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Sakaie K, Koenig K, Lerner A, Appleby B, Ogrocki P, Pillai JA, Rao S, Leverenz JB, Lowe MJ. Multi-shell diffusion MRI of the fornix as a biomarker for cognition in Alzheimer's disease. Magn Reson Imaging 2024; 109:221-226. [PMID: 38521367 DOI: 10.1016/j.mri.2024.03.030] [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: 07/25/2023] [Revised: 03/05/2024] [Accepted: 03/19/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND AND PURPOSE A substantial fraction of those who had Alzheimer's Disease (AD) pathology on autopsy did not have dementia in life. While biomarkers for AD pathology are well-developed, biomarkers specific to cognitive domains affected by early AD are lagging. Diffusion MRI (dMRI) of the fornix is a candidate biomarker for early AD-related cognitive changes but is susceptible to bias due to partial volume averaging (PVA) with cerebrospinal fluid. The purpose of this work is to leverage multi-shell dMRI to correct for PVA and to evaluate PVA-corrected dMRI measures in fornix as a biomarker for cognition in AD. METHODS Thirty-three participants in the Cleveland Alzheimer's Disease Research Center (CADRC) (19 with normal cognition (NC), 10 with mild cognitive impairment (MCI), 4 with dementia due to AD) were enrolled in this study. Multi-shell dMRI was acquired, and voxelwise fits were performed with two models: 1) diffusion tensor imaging (DTI) that was corrected for PVA and 2) neurite orientation dispersion and density imaging (NODDI). Values of tissue integrity in fornix were correlated with neuropsychological scores taken from the Uniform Data Set (UDS), including the UDS Global Composite 5 score (UDSGC5). RESULTS Statistically significant correlations were found between the UDSGC5 and PVA-corrected measure of mean diffusivity (MDc, r = -0.35, p < 0.05) from DTI and the intracelluar volume fraction (ficvf, r = 0.37, p < 0.04) from NODDI. A sensitivity analysis showed that the relationship to MDc was driven by episodic memory, which is often affected early in AD, and language. CONCLUSION This cross-sectional study suggests that multi-shell dMRI of the fornix that has been corrected for PVA is a potential biomarker for early cognitive domain changes in AD. A longitudinal study will be necessary to determine if the imaging measure can predict cognitive decline.
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Affiliation(s)
- Ken Sakaie
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA.
| | - Katherine Koenig
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA
| | - Alan Lerner
- Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Brian Appleby
- Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Paula Ogrocki
- Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jagan A Pillai
- Lou Ruvo Center for Brain Health, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-10, Cleveland, OH 44195, USA
| | - Stephen Rao
- Lou Ruvo Center for Brain Health, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-10, Cleveland, OH 44195, USA
| | - James B Leverenz
- Lou Ruvo Center for Brain Health, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-10, Cleveland, OH 44195, USA
| | - Mark J Lowe
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA
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2
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Davidson B, Vetkas A, Germann J, Tang-Wai D, Lozano AM. Deep brain stimulation for Alzheimer's disease - current status and next steps. Expert Rev Med Devices 2024; 21:285-292. [PMID: 38573133 DOI: 10.1080/17434440.2024.2337298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/26/2024] [Indexed: 04/05/2024]
Abstract
INTRODUCTION Alzheimer's disease (AD) requires novel therapeutic approaches due to limited efficacy of current treatments. AREAS COVERED This article explores AD as a manifestation of neurocircuit dysfunction and evaluates deep brain stimulation (DBS) as a potential intervention. Focusing on fornix-targeted stimulation (DBS-f), the article summarizes safety, feasibility, and outcomes observed in phase 1/2 trials, highlighting findings such as cognitive improvement, increased metabolism, and hippocampal growth. Topics for further study include optimization of electrode placement, and the role of stimulation-induced autobiographical-recall. Nucleus basalis of Meynert (DBS-NBM) DBS is also discussed and compared with DBS-f. Challenges with both DBS-f and DBS-NBM are identified, emphasizing the need for further research on optimal stimulation parameters. The article also reviews alternative DBS targets, including medial temporal lobe structures and the ventral capsule/ventral striatum. EXPERT OPINION Looking ahead, a phase-3 DBS-f trial, and the prospect of closed-loop stimulation using EEG-derived biomarkers or hippocampal theta activity are highlighted. Recent FDA-approved therapies and other neuromodulation techniques like temporal interference and low-intensity ultrasound are considered. The article concludes by underscoring the importance of imaging-based diagnosis and staging to allow for circuit-targeted therapies, given the heterogeneity of AD and varied stages of neurocircuit dysfunction.
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Affiliation(s)
- Benjamin Davidson
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada
| | - Artur Vetkas
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada
| | - Jürgen Germann
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada
- Krembil Research Institute, Toronto, ON, Canada
| | - David Tang-Wai
- Krembil Research Institute, Toronto, ON, Canada
- Department of Neurology, Toronto Western Hospital, University Health Network, Toronto, University of Toronto, ON, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada
- Krembil Research Institute, Toronto, ON, Canada
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Brenner EK, Bangen KJ, Clark AL, Delano-Wood L, Evangelista ND, Edwards L, Sorg SF, Jak AJ, Bondi MW, Deoni SCL, Lamar M. Sex moderates the association between age and myelin water fraction in the cingulum and fornix among older adults without dementia. Front Aging Neurosci 2023; 15:1267061. [PMID: 38161592 PMCID: PMC10757372 DOI: 10.3389/fnagi.2023.1267061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/27/2023] [Indexed: 01/03/2024] Open
Abstract
Background Decreasing white matter integrity in limbic pathways including the fornix and cingulum have been reported in Alzheimer's disease (AD), although underlying mechanisms and potential sex differences remain understudied. We therefore sought to explore sex as a moderator of the effect of age on myelin water fraction (MWF), a measure of myelin content, in older adults without dementia (N = 52). Methods Participants underwent neuropsychological evaluation and 3 T MRI at two research sites. Multicomponent driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) quantified MWF in 3 a priori regions including the fornix, hippocampal cingulum (CgH), and cingulate cingulum (CgC). The California Verbal Learning Test-Second Edition assessed learning and delayed recall. Multiple linear regressions assessed for (1) interactions between age and sex on regional MWF and (2) associations of regional MWF and memory. Results (1) There was a significant age by sex interaction on MWF of the fornix (p = 0.002) and CgC (p = 0.005), but not the CgH (p = 0.192); as age increased, MWF decreased in women but not men. (2) Fornix MWF was associated with both learning and recall (ps < 0.01), but MWF of the two cingulum regions were not (p > 0.05). Results were unchanged when adjusting for hippocampal volume. Conclusion The current work adds to the literature by illuminating sex differences in age-related myelin decline using a measure sensitive to myelin and may help facilitate detection of AD risk for women.
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Affiliation(s)
- Einat K. Brenner
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
| | - Katherine J. Bangen
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | - Alexandra L. Clark
- Department of Psychology, The University of Texas at Austin, Austin, TX, United States
| | - Lisa Delano-Wood
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | - Nicole D. Evangelista
- Department of Clinical and Health Psychology, Center for Cognitive Aging and Memory, College of Public Health and Health Professions, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Lauren Edwards
- Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California San Diego, San Diego, CA, United States
| | - Scott F. Sorg
- Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, Boston, MA, United States
| | - Amy J. Jak
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | - Mark W. Bondi
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | | | - Melissa Lamar
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, United States
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, IL, United States
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4
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Liu Z, Shu K, Geng Y, Cai C, Kang H. Deep brain stimulation of fornix in Alzheimer's disease: From basic research to clinical practice. Eur J Clin Invest 2023; 53:e13995. [PMID: 37004153 DOI: 10.1111/eci.13995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/13/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023]
Abstract
Alzheimer's disease (AD) is one of the most common progressive neurodegenerative diseases associated with the degradation of memory and cognitive ability. Current pharmacotherapies show little therapeutic effect in AD treatment and still cannot prevent the pathological progression of AD. Deep brain stimulation (DBS) has shown to enhance memory in morbid obese, epilepsy and traumatic brain injury patients, and cognition in Parkinson's disease (PD) patients deteriorates during DBS off. Some relevant animal studies and clinical trials have been carried out to discuss the DBS treatment for AD. Reviewing the fornix trials, no unified conclusion has been reached about the clinical benefits of DBS in AD, and the dementia ratings scale has not been effectively improved in the long term. However, some patients have presented promising results, such as improved glucose metabolism, increased connectivity in cognition-related brain regions and even elevated cognitive function rating scale scores. The fornix plays an important regulatory role in memory, attention, and emotion through its complex fibre projection to cognition-related structures, making it a promising target for DBS for AD treatment. Moreover, the current stereotaxic technique and various evaluation methods have provided references for the operator to select accurate stimulation points. Related adverse events and relatively higher costs in DBS have been emphasized. In this article, we summarize and update the research progression on fornix DBS in AD and seek to provide a reliable reference for subsequent experimental studies on DBS treatment of AD.
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Affiliation(s)
- Zhikun Liu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Kai Shu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Yumei Geng
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Chang Cai
- National Engineering Research Center for E-Learning, Central China Normal University, Wuhan, Hubei Province, China
| | - Huicong Kang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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Tan J, Wang Z, Tang Y, Tian Y. Alterations in Human Hippocampus Subregions across the Lifespan: Reflections on White Matter Structure and Functional Connectivity. Neural Plast 2023; 2023:7948140. [PMID: 37025422 PMCID: PMC10072963 DOI: 10.1155/2023/7948140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/08/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023] Open
Abstract
During growth and aging, the role of the hippocampus in memory depends on its interactions with related brain regions. Particularly, two subregions, anterior hippocampus (aHipp) and posterior hippocampus (pHipp), play different and critical roles in memory processing. However, age-related changes of hippocampus subregions on structure and function are still unclear. Here, we investigated age-related structural and functional characteristics of 106 participants (7-85 years old) in resting state based on fractional anisotropy (FA) and functional connectivity (FC) in aHipp and pHipp in the lifespan. The correlation between FA and FC was also explored to identify the coupling. Furthermore, the Wechsler Abbreviated Scale of Intelligence (WASI) was used to explore the relationship between cognitive ability and hippocampal changes. Results showed that there was functional separation and integration in aHipp and pHipp, and the number of functional connections in pHipp was more than that in aHipp across the lifespan. The age-related FC changes showed four different trends (U-shaped/inverted U-shaped/linear upward/linear downward). And around the age of 40 was a critical period for transformation. Then, FA analyses indicated that all effects of age on the hippocampal structures were nonlinear, and the white matter integrity of pHipp was higher than that of aHipp. In the functional-structural coupling, we found that the age-related FA of the right aHipp (aHipp.R) was negatively related to the FC. Finally, through the WASI, we found that the age-related FA of the left aHipp (aHipp.L) was positively correlated with verbal IQ (VERB) and vocabulary comprehension (VOCAB.T), the FA of aHipp.R was only positively correlated with VERB, and the FA of the left pHipp (pHipp.L) was only positively correlated with VOCAB.T. These FC and FA results supported that age-related normal memory changes were closely related to the hippocampus subregions. We also provided empirical evidence that memory ability was altered with the hippocampus, and its efficiency tended to decline after age 40.
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Fuentes M, Sales A, Charquero-Ballester M, García-Martí G, Meléndez JC, Espert R, Scheel M, Bauknecht HC, Simon K, Köpstein U, Gebauer S, Algarabel S. Impaired recollection and initially preserved familiarity in a patient with bilateral fornix transection following third ventricle colloid cyst removal: A two-year follow-up study. APPLIED NEUROPSYCHOLOGY. ADULT 2022:1-13. [PMID: 35917584 DOI: 10.1080/23279095.2022.2104162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
OBJECTIVE Recognition memory is widely accepted as a dual process-based model, namely familiarity and recollection. However, the location of their specific neurobiological substrates remains unclear. Similar to hippocampal damage, fornix damage has been associated with recollection memory but not familiarity memory deficits. To understand the neural basis of recognition memory, determining the importance of the fornix and its hippocampal connections is essential. METHODS Recognition memory was examined in a 45-year-old male who underwent a complete bilateral fornix section following the removal of a third ventricle colloid cyst. The application of familiarity and recollection for recognition memory decisions was investigated via an immediate and delayed associative recognition test and an immediate and delayed forced-choice task in the patient and a control group (N = 15) over a two-year follow-up period. Complete demographic, neuropsychological, neuropsychiatric, and neuroradiological characterizations of this patient were performed. RESULTS Persistent immediate and delayed verbal recollection memory deficits were observed in the patient. Moreover, delayed familiarity-based recognition memory declined gradually over the follow-up period, immediate familiarity-based recognition memory was unaffected, and reduced non-verbal memory improved. CONCLUSION The present findings support models that the extended hippocampal system, including the fornices, does not appear to play a role in familiarity memory but is particularly important for recollection memory. Moreover, our study suggests that bilateral fornix transection may be associated with relatively functional recovery of non-verbal memory.
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Affiliation(s)
- Manuel Fuentes
- Department of Geriatrics and Day Centre, Geriatric Orthopaedic Surgery Centre, Caritas-Klinik Dominikus, Berlin-Reinickendorf, Berlin, Germany
| | - Alicia Sales
- Department of Psychology, University of Valencia, Valencia, Spain
| | | | - Gracián García-Martí
- CIBER of Mental Health (CIBERSAM), Hospital Clínico Universitario de Valencia, Valencia, Spain
- Quirónsalud Hospital, Valencia, Spain
| | | | - Raul Espert
- Department of Psychology, University of Valencia, Valencia, Spain
| | - Michael Scheel
- Department of Neuroradiology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Hans-Christian Bauknecht
- Department of Neuroradiology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Katja Simon
- Department of Geriatrics and Day Centre, Geriatric Orthopaedic Surgery Centre, Caritas-Klinik Dominikus, Berlin-Reinickendorf, Berlin, Germany
| | - Uta Köpstein
- Department of Geriatrics and Day Centre, Geriatric Orthopaedic Surgery Centre, Caritas-Klinik Dominikus, Berlin-Reinickendorf, Berlin, Germany
| | - Sibylle Gebauer
- Department of Geriatrics and Day Centre, Geriatric Orthopaedic Surgery Centre, Caritas-Klinik Dominikus, Berlin-Reinickendorf, Berlin, Germany
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7
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Predovan D, Gazes Y, Lee S, Li P, Sloan RP, Stern Y. Effect of Aerobic Exercise on White Matter Tract Microstructure in Young and Middle-Aged Healthy Adults. Front Hum Neurosci 2021; 15:681634. [PMID: 34276329 PMCID: PMC8283503 DOI: 10.3389/fnhum.2021.681634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Recent evidence suggests that being physically active can mitigate age-related white matter (WM) changes. In a randomized clinical trial, the effect of 6-month aerobic exercise (AE) or stretching/toning interventions on measures of WM microstructure (WMM) was assessed in a sample of 74 adults aged 20-67 years. Major WM pathways were reconstructed. No significant group-level change in WM tract microstructure following an AE training was observed. Without adjustment for multiple comparisons, an increase in fractional anisotropy (FA) and a decrease in mean diffusivity (MD) of the uncinate fasciculus were observed post-intervention in the AE group in comparison with the stretching group. In the AE group, a significant increase in cardiorespiratory fitness was measured but did not correlate with FA and MD change. The present results of this study are in accordance with similar studies in healthy adults that did not show significant benefit on WMM after participating in an AE program. Clinical Trial Registration: Clinicaltrials.gov identifier, NCT01179958.
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Affiliation(s)
- David Predovan
- Cognitive Neuroscience Division, The Taub Institute for Research on Aging and Alzheimer's Disease, Columbia University, New York, NY, United States
| | - Yunglin Gazes
- Cognitive Neuroscience Division, The Taub Institute for Research on Aging and Alzheimer's Disease, Columbia University, New York, NY, United States
| | - Seonjoo Lee
- Department of Biostatistics, Columbia University, New York, NY, United States.,Mental Health Data Science, New York State Psychiatric Institute, New York, NY, United States
| | - Peipei Li
- Cognitive Neuroscience Division, The Taub Institute for Research on Aging and Alzheimer's Disease, Columbia University, New York, NY, United States
| | - Richard P Sloan
- Division of Behavioral Medicine, Department of Psychiatry, Columbia University, New York, NY, United States
| | - Yaakov Stern
- Cognitive Neuroscience Division, The Taub Institute for Research on Aging and Alzheimer's Disease, Columbia University, New York, NY, United States
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Diffusion properties of the fornix assessed by deterministic tractography shows age, sex, volume, cognitive, hemispheric, and twin relationships in young adults from the Human Connectome Project. Brain Struct Funct 2021; 226:381-395. [PMID: 33386420 DOI: 10.1007/s00429-020-02181-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
The fornix is the primary efferent pathway of the hippocampus and plays a central role in memory circuitry. Diffusion tensor imaging has shown changes in the fornix with typical development and aging. Here, the fornix was investigated in 903 healthy young adult participants aged 22-36 years old from the high-spatial resolution 1.25 mm isotropic Human Connectome Project (HCP) diffusion dataset. Manual deterministic tractography was used to assess relationships between fornix diffusion parameters and age, sex, laterality, hippocampus volume, memory scores, and genetic effects in a subgroup of mono- and dizygotic twins. Fornix diffusion metrics were weakly correlated with age over the given age span. While significant hemispheric and sex differences were observed (greater fractional anisotropy (FA) and volume in the right hemisphere; greater FA and volume in females), there was great overlap between the groups. Hippocampus volume measurements showed greater volume in the right hemisphere, were found to be larger in males, and were weakly correlated with fornix FA and volume. Interestingly, all fornix diffusion measurements correlated strongly with fornix volume, suggesting the presence of partial volume effects despite the high-spatial resolution of the data. Both fornix diffusion parameters and hippocampal volumes were able to explain some variance (0.6-5.5%) in the memory tests evaluated. The fornix diffusion parameters were influenced by both genetic and shared environmental factors, displaying greater variability in dizygotic than in monozygotic twins. These findings provide a comprehensive depiction of the fornix in healthy, young individuals, upon which future typical development/aging and pathological studies could anchor.
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Nicolas R, Hiba B, Dilharreguy B, Barse E, Baillet M, Edde M, Pelletier A, Periot O, Helmer C, Allard M, Dartigues JF, Amieva H, Pérès K, Fernandez P, Catheline G. Changes Over Time of Diffusion MRI in the White Matter of Aging Brain, a Good Predictor of Verbal Recall. Front Aging Neurosci 2020; 12:218. [PMID: 32922282 PMCID: PMC7456903 DOI: 10.3389/fnagi.2020.00218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/19/2020] [Indexed: 11/13/2022] Open
Abstract
Objective: Extensive research using water-diffusion MRI reported age-related modifications of cerebral White Matter (WM). Moreover, water-diffusion parameter modifications have been frequently associated with cognitive performances in the elderly sample, reinforcing the idea of aging inducing microstructural disconnection of the brain which in turn impacts cognition. However, only few studies really assessed over-time modifications of these parameters and their relationship with episodic memory outcome of elderly. Materials and Methods: One-hundred and thirty elderly subjects without dementia (74.1 ± 4.1 years; 47% female) were included in this study. Diffusion tensor imaging (DTI) was performed at two-time points (3.49 ± 0.68 years apart), allowing the assessment of changes in water-diffusion parameters over time using a specific longitudinal pipeline. White matter hyperintensity (WMH) burden and gray matter (GM) atrophy were also measured on FLAIR and T1-weighted sequences collected during these two MRI sessions. Free and cued verbal recall scores assessed at the last follow-up of the cohort were used as episodic memory outcome. Changes in water-diffusion parameters over time were included in serial linear regression models to predict retrieval or storage ability of elderly. Results: GM atrophy and an increase in mean diffusivity (MD) and WMH load between the two-time points were observed. The increase in MD was significantly correlated with WMH load and the different memory scores. In models accounting for the baseline cognitive score, GM atrophy, or WMH load, MD changes still significantly predict free verbal recall, and not total verbal recall, suggesting the specific association with the retrieval deficit in healthy aging. Conclusion: In elderly, microstructural WM changes are good predictors of lower free verbal recall performances. Moreover, this contribution is not only driven by WMH load increase. This last observation is in line with studies reporting early water-diffusion modification in WM tissue during aging, resulting lately in the appearance of WMH on conventional MRI.
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Affiliation(s)
- Renaud Nicolas
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France
| | - Bassem Hiba
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France
| | - Bixente Dilharreguy
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France
| | - Elodie Barse
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Laboratoire Neuroimagerie et vie quotidienne, EPHE-PSL University, Bordeaux, France
| | - Marion Baillet
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Laboratoire Neuroimagerie et vie quotidienne, EPHE-PSL University, Bordeaux, France
| | - Manon Edde
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Laboratoire Neuroimagerie et vie quotidienne, EPHE-PSL University, Bordeaux, France
| | - Amandine Pelletier
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Laboratoire Neuroimagerie et vie quotidienne, EPHE-PSL University, Bordeaux, France
| | - Olivier Periot
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France
| | - Catherine Helmer
- Université de Bordeaux, ISPED, Centre INSERM U1219-Bordeaux Population Health Research Center, Bordeaux, France.,INSERM, ISPED, Centre INSERM U1219-Bordeaux Population Heath Research Center, Bordeaux, France
| | - Michele Allard
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Service de Médecine Nucléaire, CHU de Bordeaux, Bordeaux, France
| | - Jean-François Dartigues
- Université de Bordeaux, ISPED, Centre INSERM U1219-Bordeaux Population Health Research Center, Bordeaux, France.,INSERM, ISPED, Centre INSERM U1219-Bordeaux Population Heath Research Center, Bordeaux, France.,CMRR, CHU de Bordeaux, Bordeaux, France
| | - Hélène Amieva
- Université de Bordeaux, ISPED, Centre INSERM U1219-Bordeaux Population Health Research Center, Bordeaux, France.,INSERM, ISPED, Centre INSERM U1219-Bordeaux Population Heath Research Center, Bordeaux, France
| | - Karine Pérès
- Université de Bordeaux, ISPED, Centre INSERM U1219-Bordeaux Population Health Research Center, Bordeaux, France.,INSERM, ISPED, Centre INSERM U1219-Bordeaux Population Heath Research Center, Bordeaux, France
| | - Philippe Fernandez
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Service de Médecine Nucléaire, CHU de Bordeaux, Bordeaux, France
| | - Gwénaëlle Catheline
- Université de Bordeaux, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,CNRS, INCIA, UMR 5287-équipe NeuroImagerie et Cognition Humaine, Bordeaux, France.,Laboratoire Neuroimagerie et vie quotidienne, EPHE-PSL University, Bordeaux, France
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Hayek D, Thams F, Flöel A, Antonenko D. Dentate Gyrus Volume Mediates the Effect of Fornix Microstructure on Memory Formation in Older Adults. Front Aging Neurosci 2020; 12:79. [PMID: 32265687 PMCID: PMC7098987 DOI: 10.3389/fnagi.2020.00079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 03/04/2020] [Indexed: 12/25/2022] Open
Abstract
Age-related deterioration in white and gray matter is linked to cognitive deficits. Reduced microstructure of the fornix, the major efferent pathway of the hippocampus, and volume of the dentate gyrus (DG), may cause age-associated memory decline. However, the linkage between these anatomical determinants and memory retrieval in healthy aging are poorly understood. In 30 older adults, we acquired diffusion tensor and T1-weighted images for individual deterministic tractography and volume estimation. A memory task, administered outside of the scanner to assess retrieval of learned associations, required discrimination of previously acquired picture-word pairs. The results showed that fornix fractional anisotropy (FA) and left DG volumes were related to successful retrieval. These brain-behavior associations were observed for correct rejections, but not hits, indicating specificity of memory network functioning for detecting false associations. Mediation analyses showed that left DG volume mediated the effect of fornix FA on memory (48%), but not vice versa. These findings suggest that reduced microstructure induces volume loss and thus negatively affects retrieval of learned associations, complementing evidence of a pivotal role of the fornix in healthy aging. Our study offers a neurobehavioral model to explain variability in memory retrieval in older adults, an important prerequisite for the development of interventions to counteract cognitive decline.
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Affiliation(s)
- Dayana Hayek
- Department of Neurology, NeuroCure Clinical Research Center, Berlin Institute of Health, Corporate Member of Freie Universität Berlin, Charité - Universitätsmedizin Berlin, Humboldt-Universität Berlin, Berlin, Germany.,Department of Neurology, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Friederike Thams
- Department of Neurology, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Agnes Flöel
- Department of Neurology, NeuroCure Clinical Research Center, Berlin Institute of Health, Corporate Member of Freie Universität Berlin, Charité - Universitätsmedizin Berlin, Humboldt-Universität Berlin, Berlin, Germany.,Department of Neurology, Universitätsmedizin Greifswald, Greifswald, Germany.,German Centre for Neurodegenerative Diseases (DZNE) Standort Greifswald, Greifswald, Germany
| | - Daria Antonenko
- Department of Neurology, NeuroCure Clinical Research Center, Berlin Institute of Health, Corporate Member of Freie Universität Berlin, Charité - Universitätsmedizin Berlin, Humboldt-Universität Berlin, Berlin, Germany.,Department of Neurology, Universitätsmedizin Greifswald, Greifswald, Germany
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11
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Coad BM, Craig E, Louch R, Aggleton JP, Vann SD, Metzler-Baddeley C. Precommissural and postcommissural fornix microstructure in healthy aging and cognition. Brain Neurosci Adv 2020; 4:2398212819899316. [PMID: 32219177 PMCID: PMC7085915 DOI: 10.1177/2398212819899316] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 12/11/2019] [Indexed: 11/23/2022] Open
Abstract
The fornix is a key tract of the hippocampal formation, whose status is presumed to contribute to age-related cognitive decline. The precommissural and postcommissural fornix subdivisions form respective basal forebrain/frontal and diencephalic networks that may differentially affect aging and cognition. We employed multi-parametric magnetic resonance imaging (MRI) including neurite orientation density and dispersion imaging, quantitative magnetization transfer (qMT), and T1-relaxometry MRI to investigate the microstructural properties of these fornix subdivisions and their relationship with aging and cognition in 149 asymptomatic participants (38-71 years). Aging was associated with increased free water signal and reductions in myelin-sensitive R1 and qMT indices but no apparent axon density differences in both precommissural and postcommissural fibers. Precommissural relative to postcommissural fibers showed a distinct microstructural pattern characterised by larger free water signal and axon orientation dispersion, with lower apparent myelin and axon density. Furthermore, differences in postcommissural microstructure were related to performance differences in object-location paired-associate learning. These results provide novel in vivo neuroimaging evidence for distinct microstructural properties of precommissural and postcommissural fibers that are consistent with their anatomy as found in axonal tracer studies, as well as for a contribution of postcommissural fibers to the learning of spatial configurations.
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Affiliation(s)
- Bethany M. Coad
- Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff, UK
- School of Psychology, Cardiff University, Cardiff, UK
| | - Emma Craig
- School of Psychology, Cardiff University, Cardiff, UK
| | - Rebecca Louch
- School of Psychology, Cardiff University, Cardiff, UK
| | | | | | - Claudia Metzler-Baddeley
- Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff, UK
- School of Psychology, Cardiff University, Cardiff, UK
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12
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Foster CM, Kennedy KM, Hoagey DA, Rodrigue KM. The role of hippocampal subfield volume and fornix microstructure in episodic memory across the lifespan. Hippocampus 2019; 29:1206-1223. [PMID: 31334583 DOI: 10.1002/hipo.23133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/12/2019] [Accepted: 06/07/2019] [Indexed: 12/25/2022]
Abstract
Advancing age is associated with both declines in episodic memory and degradation of medial temporal lobe (MTL) structure. The contribution of MTL to episodic memory is complex and depends upon the interplay among hippocampal subfields and surrounding structures that participate in anatomical connectivity to the cortex through inputs (parahippocampal and entorhinal cortices) and outputs (fornix). However, the differential contributions of MTL system components in mediating age effects on memory remain unclear. In a sample of 177 healthy individuals aged 20-94 we collected high-resolution T1-weighted, ultrahigh-resolution T2/PD, and diffusion tensor imaging (DTI) MRI sequences on a 3T Phillips Achieva scanner. Hippocampal subfield and entorhinal cortex (ERC) volumes were measured from T2/PD scans using a combination of manual tracings and training of a semiautomated pipeline. Parahippocampal gyrus volume was estimated using Freesurfer and DTI scans were used to obtain diffusion metrics from tractography of the fornix. Item and associative episodic memory constructs were formed from multiple tests. Competing structural equation models estimating differential association among these structural variables were specified and tested to investigate whether and how fornix diffusion and volume of parahippocampal gyrus, ERC, and hippocampal subfields mediate age effects on associative and/or item memory. The most parsimonious, best-fitting model included an anatomically based path through the MTL as well as a single hippocampal construct which combined all subfields. Results indicated that fornix microstructure independently mediated the effect of age on associative memory, but not item memory. Additionally, all regions and estimated paths (including fornix) combined to significantly mediate the age-associative memory relationship. These findings suggest that preservation of fornix connectivity and MTL structure with aging is important for maintenance of associative memory performance across the lifespan.
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Affiliation(s)
- Chris M Foster
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, Texas
| | - Kristen M Kennedy
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, Texas
| | - David A Hoagey
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, Texas
| | - Karen M Rodrigue
- Center for Vital Longevity, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, Texas
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