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Yang T, Wei F, Guo Y, Zhu M, Hou H, Guo Z, Liu X. The increased effective connectivity from left middle occipital gyrus to right medial septum/diagonal bands in AD patients after donepezil intervention. Front Aging Neurosci 2024; 16:1362790. [PMID: 38659702 PMCID: PMC11039922 DOI: 10.3389/fnagi.2024.1362790] [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: 12/29/2023] [Accepted: 03/27/2024] [Indexed: 04/26/2024] Open
Abstract
Introduction Donepezil enhances the function of cholinergic nerves by increasing the concentration of acetylcholine, thereby improving clinical symptoms in patients with Alzheimer's disease (AD). However, the neural mechanisms of how donepezil modulates the effective connectivity (EC) network of cholinergic system in AD patients remain unknown. We speculated that the effective network of the cholinergic system changes in AD patients after donepezil intervention. Methods We employed resting-state functional magnetic resonance imaging and Granger causality analysis approach to explore changes in the effective connectivity network of the basal forebrain in AD patients before and after donepezil intervention. This study included 32 participants, including 16 healthy controls (HCs) and 16 AD patients. In a 3T MRI scanner, the 16 AD patients were scanned before and after the donepezil intervention. To compare EC differences between the three groups of participants, ANOVA and post-hoc t-tests analysis were employed. Results Compared to baseline status, AD patients after donepezil intervention had an increased EC from left middle occipital gyrus to right medial septum/diagonal bands. Compared to HCs, AD patients after donepezil intervention had an increased EC from right inferior frontal gyrus/orbit part to right medial septum/diagonal bands, AD patients before donepezil intervention had a reduced EC from right precuneus to right medial septum/diagonal bands. A significant positive correlation was found between EC values in right precuneus and Mini-Mental State Examination in pre-intervention AD patients (r = 0.7338, p = 0.0012). Discussion Our study showed that effective connectivity of brain regions associated with the default mode network in the cholinergic pathway was enhanced after donepezil intervention. The results of this study will help us to better understand the neural mechanisms of donepezil intervention in AD and to find clinical targets for intervention.
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Affiliation(s)
- Ting Yang
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fuquan Wei
- Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China
| | - Yufei Guo
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Mengxiao Zhu
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Hongtao Hou
- Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China
| | - Zhongwei Guo
- Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China
| | - Xiaozheng Liu
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
- Wenzhou Key Laboratory of Structural and Functional Imaging, Wenzhou, Zhejiang, China
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Fessel J. Personalized, Precision Medicine to Cure Alzheimer's Dementia: Approach #1. Int J Mol Sci 2024; 25:3909. [PMID: 38612719 PMCID: PMC11012190 DOI: 10.3390/ijms25073909] [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: 02/14/2024] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
The goal of the treatment for Alzheimer's dementia (AD) is the cure of dementia. A literature review revealed 18 major elements causing AD and 29 separate medications that address them. For any individual with AD, one is unlikely to discern which major causal elements produced dementia. Thus, for personalized, precision medicine, all causal elements must be treated so that each individual patient will have her or his causal elements addressed. Twenty-nine drugs cannot concomitantly be administered, so triple combinations of drugs taken from that list are suggested, and each triple combination can be administered sequentially, in any order. Ten combinations given over 13 weeks require 2.5 years, or if given over 26 weeks, they require 5.0 years. Such sequential treatment addresses all 18 elements and should cure dementia. In addition, any comorbid risk factors for AD whose first presence or worsening was within ±1 year of when AD first appeared should receive appropriate, standard treatment together with the sequential combinations. The article outlines a randomized clinical trial that is necessary to assess the safety and efficacy of the proposed treatments; it includes a triple-drug Rx for equipoise. Clinical trials should have durations of both 2.5 and 5.0 years unless the data safety monitoring board (DSMB) determines earlier success or futility since it is uncertain whether three or six months of treatment will be curative in humans, although studies in animals suggest that the briefer duration of treatment might be effective and restore defective neural tracts.
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Affiliation(s)
- Jeffrey Fessel
- Clinical Medicine, Department of Medicine, University of California, 2069 Filbert Street, San Francisco, CA 94123, USA
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Dávila G, Torres-Prioris MJ, López-Barroso D, Berthier ML. Turning the Spotlight to Cholinergic Pharmacotherapy of the Human Language System. CNS Drugs 2023; 37:599-637. [PMID: 37341896 PMCID: PMC10374790 DOI: 10.1007/s40263-023-01017-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/24/2023] [Indexed: 06/22/2023]
Abstract
Even though language is essential in human communication, research on pharmacological therapies for language deficits in highly prevalent neurodegenerative and vascular brain diseases has received little attention. Emerging scientific evidence suggests that disruption of the cholinergic system may play an essential role in language deficits associated with Alzheimer's disease and vascular cognitive impairment, including post-stroke aphasia. Therefore, current models of cognitive processing are beginning to appraise the implications of the brain modulator acetylcholine in human language functions. Future work should be directed further to analyze the interplay between the cholinergic system and language, focusing on identifying brain regions receiving cholinergic innervation susceptible to modulation with pharmacotherapy to improve affected language domains. The evaluation of language deficits in pharmacological cholinergic trials for Alzheimer's disease and vascular cognitive impairment has thus far been limited to coarse-grained methods. More precise, fine-grained language testing is needed to refine patient selection for pharmacotherapy to detect subtle deficits in the initial phases of cognitive decline. Additionally, noninvasive biomarkers can help identify cholinergic depletion. However, despite the investigation of cholinergic treatment for language deficits in Alzheimer's disease and vascular cognitive impairment, data on its effectiveness are insufficient and controversial. In the case of post-stroke aphasia, cholinergic agents are showing promise, particularly when combined with speech-language therapy to promote trained-dependent neural plasticity. Future research should explore the potential benefits of cholinergic pharmacotherapy in language deficits and investigate optimal strategies for combining these agents with other therapeutic approaches.
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Affiliation(s)
- Guadalupe Dávila
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Marqués de Beccaria 3, 29010, Malaga, Spain
- Instituto de Investigación Biomédica de Malaga-IBIMA, Malaga, Spain
- Department of Psychobiology and Methodology of Behavioral Sciences, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
- Language Neuroscience Research Laboratory, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
| | - María José Torres-Prioris
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Marqués de Beccaria 3, 29010, Malaga, Spain
- Instituto de Investigación Biomédica de Malaga-IBIMA, Malaga, Spain
- Department of Psychobiology and Methodology of Behavioral Sciences, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
- Language Neuroscience Research Laboratory, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
| | - Diana López-Barroso
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Marqués de Beccaria 3, 29010, Malaga, Spain
- Instituto de Investigación Biomédica de Malaga-IBIMA, Malaga, Spain
- Department of Psychobiology and Methodology of Behavioral Sciences, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
- Language Neuroscience Research Laboratory, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
| | - Marcelo L Berthier
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Marqués de Beccaria 3, 29010, Malaga, Spain.
- Instituto de Investigación Biomédica de Malaga-IBIMA, Malaga, Spain.
- Language Neuroscience Research Laboratory, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain.
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Schiffmann R, Cox TM, Dedieu JF, Gaemers SJM, Hennermann JB, Ida H, Mengel E, Minini P, Mistry P, Musholt PB, Scott D, Sharma J, Peterschmitt MJ. Venglustat combined with imiglucerase for neurological disease in adults with Gaucher disease type 3: the LEAP trial. Brain 2023; 146:461-474. [PMID: 36256599 PMCID: PMC9924909 DOI: 10.1093/brain/awac379] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 08/15/2022] [Accepted: 09/11/2022] [Indexed: 11/14/2022] Open
Abstract
Gaucher disease type 3 is a chronic neuronopathic disorder with wide-ranging effects, including hepatosplenomegaly, anaemia, thrombocytopenia, skeletal disease and diverse neurological manifestations. Biallelic mutations in GBA1 reduce lysosomal acid β-glucosidase activity, and its substrates, glucosylceramide and glucosylsphingosine, accumulate. Enzyme replacement therapy and substrate reduction therapy ameliorate systemic features of Gaucher disease, but no therapies are approved for neurological manifestations. Venglustat is an investigational, brain-penetrant, glucosylceramide synthase inhibitor with potential to improve the disease by rebalancing influx of glucosylceramide with impaired lysosomal recycling. The Phase 2, open-label LEAP trial (NCT02843035) evaluated orally administered venglustat 15 mg once-daily in combination with maintenance dose of imiglucerase enzyme replacement therapy during 1 year of treatment in 11 adults with Gaucher disease type 3. Primary endpoints were venglustat safety and tolerability and change in concentration of glucosylceramide and glucosylsphingosine in CSF from baseline to Weeks 26 and 52. Secondary endpoints included change in plasma concentrations of glucosylceramide and glucosylsphingosine, venglustat pharmacokinetics in plasma and CSF, neurologic function, infiltrative lung disease and systemic disease parameters. Exploratory endpoints included changes in brain volume assessed with volumetric MRI using tensor-based morphometry, and resting functional MRI analysis of regional brain activity and connectivity between resting state networks. Mean (SD) plasma venglustat AUC0-24 on Day 1 was 851 (282) ng•h/ml; Cmax of 58.1 (26.4) ng/ml was achieved at a median tmax 2.00 h. After once-daily venglustat, plasma concentrations (4 h post-dose) were higher compared with Day 1, indicating ∼2-fold accumulation. One participant (Patient 9) had low-to-undetectable venglustat exposure at Weeks 26 and 52. Based on mean plasma and CSF venglustat concentrations (excluding Patient 9), steady state appeared to be reached on or before Week 4. Mean (SD) venglustat concentration at Week 52 was 114 (65.8) ng/ml in plasma and 6.14 (3.44) ng/ml in CSF. After 1 year of treatment, median (inter-quartile range) glucosylceramide decreased 78% (72, 84) in plasma and 81% (77, 83) in CSF; median (inter-quartile range) glucosylsphingosine decreased 56% (41, 60) in plasma and 70% (46, 76) in CSF. Ataxia improved slightly in nine patients: mean (SD, range) total modified Scale for Assessment and Rating of Ataxia score decreased from 2.68 [1.54 (0.0 to 5.5)] at baseline to 1.55 [1.88 (0.0 to 5.0)] at Week 52 [mean change: -1.14 (95% CI: -2.06 to -0.21)]. Whole brain volume increased slightly in patients with venglustat exposure and biomarker reduction in CSF (306.7 ± 4253.3 mm3) and declined markedly in Patient 9 (-13894.8 mm3). Functional MRI indicated stronger connectivity at Weeks 26 and 52 relative to baseline between a broadly distributed set of brain regions in patients with venglustat exposure and biomarker reduction but not Patient 9, although neurocognition, assessed by Vineland II, deteriorated in all domains over time, which illustrates disease progression despite the intervention. There were no deaths, serious adverse events or discontinuations. In adults with Gaucher disease type 3 receiving imiglucerase, addition of once-daily venglustat showed acceptable safety and tolerability and preliminary evidence of clinical stability with intriguing but intrinsically inconsistent signals in selected biomarkers, which need to be validated and confirmed in future research.
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Affiliation(s)
- Raphael Schiffmann
- Correspondence to: Raphael Schiffmann, MD, MHSc, FAAN Texas Neurology 6080 N Central Expy, Ste 100, Dallas, TX 75246, USA E-mail:
| | - Timothy M Cox
- Department of Medicine, University of Cambridge and Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | | | | | - Julia B Hennermann
- Center for Pediatric and Adolescent Medicine Villa Metabolica, University Medical Center Mainz, 55131 Mainz, Germany
| | - Hiroyuki Ida
- Department of Pediatrics, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Eugen Mengel
- Center for Pediatric and Adolescent Medicine Villa Metabolica, University Medical Center Mainz, 55131 Mainz, Germany
- Clinical Science for LSD, SphinCS, 65239 Hochheim, Germany
| | - Pascal Minini
- Biostatistics and Programming, Sanofi, 91385 Chilly-Mazarin, France
| | - Pramod Mistry
- Yale Lysosomal Disease Center and Gaucher Disease Treatment Center, Yale School of Medicine, New Haven, CT 06510, USA
| | | | - David Scott
- Medical and Scientific Affairs, Neuroscience, Clario, San Mateo, CA 94404, USA
| | - Jyoti Sharma
- Pharmacokinetics, Dynamics and Metabolism, Sanofi, Bridgewater, NJ 08807, USA
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Budak M, Bayraktaroglu Z, Hanoglu L. The effects of repetitive transcranial magnetic stimulation and aerobic exercise on cognition, balance and functional brain networks in patients with Alzheimer's disease. Cogn Neurodyn 2023; 17:39-61. [PMID: 36704634 PMCID: PMC9871139 DOI: 10.1007/s11571-022-09818-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 04/20/2022] [Accepted: 05/02/2022] [Indexed: 01/29/2023] Open
Abstract
The purpose of this study was to investigate the effects of high-frequency repetitive Transcranial Magnetic Stimulation (rTMS) and aerobic exercises (AE) in addition to the pharmacological therapy (PT) in Alzheimer's Disease (AD). Twenty-seven patients with AD aged ≥ 60 years were included in the study and divided into 3 groups (rTMS, AE and control). All groups received PT. rTMS group (n = 10) received 20 Hz rTMS over dorsolateral prefrontal cortex (dlPFC) bilaterally and AE group (n = 9) received the structured moderate-intensity AE for 5 consecutive days/week over 2 weeks. Control group (n = 8) only received PT. Cognition, balance, mobility, quality of life (QoL), and resting state functional brain activity were evaluated one week before and one week after the interventions. (ClinicalTrials.gov ID:NCT05102045). Significant improvements were found in executive functions, behavior, and QoL in the rTMS group, in balance and mobility in the AE group, and in the visual memory and behavior in the control group (p < 0.05). Significant differences were found in the behavior in favor of the rTMS group, and balance in favor of the AE group (p < 0.05). There was a significant increase in activation on middle temporal gyrus, intra calcarine, central opercular cortex, superior parietal lobule, and paracingulate cortex in Default Mode Network (DMN) in the rTMS group (p < 0.05). High-frequency rTMS over bilateral dlPFC may improve executive functions and behavior and lead to increased activation in DMN, structured moderate-intensity AE may improve balance and mobility, and PT may improve memory and behaviour compared to pretreatment in AD.
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Affiliation(s)
- Miray Budak
- Functional Imaging and Cognitive-Affective Neuroscience Lab (fINCAN), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Department of Physical Therapy and Rehabilitation, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey
- Department of Ergotherapy, School of Health Sciences, Istanbul Medipol University, Istanbul, Turkey
| | - Zubeyir Bayraktaroglu
- Functional Imaging and Cognitive-Affective Neuroscience Lab (fINCAN), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Department of Physiology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Lutfu Hanoglu
- Functional Imaging and Cognitive-Affective Neuroscience Lab (fINCAN), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Department of Neurology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey
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Berthier ML, Edelkraut L, López-González FJ, López-Barroso D, Mohr B, Pulvermüller F, Starkstein SE, Jorge RE, Torres-Prioris MJ, Dávila G. Donepezil alone and combined with intensive language-action therapy on depression and apathy in chronic post-stroke aphasia: A feasibility study. BRAIN AND LANGUAGE 2023; 236:105205. [PMID: 36495749 DOI: 10.1016/j.bandl.2022.105205] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 10/17/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
This study explored the feasibility and effectiveness of a short-term (10-week) intervention trial using Donepezil administered alone and combined with intensive language action therapy (ILAT) for the treatment of apathy and depression in ten people with chronic post-stroke aphasia. Outcome measures were the Western Aphasia Battery and the Stroke Aphasia Depression Questionnaire-21. Structural magnetic resonance imaging and 18fluorodeoxyglucose positron emission tomography were acquired at baseline and after two endpoints (Donepezil alone and Donepezil-ILAT). The intervention was found to be feasible to implement. Large treatment effects were found. Donepezil alone and combined with ILAT reduced aphasia severity, while apathy and depression only improved with Donepezil-ILAT. Structural and functional neuroimaging data did not show conclusive results but provide hints for future research. Given these overall positive findings on feasibility, language and behavioral benefits, further studies in larger sample sizes and including a placebo-control group are indicated.
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Affiliation(s)
- Marcelo L Berthier
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Malaga, Spain; Instituto de Investigación Biomédica de Málaga - IBIMA, Malaga, Spain
| | - Lisa Edelkraut
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Malaga, Spain; Instituto de Investigación Biomédica de Málaga - IBIMA, Malaga, Spain; Area of Psychobiology, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
| | - Francisco J López-González
- Molecular Imaging Unit, Centro de Investigaciones Médico-Sanitarias, General Foundation of the University of Malaga, Malaga, Spain; Molecular Imaging Group, Radiology Department, Faculty of Medicine, University of Santiago de Compostela, Galicia, Spain
| | - Diana López-Barroso
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Malaga, Spain; Instituto de Investigación Biomédica de Málaga - IBIMA, Malaga, Spain; Area of Psychobiology, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
| | - Bettina Mohr
- Zentrum für Neuropsychologie und Intensive Sprachtherapie - ZeNIS, Berlin, Germany
| | - Friedemann Pulvermüller
- Brain Language Laboratory, Department of Philosophy and Humanities, WE4, Freie Universität Berlin, Germany; Berlin School of Mind and Brain, Humboldt Universität zu Berlin, Germany
| | - Sergio E Starkstein
- Faculty of Health and Medical Sciences, The University of Western Australia (M704), Perth, Australia
| | - Ricardo E Jorge
- Department of Psychiatry and Behavioural Sciences, Baylor College of Medicine, Houston, TX, United States
| | - María José Torres-Prioris
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Malaga, Spain; Instituto de Investigación Biomédica de Málaga - IBIMA, Malaga, Spain; Area of Psychobiology, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain
| | - Guadalupe Dávila
- Cognitive Neurology and Aphasia Unit, Centro de Investigaciones Médico-Sanitarias, University of Malaga, Malaga, Spain; Instituto de Investigación Biomédica de Málaga - IBIMA, Malaga, Spain; Area of Psychobiology, Faculty of Psychology and Speech Therapy, University of Malaga, Malaga, Spain.
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Wei L, Zhang Y, Wang J, Xu L, Yang K, Lv X, Zhu Z, Gong Q, Hu W, Li X, Qian M, Shen Y, Chen W. Parietal-hippocampal rTMS improves cognitive function in Alzheimer's disease and increases dynamic functional connectivity of default mode network. Psychiatry Res 2022; 315:114721. [PMID: 35839637 DOI: 10.1016/j.psychres.2022.114721] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 11/26/2022]
Abstract
Parietal-hippocampal repetitive transcranial magnetic stimulation (rTMS) improves cognitive function in Alzheimer's disease (AD), however, the underlying therapeutic mechanism has not been elucidated. A double-blind, randomized, sham-controlled parietal-hippocampal rTMS trial (five sessions/week for a total of 10 sessions) of mild-to-moderate AD patients was conducted in the study. High-frequency rTMS was applied to a subject-specific left lateral parietal region with the highest functional connectivity with the hippocampus based on resting-state fMRI. A multimodal MRI scan and a complete neuropsychological battery of tests were conducted at baseline, immediately after the intervention and 12-week follow-up after the rTMS treatment. Compared to sham treatment (n = 27), patients undergoing active rTMS treatment (n = 29) showed higher Mini Mental State Examination (MMSE) score and dynamic functional connectivity (dFC) magnitude of the default mode network (DMN) after two weeks of rTMS treatment, but not at 12-week follow-up. A significant positive correlation was observed between changes in MMSE and changes in the dFC magnitude of DMN in patients who underwent active-rTMS treatment, but not in those who received sham-rTMS treatment. The findings of the current study indicate that fMRI-guided rTMS treatment improves cognitive function of AD patients in the short term, and DMN functional connectivity contributes to therapeutic effectiveness of rTMS.
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Affiliation(s)
- Lili Wei
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Yingchun Zhang
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Jintao Wang
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Luoyi Xu
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Kehua Yang
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Xinghui Lv
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Zhenwei Zhu
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Qian Gong
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China
| | - Weiming Hu
- Third People's Hospital of Quzhou, Quzhou, Zhejiang 324003, China
| | - Xia Li
- Shanghai Mental Health Center, Shanghai 200030, China
| | - Mincai Qian
- Third People's Hospital of Huzhou, Huzhou, Zhejiang 313002, China.
| | - Yuedi Shen
- Hangzhou Normal University School of Medicine, Hangzhou, Zhejiang 311121, China.
| | - Wei Chen
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, East Qingchun Road 3#, Hangzhou, Zhejiang 310016, China; Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou 310007, China; Key Laboratory of Medical Neurobiology of Zhejiang Province, Hangzhou 310016, China.
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Raikes AC, Hernandez GD, Matthews DC, Lukic AS, Law M, Shi Y, Schneider LS, Brinton RD. Exploratory imaging outcomes of a phase 1b/2a clinical trial of allopregnanolone as a regenerative therapeutic for Alzheimer's disease: Structural effects and functional connectivity outcomes. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2022; 8:e12258. [PMID: 35310526 PMCID: PMC8919249 DOI: 10.1002/trc2.12258] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/18/2021] [Accepted: 12/21/2021] [Indexed: 01/14/2023]
Abstract
Introduction Allopregnanolone (ALLO), an endogenous neurosteroid, promoted neurogenesis and oligogenesis and restored cognitive function in animal models of Alzheimer's disease (AD). Based on these discovery research findings, we conducted a randomized-controlled phase 1b/2a multiple ascending dose trial of ALLO in persons with early AD (NCT02221622) to assess safety, tolerability, and pharmacokinetics. Exploratory imaging outcomes to determine whether ALLO impacted hippocampal structure, white matter integrity, and functional connectivity are reported. Methods Twenty-four individuals participated in the trial (n = 6 placebo; n = 18 ALLO) and underwent brain magnetic resonance imaging (MRI) before and after 12 weeks of treatment. Hippocampal atrophy rate was determined from volumetric MRI, computed as rate of change, and qualitatively assessed between ALLO and placebo sex, apolipoprotein E (APOE) ε4 allele, and ALLO dose subgroups. White matter microstructural integrity was compared between placebo and ALLO using fractional and quantitative anisotropy (QA). Changes in local, inter-regional, and network-level functional connectivity were also compared between groups using resting-state functional MRI. Results Rate of decline in hippocampal volume was slowed, and in some cases reversed, in the ALLO group compared to placebo. Gain of hippocampal volume was evident in APOE ε4 carriers (range: 0.6% to 7.8% increased hippocampal volume). Multiple measures of white matter integrity indicated evidence of preserved or improved integrity. ALLO significantly increased fractional anisotropy (FA) in 690 of 690 and QA in 1416 of 1888 fiber tracts, located primarily in the corpus callosum, bilateral thalamic radiations, and bilateral corticospinal tracts. Consistent with structural changes, ALLO strengthened local, inter-regional, and network level functional connectivity in AD-vulnerable regions, including the precuneus and posterior cingulate, and network connections between the default mode network and limbic system. Discussion Indicators of regeneration from previous preclinical studies and these exploratory MRI-based outcomes from this phase 1b/2a clinical cohort support advancement to a phase 2 proof-of-concept efficacy clinical trial of ALLO as a regenerative therapeutic for mild AD (REGEN-BRAIN study; NCT04838301).
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Affiliation(s)
- Adam C. Raikes
- Center for Innovation in Brain ScienceUniversity of ArizonaTucsonArizonaUSA
| | | | - Dawn C. Matthews
- Departments of Pharmacology and Neurology, College of MedicineADM DiagnosticsNorthbrookIllinoisUSA
| | - Ana S. Lukic
- Departments of Pharmacology and Neurology, College of MedicineADM DiagnosticsNorthbrookIllinoisUSA
| | - Meng Law
- Department of RadiologyAlfred HealthDepartment of Neuroscience and Computer Systems EngineeringMonash UniversityMelbourneAustralia
| | - Yonggang Shi
- Stevens Neuroimaging and Informatics InstituteKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Lon S. Schneider
- Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Roberta D. Brinton
- Center for Innovation in Brain ScienceUniversity of ArizonaTucsonArizonaUSA
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Péran P, Salabert AS, Dondaine T, Leclerc X, Gros-Dagnac H, Ranjeva JP, Lopes R, Lanteaume L, Blin O, Thalamas C, Bordet R, Payoux P. Functional connectivity and cognitive changes after donepezil treatment in healthy participants. Psychopharmacology (Berl) 2021; 238:3071-3082. [PMID: 34370064 DOI: 10.1007/s00213-021-05923-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
RATIONALE Donepezil is a potent, noncompetitive, reversible, clinically effective acetylcholinesterase inhibitor. The effects of this drug on healthy brains have seldom been investigated. OBJECTIVES The primary objective of the present study was to identify possible functional connectivity markers of the effect of donepezil in healthy young adult volunteers. METHODS The study had a double-blind, randomized, crossover design. 30 healthy adult volunteers underwent resting-state MRI scans during 15 days of donepezil or placebo treatment, in accordance with the design. RESULTS Results showed significant differences in intrinsic functional connectivity between donepezil and placebo, mainly in the right executive control network (RECN). More specifically, we found a decrease in the connectivity of the right inferior parietal node with other RECN nodes. Analysis using the cingulate cortex and parahippocampal regions as seeds also revealed complex modulation of functional connectivity in the donepezil condition. CONCLUSIONS In conclusion, donepezil treatment for 15 days may result in reorganization of resting-state networks, compared with placebo.
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Affiliation(s)
- P Péran
- Toulouse NeuroImaging Center (ToNIC), Université de Toulouse, INSERM, UPS, 31024, Toulouse Cedex 3, France.
| | - A S Salabert
- Toulouse NeuroImaging Center (ToNIC), Université de Toulouse, INSERM, UPS, 31024, Toulouse Cedex 3, France
| | - T Dondaine
- Degenerative & Vascular Cognitive Disorders Research Unit, INSERM-Lille University-Lille University Hospital, Lille, France
| | - X Leclerc
- Degenerative & Vascular Cognitive Disorders Research Unit, INSERM-Lille University-Lille University Hospital, Lille, France
| | - H Gros-Dagnac
- Toulouse NeuroImaging Center (ToNIC), Université de Toulouse, INSERM, UPS, 31024, Toulouse Cedex 3, France
| | - J-P Ranjeva
- Centre for Metabolic Exploration by Magnetic Resonance (CEMEREM), Aix-Marseille University-CNRS-CRMBM-Timone University Hospital, Marseille, France
| | - R Lopes
- Degenerative & Vascular Cognitive Disorders Research Unit, INSERM-Lille University-Lille University Hospital, Lille, France
| | - L Lanteaume
- Centre for Metabolic Exploration by Magnetic Resonance (CEMEREM), Aix-Marseille University-CNRS-CRMBM-Timone University Hospital, Marseille, France.,Department of Clinical Pharmacology (UPCET), Aix-Marseille University-INSERM-Timone University Hospital, Marseille, France
| | - O Blin
- Centre for Metabolic Exploration by Magnetic Resonance (CEMEREM), Aix-Marseille University-CNRS-CRMBM-Timone University Hospital, Marseille, France.,Department of Clinical Pharmacology (UPCET), Aix-Marseille University-INSERM-Timone University Hospital, Marseille, France
| | - C Thalamas
- Clinical Investigation Center (CIC1436), Toulouse, France
| | - R Bordet
- Degenerative & Vascular Cognitive Disorders Research Unit, INSERM-Lille University-Lille University Hospital, Lille, France
| | - P Payoux
- Toulouse NeuroImaging Center (ToNIC), Université de Toulouse, INSERM, UPS, 31024, Toulouse Cedex 3, France
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10
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Schumacher J, Taylor JP, Hamilton CA, Firbank M, Donaghy PC, Roberts G, Allan L, Durcan R, Barnett N, O'Brien JT, Thomas AJ. Functional connectivity in mild cognitive impairment with Lewy bodies. J Neurol 2021; 268:4707-4720. [PMID: 33928432 PMCID: PMC8563567 DOI: 10.1007/s00415-021-10580-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/23/2021] [Accepted: 04/24/2021] [Indexed: 12/13/2022]
Abstract
Previous resting-state fMRI studies in dementia with Lewy bodies have described changes in functional connectivity in networks related to cognition, motor function, and attention as well as alterations in connectivity dynamics. However, whether these changes occur early in the course of the disease and are already evident at the stage of mild cognitive impairment is not clear. We studied resting-state fMRI data from 31 patients with mild cognitive impairment with Lewy bodies compared to 28 patients with mild cognitive impairment due to Alzheimer’s disease and 24 age-matched controls. We compared the groups with respect to within- and between-network functional connectivity. Additionally, we applied two different approaches to study dynamic functional connectivity (sliding-window analysis and leading eigenvector dynamic analysis). We did not find any significant changes in the mild cognitive impairment groups compared to controls and no differences between the two mild cognitive impairment groups, using static as well as dynamic connectivity measures. While patients with mild cognitive impairment with Lewy bodies already show clear functional abnormalities on EEG measures, the fMRI analyses presented here do not appear to be sensitive enough to detect such early and subtle changes in brain function in these patients.
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Affiliation(s)
- Julia Schumacher
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK.
| | - John-Paul Taylor
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Calum A Hamilton
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Michael Firbank
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Paul C Donaghy
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Gemma Roberts
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Louise Allan
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK.,Institute of Health Research, University of Exeter, Exeter, UK
| | - Rory Durcan
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Nicola Barnett
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - John T O'Brien
- Department of Psychiatry, University of Cambridge School of Medicine, Cambridge, CB2 0SP, UK
| | - Alan J Thomas
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
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11
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Zhu Y, Gong L, He C, Wang Q, Ren Q, Xie C. Default Mode Network Connectivity Moderates the Relationship Between the APOE Genotype and Cognition and Individualizes Identification Across the Alzheimer's Disease Spectrum. J Alzheimers Dis 2020; 70:843-860. [PMID: 31282419 DOI: 10.3233/jad-190254] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although previous studies have investigated the effects of the apolipoprotein E (APOE) ɛ4 genotype on the default mode network (DMN) in the Alzheimer's disease (AD) spectrum, it is still unclear how the APOE genotype regulates the DMN and subsequently affects cognitive decline in the AD spectrum. One hundred sixty-nine subjects with resting-state functional magnetic resonance imaging data and neuropsychological test scores were selected from the Alzheimer's Disease Neuroimaging Initiative. The main effects and interaction of the APOE genotype and disease status on the DMN were explored. A moderation analysis was performed to investigate the relationship among the APOE genotype, DMN connectivity, and cognition. Additionally, the pair-wised DMN connectivity was used to classify AD spectrum, and the classification accuracy was validated. Compared to APOEɛ4 non-carriers, APOEɛ4 carriers showed the opposite trajectory of DMN connectivity across the AD spectrum. Specifically, the strengths in the posterior cingulate cortex (PCC) connecting with the right precuneus, insular, and fusiform area (FFA) were positively correlated with Mini-Mental State Examination (MMSE) scores in APOEɛ4 non-carriers but not in APOEɛ4 carriers. Furthermore, PCC-right FFA connectivity could moderate the effects of the APOE genotype on MMSE scores across the disease groups. More importantly, using a receiver operating characteristic analysis, these altered connectivities yielded strong classification powers in a pathological stage-dependent manner in the AD spectrum. These findings first identified the intrinsic DMN connectivity moderating the effect of the APOE genotype on cognition and provided a pathological stage-dependent neuroimaging biomarker for early differentiation of the AD spectrum.
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Affiliation(s)
- Yao Zhu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Liang Gong
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Cancan He
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Qing Wang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Qingguo Ren
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Chunming Xie
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
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12
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Donepezil's Effects on Brain Functions of Patients With Alzheimer Disease: A Regional Homogeneity Study Based on Resting-State Functional Magnetic Resonance Imaging. Clin Neuropharmacol 2019; 42:42-48. [PMID: 30875345 PMCID: PMC6426347 DOI: 10.1097/wnf.0000000000000324] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Donepezil is known to increase cholinergic synaptic transmission in Alzheimer disease (AD), although how it affects cortical brain activity and how it consequently affects brain functions need further clarification. To investigate the therapeutic mechanism of donepezil underlying its effect on brain function, regional homogeneity (ReHo) technology was used in this study. PATIENTS AND METHODS This study included 11 mild-to-moderate AD patients who completed 24 weeks of donepezil treatment and 11 matched healthy controls. All participants finished neuropsychological assessment and resting-state functional magnetic resonance imaging scanning to compare whole-brain ReHo before and after donepezil treatment. RESULTS Significantly decreased Alzheimer's Disease Assessment Scale-Cognitive Subscale scores (P = 0.010) and increased Mini-Mental State Examination scores (P = 0.043) were observed in the AD patients. In addition, in the right gyrus rectus (P = 0.021), right precentral gyrus (P = 0.026), and left superior temporal gyrus (P = 0.043) of the AD patients, decreased ReHo was exhibited. CONCLUSION Donepezil-mediated improvement of cognitive function in AD patients is linked to spontaneous brain activities of the right gyrus rectus, right precentral gyrus, and left superior temporal gyrus, which could be used as potential biomarkers for monitoring the therapeutic effect of donepezil.
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13
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Klaassens BL, van Gerven JMA, Klaassen ES, van der Grond J, Rombouts SARB. Cholinergic and serotonergic modulation of resting state functional brain connectivity in Alzheimer's disease. Neuroimage 2019; 199:143-152. [PMID: 31112788 DOI: 10.1016/j.neuroimage.2019.05.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 11/19/2022] Open
Abstract
Disruption of cholinergic and serotonergic neurotransmitter systems is associated with cognitive, emotional and behavioural symptoms of Alzheimer's disease (AD). To investigate the responsiveness of these systems in AD we measured the effects of a single-dose of the selective serotonin reuptake inhibitor citalopram and acetylcholinesterase inhibitor galantamine in 12 patients with AD and 12 age-matched controls on functional brain connectivity with resting state functional magnetic resonance imaging. In this randomized, double blind, placebo-controlled crossover study, functional magnetic resonance images were repeatedly obtained before and after dosing, resulting in a dataset of 432 scans. Connectivity maps of ten functional networks were extracted using a dual regression method and drug vs. placebo effects were compared between groups with a multivariate analysis with signals coming from cerebrospinal fluid and white matter as covariates at the subject level, and baseline and heart rate measurements as confound regressors in the higher-level analysis (at p < 0.05, corrected). A galantamine induced difference between groups was observed for the cerebellar network. Connectivity within the cerebellar network and between this network and the thalamus decreased after galantamine vs. placebo in AD patients, but not in controls. For citalopram, voxelwise network connectivity did not show significant group × treatment interaction effects. However, we found default mode network connectivity with the precuneus and posterior cingulate cortex to be increased in AD patients, which could not be detected within the control group. Further, in contrast to the AD patients, control subjects showed a consistent reduction in mean connectivity with all networks after administration of citalopram. Since AD has previously been characterized by reduced connectivity between the default mode network and the precuneus and posterior cingulate cortex, the effects of citalopram on the default mode network suggest a restoring potential of selective serotonin reuptake inhibitors in AD. The results of this study also confirm a change in cerebellar connections in AD, which is possibly related to cholinergic decline.
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Affiliation(s)
- Bernadet L Klaassens
- Leiden University, Institute of Psychology, Leiden, the Netherlands; Leiden University Medical Center, Department of Radiology, Leiden, the Netherlands; Leiden University, Leiden Institute for Brain and Cognition, Leiden, the Netherlands; Centre for Human Drug Research, Leiden, the Netherlands.
| | | | | | - Jeroen van der Grond
- Leiden University Medical Center, Department of Radiology, Leiden, the Netherlands
| | - Serge A R B Rombouts
- Leiden University, Institute of Psychology, Leiden, the Netherlands; Leiden University Medical Center, Department of Radiology, Leiden, the Netherlands; Leiden University, Leiden Institute for Brain and Cognition, Leiden, the Netherlands
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14
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Chao LL. Effects of Home Photobiomodulation Treatments on Cognitive and Behavioral Function, Cerebral Perfusion, and Resting-State Functional Connectivity in Patients with Dementia: A Pilot Trial. PHOTOBIOMODULATION PHOTOMEDICINE AND LASER SURGERY 2019; 37:133-141. [PMID: 31050950 DOI: 10.1089/photob.2018.4555] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Objective: To examine the effects of transcranial and intranasal photobiomodulation (PBM) therapy, administered at home, in patients with dementia. Background: This study sought to replicate and build upon a previously published case series report describing improved cognitive function in five patients with mild-to-moderate dementia after 12 weeks of transcranial and intranasal near-infrared (NIR) PBM therapy. Materials and methods: Eight participants (mean age: 79.8 ± 5.8 years old) diagnosed with dementia by their physicians were randomized to 12 weeks of usual care (UC, n = 4) or home PBM treatments (n = 4). The NIR PBM treatments were administered by a study partner at home three times per week with the Vielight Neuro Gamma device. The participants were assessed with the Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog) subscale and the Neuropsychiatric Inventory (NPI) at baseline and 6 and 12 weeks, and with arterial spin-labeled perfusion magnetic resonance imaging (MRI) and resting-state functional MRI at baseline and 12 weeks. Results: At baseline, the UC and PBM groups did not differ demographically or clinically. However, after 12 weeks, there were improvements in ADAS-cog (group × time interaction: F1,6 = 16.35, p = 0.007) and NPI (group × time interaction: F1,6 = 7.52, p = 0.03), increased cerebral perfusion (group × time interaction: F1,6 = 8.46, p < 0.03), and increased connectivity between the posterior cingulate cortex and lateral parietal nodes within the default-mode network in the PBM group. Conclusions: Because PBM was well tolerated and associated with no adverse side effects, these results support the potential of PBM therapy as a viable home treatment for individuals with dementia.
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Affiliation(s)
- Linda L Chao
- 1 Center for Imaging of Neurodegenerative Diseases, San Francisco VA Medical Center, San Francisco, California.,2 Department of Radiology and Biomedical Imaging and University of California, San Francisco, San Francisco, California.,3 Department of Psychiatry, University of California, San Francisco, San Francisco, California
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15
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Knight R, Khondoker M, Magill N, Stewart R, Landau S. A Systematic Review and Meta-Analysis of the Effectiveness of Acetylcholinesterase Inhibitors and Memantine in Treating the Cognitive Symptoms of Dementia. Dement Geriatr Cogn Disord 2018; 45:131-151. [PMID: 29734182 DOI: 10.1159/000486546] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/29/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Acetylcholinesterase inhibitors (AChEIs) and memantine are commonly used in the management of dementia. In routine clinical practice, dementia is often monitored via the Mini-Mental State Examination (MMSE). We conducted a systematic review and meta-analysis of the effects of these drugs on MMSE scores. SUMMARY Eighty trials were identified. Pooled effect estimates were in favour of both AChEIs and memantine at 6 months. Meta-regression indicated that dementia subtype was a moderator of AChEI treatment effect, with the effect of treatment versus control twice as high for patients with Parkinson disease dementia/ dementia with Lewy bodies (2.11 MMSE points at 6 months) as for patients with Alzheimer disease/vascular dementia (0.91 MMSE points at 6 months). Key Messages: AChEIs demonstrate a modest effect versus control on MMSE scores which is moderated by dementia subtype. For memantine the effect is smaller.
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Affiliation(s)
- Ruth Knight
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Mizanur Khondoker
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Nicholas Magill
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Robert Stewart
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,South London and Maudsley NHS Foundation Trust, London, United Kingdom
| | - Sabine Landau
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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16
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ten Kate M, Ingala S, Schwarz AJ, Fox NC, Chételat G, van Berckel BNM, Ewers M, Foley C, Gispert JD, Hill D, Irizarry MC, Lammertsma AA, Molinuevo JL, Ritchie C, Scheltens P, Schmidt ME, Visser PJ, Waldman A, Wardlaw J, Haller S, Barkhof F. Secondary prevention of Alzheimer's dementia: neuroimaging contributions. Alzheimers Res Ther 2018; 10:112. [PMID: 30376881 PMCID: PMC6208183 DOI: 10.1186/s13195-018-0438-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/10/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND In Alzheimer's disease (AD), pathological changes may arise up to 20 years before the onset of dementia. This pre-dementia window provides a unique opportunity for secondary prevention. However, exposing non-demented subjects to putative therapies requires reliable biomarkers for subject selection, stratification, and monitoring of treatment. Neuroimaging allows the detection of early pathological changes, and longitudinal imaging can assess the effect of interventions on markers of molecular pathology and rates of neurodegeneration. This is of particular importance in pre-dementia AD trials, where clinical outcomes have a limited ability to detect treatment effects within the typical time frame of a clinical trial. We review available evidence for the use of neuroimaging in clinical trials in pre-dementia AD. We appraise currently available imaging markers for subject selection, stratification, outcome measures, and safety in the context of such populations. MAIN BODY Amyloid positron emission tomography (PET) is a validated in-vivo marker of fibrillar amyloid plaques. It is appropriate for inclusion in trials targeting the amyloid pathway, as well as to monitor treatment target engagement. Amyloid PET, however, has limited ability to stage the disease and does not perform well as a prognostic marker within the time frame of a pre-dementia AD trial. Structural magnetic resonance imaging (MRI), providing markers of neurodegeneration, can improve the identification of subjects at risk of imminent decline and hence play a role in subject inclusion. Atrophy rates (either hippocampal or whole brain), which can be reliably derived from structural MRI, are useful in tracking disease progression and have the potential to serve as outcome measures. MRI can also be used to assess comorbid vascular pathology and define homogeneous groups for inclusion or for subject stratification. Finally, MRI also plays an important role in trial safety monitoring, particularly the identification of amyloid-related imaging abnormalities (ARIA). Tau PET to measure neurofibrillary tangle burden is currently under development. Evidence to support the use of advanced MRI markers such as resting-state functional MRI, arterial spin labelling, and diffusion tensor imaging in pre-dementia AD is preliminary and requires further validation. CONCLUSION We propose a strategy for longitudinal imaging to track early signs of AD including quantitative amyloid PET and yearly multiparametric MRI.
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Affiliation(s)
- Mara ten Kate
- Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, PO Box 7056, 1007 MB Amsterdam, the Netherlands
| | - Silvia Ingala
- Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Adam J. Schwarz
- Takeda Pharmaceuticals Comparny, Cambridge, MA USA
- Eli Lilly and Company, Indianapolis, Indiana USA
| | - Nick C. Fox
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Gaël Chételat
- Institut National de la Santé et de la Recherche Médicale, Inserm UMR-S U1237, Université de Caen-Normandie, GIP Cyceron, Caen, France
| | - Bart N. M. van Berckel
- Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Michael Ewers
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität LMU, Munich, Germany
| | | | - Juan Domingo Gispert
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
| | | | | | - Adriaan A. Lammertsma
- Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - José Luis Molinuevo
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
| | - Craig Ritchie
- Centre for Dementia Prevention, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Philip Scheltens
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, PO Box 7056, 1007 MB Amsterdam, the Netherlands
| | | | - Pieter Jelle Visser
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, PO Box 7056, 1007 MB Amsterdam, the Netherlands
| | - Adam Waldman
- Centre for Dementia Prevention, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Joanna Wardlaw
- Centre for Dementia Prevention, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
- Dementia Research Centre, University of Edinburgh, Edinburgh, UK
| | - Sven Haller
- Affidea Centre de Diagnostic Radiologique de Carouge, Geneva, Switzerland
| | - Frederik Barkhof
- Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
- Insititutes of Neurology and Healthcare Engineering, University College London, London, UK
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17
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Guo H, Grajauskas L, Habash B, D'Arcy RCN, Song X. Functional MRI technologies in the study of medication treatment effect on Alzheimer's disease. Aging Med (Milton) 2018; 1:75-95. [PMID: 31942484 PMCID: PMC6880690 DOI: 10.1002/agm2.12017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/02/2018] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of late-life dementia. Characterized by progressive neurodegeneration, the disease is expressed as gradual memory loss together with decline in cognitive abilities and other brain functions. Despite extensive research over the past decade, the cause and cure of AD both remain largely unknown. Several AD-associated deficits have been targeted for interventions, including those based on amyloid-beta, tau, and inflammation hypotheses. Only 2 types of medications-cholinesterase inhibitors and memantine-have been approved, to control the cognitive symptoms of AD such as the loss of memory, language, and executive function. Noninvasive in vivo functional magnetic resonance imaging (MRI) technologies, including the blood oxygen level-dependent functional MRI, arterial spin labeling-based perfusion MRI, and the proton magnetic resonance spectroscopy have been used to study the effect of ChEIs and memantine in the brain. Most of these studies have demonstrated increased functional activation and connectivity, increased regional brain blood flow and volume post-treatment, and positive responses of critical brain metabolites reflecting neuronal status and functionality in patients with AD and mild cognitive impairment. The findings have contributed to the understanding of the mechanisms underlying the medication treatments and support the crucial role of functional MRI technologies in the development and refinement of AD medication therapies.
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Affiliation(s)
- Hui Guo
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Diagnostic ImagingTianjin Medical University General HospitalTianjinChina
| | - Lukas Grajauskas
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
| | - Baraa Habash
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Ryan CN D'Arcy
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
- Department of Computing ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Xiaowei Song
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
- Department of Computing ScienceSimon Fraser UniversityBurnabyBCCanada
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18
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Hohenfeld C, Werner CJ, Reetz K. Resting-state connectivity in neurodegenerative disorders: Is there potential for an imaging biomarker? Neuroimage Clin 2018; 18:849-870. [PMID: 29876270 PMCID: PMC5988031 DOI: 10.1016/j.nicl.2018.03.013] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/06/2018] [Accepted: 03/14/2018] [Indexed: 12/14/2022]
Abstract
Biomarkers in whichever modality are tremendously important in diagnosing of disease, tracking disease progression and clinical trials. This applies in particular for disorders with a long disease course including pre-symptomatic stages, in which only subtle signs of clinical progression can be observed. Magnetic resonance imaging (MRI) biomarkers hold particular promise due to their relative ease of use, cost-effectiveness and non-invasivity. Studies measuring resting-state functional MR connectivity have become increasingly common during recent years and are well established in neuroscience and related fields. Its increasing application does of course also include clinical settings and therein neurodegenerative diseases. In the present review, we critically summarise the state of the literature on resting-state functional connectivity as measured with functional MRI in neurodegenerative disorders. In addition to an overview of the results, we briefly outline the methods applied to the concept of resting-state functional connectivity. While there are many different neurodegenerative disorders cumulatively affecting a substantial number of patients, for most of them studies on resting-state fMRI are lacking. Plentiful amounts of papers are available for Alzheimer's disease (AD) and Parkinson's disease (PD), but only few works being available for the less common neurodegenerative diseases. This allows some conclusions on the potential of resting-state fMRI acting as a biomarker for the aforementioned two diseases, but only tentative statements for the others. For AD, the literature contains a relatively strong consensus regarding an impairment of the connectivity of the default mode network compared to healthy individuals. However, for AD there is no considerable documentation on how that alteration develops longitudinally with the progression of the disease. For PD, the available research points towards alterations of connectivity mainly in limbic and motor related regions and networks, but drawing conclusions for PD has to be done with caution due to a relative heterogeneity of the disease. For rare neurodegenerative diseases, no clear conclusions can be drawn due to the few published results. Nevertheless, summarising available data points towards characteristic connectivity alterations in Huntington's disease, frontotemporal dementia, dementia with Lewy bodies, multiple systems atrophy and the spinocerebellar ataxias. Overall at this point in time, the data on AD are most promising towards the eventual use of resting-state fMRI as an imaging biomarker, although there remain issues such as reproducibility of results and a lack of data demonstrating longitudinal changes. Improved methods providing more precise classifications as well as resting-state network changes that are sensitive to disease progression or therapeutic intervention are highly desirable, before routine clinical use could eventually become a reality.
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Affiliation(s)
- Christian Hohenfeld
- RWTH Aachen University, Department of Neurology, Aachen, Germany; JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Cornelius J Werner
- RWTH Aachen University, Department of Neurology, Aachen, Germany; RWTH Aachen University, Section Interdisciplinary Geriatrics, Aachen, Germany
| | - Kathrin Reetz
- RWTH Aachen University, Department of Neurology, Aachen, Germany; JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany.
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19
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Canu E, Sarasso E, Filippi M, Agosta F. Effects of pharmacological and nonpharmacological treatments on brain functional magnetic resonance imaging in Alzheimer's disease and mild cognitive impairment: a critical review. ALZHEIMERS RESEARCH & THERAPY 2018; 10:21. [PMID: 29458420 PMCID: PMC5819240 DOI: 10.1186/s13195-018-0347-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 01/22/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND A growing number of pharmacological and nonpharmacological trials have been performed to test the efficacy of approved or experimental treatments in Alzheimer disease (AD) and mild cognitive impairment (MCI). In this context, functional magnetic resonance imaging (fMRI) may be a good candidate to detect brain changes after a short period of treatment. MAIN BODY This critical review aimed to identify and discuss the available studies that have tested the efficacy of pharmacological and nonpharmacological treatments in AD and MCI cases using task-based or resting-state fMRI measures as primary outcomes. A PubMed-based literature search was performed with the use of the three macro-areas: 'disease', 'type of MRI', and 'type of treatment'. Each contribution was individually reviewed according to the Cochrane Collaboration's tool for assessing risk of bias. Study limitations were systematically detected and critically discussed. We selected 34 pharmacological and 13 nonpharmacological articles. According to the Cochrane Collaboration's tool for assessing risk of bias, 40% of these studies were randomized but only a few described clearly the randomization procedure, 36% declared the blindness of participants and personnel, and only 21% reported the blindness of outcome assessment. In addition, 28% of the studies presented more than 20% drop-outs at short- and/or long-term assessments. Additional common shortcomings of the reviewed works were related to study design, patient selection, sample size, choice of outcome measures, management of drop-out cases, and fMRI methods. CONCLUSION There is an urgent need to obtain efficient treatments for AD and MCI. fMRI is powerful enough to detect even subtle changes over a short period of treatment; however, the soundness of methods should be improved to enable meaningful data interpretation.
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Affiliation(s)
- Elisa Canu
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy
| | - Elisabetta Sarasso
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.,Laboratory of Movement Analysis, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.,Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Federica Agosta
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
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20
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Huang H, Tanner J, Parvataneni H, Rice M, Horgas A, Ding M, Price C. Impact of Total Knee Arthroplasty with General Anesthesia on Brain Networks: Cognitive Efficiency and Ventricular Volume Predict Functional Connectivity Decline in Older Adults. J Alzheimers Dis 2018; 62:319-333. [PMID: 29439328 PMCID: PMC5827939 DOI: 10.3233/jad-170496] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Using resting state functional magnetic resonance imaging (RS-fMRI), we explored: 1) pre- to post-operative changes in functional connectivity in default mode, salience, and central executive networks after total knee arthroplasty (TKA) with general anesthesia, and 2) the contribution of cognitive/brain reserve metrics these resting state functional declines. Individuals age 60 and older electing unilateral total knee arthroplasty (TKA; n = 48) and non-surgery peers with osteoarthritis (n = 45) completed baseline cognitive testing and baseline and post-surgery (post-baseline, 48-h post-surgery) brain MRI. We acquired cognitive and brain estimates for premorbid (vocabulary, reading, education, intracranial volume) and current (working memory, processing speed, declarative memory, ventricular volume) reserve. Functional network analyses corrected for pain severity and pain medication. The surgery group declined in every functional network of interest (p < 0.001). Relative to non-surgery peers, 23% of surgery participants declined in at least one network and 15% of the total TKA sample declined across all networks. Larger preoperative ventricular volume and lower scores on preoperative metrics of processing speed and working memory predicted default mode network connectivity decline. Premorbid cognitive and premorbid brain reserve did not predict decline. Within 48 hours after surgery, at least one fourth of the older adult sample showed significant functional network decline. Metrics of current brain status (ventricular volume), working memory, and processing speed predicted the severity of default mode network connectivity decline. These findings demonstrate the relevance of preoperative cognition and brain integrity on acute postoperative functional network change.
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Affiliation(s)
- Haiqing Huang
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Jared Tanner
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Hari Parvataneni
- Department of Orthopedic Surgery, University of Florida, Gainesville, FL, USA
| | - Mark Rice
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA
| | - Ann Horgas
- College of Nursing, University of Florida, Gainesville, FL, USA
| | - Mingzhou Ding
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Catherine Price
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA
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21
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Serotonergic and cholinergic modulation of functional brain connectivity: A comparison between young and older adults. Neuroimage 2017; 169:312-322. [PMID: 29258890 DOI: 10.1016/j.neuroimage.2017.12.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/08/2017] [Accepted: 12/13/2017] [Indexed: 12/16/2022] Open
Abstract
Aging is accompanied by changes in neurotransmission. To advance our understanding of how aging modifies specific neural circuitries, we examined serotonergic and cholinergic stimulation with resting state functional magnetic resonance imaging (RS-fMRI) in young and older adults. The instant response to the selective serotonin reuptake inhibitor citalopram (30 mg) and the acetylcholinesterase inhibitor galantamine (8 mg) was measured in 12 young and 17 older volunteers during a randomized, double blind, placebo-controlled, crossover study. A powerful dataset consisting of 522 RS-fMRI scans was obtained by acquiring multiple scans per subject before and after drug administration. Group × treatment interaction effects on voxelwise connectivity with ten functional networks were investigated (p < .05, FWE-corrected) using a non-parametric multivariate analysis technique with cerebrospinal fluid, white matter, heart rate and baseline measurements as covariates. Both groups showed a decrease in sensorimotor network connectivity after citalopram administration. The comparable findings after citalopram intake are possibly due to relatively similar serotonergic systems in the young and older subjects. Galantamine altered connectivity between the occipital visual network and regions that are implicated in learning and memory in the young subjects. The lack of a cholinergic response in the elderly might relate to the well-known association between cognitive and cholinergic deterioration at older age.
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22
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Brain Networks are Independently Modulated by Donepezil, Sleep, and Sleep Deprivation. Brain Topogr 2017; 31:380-391. [PMID: 29170853 DOI: 10.1007/s10548-017-0608-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 11/13/2017] [Indexed: 01/12/2023]
Abstract
Resting-state connectivity has been widely studied in the healthy and pathological brain. Less well-characterized are the brain networks altered during pharmacological interventions and their possible interaction with vigilance. In the hopes of finding new biomarkers which can be used to identify cortical activity and cognitive processes linked to the effects of drugs to treat neurodegenerative diseases such as Alzheimer's disease, the analysis of networks altered by medication would be particularly interesting. Eleven healthy subjects were recruited in the context of the European Innovative Medicines Initiative 'PharmaCog'. Each underwent five sessions of simultaneous EEG-fMRI in order to investigate the effects of donepezil and memantine before and after sleep deprivation (SD). The SD approach has been previously proposed as a model for cognitive impairment in healthy subjects. By applying network based statistics (NBS), we observed altered brain networks significantly linked to donepezil intake and sleep deprivation. Taking into account the sleep stages extracted from the EEG data we revealed that a network linked to sleep is interacting with sleep deprivation but not with medication intake. We successfully extracted the functional resting-state networks modified by donepezil intake, sleep and SD. We observed donepezil induced whole brain connectivity alterations forming a network separated from the changes induced by sleep and SD, a result which shows the utility of this approach to check for the validity of pharmacological resting-state analysis of the tested medications without the need of taking into account the subject specific vigilance.
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23
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Reduced basal forebrain atrophy progression in a randomized Donepezil trial in prodromal Alzheimer's disease. Sci Rep 2017; 7:11706. [PMID: 28916821 PMCID: PMC5601919 DOI: 10.1038/s41598-017-09780-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/31/2017] [Indexed: 01/20/2023] Open
Abstract
Acetylcholinesterase inhibitors are approved drugs currently used for the treatment of Alzheimer's disease (AD) dementia. Basal forebrain cholinergic system (BFCS) atrophy is reported to precede both entorhinal cortex atrophy and memory impairment in AD, challenging the traditional model of the temporal sequence of topographical pathology associated with AD. We studied the effect of one-year Donepezil treatment on the rate of BFCS atrophy in prodromal AD patients using a double-blind, randomized, placebo-controlled trial of Donepezil (10 mg/day). Reduced annual BFCS rates of atrophy were found in the Donepezil group compared to the Placebo treated arm. Secondary analyses on BFCS subregions demonstrated the largest treatment effects in the Nucleus Basalis of Meynert (NbM) and the medial septum/diagonal band (Ch1/2). Donepezil administered at a prodromal stage of AD seems to substantially reduce the rate of atrophy of the BFCS nuclei with highest concentration of cholinergic neurons projecting to the cortex (NbM), hippocampus and entorhinal cortex (Ch1/2).
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24
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Giulietti A, Vignini A, Nanetti L, Mazzanti L, Di Primio R, Salvolini E. Alzheimer's Disease Risk and Progression: The Role of Nutritional Supplements and their Effect on Drug Therapy Outcome. Curr Neuropharmacol 2016; 14:177-90. [PMID: 26415975 PMCID: PMC4825948 DOI: 10.2174/1570159x13666150928155321] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 07/28/2015] [Accepted: 08/27/2015] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease in the elderly population. Despite significant advancements in understanding the genetic and molecular basis of AD, the pathology still lacks treatments that can slow down or reverse the progression of cognitive deterioration. Recently, the relationship between nutrient deficiency and dementia onset has been highlighted. AD is in fact a multifactorial pathology, so that a multi-target approach using combinations of micronutrients and drugs could have beneficial effects on cognitive function in neurodegenerative brain disorders leading to synaptic degeneration. Primarily, this review examines the most recent literature regarding the effects of nutrition on the risk/progression of the disease, focusing attention mostly on antioxidants agents, polyunsaturated fatty acids and metals. Secondly, it aims to figure out if nutritional supplements might have beneficial effects on drug therapy outcome. Even if nutritional supplements showed contrasting evidence of a likely effect of decreasing the risk of AD onset that could be studied more deeply in other clinical trials, no convincing data are present about their usefulness in combination with drug therapies and their effectiveness in slowing down the disease progression.
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Affiliation(s)
| | | | | | - L Mazzanti
- Department of Clinical Sciences, Faculty of Medicine, Università Politecnica delle Marche, Via Tronto 10/A, Ancona, Italy.
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25
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26
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Griffanti L, Wilcock GK, Voets N, Bonifacio G, Mackay CE, Jenkinson M, Zamboni G. Donepezil Enhances Frontal Functional Connectivity in Alzheimer's Disease: A Pilot Study. Dement Geriatr Cogn Dis Extra 2016; 6:518-528. [PMID: 27920795 PMCID: PMC5123022 DOI: 10.1159/000450546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We have previously shown that increased resting-state functional magnetic resonance imaging (fMRI)-based functional connectivity (FC) within the frontal resting-state networks in Alzheimer's disease (AD) patients reflects residual, possibly compensatory, function. This suggests that symptomatic treatments should aim to enhance FC specifically in these networks. METHODS 18 patients with probable AD underwent brain MRI and neuropsychological assessment at baseline and after 12 weeks of treatment with donepezil. We tested if changes in cognitive performance after treatment correlated with changes in FC in resting-state networks known to be altered in AD. RESULTS We found increases in FC in the orbitofrontal network that correlated with cognitive improvement after treatment. The increased FC was greatest in patients who responded most to treatment. CONCLUSION This 'proof of concept' study suggests that changes in network-specific FC might be a biomarker of pharmacological intervention efficacy in AD.
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Affiliation(s)
- Ludovica Griffanti
- Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK
| | - Gordon K Wilcock
- Oxford Project to Investigate Memory and Ageing, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK, Oxford, UK
| | - Natalie Voets
- Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK
| | - Guendalina Bonifacio
- Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Università di Modena e Reggio Emilia, Modena, Italy
| | - Clare E Mackay
- Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK; Department of Psychiatry, University of Oxford, Oxford, UK
| | - Mark Jenkinson
- Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK
| | - Giovanna Zamboni
- Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK; Oxford Project to Investigate Memory and Ageing, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK, Oxford, UK; Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Università di Modena e Reggio Emilia, Modena, Italy
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27
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Klaassens BL, Rombouts SARB, Winkler AM, van Gorsel HC, van der Grond J, van Gerven JMA. Time related effects on functional brain connectivity after serotonergic and cholinergic neuromodulation. Hum Brain Mapp 2016; 38:308-325. [PMID: 27622387 PMCID: PMC5215384 DOI: 10.1002/hbm.23362] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 07/22/2016] [Accepted: 08/22/2016] [Indexed: 01/12/2023] Open
Abstract
Psychopharmacological research, if properly designed, may offer insight into both timing and area of effect, increasing our understanding of the brain's neurotransmitter systems. For that purpose, the acute influence of the selective serotonin reuptake inhibitor citalopram (30 mg) and the acetylcholinesterase inhibitor galantamine (8 mg) was repeatedly measured in 12 healthy young volunteers with resting state functional magnetic resonance imaging (RS‐fMRI). Eighteen RS‐fMRI scans were acquired per subject during this randomized, double blind, placebo‐controlled, crossover study. Within‐group comparisons of voxelwise functional connectivity with 10 functional networks were examined (P < 0.05, FWE‐corrected) using a non‐parametric multivariate approach with cerebrospinal fluid, white matter, heart rate, and baseline measurements as covariates. Although both compounds did not change cognitive performance on several tests, significant effects were found on connectivity with multiple resting state networks. Serotonergic stimulation primarily reduced connectivity with the sensorimotor network and structures that are related to self‐referential mechanisms, whereas galantamine affected networks and regions that are more involved in learning, memory, and visual perception and processing. These results are consistent with the serotonergic and cholinergic trajectories and their functional relevance. In addition, this study demonstrates the power of using repeated measures after drug administration, which offers the chance to explore both combined and time specific effects. Hum Brain Mapp 38:308–325, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Bernadet L Klaassens
- Leiden University, Institute of Psychology, Leiden, the Netherlands.,Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Leiden University, Leiden Institute for Brain and Cognition, Leiden, the Netherlands.,Centre for Human Drug Research, Leiden, the Netherlands
| | - Serge A R B Rombouts
- Leiden University, Institute of Psychology, Leiden, the Netherlands.,Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Leiden University, Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Anderson M Winkler
- Oxford Centre for Functional MRI of the Brain, Oxford University, Oxford, United Kingdom
| | - Helene C van Gorsel
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Leiden University, Leiden Institute for Brain and Cognition, Leiden, the Netherlands.,Centre for Human Drug Research, Leiden, the Netherlands
| | - Jeroen van der Grond
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
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Murray LL, Paek EJ. Behavioral/Nonpharmacological Approaches to Addressing Cognitive-Linguistic Symptoms in Individuals With Dementia. ACTA ACUST UNITED AC 2016. [DOI: 10.1044/persp1.sig15.12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Despite current barriers to developing and implementing nonpharmacological or behavioral cognitive-linguistic treatments for dementia, a growing evidence base indicates that individuals with dementia may indeed benefit from a range of nonpharmacological intervention approaches in terms of helping them maintain and/or improve their language and cognitive abilities as well as general functioning and emotional well being. With respect to the current dementia literature, this article describes restorative and compensatory approaches for cognitive symptoms, including direct stimulation of cognitive functions and internal and external strategies to maximize use of residual cognitive skills. We also summarize various language treatment techniques designed to address word retrieval deficits or functional communication issues in a range of dementia types and severity. Broader stimulation approaches such as Montessori-based treatment, reminiscence therapy, and exercise/movement therapy are also reviewed given their potential to benefit not only the cognitive-linguistic symptoms of individuals with dementia, but also other aspects of physical, emotional, and behavioral functioning. Last, we conclude by highlighting limitations in the current research literature along with factors to consider for maximizing nonpharmacological treatment effects (i.e., generalization and maintenance of treatment gains) in clinical or research settings.
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Affiliation(s)
- Laura L. Murray
- Department of Speech and Hearing Sciences, Indiana University
Bloomington, IN
| | - Eun Jin Paek
- Department of Speech and Hearing Sciences, Indiana University
Bloomington, IN
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Functional connectivity increase in the default-mode network of patients with Alzheimer's disease after long-term treatment with Galantamine. Eur Neuropsychopharmacol 2016; 26:602-13. [PMID: 26796681 DOI: 10.1016/j.euroneuro.2015.12.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 10/14/2015] [Accepted: 12/01/2015] [Indexed: 11/23/2022]
Abstract
Acetylcholinesterase inhibitors (AChEIs) are efficacious for the treatment of mild to moderate forms of Alzheimer's dementia (AD). Default-mode network (DMN) connectivity is considered to be early impaired in AD. Long-term effects of AChEIs on the DMN in AD have not yet been investigated. Twenty-eight AD patients and 11 age-matched healthy volunteers (HC) participated in the prospective study. AD patients were randomly assigned to either a pharmacotherapy arm (Galantamine, AD G) or to a placebo arm (AD P+G) for the period of 6 months followed by open-label Galantamine therapy from month 7-12. All subjects underwent neuropsychological testing, resting-state functional and structural MRI at baseline and after 12 months, AD patients additionally in between after 6 months. Thirteen AD patients completed the treatment trial and underwent all functional MRI follow-up sequences of good quality. Functional connectivity significantly increased within the AD G group in the posterior cingulate cortex and in the Precuneus between baseline and 12 months follow-up (pcorr<0.05). Between-group analyses demonstrated that functional connectivity in the AD G group significantly increased in the posterior cingulate cortex as well as in the Precuneus compared to the HC group and in the anteromedial aspect of the temporal lobes compared to the AD P+G group, respectively, at 12 months follow-up (pcorr<0.05). Cognitive performance remained stable within groups over time indicating that resting-state fMRI may be sensitive for the detection of pharmacologically induced effects on brain function of AD patients.
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Dalmases M, Solé-Padullés C, Torres M, Embid C, Nuñez MD, Martínez-Garcia MÁ, Farré R, Bargalló N, Bartrés-Faz D, Montserrat JM. Effect of CPAP on Cognition, Brain Function, and Structure Among Elderly Patients With OSA: A Randomized Pilot Study. Chest 2016; 148:1214-1223. [PMID: 26065720 DOI: 10.1378/chest.15-0171] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Despite the increasing aging population and the high prevalence of OSA in elderly adults, little is known about cognitive effects of OSA and the effectiveness of CPAP treatment. Therefore, this study investigated whether elderly patients with OSA present cognitive deficits and functional and structural alterations of the brain that could be improved by CPAP treatment. METHODS This randomized, evaluator-blinded, parallel-group, single-center pilot study involved patients aged ≥ 65 years with newly-diagnosed severe OSA syndrome. Thirty-three patients were assigned to receive either conservative care (CC) or CPAP plus CC for 3 months. At baseline and 3 months after treatment, patients underwent a neuropsychologic evaluation and a functional and structural MRI study of connectivity within the default mode network (DMN) and of cortical thickness. RESULTS Neuropsychologic evaluation revealed no differences in cognitive performance between OSA groups at baseline. By contrast, after CPAP treatment, patients showed a significant improvement in episodic (between-group difference in change, 7.60; 95% CI, 1.66-13.55; P = .014) and short-term memory (between-group difference in change, 1.06; 95% CI, 0.10-2.01; P = .032) and in executive function (speed of mental processing, 5.74; 95% CI, 1.69-9.79; P = .007; mental flexibility, -47.64; 95% CI, -81.83 to -13.45; P = .008), whereas no changes were observed in the CC group. Neuroimaging revealed an increase in the connectivity in the right middle frontal gyrus after 3 months of CPAP treatment and a higher percentage of cortical thinning in the CC group. No association was seen between cognition and brain functional connectivity changes within the DMN. CONCLUSIONS Elderly patients with severe OSA who present with cognitive difficulties could benefit from CPAP treatment. Moreover, CPAP treatment increases the connectivity of the DMN and attenuates cortical thinning. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01826032; URL: www.clinicaltrials.gov.
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Affiliation(s)
- Mireia Dalmases
- Sleep Unit, Pneumology Department, Hospital Clínic de Barcelona-Facultat de Medicina, Universitat de Barcelona, Barcelona; CIBERES, Madrid
| | - Cristina Solé-Padullés
- Psychiatry and Clinical Psychobiology Department, Facultat de Medicina, Universitat de Barcelona, Barcelona
| | - Marta Torres
- Sleep Unit, Pneumology Department, Hospital Clínic de Barcelona-Facultat de Medicina, Universitat de Barcelona, Barcelona; CIBERES, Madrid
| | - Cristina Embid
- Sleep Unit, Pneumology Department, Hospital Clínic de Barcelona-Facultat de Medicina, Universitat de Barcelona, Barcelona; CIBERES, Madrid
| | - Maria Dolores Nuñez
- Sleep Unit, Pneumology Department, Hospital Clínic de Barcelona-Facultat de Medicina, Universitat de Barcelona, Barcelona
| | | | - Ramon Farré
- CIBERES, Madrid; Biophysics and Bioengineering Department, Facultat de Medicina, Universitat de Barcelona - The August Pi Sunyer Biomedical Research Institute (IDIBAPS), Barcelona
| | - Nuria Bargalló
- Image Diagnostic Center, Hospital Clínic de Barcelona, Barcelona; Magnetic Resonance Image Core Facility, IDIBAPS, Barcelona, Spain
| | - David Bartrés-Faz
- Psychiatry and Clinical Psychobiology Department, Facultat de Medicina, Universitat de Barcelona, Barcelona
| | - Josep M Montserrat
- Sleep Unit, Pneumology Department, Hospital Clínic de Barcelona-Facultat de Medicina, Universitat de Barcelona, Barcelona; CIBERES, Madrid.
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31
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fMRI in Neurodegenerative Diseases: From Scientific Insights to Clinical Applications. NEUROMETHODS 2016. [DOI: 10.1007/978-1-4939-5611-1_23] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Cognitive stimulation of the default-mode network modulates functional connectivity in healthy aging. Brain Res Bull 2015; 121:26-41. [PMID: 26688237 DOI: 10.1016/j.brainresbull.2015.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/03/2015] [Accepted: 12/04/2015] [Indexed: 11/21/2022]
Abstract
A cognitive-stimulation tool was created to regulate functional connectivity within the brain Default-Mode Network (DMN). Computerized exercises were designed based on the hypothesis that repeated task-dependent coactivation of multiple DMN regions would translate into regulation of resting-state network connectivity. Forty seniors (mean age: 65.90 years; SD: 8.53) were recruited and assigned either to an experimental group (n=21) who received one month of intensive cognitive stimulation, or to a control group (n=19) who maintained a regime of daily-life activities explicitly focused on social interactions. An MRI protocol and a battery of neuropsychological tests were administered at baseline and at the end of the study. Changes in the DMN (measured via functional connectivity of posterior-cingulate seeds), in brain volumes, and in cognitive performance were measured with mixed models assessing group-by-timepoint interactions. Moreover, regression models were run to test gray-matter correlates of the various stimulation tasks. Significant associations were found between task performance and gray-matter volume of multiple DMN core regions. Training-dependent up-regulation of functional connectivity was found in the posterior DMN component. This interaction was driven by a pattern of increased connectivity in the training group, while little or no up-regulation was seen in the control group. Minimal changes in brain volumes were found, but there was no change in cognitive performance. The training-dependent regulation of functional connectivity within the posterior DMN component suggests that this stimulation program might exert a beneficial impact in the prevention and treatment of early AD neurodegeneration, in which this neurofunctional pathway is progressively affected by the disease.
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Griffanti L, Rolinski M, Szewczyk-Krolikowski K, Menke RA, Filippini N, Zamboni G, Jenkinson M, Hu MTM, Mackay CE. Challenges in the reproducibility of clinical studies with resting state fMRI: An example in early Parkinson's disease. Neuroimage 2015; 124:704-713. [PMID: 26386348 PMCID: PMC4655939 DOI: 10.1016/j.neuroimage.2015.09.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 11/06/2022] Open
Abstract
Resting state fMRI (rfMRI) is gaining in popularity, being easy to acquire and with promising clinical applications. However, rfMRI studies, especially those involving clinical groups, still lack reproducibility, largely due to the different analysis settings. This is particularly important for the development of imaging biomarkers. The aim of this work was to evaluate the reproducibility of our recent study regarding the functional connectivity of the basal ganglia network in early Parkinson's disease (PD) (Szewczyk-Krolikowski et al., 2014). In particular, we systematically analysed the influence of two rfMRI analysis steps on the results: the individual cleaning (artefact removal) of fMRI data and the choice of the set of independent components (template) used for dual regression. Our experience suggests that the use of a cleaning approach based on single-subject independent component analysis, which removes non neural-related sources of inter-individual variability, can help to increase the reproducibility of clinical findings. A template generated using an independent set of healthy controls is recommended for studies where the aim is to detect differences from a “healthy” brain, rather than an “average” template, derived from an equal number of patients and controls. While, exploratory analyses (e.g. testing multiple resting state networks) should be used to formulate new hypotheses, careful validation is necessary before promising findings can be translated into useful biomarkers. Reproducibility of clinical findings is crucial for imaging biomarker development. We addressed the impact on reproducibility of different analysis settings in rfMRI. ICA-based cleaning of rfMRI data increases reproducibility. The effect of the template choice for dual regression is evaluated.
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Affiliation(s)
- Ludovica Griffanti
- Centre for the functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK
| | - Michal Rolinski
- Oxford Parkinson's Disease Centre (OPDC), University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Konrad Szewczyk-Krolikowski
- Oxford Parkinson's Disease Centre (OPDC), University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Ricarda A Menke
- Centre for the functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK
| | - Nicola Filippini
- Centre for the functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK; Department of Psychiatry, University of Oxford, Oxford, UK
| | - Giovanna Zamboni
- Centre for the functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK
| | - Mark Jenkinson
- Centre for the functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK
| | - Michele T M Hu
- Oxford Parkinson's Disease Centre (OPDC), University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Clare E Mackay
- Centre for the functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK; Oxford Parkinson's Disease Centre (OPDC), University of Oxford, Oxford, UK; Department of Psychiatry, University of Oxford, Oxford, UK.
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Chen G, Ward BD, Chen G, Li SJ. Decreased effective connectivity from cortices to the right parahippocampal gyrus in Alzheimer's disease subjects. Brain Connect 2015; 4:702-8. [PMID: 25132215 DOI: 10.1089/brain.2014.0295] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The purpose of this study was to detect effective connectivity (EC) changes in the default mode network and hippocampus network in 20 patients with Alzheimer's disease (AD) and 20 cognitively normal (CN) subjects, using multivariate Granger causality. The authors used the maximum coefficients in the multivariate autoregression model to quantitatively measure the different EC strength levels between the CN and AD groups. It was demonstrated that the EC strength difference can classify AD from CN subjects. Further, the right parahippocampal gyrus (PHP_R) showed imbalanced bidirectional EC connections. The PHP_R received weaker input connections from the neocortices, but its output connections were significantly increased in AD. These findings may provide neural physiological mechanisms for interpreting AD subjects' memory deficits during the encoding processes.
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Affiliation(s)
- Guangyu Chen
- Department of Biophysics, Medical College of Wisconsin , Milwaukee, Wisconsin
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Disruption of Resting Functional Connectivity in Alzheimer’s Patients and At-Risk Subjects. Curr Neurol Neurosci Rep 2014; 14:491. [DOI: 10.1007/s11910-014-0491-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Prvulovic D, Schneider B. Pharmacokinetic and pharmacodynamic evaluation of donepezil for the treatment of Alzheimer's disease. Expert Opin Drug Metab Toxicol 2014; 10:1039-50. [PMID: 24785550 DOI: 10.1517/17425255.2014.915028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Donepezil is a highly selective acetylcholinesterase inhibitor and one of the only four drugs currently approved for treatment of Alzheimer's dementia. Providing high bioavailability and a very long half-time, donepezil is regarded as effective and well tolerable in Alzheimer's disease patients, even in difficult clinical conditions such as hepatic or renal impairment. It moderately improves cognitive and global functioning scores in patients with mild to moderate Alzheimer's disease over the course of 6 - 12 months, with open-label extension studies suggesting effects of even longer duration. AREAS COVERED We summarized relevant pharmacokinetic, pharmacodynamic, clinical trial and neuroimaging data of donepezil. A literature search was performed in the PubMed database; articles published until October 2013 have been considered for this review. Moreover, references from original work and reviews have been searched for further relevant literature. EXPERT OPINION Donepezil is one of the most frequently prescribed anti-dementia drugs. The recent additional approval of the 23 mg formulation will expand its use in patients with moderate to severe Alzheimer's disease. After numerous Phase III study failures of novel disease-modifying drugs for Alzheimer's disease, donepezil is likely going to stay a first-line therapeutic option in Alzheimer's disease in the upcoming years.
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Affiliation(s)
- David Prvulovic
- Goethe-University of Frankfurt, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy , Heinrich-Hoffmann-Straße 10, 60528 Frankfurt/ Main , Germany
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Risacher SL, Wang Y, Wishart HA, Rabin LA, Flashman LA, McDonald BC, West JD, Santulli RB, Saykin AJ. Cholinergic Enhancement of Brain Activation in Mild Cognitive Impairment during Episodic Memory Encoding. Front Psychiatry 2013; 4:105. [PMID: 24062699 PMCID: PMC3775540 DOI: 10.3389/fpsyt.2013.00105] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/30/2013] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To determine the physiological impact of treatment with donepezil (Aricept) on neural circuitry supporting episodic memory encoding in patients with amnestic mild cognitive impairment (MCI) using functional magnetic resonance imaging (fMRI). METHODS Eighteen patients with MCI and 20 age-matched healthy controls (HC) were scanned twice while performing an event-related verbal episodic encoding task. MCI participants were scanned before treatment and after approximately 3 months on donepezil; HC were untreated but rescanned at the same interval. Voxel-level analyses assessed treatment effects on activation profiles in MCI patients relative to retest changes in non-treated HC. Changes in task-related connectivity in medial temporal circuitry were also evaluated, as were associations between brain activation, task-related functional connectivity, task performance, and clinical measures of cognition. RESULTS At baseline, the MCI group showed reduced activation during encoding relative to HC in the right medial temporal lobe (MTL; hippocampal/parahippocampal) and additional regions, as well as attenuated task-related deactivation, relative to rest, in a medial parietal lobe cluster. After treatment, the MCI group showed normalized MTL activation and improved parietal deactivation. These changes were associated with cognitive performance. After treatment, the MCI group also demonstrated increased task-related functional connectivity from the right MTL cluster seed region to a network of other sites including the basal nucleus/caudate and bilateral frontal lobes. Increased functional connectivity was associated with improved task performance. CONCLUSION Pharmacologic enhancement of cholinergic function in amnestic MCI is associated with changes in brain activation and functional connectivity during episodic memory processing which are in turn related to increased cognitive performance. fMRI is a promising biomarker for assessing treatment related changes in brain function.
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Affiliation(s)
- Shannon L Risacher
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine , Indianapolis, IN , USA ; Indiana Alzheimer Disease Center, Indiana University School of Medicine , Indianapolis, IN , USA
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