, Eyler LT, Fennema-Notestine C, Fiecas MJA, Fischl B, Franz CE, Grant MD, Jak AJ, Lyons MJ, Neale MC, Thompson WK, Tsuang MT, Xian H, Dale AM, Kremen WS. Cognitive reserve moderates the association between hippocampal volume and episodic memory in middle age. Neuropsychologia 2013; 51:1124-31. [PMID: 23499725 DOI: 10.1016/j.neuropsychologia.2013.02.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 02/26/2013] [Accepted: 02/28/2013] [Indexed: 10/27/2022]
Abstract
Cognitive reserve is hypothesized to help people withstand greater brain pathology without manifesting clinical symptoms, and may be regarded as a preventive factor of dementia. It is unclear whether the effect of cognitive reserve is evident only among the older adults or after conversion to dementia, or if it can also be seen earlier in life before the prominent effects of cognitive aging become apparent. While finding a main effect of cognitive reserve on cognitive outcome may be consistent with the reserve hypothesis, in our view, it is unnecessary to invoke the idea of reserve if only a main effect is present. Rather, it is the interaction between a measure of reserve and a brain measure on cognitive outcome that is key for confirming that the effects of brain pathology affect people differently according to their cognitive reserve. We studied whether general cognitive ability at an average age of 20 years, as a direct measure of cognitive reserve, moderates the association between hippocampal volume and episodic memory performance in 494 middle-aged men ages 51 to 60. Whereas there was no statistically significant direct relationship between hippocampal volume and episodic memory performance in middle age, we found a statistically significant interaction such that there was a positive association between hippocampal volume and episodic memory only among people with lower general cognitive ability at age 20, i.e., lower levels of cognitive reserve. Our results provide support for the hypothesis that cognitive reserve moderates the relationship between brain structure and cognition in middle age, well before the onset of dementia.
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Affiliation(s)
- Eero Vuoksimaa
- Department of Psychiatry, University of California-San Diego, La Jolla, CA, USA.
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23
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DeCarli C. Clinically asymptomatic vascular brain injury: a potent cause of cognitive impairment among older individuals. J Alzheimers Dis 2013; 33 Suppl 1:S417-26. [PMID: 23034523 PMCID: PMC3786369 DOI: 10.3233/jad-2012-129004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cerebrovascular risk factors and stroke are highly prevalent with advancing age, and stroke may be more common than Alzheimer's disease, particularly among older men. While stroke mortality continues to decline, the prevalence of individuals with various vascular risk factors continues to rise and many are undiagnosed or undertreated. Asymptomatic cerebrovascular brain injury that includes asymptomatic brain infarction and white matter hyperintensities as well as accelerated brain atrophy is even more frequent than clinical stroke. Moreover, the impact of cerebrovascular risk factors on brain injury appears to begin in middle life and additively increases the likelihood of later life dementia. This review focuses on the use of neuroimaging and genetics to understand the impact of asymptomatic vascular risk factors on the trajectories of cognitive aging as well as incident cognitive impairment, stroke, and mortality. Results of this review emphasize the need for early detection and treatment of vascular risk factors to improve the cognitive health of our rapidly aging population.
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Affiliation(s)
- Charles DeCarli
- Alzheimer's Disease Center, Imaging of Dementia and Aging (IDeA) Laboratory, Department of Neurology and Center for Neuroscience, University of California at Davis, CA 95817, USA.
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Rogers BP, Sheffield JM, Luksik AS, Heckers S. Systematic Error in Hippocampal Volume Asymmetry Measurement is Minimal with a Manual Segmentation Protocol. Front Neurosci 2012; 6:179. [PMID: 23248580 PMCID: PMC3521226 DOI: 10.3389/fnins.2012.00179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 11/26/2012] [Indexed: 11/13/2022] Open
Abstract
Hemispheric asymmetry of hippocampal volume is a common finding that has biological relevance, including associations with dementia and cognitive performance. However, a recent study has reported the possibility of systematic error in measurements of hippocampal asymmetry by magnetic resonance volumetry. We manually traced the volumes of the anterior and posterior hippocampus in 40 healthy people to measure systematic error related to image orientation. We found a bias due to the side of the screen on which the hippocampus was viewed, such that hippocampal volume was larger when traced on the left side of the screen than when traced on the right (p = 0.05). However, this bias was smaller than the anatomical right > left asymmetry of the anterior hippocampus. We found right > left asymmetry of hippocampal volume regardless of image presentation (radiological versus neurological). We conclude that manual segmentation protocols can minimize the effect of image orientation in the study of hippocampal volume asymmetry, but our confirmation that such bias exists suggests strategies to avoid it in future studies.
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Affiliation(s)
- Baxter P Rogers
- Department of Radiology and Radiological Sciences, Vanderbilt University Nashville, TN, USA ; Department of Biomedical Engineering, Vanderbilt University Nashville, TN, USA
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25
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den Heijer T, der Lijn FV, Vernooij M, de Groot M, Koudstaal P, der Lugt AV, Krestin G, Hofman A, Niessen W, Breteler M. Structural and diffusion MRI measures of the hippocampus and memory performance. Neuroimage 2012; 63:1782-9. [DOI: 10.1016/j.neuroimage.2012.08.067] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 08/23/2012] [Accepted: 08/27/2012] [Indexed: 10/27/2022] Open
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Wisse LEM, Gerritsen L, Zwanenburg JJM, Kuijf HJ, Luijten PR, Biessels GJ, Geerlings MI. Subfields of the hippocampal formation at 7T MRI: In vivo volumetric assessment. Neuroimage 2012; 61:1043-9. [PMID: 22440643 DOI: 10.1016/j.neuroimage.2012.03.023] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 02/17/2012] [Accepted: 03/01/2012] [Indexed: 11/29/2022] Open
Affiliation(s)
- L E M Wisse
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
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The age-related deficit in LTP is associated with changes in perfusion and blood-brain barrier permeability. Neurobiol Aging 2012; 33:1005.e23-35. [DOI: 10.1016/j.neurobiolaging.2011.09.035] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 09/22/2011] [Accepted: 09/30/2011] [Indexed: 12/11/2022]
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Smith CD. Structural imaging in early pre-states of dementia. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1822:317-24. [PMID: 21777674 PMCID: PMC3223541 DOI: 10.1016/j.bbadis.2011.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Revised: 06/19/2011] [Accepted: 07/06/2011] [Indexed: 01/18/2023]
Abstract
In this review focus is on structural imaging in the Alzheimer's disease (AD) pre-states, particularly cognitively normal (CN) persons at future dementia risk. Findings in mild cognitive impairment (MCI) are described here only for comparison with CN. Cited literature evidence and commentary address issues of structural imaging alterations in CN that precede MCI and AD, regional patterns of such alterations, and the time relationship between structural imaging alterations and the appearance of symptoms of AD, issues relevant to the conduct of future AD prevention trials. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.
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Affiliation(s)
- Charles D Smith
- Alzheimer's Disease Center, Sanders-Brown Center on Aging, University of Kentucky, USA.
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29
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Frota de Almeida MN, de Siqueira Mendes FDCC, Gurgel Felício AP, Falsoni M, Ferreira de Andrade ML, Bento-Torres J, da Costa Vasconcelos PF, Perry VH, Picanço-Diniz CW, Kronka Sosthenes MC. Spatial memory decline after masticatory deprivation and aging is associated with altered laminar distribution of CA1 astrocytes. BMC Neurosci 2012; 13:23. [PMID: 22376223 PMCID: PMC3355053 DOI: 10.1186/1471-2202-13-23] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 02/29/2012] [Indexed: 01/27/2023] Open
Abstract
Background Chewing imbalances are associated with neurodegeneration and are risk factors for senile dementia in humans and memory deficits in experimental animals. We investigated the impact of long-term reduced mastication on spatial memory in young, mature and aged female albino Swiss mice by stereological analysis of the laminar distribution of CA1 astrocytes. A soft diet (SD) was used to reduce mastication in the experimental group, whereas the control group was fed a hard diet (HD). Assays were performed in 3-, 6- and 18-month-old SD and HD mice. Results Eating a SD variably affected the number of astrocytes in the CA1 hippocampal field, and SD mice performed worse on water maze memory tests than HD mice. Three-month-old mice in both groups could remember/find a hidden platform in the water maze. However, 6-month-old SD mice, but not HD mice, exhibited significant spatial memory dysfunction. Both SD and HD 18-month-old mice showed spatial memory decline. Older SD mice had astrocyte hyperplasia in the strata pyramidale and oriens compared to 6-month-old mice. Aging induced astrocyte hypoplasia at 18 months in the lacunosum-moleculare layer of HD mice. Conclusions Taken together, these results suggest that the impaired spatial learning and memory induced by masticatory deprivation and aging may be associated with altered astrocyte laminar distribution and number in the CA1 hippocampal field. The underlying molecular mechanisms are unknown and merit further investigation.
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Affiliation(s)
- Marina Negrão Frota de Almeida
- Universidade Federal do Pará-UFPA, Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, PA, Brazil
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Woolard AA, Heckers S. Anatomical and functional correlates of human hippocampal volume asymmetry. Psychiatry Res 2012; 201:48-53. [PMID: 22285719 PMCID: PMC3289761 DOI: 10.1016/j.pscychresns.2011.07.016] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 07/24/2011] [Accepted: 07/28/2011] [Indexed: 10/14/2022]
Abstract
Hemispheric asymmetry of the human hippocampus is well established, but poorly understood. We studied 110 healthy subjects with 3-Tesla MRI to explore the anatomical and functional correlates of the R>L volume asymmetry. We found that the asymmetry is limited to the anterior hippocampus (hemisphere×region interaction: F(1,109)=42.6, p<.001). Anterior hippocampal volume was correlated strongly with the volumes of all four cortical lobes. In contrast, posterior hippocampal volume was correlated strongly only with occipital lobe volume, moderately with the parietal and temporal lobe volumes and not with the frontal lobe volume. The degree of R>L anterior hippocampal volume asymmetry predicted performance on a measure of basic cognitive abilities. This provides evidence for regional specificity and functional implications of the well-known hemispheric asymmetry of hippocampal volume. We suggest that the developmental profile, genetic mechanisms and functional implications of R>L anterior hippocampal volume asymmetry in the human brain deserve further study.
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Affiliation(s)
- Austin A Woolard
- Vaderbilt University, Department of Osychiatry, Nashville, TN, USA
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Archer T, Kostrzewa RM, Beninger RJ, Palomo T. Staging neurodegenerative disorders: structural, regional, biomarker, and functional progressions. Neurotox Res 2011; 19:211-34. [PMID: 20393891 DOI: 10.1007/s12640-010-9190-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 03/02/2010] [Accepted: 03/30/2010] [Indexed: 12/11/2022]
Abstract
The notion of staging in the neurodegenerative disorders is modulated by the constant and progressive loss of several aspects of brain structural integrity, circuitry, and neuronal processes. These destructive processes eventually remove individuals' abilities to perform at sufficient and necessary functional capacity at several levels of disease severity. The classification of (a) patients on the basis of diagnosis, risk prognosis, and intervention outcome, forms the basis of clinical staging, and (b) laboratory animals on the basis of animal model of brain disorder, extent of insult, and dysfunctional expression, provides the components for the clinical staging and preclinical staging, respectively, expressing associated epidemiological, biological, and genetic characteristics. The major focus of clinical staging in the present account stems from the fundamental notions of Braak staging as they describe the course and eventual prognosis for Alzheimer's disease, Lewy Body dementia, and Parkinson's disease. Mild cognitive impairment, which expresses the decline in episodic and semantic memory performance below the age-adjusted normal range without marked loss of global cognition or activities of daily living, and the applications of longitudinal magnetic resonance imaging, major instruments for the monitoring of either disease progression in dementia, present important challenges for staging concepts. Although Braak notions present the essential basis for further developments, current staging conceptualizations seem inadequate to comply with the massive influx of information dealing with neurodegenerative processes in brain, advanced both under clinical realities, and discoveries in the laboratory setting. The contributions of various biomarkers of disease progression, e.g., amyloid precursor protein, and neurotransmitter system imbalances, e.g., dopamine receptor supersensitivity and interactive propensities, await their incorporation into the existing staging models thereby underlining the ongoing, dynamic feature of the staging of brain disorders.
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Affiliation(s)
- Trevor Archer
- Department of Psychology, University of Gothenburg, Box 500, SE-405 30 Gothenburg, Sweden.
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Atienza M, Atalaia-Silva KC, Gonzalez-Escamilla G, Gil-Neciga E, Suarez-Gonzalez A, Cantero JL. Associative memory deficits in mild cognitive impairment: the role of hippocampal formation. Neuroimage 2011; 57:1331-42. [PMID: 21640840 DOI: 10.1016/j.neuroimage.2011.05.047] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/20/2011] [Accepted: 05/17/2011] [Indexed: 10/18/2022] Open
Abstract
Neuropathological events featuring early stages of Alzheimer's disease (AD) appear in the entorhinal cortex (EC), subiculum (SB) and cornu ammonis 1 (CA1) of hippocampus, which may account for associative memory deficits in non-demented people with mild cognitive impairment (MCI). To test this hypothesis in vivo, we investigated whether volume changes in these regions are related to failures in associative memory in MCI as compared to cognitively normal (CN) elderly subjects. Volume changes in EC and hippocampal subfields were determined by using deformation-based morphometry techniques applied to probabilistic cytoarchitectonic maps derived from post mortem human brains. CN subjects were distinguished from MCI patients by firstly identifying local volume differences in EC and hippocampus, and then evaluating the way in which these anatomical changes correlated with performance in a non-intentional face-location association task. MCI patients not only performed worse than CN elders in building new associations, but they were further unable to benefit from semantic encoding to improve episodic binding. According to our initial hypothesis, local volume reductions in both EC and hippocampal CA accounted for group differences in associative memory whereas atrophy in CA, but not in EC, accounted for semantic encoding of associations. Two main conclusions can be drawn from the present study: i) access to semantic information during encoding does not reduce the episodic deficit in MCI; and ii) EC and hippocampal CA, two regions early affected by AD neuropathology, are responsible, at least partially, for associative memory deficits observed in MCI patients.
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Affiliation(s)
- M Atienza
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), University Pablo de Olavide, Seville, Spain.
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Abstract
The hippocampus is a vulnerable and plastic brain structure that is damaged by a variety of stimuli, e.g. hypoxia, hypoperfusion, hypoglycaemia, stress and seizures. Alzheimer's disease is a common and important disorder in which hippocampal atrophy is reported. Indeed, the available evidence suggests that hippocampal atrophy is the starting point of the pathogenesis of Alzheimer's disease and a significant number of patients with hippocampal atrophy will develop Alzheimer's disease. Studies indicate that hippocampal atrophy has functional consequences, e.g. cognitive impairment. Deposition of tau protein, formation of neurofibrillary tangles and accumulation of β-amyloid (Aβ) contributes to hippocampal atrophy together with damage caused by several other factors. Some of the factors associated with the development of hippocampal atrophy in Alzheimer's disease have been identified, e.g. hypertension, diabetes mellitus, hyperlipidaemia, seizures, affective disturbances and stress, and more is being learnt about other factors. Hypertension can potentially damage the hippocampus through ischaemia caused by atherosclerosis and cerebral amyloid angiopathy. Diabetes can produce hippocampal lesions via both vascular and non-vascular pathologies and can reduce the threshold for hippocampal damage. Carriers of the apolipoprotein E (ApoE)-ε4 genotype have been shown to have greater mesial temporal atrophy and poorer memory functions than non-carriers. In addition to giving rise to abnormal lipid metabolism, the ApoE-ε4 allele can affect the course of Alzheimer's disease via both Aβ-dependent and -independent pathways. Repetitive seizures can increase Aβ-peptide production and cause neurotransmission dysfunction and cytoskeletal abnormalities or a combination of these. Affective disturbances and stress are proposed to increase corticosteroid-induced hippocampal damage in many different ways. In the absence of any specific markers for predicting Alzheimer's disease progression, it seems appropriate to learn more about the various predictors of hippocampal atrophy that determine the progression of Alzheimer's disease from mild cognitive impairment (MCI), and then attempt to address these. It would be interesting to know to what extent these predictors play a role in the development of MCI or hasten the conversion of MCI to full-blown Alzheimer's disease. Finally, it would be useful to know the extent to which these predictors can worsen or aggravate existing Alzheimer's disease. Of the clinically used drugs in Alzheimer's disease, anticholinesterases have been shown to slow down the rate of progression of hippocampal atrophy. One study observed that the neuroprotective effect of these agents is possibly due to an anti-Aβ effect produced by cholinergic stimulation. Similarly, antihypertensive and antihyperglycaemic drugs (pioglitazone and insulin) have been shown to reduce the risk of Alzheimer's disease or disease progression. Currently, there are no disease-modifying therapies available for Alzheimer's disease. It has been suggested that for treatment to be most effective, the regimen must be started before significant downstream damage has occurred (i.e. before the clinical diagnosis of Alzheimer's disease, at the stage of MCI or earlier). Since the hippocampus is a plastic structure and atrophy of this structure is closely related to the pathophysiology of Alzheimer's disease, if we could control blood pressure, regulate blood sugar, treat behavioural and psychological symptoms, achieve satisfactory lipid lowering and maintain a seizure-free state in patients with Alzheimer's disease, this may not only improve disease control but could also potentially affect the rate of disease progression.
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Affiliation(s)
- Vikas Dhikav
- Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India.
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Kerchner GA, Hess CP, Hammond-Rosenbluth KE, Xu D, Rabinovici GD, Kelley DAC, Vigneron DB, Nelson SJ, Miller BL. Hippocampal CA1 apical neuropil atrophy in mild Alzheimer disease visualized with 7-T MRI. Neurology 2010; 75:1381-7. [PMID: 20938031 DOI: 10.1212/wnl.0b013e3181f736a1] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES In Alzheimer disease (AD), mounting evidence points to a greater role for synaptic loss than neuronal loss. Supporting this notion, multiple postmortem studies have demonstrated that the hippocampal CA1 apical neuropil is one of the earliest sites of pathology, exhibiting tau aggregates and then atrophy before there is substantial loss of the CA1 pyramidal neurons themselves. In this cross-sectional study, we tested whether tissue loss in the CA1 apical neuropil layer can be observed in vivo in patients with mild AD. METHODS We performed ultra-high-field 7-T MRI on subjects with mild AD (n = 14) and age-matched normal controls (n = 16). With a 2-dimensional T2*-weighted gradient-recalled echo sequence that was easily tolerated by subjects, we obtained cross-sectional slices of the hippocampus at an in-plane resolution of 195 μm. RESULTS On images revealing the anatomic landmarks of hippocampal subfields and strata, we observed thinning of the CA1 apical neuropil in subjects with mild AD compared to controls. By contrast, the 2 groups exhibited no difference in the thickness of the CA1 cell body layer or of the entire CA1 subfield. Hippocampal volume, measured on a conventional T1-weighted sequence obtained at 3T, also did not differentiate these patients with mild AD from controls. CONCLUSIONS CA1 apical neuropil atrophy is apparent in patients with mild AD. With its superior spatial resolution, 7-T MRI permits in vivo analysis of a very focal, early site of AD pathology.
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Affiliation(s)
- G A Kerchner
- Stanford Center for Memory Disorders, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5235, USA.
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Abstract
The structure of the brain is constantly changing from birth throughout the lifetime, meaning that normal aging, free from dementia, is associated with structural brain changes. This paper reviews recent evidence from magnetic resonance imaging (MRI) studies about age-related changes in the brain. The main conclusions are that (1) the brain shrinks in volume and the ventricular system expands in healthy aging. However, the pattern of changes is highly heterogeneous, with the largest changes seen in the frontal and temporal cortex, and in the putamen, thalamus, and accumbens. With modern approaches to analysis of MRI data, changes in cortical thickness and subcortical volume can be tracked over periods as short as one year, with annual reductions of between 0.5% and 1.0% in most brain areas. (2) The volumetric brain reductions in healthy aging are likely only to a minor extent related to neuronal loss. Rather, shrinkage of neurons, reductions of synaptic spines, and lower numbers of synapses probably account for the reductions in grey matter. In addition, the length of myelinated axons is greatly reduced, up to almost 50%. (3) Reductions in specific cognitive abilities--for instance processing speed, executive functions, and episodic memory--are seen in healthy aging. Such reductions are to a substantial degree mediated by neuroanatomical changes, meaning that between 25% and 100% of the differences between young and old participants in selected cognitive functions can be explained by group differences in structural brain characteristics.
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Affiliation(s)
- Anders M Fjell
- Center for the Study of Human Cognition, Department of Psychology, University of Oslo, Norway.
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36
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Entorhinal cortex volume in older adults: reliability and validity considerations for three published measurement protocols. J Int Neuropsychol Soc 2010; 16:846-55. [PMID: 20937164 PMCID: PMC3070302 DOI: 10.1017/s135561771000072x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Measuring the entorhinal cortex (ERC) is challenging due to lateral border discrimination from the perirhinal cortex. From a sample of 39 nondemented older adults who completed volumetric image scans and verbal memory indices, we examined reliability and validity concerns for three ERC protocols with different lateral boundary guidelines (i.e., Goncharova, Dickerson, Stoub, & deToledo-Morrell, 2001; Honeycutt et al., 1998; Insausti et al., 1998). We used three novice raters to assess inter-rater reliability on a subset of scans (216 total ERCs), with the entire dataset measured by one rater with strong intra-rater reliability on each technique (234 total ERCs). We found moderate to strong inter-rater reliability for two techniques with consistent ERC lateral boundary endpoints (Goncharova, Honeycutt), with negligible to moderate reliability for the technique requiring consideration of collateral sulcal depth (Insausti). Left ERC and story memory associations were moderate and positive for two techniques designed to exclude the perirhinal cortex (Insausti, Goncharova), with the Insausti technique continuing to explain 10% of memory score variance after additionally controlling for depression symptom severity. Right ERC-story memory associations were nonexistent after excluding an outlier. Researchers are encouraged to consider challenges of rater training for ERC techniques and how lateral boundary endpoints may impact structure-function associations.
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Avila J, Insausti R, Del Rio J. Memory and neurogenesis in aging and Alzheimer's disease. Aging Dis 2010; 1:30-36. [PMID: 22396855 PMCID: PMC3295021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 05/11/2010] [Accepted: 05/12/2010] [Indexed: 05/31/2023] Open
Abstract
A possible link between a deficient neurogenesis at the dentate gyrus, and the loss of memory found in Alzheimer's disease patients is discussed. First is indicated that Alzheimer disease is a memory disorder. Since adult neurogenesis at the dentate gyrus plays a role in declarative memory, a brief comment on the structure and function of dentate gyrus has been included. At molecular level, we have discussed the function of the enzyme GSK3 on the development of neurogenesis at the subgranular zone of the dentate gyrus. Finally, we have indicated that in Alzheimer disease there is an increase in GSK3 activity. This increase could impair the neurogenesis process and it could result in the memory deficit found in Alzheimer patients.
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Affiliation(s)
- Jesus Avila
- Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Spanish Network of Excellence on Neurodegenerative Diseases (CIBERNED), Campus de Cantoblanco, 28049 Madrid, Spain
| | - Ricardo Insausti
- Human Neuroanatomy Laboratory, School of Medicine and CRIB, University of Castilla-La Mancha, 02006 Albacete, Spain
| | - Joaquin Del Rio
- Division of Neuroscience, Center for Applied Medical Research, University of Navarra, Spanish Network of Excellence on Neurodegenerative Diseases (CIBERNED), 31008 Pamplona, Spain
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Dolan D, Troncoso J, Resnick SM, Crain BJ, Zonderman AB, O'Brien RJ. Age, Alzheimer's disease and dementia in the Baltimore Longitudinal Study of Ageing. Brain 2010; 133:2225-31. [PMID: 20647264 DOI: 10.1093/brain/awq141] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Recent studies suggest that dementia in the most elderly (90 years of age and above) is only modestly related to Alzheimer's disease pathology. This raises the possibility that other, as yet unknown, disease processes may underlie dementia in this rapidly growing demographic group, and that efforts designed to combat Alzheimer's disease may not be appropriate for treating dementia in very elderly subjects. To study this question more closely, we examined the relationship between neocortical Alzheimer-type brain pathology and dementia in consecutive autopsies from 209 participants in the Baltimore Longitudinal Study of Ageing, a prospective longitudinal cohort study of the effect of ageing on cognition. Almost half of the cohort was older than 90 years of age at death. We found that several measures of neocortical Alzheimer's pathology, including the Consortium to Establish a Registry of Alzheimer's Disease neuritic plaque score and the Braak neurofibrillary tangle score, remained significant predictors of dementia, independent of age. In participants older than 90 years of age, intracranial atherosclerosis emerged as an important predictor of dementia in subjects with low Alzheimer's pathology scores, but did not mitigate the importance or population attributable risk of high Alzheimer's pathology scores on the odds of dementia. There was evidence that the threshold score for neurofibrillary pathology to cause dementia increased in the oldest subjects, but this was offset by an overall increase in neurofibrillary pathology in this age group. We conclude that neocortical Alzheimer's disease pathology remains significantly correlated with dementia, independent of age. In the most elderly, atherosclerosis also emerged as a cause of dementia in subjects with low Alzheimer's pathology scores. We found no evidence for a significant number of elderly subjects having dementia without an apparent cause.
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Affiliation(s)
- David Dolan
- Department of Neurology, Johns Hopkins Bayview Medical Centre, Baltimore, MD 21224, USA
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39
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Hippocampal atrophy in relapsing-remitting and primary progressive MS: a comparative study. Mult Scler 2010; 16:1083-90. [DOI: 10.1177/1352458510374893] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: In multiple sclerosis (MS), demyelination and neuroaxonal damage are seen in the hippocampus, and MRI has revealed hippocampal atrophy. Objectives: To investigate and compare hippocampal volume loss in patients with relapsing—remitting MS (RRMS) and primary progressive MS (PPMS) using manual volumetry, and explore its association with memory dysfunction. Methods: Hippocampi were manually delineated on volumetric MRI of 34 patients with RRMS, 23 patients with PPMS and 18 controls. Patients underwent neuropsychological tests of verbal and visuospatial recall memory. Linear regression was used to compare hippocampal volumes between subject groups, and to assess the association with memory function. Results: Hippocampal volumes were smaller in MS patients compared with controls, and were similar in patients with RRMS and PPMS. The mean decrease in hippocampal volume in MS patients was 317 mm3 (9.4%; 95% CI 86 to 549; p = 0.008) on the right and 284 mm3 (8.9%; 95% CI 61 to 508; p = 0.013) on the left. A borderline association of hippocampal volume with memory performance was observed only in patients with PPMS. Conclusion: Hippocampal atrophy occurs in patients with RRMS and PPMS. Factors additional to hippocampal atrophy may impact on memory performance.
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Abstract
The hippocampus is abnormal in schizophrenia. Smaller hippocampal volume is the most consistent finding and is present already in the early stages of the illness. The underlying cellular substrate is a subtle, yet functionally significant reduction of hippocampal interneurons. Neuroimaging studies have revealed a pattern of increased hippocampal activity at baseline and decreased recruitment during the performance of memory tasks. Hippocampal lesion models in rodents have replicated some of the pharmacological, anatomical and behavioral phenotype of schizophrenia. Taken together, this pattern of findings points to a disinhibition of hippocampal pyramidal cells and abnormal cortico-hippocampal interactions in schizophrenia.
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Affiliation(s)
- Stephan Heckers
- Department of Psychiatry, Vanderbilt University, 1601 23rd Avenue South, Room 3060, Nashville, TN 37212, USA.
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