1
|
Fray S, Achouri-Rassas A, Belal S, Messaoud T. Missing apolipoprotein E ɛ4 allele associated with nonamnestic Alzheimer’s disease in a Tunisian population. J Genet 2022. [DOI: 10.1007/s12041-022-01384-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
2
|
Chen XR, Shao Y, Sadowski MJ. Segmented Linear Mixed Model Analysis Reveals Association of the APOEɛ4 Allele with Faster Rate of Alzheimer's Disease Dementia Progression. J Alzheimers Dis 2021; 82:921-937. [PMID: 34120907 PMCID: PMC8461709 DOI: 10.3233/jad-210434] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Background: APOEɛ4 allele carriers present with an increased risk for late-onset Alzheimer’s disease (AD), show cognitive symptoms at an earlier age, and are more likely to transition from mild cognitive impairment (MCI) to dementia but despite this, it remains unclear whether or not the ɛ4 allele controls the rate of disease progression. Objective: To determine the effects of the ɛ4 allele on rates of cognitive decline and brain atrophy during MCI and dementia stages of AD. Methods: A segmented linear mixed model was chosen for longitudinal modeling of cognitive and brain volumetric data of 73 ɛ3/ɛ3, 99 ɛ3/ɛ4, and 39 ɛ4/ɛ4 Alzheimer’s Disease Neuroimaging Initiative participants who transitioned during the study from MCI to AD dementia. Results: ɛ4 carriers showed faster decline on MMSE, ADAS-11, CDR-SB, and MoCA scales, with the last two measures showing significant ɛ4 allele-dose effects after dementia transition but not during MCI. The ɛ4 effect was more prevalent in younger participants and in females. ɛ4 carriers also demonstrated faster rates of atrophy of the whole brain, the hippocampus, the entorhinal cortex, the middle temporal gyrus, and expansion of the ventricles after transitioning to dementia but not during MCI. Conclusion: Possession of the ɛ4 allele is associated with a faster progression of dementia due to AD. Our observations support the notion that APOE genotype not only controls AD risk but also differentially regulates mechanisms of neurodegeneration underlying disease advancement. Furthermore, our findings carry significance for AD clinical trial design.
Collapse
Affiliation(s)
- X Richard Chen
- University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
| | - Yongzhao Shao
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA.,Department of Environmental Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Martin J Sadowski
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA.,Department of Psychiatry, NYU Grossman School of Medicine, New York, NY, USA.,Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY, USA
| | | |
Collapse
|
3
|
Pfeil J, Hoenig MC, Doering E, van Eimeren T, Drzezga A, Bischof GN. Unique regional patterns of amyloid burden predict progression to prodromal and clinical stages of Alzheimer's disease. Neurobiol Aging 2021; 106:119-129. [PMID: 34284259 PMCID: PMC8461082 DOI: 10.1016/j.neurobiolaging.2021.06.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/22/2021] [Accepted: 06/15/2021] [Indexed: 01/21/2023]
Abstract
Although beta-amyloid (Aβ) positivity has shown to be associated with higher risk of progression to Alzheimer's disease (AD) in mild cognitive impairment (MCI), information on the time to conversion to manifest dementia cannot be readily deduced from this binary classification. Here, we assessed if regional patterns of Aβ deposition measured with 18F-florbetapir may serve as biomarker for progression risk in Aβ-positive cognitively normal (CN) and MCI patients, including clinical follow-up data and cerebrospinal fluid (CSF) biomarkers. Voxel-wise group comparisons between age and sex-matched Aβ-positive groups (i.e., CN-stables [n = 38] vs. CN-to-MCI/AD progressors [n = 38], MCI-stables [n = 104] versus MCI-to-AD progressors [n = 104]) revealed higher Aβ burden in precuneus, subcortical, and parietal regions in CN-to-MCI/AD progressors and cingulate, temporal, and frontal regions in MCI-to-AD progressors. Importantly, these regional patterns predicted progression to advanced stages on the AD spectrum in the short and the long-term beyond global Aβ burden and CSF biomarkers. These results suggest that distinct regional patterns of Aβ burden are a valuable biomarker for risk of disease progression in CN and MCI.
Collapse
Affiliation(s)
- Julia Pfeil
- Department of Nuclear Medicine, Multimodal Neuroimaging Group, University of Cologne, University Hospital of Cologne, Cologne, Germany.
| | - Merle C Hoenig
- Department of Nuclear Medicine, Multimodal Neuroimaging Group, University of Cologne, University Hospital of Cologne, Cologne, Germany; Research Center Juelich, Institute for Neuroscience and Medicine II, Molecular Organization of the Brain, Juelich, Germany
| | - Elena Doering
- Department of Nuclear Medicine, Multimodal Neuroimaging Group, University of Cologne, University Hospital of Cologne, Cologne, Germany; German Center for Neurodegenerative Diseases, Bonn/Cologne, Germany
| | - Thilo van Eimeren
- Department of Nuclear Medicine, Multimodal Neuroimaging Group, University of Cologne, University Hospital of Cologne, Cologne, Germany; German Center for Neurodegenerative Diseases, Bonn/Cologne, Germany; University of Cologne, University Hospital of Cologne, Department of Neurology, Cologne, Germany
| | - Alexander Drzezga
- Department of Nuclear Medicine, Multimodal Neuroimaging Group, University of Cologne, University Hospital of Cologne, Cologne, Germany; Research Center Juelich, Institute for Neuroscience and Medicine II, Molecular Organization of the Brain, Juelich, Germany; German Center for Neurodegenerative Diseases, Bonn/Cologne, Germany
| | - Gérard N Bischof
- Department of Nuclear Medicine, Multimodal Neuroimaging Group, University of Cologne, University Hospital of Cologne, Cologne, Germany
| |
Collapse
|
4
|
Loeffler DA. Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease. J Alzheimers Dis 2021; 80:1-27. [PMID: 33459643 DOI: 10.3233/jad-201182] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.
Collapse
Affiliation(s)
- David A Loeffler
- Beaumont Research Institute, Department of Neurology, Beaumont Health, Royal Oak, MI, USA
| |
Collapse
|
5
|
Katzourou I, Leonenko G, Ivanov D, Meggy A, Marshall R, Sims R, Williams J, Holmans P, Escott-Price V. Cognitive Decline in Alzheimer's Disease Is Not Associated with APOE. J Alzheimers Dis 2021; 84:141-149. [PMID: 34487047 DOI: 10.3233/jad-210685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The rate of cognitive decline in Alzheimer's disease (AD) has been found to vary widely between individuals, with numerous factors driving this heterogeneity. OBJECTIVE This study aimed to compute a measure of cognitive decline in patients with AD based on clinical information and to utilize this measure to explore the genetic architecture of cognitive decline in AD. METHODS An in-house cohort of 616 individuals, hereby termed the Cardiff Genetic Resource for AD, as well as a subset of 577 individuals from the publicly available ADNI dataset, that have been assessed at multiple timepoints, were used in this study. Measures of cognitive decline were computed using various mixed effect linear models of Mini-Mental State Examination (MMSE). After an optimal model was selected, a metric of cognitive decline for each individual was estimated as the random slope derived from this model. This metric was subsequently used for testing the association of cognitive decline with apolipoprotein E (APOE) genotype. RESULTS No association was found between the number of APOEɛ2 or ɛ4 alleles and the rate of cognitive decline in either of the datasets examined. CONCLUSION Further exploration is required to uncover possible genetic variants that affect the rate of decline in patients with AD.
Collapse
Affiliation(s)
| | - Ganna Leonenko
- UK Dementia Research Institute, Cardiff University, Cardiff, UK
| | - Dobril Ivanov
- UK Dementia Research Institute, Cardiff University, Cardiff, UK
| | - Alun Meggy
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Rachel Marshall
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Rebecca Sims
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Julie Williams
- UK Dementia Research Institute, Cardiff University, Cardiff, UK
| | - Peter Holmans
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | | | | |
Collapse
|
6
|
Casanova R, Saldana S, Lutz MW, Plassman BL, Kuchibhatla M, Hayden KM. Investigating Predictors of Cognitive Decline Using Machine Learning. J Gerontol B Psychol Sci Soc Sci 2020; 75:733-742. [PMID: 29718387 DOI: 10.1093/geronb/gby054] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES Genetic risks for cognitive decline are not modifiable; however their relative importance compared to modifiable factors is unclear. We used machine learning to evaluate modifiable and genetic risk factors for Alzheimer's disease (AD), to predict cognitive decline. METHODS Health and Retirement Study participants, aged 65-90 years, with DNA and >2 cognitive evaluations, were included (n = 7,142). Predictors included age, body mass index, gender, education, APOE ε4, cardiovascular, hypertension, diabetes, stroke, neighborhood socioeconomic status (NSES), and AD risk genes. Latent class trajectory analyses of cognitive scores determined the form and number of classes. Random Forests (RF) classification investigated predictors of cognitive trajectories. Performance metrics (accuracy, sensitivity, and specificity) were reported. RESULTS Three classes were identified. Discriminating highest from lowest classes produced the best RF performance: accuracy = 78% (1.0%), sensitivity = 75% (1.0%), and specificity = 81% (1.0%). Top ranked predictors were education, age, gender, stroke, NSES, and diabetes, APOE ε4 carrier status, and body mass index (BMI). When discriminating high from medium classes, top predictors were education, age, gender, stroke, diabetes, NSES, and BMI. When discriminating medium from the low classes, education, NSES, age, diabetes, and stroke were top predictors. DISCUSSION The combination of latent trajectories and RF classification techniques suggested that nongenetic factors contribute more to cognitive decline than genetic factors. Education was the most relevant predictor for discrimination.
Collapse
Affiliation(s)
- Ramon Casanova
- Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston Salem, North Carolina
| | - Santiago Saldana
- Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston Salem, North Carolina
| | - Michael W Lutz
- Department of Neurology, Duke University Medical Center, Durham, North Carolina
| | - Brenda L Plassman
- Department of Neurology, Duke University Medical Center, Durham, North Carolina.,Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina
| | - Maragatha Kuchibhatla
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina
| | - Kathleen M Hayden
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston Salem, North Carolina
| |
Collapse
|
7
|
Emrani S, Arain HA, DeMarshall C, Nuriel T. APOE4 is associated with cognitive and pathological heterogeneity in patients with Alzheimer's disease: a systematic review. ALZHEIMERS RESEARCH & THERAPY 2020; 12:141. [PMID: 33148345 PMCID: PMC7643479 DOI: 10.1186/s13195-020-00712-4] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/22/2020] [Indexed: 02/06/2023]
Abstract
Possession of the ε4 allele of apolipoprotein E (APOE) is the primary genetic risk factor for the sporadic form of Alzheimer’s disease (AD). While researchers have extensively characterized the impact that APOE ε4 (APOE4) has on the susceptibility of AD, far fewer studies have investigated the phenotypic differences of patients with AD who are APOE4 carriers vs. those who are non-carriers. In order to understand these differences, we performed a qualitative systematic literature review of the reported cognitive and pathological differences between APOE4-positive (APOE4+) vs. APOE4-negative (APOE4−) AD patients. The studies performed on this topic to date suggest that APOE4 is not only an important mediator of AD susceptibility, but that it likely confers specific phenotypic heterogeneity in AD presentation, as well. Specifically, APOE4+ AD patients appear to possess more tau accumulation and brain atrophy in the medial temporal lobe, resulting in greater memory impairment, compared to APOE4− AD patients. On the other hand, APOE4− AD patients appear to possess more tau accumulation and brain atrophy in the frontal and parietal lobes, resulting in greater impairment in executive function, visuospatial abilities, and language, compared to APOE4+ AD patients. Although more work is necessary to validate and interrogate these findings, these initial observations of pathological and cognitive heterogeneity between APOE4+ vs. APOE4− AD patients suggest that there is a fundamental divergence in AD manifestation related to APOE genotype, which may have important implications in regard to the therapeutic treatment of these two patient populations.
Collapse
Affiliation(s)
- Sheina Emrani
- Department of Psychology, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA
| | - Hirra A Arain
- Department of Pathology and Cell Biology, Columbia University, 630 West 168th Street, New York, NY, 10032, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, 630 West 168th Street, New York, NY, 10032, USA
| | - Cassandra DeMarshall
- Department of Geriatrics and Gerontology, Rowan University School of Osteopathic Medicine, One Medical Center Drive, Stratford, NJ, 08084, USA
| | - Tal Nuriel
- Department of Pathology and Cell Biology, Columbia University, 630 West 168th Street, New York, NY, 10032, USA. .,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, 630 West 168th Street, New York, NY, 10032, USA.
| |
Collapse
|
8
|
Sohn JH, Lee SH, Kwon YS, Kim JH, Kim Y, Lee JJ. The impact of tamsulosin on cognition in Alzheimer disease with benign prostate hyperplasia: A study using the Hallym Smart Clinical Data Warehouse. Medicine (Baltimore) 2020; 99:e20240. [PMID: 32481389 DOI: 10.1097/md.0000000000020240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Studies suggest that the use of alpha-blockers increases the risk of dementia in patients with benign prostate hyperplasia (BPH). Due to study limitations, the relationship between the use of alpha-blockers, such as tamsulosin, and the risk of dementia is still unclear. However, alpha1-adrenoreceptors are also present in the brain, so there is potential for adverse effects on cognitive function. Therefore, we investigated possible associations between the use of alpha-blockers and aggravation of cognitive decline in dementia patients using a clinical data analytic solution called the Smart Clinical Data Warehouse (CDW).We retrospectively investigated clinical data using the Smart CDW of Hallym University Medical Center from 2009 to 2019. We enrolled patients with probable Alzheimer disease (AD) who had completed the Mini-Mental State Examination (MMSE) at least twice during follow-up, and who had BPH. We compared the difference in MMSE scores between patients who took tamsulosin for >1000 days and those who did not take any alpha-blocker. We tested the effect of tamsulosin on cognitive decline in patients with AD, using propensity score-matched logistic regression analysis.Eligible cases were included in the tamsulosin (n = 68) or no-medication (n = 153) groups. After propensity score matching, clinical characteristics such as educational attainment and vascular risk factors were similar in the tamsulosin and no-medication groups. The MMSE scores did not differ significantly between the tamsulosin and no-medication groups (P = .470).The results suggest that tamsulosin for BPH is not associated with worsening of the cognitive decline in patients with AD.
Collapse
Affiliation(s)
| | | | - Young-Suk Kwon
- Department of Anesthesiology and Pain Medicine, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine
- Institute of New Frontier Research, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jong-Ho Kim
- Department of Anesthesiology and Pain Medicine, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine
- Institute of New Frontier Research, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Youngmi Kim
- Institute of New Frontier Research, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jae Jun Lee
- Department of Anesthesiology and Pain Medicine, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine
- Institute of New Frontier Research, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| |
Collapse
|
9
|
Choi KY, Lee JJ, Gunasekaran TI, Kang S, Lee W, Jeong J, Lim HJ, Zhang X, Zhu C, Won SY, Choi YY, Seo EH, Lee SC, Gim J, Chung JY, Chong A, Byun MS, Seo S, Ko PW, Han JW, McLean C, Farrell J, Lunetta KL, Miyashita A, Hara N, Won S, Choi SM, Ha JM, Jeong JH, Kuwano R, Song MK, An SSA, Lee YM, Park KW, Lee HW, Choi SH, Rhee S, Song WK, Lee JS, Mayeux R, Haines JL, Pericak-Vance MA, Choo ILH, Nho K, Kim KW, Lee DY, Kim S, Kim BC, Kim H, Jun GR, Schellenberg GD, Ikeuchi T, Farrer LA, Lee KH, Neuroimaging Initative AD. APOE Promoter Polymorphism-219T/G is an Effect Modifier of the Influence of APOE ε4 on Alzheimer's Disease Risk in a Multiracial Sample. J Clin Med 2019; 8:jcm8081236. [PMID: 31426376 PMCID: PMC6723529 DOI: 10.3390/jcm8081236] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/09/2019] [Accepted: 08/12/2019] [Indexed: 12/21/2022] Open
Abstract
Variants in the APOE gene region may explain ethnic differences in the association of Alzheimer’s disease (AD) with ε4. Ethnic differences in allele frequencies for three APOE region SNPs (single nucleotide polymorphisms) were identified and tested for association in 19,398 East Asians (EastA), including Koreans and Japanese, 15,836 European ancestry (EuroA) individuals, and 4985 African Americans, and with brain imaging measures of cortical atrophy in sub-samples of Koreans and EuroAs. Among ε4/ε4 individuals, AD risk increased substantially in a dose-dependent manner with the number of APOE promoter SNP rs405509 T alleles in EastAs (TT: OR (odds ratio) = 27.02, p = 8.80 × 10−94; GT: OR = 15.87, p = 2.62 × 10−9) and EuroAs (TT: OR = 18.13, p = 2.69 × 10−108; GT: OR = 12.63, p = 3.44 × 10−64), and rs405509-T homozygotes had a younger onset and more severe cortical atrophy than those with G-allele. Functional experiments using APOE promoter fragments demonstrated that TT lowered APOE expression in human brain and serum. The modifying effect of rs405509 genotype explained much of the ethnic variability in the AD/ε4 association, and increasing APOE expression might lower AD risk among ε4 homozygotes.
Collapse
Affiliation(s)
- Kyu Yeong Choi
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
| | - Jang Jae Lee
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
| | - Tamil Iniyan Gunasekaran
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Biomedical Science, Chosun University, Gwangju 61452, Korea
| | - Sarang Kang
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Life Science, Chosun University, Gwangju 61452, Korea
| | - Wooje Lee
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
| | - Jangho Jeong
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Ho Jae Lim
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Life Science, Chosun University, Gwangju 61452, Korea
| | - Xiaoling Zhang
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA 02118, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Congcong Zhu
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA 02118, USA
| | - So-Yoon Won
- Department of Biochemistry and Signaling Disorder Research Center, College of Medicine, Chungbuk National University, Cheongju 28644, Korea
| | - Yu Yong Choi
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
| | - Eun Hyun Seo
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Premedical Science, Chosun University College of Medicine, Gwangju 61452, Korea
| | - Seok Cheol Lee
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
| | - Jungsoo Gim
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Biomedical Science, Chosun University, Gwangju 61452, Korea
| | - Ji Yeon Chung
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Neurology, Chosun University Hospital, Gwangju 61452, Korea
| | - Ari Chong
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Nuclear Medicine, Chosun University Hospital, Gwangju 61452, Korea
| | - Min Soo Byun
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul 03080, Korea
| | - Sujin Seo
- Department of Public Health Science, Graduate School of Public Health, Seoul National University, Seoul 08826, Korea
| | - Pan-Woo Ko
- Department of Neurology, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Ji-Won Han
- Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do 13620, Korea
| | - Catriona McLean
- Department of Pathology, The Alfred Hospital, Melbourne, Victoria 3004, Australia
| | - John Farrell
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA 02118, USA
| | - Kathryn L Lunetta
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Akinori Miyashita
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Norikazu Hara
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Sungho Won
- Department of Public Health Science, Graduate School of Public Health, Seoul National University, Seoul 08826, Korea
| | - Seong-Min Choi
- Department of Neurology, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Jung-Min Ha
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Nuclear Medicine, Chosun University Hospital, Gwangju 61452, Korea
| | - Jee Hyang Jeong
- Department of Neurology, Ewha Womans University Mokdong Hospital, Ewha Womans University School of Medicine, Seoul 07985, Korea
| | - Ryozo Kuwano
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Min Kyung Song
- Chonnam national university Gwangju 2nd geriatric hospital, Gwangju 61748, Korea
| | - Seong Soo A An
- Department of Bionanotechnology, Gachon University, Seongnam, Gyeonggi-do 13120, Korea
| | - Young Min Lee
- Department of Psychiatry, Pusan National University School of Medicine, Busan 50612, Korea
| | - Kyung Won Park
- Department of Neurology, Donga University College of Medicine, Busan 49315, Korea
| | - Ho-Won Lee
- Department of Neurology, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Seong Hye Choi
- Department of Neurology, Inha University School of Medicine, Incheon 22212, Korea
| | - Sangmyung Rhee
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Woo Keun Song
- Bio Imaging and Cell Logistics Research Center, School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Jung Sup Lee
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Biomedical Science, Chosun University, Gwangju 61452, Korea
| | - Richard Mayeux
- Department of Neurology and Sergievsky Center, Columbia University, New York, NY 10032, USA
| | - Jonathan L Haines
- Department of Population & Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Margaret A Pericak-Vance
- Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33101, USA
| | - I L Han Choo
- Department of Neuropsychiatry, Chosun University School of Medicine and Hospital, Gwangju 61453, Korea
| | - Kwangsik Nho
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Ki-Woong Kim
- Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do 13620, Korea
| | - Dong Young Lee
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul 03080, Korea
| | - SangYun Kim
- Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do 13620, Korea
| | - Byeong C Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Hoowon Kim
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea
- Department of Neurology, Chosun University Hospital, Gwangju 61452, Korea
| | - Gyungah R Jun
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA 02118, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Gerard D Schellenberg
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104-4238, USA
| | - Takeshi Ikeuchi
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Lindsay A Farrer
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA 02118, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
- Departments of Neurology, Ophthalmology, and Epidemiology, Boston University Schools of Medicine and Public Health, Boston, MA 02118, USA
| | - Kun Ho Lee
- National Research Center for Dementia, Chosun University, Gwangju 61452, Korea.
- Department of Biomedical Science, Chosun University, Gwangju 61452, Korea.
- Department of Life Science, Chosun University, Gwangju 61452, Korea.
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu 41062, Korea.
| | | |
Collapse
|
10
|
Werhane ML, Thomas KR, Edmonds EC, Bangen KJ, Tran M, Clark AL, Nation DA, Gilbert PE, Bondi MW, Delano-Wood L. Differential Effect of APOE ɛ4 Status and Elevated Pulse Pressure on Functional Decline in Cognitively Normal Older Adults. J Alzheimers Dis 2019; 62:1567-1578. [PMID: 29562507 DOI: 10.3233/jad-170918] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND/OBJECTIVE The APOE ɛ4 allele and increased vascular risk have both been independently linked to cognitive impairment and dementia. Since few studies have characterized how these risk factors affect everyday functioning, we investigated the relationship between APOE ɛ4 genotype and elevated pulse pressure (PP) on functional change in cognitively normal participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). METHODS 738 normally aging participants underwent APOE genotyping, and baseline PP was calculated from blood pressure indices. The Functional Activities Questionnaire (FAQ) was completed by participants' informant at baseline and 6, 12, 24, 36, and 48-month follow-up visits. Multiple linear regression and multilevel modeling were used to examine the effects of PP and APOE ɛ4 genotype on cross-sectional and longitudinal FAQ scores, respectively. RESULTS Adjusting for demographic and clinical covariates, results showed that both APOE ɛ4 status and elevated PP predicted greater functional difficulty trajectories across four years of follow-up. Interestingly, however, elevated PP was associated with greater functional decline over time in ɛ4 non-carriers versus carriers. CONCLUSION Results show that, although APOE ɛ4 status is the prominent predictor of functional difficulty for ɛ4 carriers, an effect of arterial stiffening on functional difficulty was observed in non-carriers. Future studies are needed in order to clarify the etiology of the association between PP and different brain aging processes, and further explore its utility as a marker of dementia risk. The present study underscores the importance of targeting modifiable risk factors such as elevated PP to prevent or slow functional decline and pathological brain aging.
Collapse
Affiliation(s)
- Madeleine L Werhane
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,San Diego State University/University of California, San Diego (SDSU/UCSD) Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Kelsey R Thomas
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Emily C Edmonds
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Katherine J Bangen
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - My Tran
- Department of Psychology, San Diego State University, San Diego, CA, USA
| | - Alexandra L Clark
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,San Diego State University/University of California, San Diego (SDSU/UCSD) Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Daniel A Nation
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - Paul E Gilbert
- San Diego State University/University of California, San Diego (SDSU/UCSD) Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA
| | - Mark W Bondi
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Lisa Delano-Wood
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | | |
Collapse
|
11
|
Geifman N, Kennedy RE, Schneider LS, Buchan I, Brinton RD. Data-driven identification of endophenotypes of Alzheimer's disease progression: implications for clinical trials and therapeutic interventions. ALZHEIMERS RESEARCH & THERAPY 2018; 10:4. [PMID: 29370871 PMCID: PMC6389228 DOI: 10.1186/s13195-017-0332-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 12/18/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Given the complex and progressive nature of Alzheimer's disease (AD), a precision medicine approach for diagnosis and treatment requires the identification of patient subgroups with biomedically distinct and actionable phenotype definitions. METHODS Longitudinal patient-level data for 1160 AD patients receiving placebo or no treatment with a follow-up of up to 18 months were extracted from an integrated clinical trials dataset. We used latent class mixed modelling (LCMM) to identify patient subgroups demonstrating distinct patterns of change over time in disease severity, as measured by the Alzheimer's Disease Assessment Scale-cognitive subscale score. The optimal number of subgroups (classes) was selected by the model which had the lowest Bayesian Information Criterion. Other patient-level variables were used to define these subgroups' distinguishing characteristics and to investigate the interactions between patient characteristics and patterns of disease progression. RESULTS The LCMM resulted in three distinct subgroups of patients, with 10.3% in Class 1, 76.5% in Class 2 and 13.2% in Class 3. While all classes demonstrated some degree of cognitive decline, each demonstrated a different pattern of change in cognitive scores, potentially reflecting different subtypes of AD patients. Class 1 represents rapid decliners with a steep decline in cognition over time, and who tended to be younger and better educated. Class 2 represents slow decliners, while Class 3 represents severely impaired slow decliners: patients with a similar rate of decline to Class 2 but with worse baseline cognitive scores. Class 2 demonstrated a significantly higher proportion of patients with a history of statins use; Class 3 showed lower levels of blood monocytes and serum calcium, and higher blood glucose levels. CONCLUSIONS Our results, 'learned' from clinical data, indicate the existence of at least three subgroups of Alzheimer's patients, each demonstrating a different trajectory of disease progression. This hypothesis-generating approach has detected distinct AD subgroups that may prove to be discrete endophenotypes linked to specific aetiologies. These findings could enable stratification within a clinical trial or study context, which may help identify new targets for intervention and guide better care.
Collapse
Affiliation(s)
- Nophar Geifman
- Centre for Health Informatics, University of Manchester, Vaughan House, Portsmouth St, Manchester, M13 9GB, UK. .,The Manchester Molecular Pathology Innovation Centre, University of Manchester, Manchester, UK.
| | - Richard E Kennedy
- School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lon S Schneider
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | | | - Roberta Diaz Brinton
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USA.,Department of Neurology, College of Medicine, University of Arizona, Tucson, AZ, USA.,Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, USA
| |
Collapse
|
12
|
Wattmo C, Wallin ÅK. Early- versus late-onset Alzheimer's disease in clinical practice: cognitive and global outcomes over 3 years. ALZHEIMERS RESEARCH & THERAPY 2017; 9:70. [PMID: 28859660 PMCID: PMC5580278 DOI: 10.1186/s13195-017-0294-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 07/27/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Whether age at onset influences Alzheimer's disease (AD) progression and the effectiveness of cholinesterase inhibitor (ChEI) therapy is not clear. We aimed to compare longitudinal cognitive and global outcomes in ChEI-treated patients with early-onset Alzheimer's disease (EOAD) versus late-onset Alzheimer's disease (LOAD) in clinical practice. METHODS This 3-year, prospective, observational, multicentre study included 1017 participants with mild to moderate AD; 143 had EOAD (age at onset < 65 years) and 874 had LOAD (age at onset ≥ 65 years). At baseline and semi-annually, patients were assessed using cognitive, global and activities of daily living (ADL) scales, and the dose of ChEI was recorded. Potential predictors of decline were analysed using mixed-effects models. RESULTS Six-month response to ChEI therapy and long-term prognosis in cognitive and global performance were similar between the age-at-onset groups. However, deterioration was significantly faster when using the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) over 3 years in participants with EOAD than in those with LOAD; hence, prediction models for the mean ADAS-Cog trajectories are presented. The younger cohort had a larger proportion of homozygote apolipoprotein E (APOE) ε4 allele carriers than the older cohort; however, APOE genotype was not a significant predictor of cognitive impairment in the multivariate models. A slower rate of cognitive progression was related to initiation of ChEIs at an earlier stage of AD, higher ChEI dose and fewer years of education in both groups. In LOAD, male sex, better instrumental ADL ability and no antipsychotic drug use were additional protective characteristics. The older patients received a lower ChEI dose than the younger individuals during most of the study period. CONCLUSIONS Although the participants with EOAD showed a faster decline in ADAS-Cog, had a longer duration of AD before diagnosis, and had a higher frequency of two APOE ε4 alleles than those with LOAD, the cognitive and global responses to ChEI treatment and the longitudinal outcomes after 3 years were similar between the age-at-onset groups. A higher mean dose of ChEI and better cognitive status at the start of therapy were independent protective factors in both groups, stressing the importance of early treatment in adequate doses for all patients with AD.
Collapse
Affiliation(s)
- Carina Wattmo
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, SE-205 02, Malmö, Sweden.
| | - Åsa K Wallin
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, SE-205 02, Malmö, Sweden
| |
Collapse
|
13
|
Royall DR, Al-Rubaye S, Bishnoi R, Palmer RF. Few serum proteins mediate APOE's association with dementia. PLoS One 2017; 12:e0172268. [PMID: 28291794 PMCID: PMC5349443 DOI: 10.1371/journal.pone.0172268] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/02/2017] [Indexed: 02/08/2023] Open
Abstract
The latent variable "δ" (for "dementia") appears to be uniquely responsible for the dementing aspects of cognitive impairment. Age, depression, gender and the apolipoprotein E (APOE) e4 allele are independently associated with δ. In this analysis, we explore serum proteins as potential mediators of APOE's specific association with δ in a large, ethnically diverse longitudinal cohort, the Texas Alzheimer's Research and Care Consortium (TARCC). APOE was associated only with C-Reactive Protein (CRP), Adiponectin (APN) and Amphiregulin (AREG), although the latter two's associations did not survive Bonferroni correction for multiple comparisons. All three proteins were associated with δ and had weak potential mediation effects on APOE's association with that construct. Our findings suggest that APOE's association with cognitive performance is specific to δ and partially mediated by serum inflammatory proteins. The majority of APOE's significant unadjusted effect on δ is unexplained. It may instead arise from direct central nervous system effects, possibly on native intelligence. If so, then APOE may exert a life-long influence over δ and therefore all-cause dementia risk.
Collapse
Affiliation(s)
- Donald R. Royall
- Department of Psychiatry, the University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Medicine, the University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Family and Community Medicine, the University of Texas Health Science Center, San Antonio, Texas, United States of America
- South Texas Veterans’ Health System Audie L. Murphy Division Geriatric Research Education and Clinical Care Center, San Antonio, Texas, United States of America
| | - Safa Al-Rubaye
- Department of Psychiatry, the University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Ram Bishnoi
- Department of Psychiatry, the Medical College of Georgia, Augusta, Georgia, United States of America
| | - Raymond F. Palmer
- Department of Family and Community Medicine, the University of Texas Health Science Center, San Antonio, Texas, United States of America
| |
Collapse
|
14
|
Jia J, Gauthier S, Pallotta S, Ji Y, Wei W, Xiao S, Peng D, Guo Q, Wu L, Chen S, Kuang W, Zhang J, Wei C, Tang Y. Consensus‐based recommendations for the management of rapid cognitive decline due to Alzheimer's disease. Alzheimers Dement 2017; 13:592-597. [PMID: 28238739 DOI: 10.1016/j.jalz.2017.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 12/20/2016] [Accepted: 01/02/2017] [Indexed: 02/05/2023]
Affiliation(s)
- Jianping Jia
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China.
| | - Serge Gauthier
- Department of Neurology, Alzheimer's Disease Research Unit, McGill Centre for Studies in Aging, Montreal, Quebec, Canada.
| | - Sarah Pallotta
- McGill University Medical School, Montreal, Quebec, Canada
| | - Yong Ji
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China
| | - Wenshi Wei
- Department of Neurology, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Shifu Xiao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dantao Peng
- Department of Neurology, China-Japan Friendship Hospital, Beijing, China
| | - Qihao Guo
- Department of Neurology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Liyong Wu
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Shengdi Chen
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weihong Kuang
- West China Hospital, Sichuan University, Sichuan, China
| | - Junjian Zhang
- Department of Neurology, Zhongnan Hospital of Wuhan University, Hubei, China
| | - Cuibai Wei
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Yi Tang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
15
|
Yoon B, Shim YS, Park HK, Park SA, Choi SH, Yang DW. Predictive factors for disease progression in patients with early-onset Alzheimer's disease. J Alzheimers Dis 2016; 49:85-91. [PMID: 26444786 DOI: 10.3233/jad-150462] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Only a few studies have investigated disease progression in patients with early-onset Alzheimer's disease (EOAD). Therefore, the aim of this study was to investigate disease progression in patients with EOAD and the influence of various factors, such as gender, education, and apolipoprotein E (APOE) genotype on disease progression. METHODS A total of 288 EOAD patients were enrolled in the study. Linear mixed models were used to investigate the rate of cognitive and functional decline in terms of age at onset, gender, education, follow-up period, and APOE genotype. RESULTS EOAD patients showed an annual decline of -1.54 points/years in the Korean version mini-mental examination score, an annual increase of 3.46 points/year in the Seoul instrumental activities of daily living (SIADL) score, and an annual increase of 1.15 points/year in the clinical dementia rating scale-sum of boxes score. After stratification, higher educated patients showed faster disease progression in all three parameters, and female patients demonstrated faster disease progression as assessed by the SIADL score. Age at onset and APOE genotype had no influence on disease progression. CONCLUSION We confirmed the rate of disease progression in Korean patients with EOAD in real-life hospital-based clinical practice. The results of this study suggest that education and female gender, not APOE genotype, may be important as independent strong predictive factors for disease progression in patients with EOAD.
Collapse
Affiliation(s)
- Bora Yoon
- Department of Neurology, Konyang University Hospital, College of Medicine, Konyang University, Daejeon, Republic of Korea
| | - Yong S Shim
- Department of Neurology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Republic of Korea
| | - Hee-Kyung Park
- Department of Neurology, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - Sun Ah Park
- Department of Neurology, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
| | - Seong Hye Choi
- Department of Neurology, Inha University School of Medicine, Incheon, Republic of Korea
| | - Dong Won Yang
- Department of Neurology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| |
Collapse
|
16
|
Apolipoprotein E (APOE) ε4 and episodic memory decline in Alzheimer's disease: A review. Ageing Res Rev 2016; 27:15-22. [PMID: 26876367 DOI: 10.1016/j.arr.2016.02.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/15/2016] [Accepted: 02/08/2016] [Indexed: 11/24/2022]
Abstract
A growing body of research has examined the relationship between episodic memory decline, the cognitive hallmark of Alzheimer's disease (AD), and the presence of Apolipoprotein E ε4 (APOE ε4) allele, a major genetic risk factor for the disease. Our review attempts to summarize and critically evaluate this literature. We performed a systematic search for studies assessing episodic memory in AD patients who were genotyped for APOE ε4 and identified fourteen papers. Although most of these papers reported significant relationships between APOE ε4 and episodic memory decline in AD, some papers did not confirm this relationship. Our review links this controversy to the conflicting literature about the effects of APOE ε4 on general cognitive functioning in AD. We identify several shortcoming and limitations of the research on the relationship between APOE ε4 and episodic memory in AD, such as small sample sizes, non-representative populations, lack of comparison of early-onset vs. late-onset disease, and lack of comparison among different genotypes that include APOE ε4 (i.e., zero, one, or two ε4 alleles). Another major shortcoming of the reviewed literature was the lack of comprehensive evaluation of episodic memory decline, since episodic memory was solely evaluated with regard to encoding and retrieval, omitting evaluation of core episodic features that decline in AD, such as context recall (e.g., how, where, and when an episodic event has occurred) and subjective experience of remembering (e.g., reliving, emotion and feeling during episodic recollection). Future research taking these limitations into consideration could illuminate the nature of the relationship between APOE ε4 and episodic memory decline in AD.
Collapse
|
17
|
Seo EH, Kim SH, Park SH, Kang SH, Choo ILH. Independent and Interactive Influences of the APOE Genotype and Beta-Amyloid Burden on Cognitive Function in Mild Cognitive Impairment. J Korean Med Sci 2016; 31:286-95. [PMID: 26839485 PMCID: PMC4729511 DOI: 10.3346/jkms.2016.31.2.286] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/09/2015] [Indexed: 12/03/2022] Open
Abstract
This study aimed to investigate the independent and interactive influences of apolipoprotein E (APOE) ε4 and beta-amyloid (Aβ) on multiple cognitive domains in a large group of cognitively normal (CN) individuals and patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Participants were included if clinical and cognitive assessments, amyloid imaging, and APOE genotype were all available from the Alzheimer's Disease Neuroimaging Initiative database (CN = 324, MCI = 502, AD = 182). Individuals with one or two copies of ε4 were designated as APOE ε4 carriers (ε4+); individuals with no ε4 were designated as APOE ε4 non-carriers (ε4-). Based on mean florbetapir standard uptake value ratios, participants were classified as Aβ burden-positive (Aβ+) or Aβ burden-negative (Aβ-). In MCI, APOE ε4 effects were predominantly observed on frontal executive function, with ε4+ participants exhibiting poorer performances; Aβ positivity had no influence on this effect. Aβ effects were observed on global cognition, memory, and visuospatial ability, with Aβ+ participants exhibiting poorer performances. Measures of frontal executive function were not influenced by Aβ. Interactive effects of APOE ε4+ and Aβ were observed on global cognition and verbal recognition memory. Aβ, not APOE ε4+, influenced clinical severity and functional status. The influences of APOE ε4+ and Aβ on cognitive function were minimal in CN and AD. In conclusion, we provide further evidence of both independent and interactive influences of APOE ε4+ and Aβ on cognitive function in MCI, with APOE ε4+ and Aβ showing dissociable effects on executive and non-executive functions, respectively.
Collapse
Affiliation(s)
- Eun Hyun Seo
- Premedical Science, College of Medicine, Chosun University, Gwangju, Korea
| | - Sang Hoon Kim
- Department of Neuropsychiatry, School of Medicine, Chosun University/Chosun University Hospital, Gwangju, Korea
| | - Sang Hag Park
- Department of Neuropsychiatry, School of Medicine, Chosun University/Chosun University Hospital, Gwangju, Korea
| | - Seong-Ho Kang
- Department of Laboratory Medicine, School of Medicine, Chosun University/Chosun University Hospital, Gwangju, Korea
| | - IL Han Choo
- Department of Neuropsychiatry, School of Medicine, Chosun University/Chosun University Hospital, Gwangju, Korea
| | | |
Collapse
|
18
|
Wattmo C, Londos E, Minthon L. Risk factors that affect life expectancy in Alzheimer's disease: a 15-year follow-up. Dement Geriatr Cogn Disord 2015; 38:286-99. [PMID: 24992891 DOI: 10.1159/000362926] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/15/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUNDS/AIMS Future disease-modifying therapies might affect the expected life span in Alzheimer's disease (AD). Our aim was to identify factors that influence life expectancy in cholinesterase inhibitor (ChEI)-treated patients. METHODS This study included 791 deceased individuals with a clinical diagnosis of AD and a Mini-Mental State Examination score of 10-26 at baseline who were recruited from a 3-year, prospective, multicenter study of ChEI therapy in clinical practice. The participants' date of death was recorded and their survival was compared with the gender- and age-matched general population. RESULTS The mean survival time after the start of ChEI therapy (time of AD diagnosis) was 5.10 years for men and 6.12 years for women. Better cognitive ability, less impaired basic functional capacity, and fewer medications, but not education level or apolipoprotein E (APOE) genotype, were independent prognostic factors of longer survival after diagnosis, after controlling for gender and age. CONCLUSION AD shortens life expectancy in ChEI-treated patients diagnosed before the age of 85 years, similar to that reported previously for untreated individuals. A longer life span was observed in the eldest patients (≥85 years) compared with untreated cohorts, which did not differ from that observed in the general population. Higher education or carrying two APOE ε4 alleles were risk factors for earlier death.
Collapse
Affiliation(s)
- Carina Wattmo
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden
| | | | | |
Collapse
|
19
|
Hanaoka T, Kimura N, Aso Y, Takemaru M, Kimura Y, Ishibashi M, Matsubara E. Relationship between white matter lesions and regional cerebral blood flow changes during longitudinal follow up in Alzheimer's disease. Geriatr Gerontol Int 2015; 16:836-42. [PMID: 26245516 DOI: 10.1111/ggi.12563] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2015] [Indexed: 11/30/2022]
Abstract
AIM The aim of the present study was to evaluate the relationship between baseline white matter lesions (WML) and changes in regional cerebral blood flow during longitudinal follow up of patients with Alzheimer's disease (AD). METHODS A total of 38 patients with AD were included in the study (16 men, 22 women; mean age 77.8 years). All patients were evaluated using the Mini-Mental State Examination and brain perfusion single-photon emission computed tomography at baseline with an approximately 2-year follow up. The patients were divided into two subgroups according to the presence of WML on magnetic resonance imaging. Single-photon emission computed tomography data were analyzed using a voxel-by-voxel group analysis with Statistical Parametric Mapping 8 and region of interest analysis using FineSRT. Changes in Mini-Mental State Examination scores and regional cerebral blood flow were analyzed using the Wilcoxon signed-rank test. RESULTS Mean Mini-Mental State Examination scores in AD patients with WML significantly decreased from 19.4 ± 4.8 to 15.5 ± 6.5 (P = 0.003). Statistical Parametric Mapping 8 and FineSRT analysis showed more severe and widespread regional cerebral blood flow reduction, mainly in the frontal and mesial temporal regions in AD patients with WML compared with those without WML. CONCLUSION Baseline WML could predict a rapid progression of cognitive and brain functional impairment during longitudinal follow up in AD. Geriatr Gerontol Int 2016; 16: 836-842.
Collapse
Affiliation(s)
- Takuya Hanaoka
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| | - Noriyuki Kimura
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| | - Yasuhiro Aso
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| | - Makoto Takemaru
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| | - Yuki Kimura
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| | - Masato Ishibashi
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| | - Etsuro Matsubara
- Department of Neurology, Faculty of Medicine, Oita University, Oita, Japan
| |
Collapse
|
20
|
Serrano-Pozo A, Qian J, Monsell SE, Betensky RA, Hyman BT. APOEε2 is associated with milder clinical and pathological Alzheimer disease. Ann Neurol 2015; 77:917-29. [PMID: 25623662 DOI: 10.1002/ana.24369] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/19/2015] [Accepted: 06/06/2015] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The Alzheimer disease (AD) APOEε4 risk allele associates with an earlier age at onset and increased amyloid-β deposition, whereas the protective APOEε2 allele delays the onset and appears to prevent amyloid-β deposition. Yet the clinical and pathological effects of APOEε2 remain uncertain because of its relative rarity. We investigated the effects of APOEε2 and ε4 alleles on AD pathology and cognition in a large US data set of well-characterized AD patients. METHODS We studied individuals from the National Alzheimer's Coordinating Center autopsy cohort across the entire clinicopathological continuum of AD. Multivariate models were built to examine the associations between APOE alleles and AD neuropathological changes, using the APOEε3/ε3 group as comparator. Mediation analysis was used to estimate the direct and indirect effects of APOE alleles on AD pathology and cognition (Clinical Dementia Rating Sum of Boxes and Mini-Mental State Examination). RESULTS Compared to APOEε3/ε3, APOEε2 is independently associated with lower Braak neurofibrillary tangle (NFT) stages and possibly fewer neuritic plaques, but has no direct effect on cerebral amyloid angiopathy (CAA) severity, whereas APOEε4 is associated with more neuritic plaques and CAA, but has no independent effect on Braak NFT stage. Unadjusted analyses showed marked differences among APOE genotypes with respect to cognitive performance (ε2 > ε3 > ε4). Mediation analysis suggests that this is largely explained through effects on pathology. INTERPRETATION Even when adjusted for age at onset, symptom duration, and other demographic variables, APOEε2 is associated with milder AD pathology and less severe antemortem cognitive impairment compared to APOEε3 and ε4 alleles, suggesting a relative neuroprotective effect of APOEε2 in AD.
Collapse
Affiliation(s)
- Alberto Serrano-Pozo
- Department of Neurology, Massachusetts General Hospital, Boston, MA.,Massachusetts Alzheimer Disease Research Center, Charlestown, MA.,Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA
| | - Jing Qian
- Division of Biostatistics and Epidemiology, University of Massachusetts, Amherst, MA
| | - Sarah E Monsell
- National Alzheimer's Coordinating Center and Department of Epidemiology, University of Washington, Seattle, WA
| | - Rebecca A Betensky
- Massachusetts Alzheimer Disease Research Center, Charlestown, MA.,Department of Biostatistics, Harvard School of Public Health, Boston, MA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Boston, MA.,Massachusetts Alzheimer Disease Research Center, Charlestown, MA
| |
Collapse
|
21
|
Smits LL, Pijnenburg YAL, van der Vlies AE, Koedam ELGE, Bouwman FH, Reuling IEW, Scheltens P, van der Flier WM. Early onset APOE E4-negative Alzheimer's disease patients show faster cognitive decline on non-memory domains. Eur Neuropsychopharmacol 2015; 25:1010-7. [PMID: 25891378 DOI: 10.1016/j.euroneuro.2015.03.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/22/2015] [Indexed: 11/28/2022]
Abstract
Age at onset and APOE E4-genotype have been shown to influence clinical manifestation of Alzheimer's disease (AD). We investigated rate of decline in specific cognitive domains according to age at onset and APOE E4-genotype in patients with AD. 199 patients with probable AD underwent at least two annual neuropsychological assessments. Patients were classified according to age-at-onset (≤ 65 years vs >65 years) and APOE genotype (positive vs negative). The neuropsychological test battery compromised tests for memory, language, attention, executive and visuo-spatial functioning. For each domain compound z-scores were calculated, based on the baseline performance of patients. Average duration of follow-up was 1.5 ± 1 years. We used linear mixed models (LMM) to estimate effects of age, APOE and age⁎APOE on cognitive decline over time. At baseline, patients were 65 ± 8 years, 98(49%) were female and MMSE was 22 ± 4. LMM showed that early onset patients declined faster on executive functioning (β ± SE:-0.09 ± 0.06) than late onset patients, but age was not related to decline in the other cognitive domains. APOE E4 negative patients declined faster on language than APOE E4 positive patients (β ± SE:-0.1 ± 0.06). When we took age and APOE genotype into account simultaneously, we found that compared to late onset-E4 positive patients, early onset-E4 negative patients declined faster on language (β ± SE:-0.36 ± 0.1), attention (β ± SE:-0.42 ± 0.1), executive (β ± SE:-0.41 ± 0.1) and visuo-spatial functioning (β ± SE:-0.43 ± 0.1). Late onset-E4 negative and early onset-E4 positive patients showed intermediate rates of decline. We found no differences in decline on memory. We found that patients who develop AD despite absence of the two most important risk factors, show steepest cognitive decline on non-memory cognitive domains.
Collapse
Affiliation(s)
- Lieke L Smits
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands.
| | - Yolande A L Pijnenburg
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Annelies E van der Vlies
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Esther L G E Koedam
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Femke H Bouwman
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Ilona E W Reuling
- Alzheimer Center and Departments of Medical Psychology, VU University Medical Center, Amsterdam, The Netherlands
| | - Philip Scheltens
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Wiesje M van der Flier
- Alzheimer Center and Departments of Neurology, VU University Medical Center, Amsterdam, The Netherlands; Alzheimer Center and Departments of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands.
| |
Collapse
|
22
|
Gallone S, Boschi S, Rubino E, De Martino P, Scarpini E, Galimberti D, Fenoglio C, Acutis PL, Maniaci MG, Pinessi L, Rainero I. Is HCRTR2 a genetic risk factor for Alzheimer's disease? Dement Geriatr Cogn Disord 2015; 38:245-53. [PMID: 24969517 DOI: 10.1159/000359964] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/20/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUNDS/AIMS Alzheimer's disease (AD) is one of the main types of dementia affecting about 50-55% of all demented patients. Sleep disturbances in AD patients are associated with the severity of dementia and are often the primary reason for institutionalization. These sleep problems partly resemble the core symptoms of narcolepsy, a sleep disorder caused by a general loss of the neurotransmitter hypocretin. The aim of our study was to investigate whether genetic variants in the hypocretin (HCRT) and in the hypocretin receptors 1 and 2 (HCRTR1, HCRTR2) genes could modify the occurrence and the clinical features of AD and to examine if these possible variants influence the role of the protein in sleep regulation. METHODS Using a case-control strategy, we genotyped 388 AD patients and 272 controls for 10 SNPs in the HCRT, HCRTR1 and HCRTR2 genes. In order to evaluate which residues belong to the HCRTR2 binding site, we built a molecular model. RESULTS The genotypic and allelic frequencies of the rs2653349 polymorphism were different (χ(2) = 5.77, p = 0.016; χ(2) = 6.728, p = 0.035) between AD patients and controls. The carriage of the G allele was associated with an increased AD risk (OR 2.53; 95% CI 1.10-5.80). No significant differences were found in the distribution of either genotypic or allelic frequencies between cases and controls in the HCRTR1 polymorphisms rs2271933, rs10914456 and rs4949449 and in the HCRTR2 polymorphism rs3122156. CONCLUSION Our data support the hypothesis that the HCRTR2 gene is likely to be a risk factor for AD. The increased risk inferred is quite small, but in the context of a multi-factorial disease, the presence of this polymorphism may significantly contribute to influencing the susceptibility for AD by interacting with other unknown genetic or environmental factors in sleep regulation.
Collapse
Affiliation(s)
- Salvatore Gallone
- Neurology II, Department of Neuroscience, University of Turin, Turin, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Ungar L, Altmann A, Greicius MD. Apolipoprotein E, gender, and Alzheimer's disease: an overlooked, but potent and promising interaction. Brain Imaging Behav 2014; 8:262-73. [PMID: 24293121 DOI: 10.1007/s11682-013-9272-x] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is an increasingly prevalent, fatal neurodegenerative disease that has proven resistant, thus far, to all attempts to prevent it, forestall it, or slow its progression. The ε4 allele of the Apolipoprotein E gene (APOE4) is a potent genetic risk factor for sporadic and late-onset familial AD. While the link between APOE4 and AD is strong, many expected effects, like increasing the risk of conversion from MCI to AD, have not been widely replicable. One critical, and commonly overlooked, feature of the APOE4 link to AD is that several lines of evidence suggest it is far more pronounced in women than in men. Here we review previous literature on the APOE4 by gender interaction with a particular focus on imaging-related studies.
Collapse
Affiliation(s)
- Leo Ungar
- Functional Imaging in Neuropsychiatric Disorders (FIND) Lab, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA,
| | | | | |
Collapse
|
24
|
Villeneuve S, Brisson D, Marchant NL, Gaudet D. The potential applications of Apolipoprotein E in personalized medicine. Front Aging Neurosci 2014; 6:154. [PMID: 25071563 PMCID: PMC4085650 DOI: 10.3389/fnagi.2014.00154] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/18/2014] [Indexed: 01/25/2023] Open
Abstract
Personalized medicine uses various individual characteristics to guide medical decisions. Apolipoprotein (ApoE), the most studied polymorphism in humans, has been associated with several diseases. The purpose of this review is to elucidate the potential role of ApoE polymorphisms in personalized medicine, with a specific focus on neurodegenerative diseases, by giving an overview of its influence on disease risk assessment, diagnosis, prognosis, and therapy. This review is not a systematic inventory of the literature, but rather a summary and discussion of novel, influential and promising works in the field of ApoE research that could be valuable for personalized medicine. Empirical evidence suggests that ApoE genotype informs pre-symptomatic risk for a wide variety of diseases, is valuable for the diagnosis of type III dysbetalipoproteinemia, increases risk of dementia in neurodegenerative diseases, and is associated with a poor prognosis following acute brain damage. ApoE status appears to influence the efficacy of certain drugs, outcome of clinical trials, and might also give insight into disease prevention. Assessing ApoE genotype might therefore help to guide medical decisions in clinical practice.
Collapse
Affiliation(s)
- Sylvia Villeneuve
- Department of Medicine, ECOGENE-21 and Lipid Clinic, Chicoutimi Hospital, Université de Montréal Chicoutimi, QC, Canada ; Helen Wills Neuroscience Institute, University of California Berkeley, CA, USA
| | - Diane Brisson
- Department of Medicine, ECOGENE-21 and Lipid Clinic, Chicoutimi Hospital, Université de Montréal Chicoutimi, QC, Canada
| | - Natalie L Marchant
- Department of Old Age Psychiatry, Institute of Psychiatry, King's College London London, UK
| | - Daniel Gaudet
- Department of Medicine, ECOGENE-21 and Lipid Clinic, Chicoutimi Hospital, Université de Montréal Chicoutimi, QC, Canada
| |
Collapse
|
25
|
Delva F, Edjolo A, Pérès K, Berr C, Barberger-Gateau P, Dartigues JF. Hierarchical structure of the activities of daily living scale in dementia. J Nutr Health Aging 2014; 18:698-704. [PMID: 25226109 DOI: 10.1007/s12603-014-0503-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVES To describe the sequence of basic activities of daily living (ADL) loss to determine whether there is a hierarchical structure of ADL in dementia in two epidemiological prospective studies: the Paquid study and the Three City Study (3C). DESIGN Two prospective population-based cohort studies: Paquid (over 22 years of follow-up) and 3C (over 10 years of follow-up). SETTING Paquid Study, Gironde, Dordogne, France; The Three Cities Study, Bordeaux, Montpellier, Dijon, France. MAIN OUTCOMES MEASURES We analyzed four ADL of the Katz scale: bathing, dressing, transferring and feeding. The a priori hierarchical relationship of the 4 activities tested was 1) no ADL-disability at all four activities; 2) moderate ADL-disability, or disability at bathing and/or dressing (and no disability in transferring nor feeding); and 3) severe ADL-disability, or disability in bathing and/or dressing and transferring and/or feeding. We performed a Guttman scale analysis to establish the hierarchical properties scale. RESULTS In total, 845 incident cases of dementia were included, among which 838 cases (99.2%) were without any missing data for ADL. Upon diagnosis of dementia, 564 subjects (67.3%) had no ADL-disability, 236 (26.2%) had moderate ADL-disability, and 38 subjects (4.5%) had severe disability. The a priori hierarchy was respected with non-discordance. CONCLUSION We defined 3 simple relevant stages of ADL functional decline in dementia that would be easy to collect in clinical practice: stage 1, subjects with no major ADL disabilities; stage 2, subjects with complete disability in bathing and/or dressing; and stage 3, subjects with complete disability in all 4 tasks.
Collapse
Affiliation(s)
- F Delva
- F. Delva, ISPED, case 11, University Bordeaux Segalen, 146 rue Léo Saignat, 33076 Bordeaux Cedex, Tel: 33557574538, Fax: 33557571486, E-mail:
| | | | | | | | | | | |
Collapse
|
26
|
Chang YL, Fennema-Notestine C, Holland D, McEvoy LK, Stricker NH, Salmon DP, Dale AM, Bondi MW. APOE interacts with age to modify rate of decline in cognitive and brain changes in Alzheimer's disease. Alzheimers Dement 2014; 10:336-48. [PMID: 23896613 PMCID: PMC3815680 DOI: 10.1016/j.jalz.2013.05.1763] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 03/29/2013] [Accepted: 05/02/2013] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To determine (1) whether age-standardized cognitive declines and brain morphometric change differ between Young-Old patients with Alzheimer's disease (YOAD) and Very-Old patients with Alzheimer's disease (VOAD), and (2) whether the apolipoprotein E (APOE) genotype modifies these neuropsychological and morphometric changes. METHODS Baseline and 12-month follow-up neuropsychological and morphometric measures were examined for healthy control subjects and patients with AD. The two AD groups were divided further into subgroups on the basis of the presence of at least one APOE ε4 allele. RESULTS The YOAD group showed more severe deficits and steeper declines in cognition than the VOAD group. Moreover, the presence of an APOE ε4 allele had a more deleterious effect on the YOAD group than the VOAD group on cognition and brain structure both cross-sectionally and longitudinally. CONCLUSIONS Results underscore the importance of integrating an individual's age and genetic susceptibility--and their interaction--when examining neuropsychological and neuroimaging changes in the early stages of Alzheimer's disease.
Collapse
Affiliation(s)
- Yu-Ling Chang
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Christine Fennema-Notestine
- Department of Psychiatry, University of California at San Diego, San Diego, CA, USA; Department of Radiology, University of California at San Diego, San Diego, CA, USA
| | - Dominic Holland
- Department of Neurosciences, University of California at San Diego, San Diego, CA, USA
| | - Linda K McEvoy
- Department of Radiology, University of California at San Diego, San Diego, CA, USA
| | - Nikki H Stricker
- Veterans Affairs Boston Healthcare System, Boston, MA, USA; Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
| | - David P Salmon
- Department of Neurosciences, University of California at San Diego, San Diego, CA, USA
| | - Anders M Dale
- Department of Radiology, University of California at San Diego, San Diego, CA, USA; Department of Neurosciences, University of California at San Diego, San Diego, CA, USA
| | - Mark W Bondi
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California at San Diego, San Diego, CA, USA.
| |
Collapse
|
27
|
The APOE ε4 allele is associated with increased frontally mediated neurobehavioral symptoms in amnestic MCI. Alzheimer Dis Assoc Disord 2013; 27:109-15. [PMID: 22874659 DOI: 10.1097/wad.0b013e318266c6c3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The apolipoprotein E ε4 allele is a risk factor for late-onset Alzheimer disease (AD), and the frontal lobes may be among the regions that manifest effects of ε4 even early in the disease. We predicted that among patients with amnestic mild cognitive impairment (aMCI) and AD, ε4 would be associated with increased neurobehavioral symptoms when assessed using a measure sensitive to frontal lobe integrity. We obtained cognitive data and caregiver ratings on the Frontal Systems Behavior Scale (FrSBe) for aMCI patients (N=29 ε4 carriers; N=29 noncarriers) and AD patients (N=47 carriers; N=42 noncarriers). In both diagnostic groups, ε4 carriers had lower scores on tests of memory but did not differ on cognitive screening measures or tests of executive functioning. There were no differences in retrospective caregiver ratings of preillness status on the FrSBe by ε4 status in either diagnostic group. However, in the aMCI group, ε4 carriers had elevated current FrSBe Executive Dysfunction scores in comparison with noncarriers. In the AD group, there were no differences in current FrSBe scores by genotype group. Results indicate that ε4-related behavior change occurs in the aMCI stage but may not be apparent by the AD stage.
Collapse
|
28
|
Abstract
BACKGROUND The rate of cognitive decline in Alzheimer's disease (AD) varies considerably between individuals. Predicting rapid cognitive decline might help clinicians provide prognostic information, select subjects for trial intervention and/or reduce costs. METHODS PubMed and PsycINFO were searched for all the English written studies published until the end of 2010 on rapid cognitive decline in AD and factors associated with it. RESULTS More than 300 individual articles were retrieved. We selected 82 relevant studies. The main findings of these papers are that younger, more educated and more impaired patients are more likely to show rapid cognitive decline. ApoE alleles seem not to modify the velocity of clinical progression of dementia, or at most could have a very small effect. No inference can be made for all the other variables analysed. CONCLUSIONS There are many studies on rapid cognitive decline. Results are heterogeneous and often contradictory. No reliable conclusions about factors that may be associated with rapid cognitive decline can yet be drawn.
Collapse
Affiliation(s)
- Alessandro Sona
- AOU San Giovanni Battista - Molinette, Geriatria e Malattie Metaboliche dell'Osso, Università degli Studi di Torino , Torino , Italia
| | | | | |
Collapse
|
29
|
Wattmo C, Wallin AK, Minthon L. Progression of mild Alzheimer's disease: knowledge and prediction models required for future treatment strategies. ALZHEIMERS RESEARCH & THERAPY 2013; 5:44. [PMID: 24099236 PMCID: PMC3978889 DOI: 10.1186/alzrt210] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 09/12/2013] [Indexed: 11/10/2022]
Abstract
Introduction Knowledge of longitudinal progression in mild Alzheimer’s disease (AD) is required for the evaluation of disease-modifying therapies. Our aim was to observe the effects of long-term cholinesterase inhibitor (ChEI) therapy in mild AD patients in a routine clinical setting. Methods This was a prospective, open-label, non-randomized, multicenter study of ChEI treatment (donepezil, rivastigmine or galantamine) conducted during clinical practice. The 734 mild AD patients (Mini-Mental State Examination (MMSE) score 20 to 26) were assessed at baseline and then semi-annually over three years. Outcome measures included the MMSE, Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog), Clinician’s Interview-Based Impression of Change (CIBIC) and Instrumental Activities of Daily Living (IADL) scale. Results After three years of ChEI therapy, 31% (MMSE) and 33% (ADAS-cog) of the patients showed improved/unchanged cognitive ability, 33% showed improved/unchanged global performance and 14% showed improved/unchanged IADL capacity. Higher mean dose of ChEI and lower educational level were both predictors of more positive longitudinal cognitive and functional outcomes. Older participants and those with a better IADL score at baseline exhibited a slower rate of cognitive decline, whereas younger participants and those with higher cognitive status showed more preserved IADL ability over time. Gender and apolipoprotein E (APOE) genotype showed inconsistent results. Prediction models using the abovementioned scales are presented. Conclusions In naturalistic mild AD patients, a marked deterioration in IADL compared with cognitive and global long-term outcomes was observed, indicating the importance of functional assessments during the early stages of the disease. The participants’ time on ChEI treatment before inclusion in studies of new therapies might affect their rate of decline and thus the comparisons of changes in scores between various studies. An increased understanding of expected disease progression in different domains and potential predictors of disease progression is essential for assessment of future therapies in AD.
Collapse
Affiliation(s)
- Carina Wattmo
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden
| | - Asa K Wallin
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden
| | - Lennart Minthon
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden
| |
Collapse
|
30
|
Foster JK, Albrecht MA, Savage G, Lautenschlager NT, Ellis KA, Maruff P, Szoeke C, Taddei K, Martins R, Masters CL, Ames D. Lack of reliable evidence for a distinctive ε4-related cognitive phenotype that is independent from clinical diagnostic status: findings from the Australian Imaging, Biomarkers and Lifestyle Study. ACTA ACUST UNITED AC 2013; 136:2201-16. [PMID: 23737466 DOI: 10.1093/brain/awt127] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Individuals who carry the apolipoprotein E ε4 polymorphism have an increased risk of late-onset Alzheimer's disease. However, because possession of the ε4 allele confers an increased risk for the diagnosis of dementia, it has proven problematic in older individuals to dissociate the influence of ε4 on cognitive capacity per se as distinct from its influence on clinical diagnostic status. We report a statistical approach that attempts to partial out the influence of diagnostic group membership (Alzheimer's disease, mild cognitive impairment, healthy control) from the influence of apolipoprotein ε4 genetic status on cognitive functioning. The cognitive phenotype hypothesis predicts that ε4-positive individuals will show cognitive deficits (relative to matched ε4-negative individuals) independent of the development of Alzheimer's disease. By contrast, the prodromal/preclinical Alzheimer's disease hypothesis proposes that the effect of apolipoprotein E status on cognitive performance is a function of the increased risk of dementia in individuals with the ε4 allele. We evaluated these hypotheses in the Australian Imaging, Biomarkers and Lifestyle cohort (n = 1112). We first determined whether previously reported findings concerning ε4 status and age-related neuropsychological performance could be explained by the inadvertent recruitment of people with mild cognitive impairment into the healthy control group. We then tested each diagnostic group in isolation to identify any neuropsychological patterns that may be attributed to the ε4 allele. Finally, as interactions between the ε4 allele and age have previously been reported in cognitive functioning within healthy elderly populations, we attempted to determine whether the inclusion of mild cognitively impaired individuals in the sample may drive this relationship. An extensive battery of standardized, well-validated neuropsychological tasks was administered to a final sample of 764 healthy control subjects, 131 individuals with mild cognitive impairment and 168 individuals with Alzheimer's disease. The effect of the ε4 allele on cognitive performance was assessed using a statistical mediation analysis and supplemented with Bayesian methods to address a number of the limitations associated with Fisherian/Neyman-Pearsonian significance testing. Our findings support the prodromal/preclinical Alzheimer's disease hypothesis and do not support the concept of a distinctive ε4-related cognitive phenotype.
Collapse
Affiliation(s)
- Jonathan K Foster
- School of Psychology and Speech Pathology and Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Head D, Bugg JM, Goate AM, Fagan AM, Mintun MA, Benzinger T, Holtzman DM, Morris JC. Exercise Engagement as a Moderator of the Effects of APOE Genotype on Amyloid Deposition. ACTA ACUST UNITED AC 2012; 69:636-43. [PMID: 22232206 DOI: 10.1001/archneurol.2011.845] [Citation(s) in RCA: 198] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE APOE ε4 status has been associated with greater cortical amyloid deposition, whereas exercise has been associated with less in cognitively normal adults. The primary objective here was to examine whether physical exercise moderates the association between APOE genotype and amyloid deposition in cognitively normal adults. DESIGN APOE genotyping data and answers to a questionnaire on physical exercise engagement over the last decade were obtained in conjunction with cerebrospinal fluid (CSF) samples and amyloid imaging with carbon 11-labeled Pittsburgh Compound B ([(11)C]PiB) positron emission tomography. Participants were classified as either low or high exercisers based on exercise guidelines of the American Heart Association. SETTING Knight Alzheimer's Disease Research Center at Washington University, St Louis, Missouri. PARTICIPANTS A total of 201 cognitively normal adults (135 of whom were women) aged 45 to 88 years were recruited from the Knight Alzheimer's Disease Research Center. Samples of CSF were collected from 165 participants. Amyloid imaging was performed for 163 participants. RESULTS APOE ε4 carriers evidenced higher [(11)C]PiB binding (P<.001) and lower CSF Aβ42 levels (P<.001) than did noncarriers. Our previous findings of higher [(11)C]PiB binding (P=.005) and lower CSF Aβ42 levels (P=.009) in more sedentary individuals were replicated. Most importantly, we observed a novel interaction between APOE status and exercise engagement for [(11)C]PiB binding (P=.008) such that a more sedentary lifestyle was significantly associated with higher [(11)C]PiB binding for ε4 carriers (P=.013) but not for noncarriers (P=.20). All findings remained significant after controlling for age; sex; educational level; body mass index; the presence or history of hypertension, diabetes mellitus, heart problems, or depression; and the interval between assessments. CONCLUSION Collectively, these results suggest that cognitively normal sedentary APOE ε4-positive individuals may be at augmented risk for cerebral amyloid deposition.
Collapse
Affiliation(s)
- Denise Head
- Department of Psychology, Washington University, St Louis, MO 63130, USA.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Schmidt C, Wolff M, von Ahsen N, Zerr I. Alzheimer's disease: genetic polymorphisms and rate of decline. Dement Geriatr Cogn Disord 2012; 33:84-9. [PMID: 22414550 DOI: 10.1159/000336790] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/17/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIM To investigate the influence of established genetic risk factors for Alzheimer's disease on the speed of disease progression. METHODS Polymorphisms (in ACE, ApoE, BIN1, CLU, CR1, CST3, EXOC3L2, GWA14q32.13, IL8, LDLR, PICALM, TNK1) of 40 Alzheimer's disease patients from a longitudinal study were analyzed. A standardized loss of Mini-Mental State Examination points was used as the progression parameter. RESULTS Polymorphisms in CST3 and EXOC3L2 as well as the absence of APOE4 were associated with more aggressive disease courses. A trend was observed for BIN1. CONCLUSION In addition to being a risk factor for disease development, some of the polymorphisms investigated here are associated with higher rates of decline and disease progression and thus might act as prognostic disease markers. This effect needs to be considered in future treatment strategies.
Collapse
Affiliation(s)
- Christian Schmidt
- Department of Neurology, Georg August University Hospital, Robert-Koch-Strasse 40, Goettingen, Germany.
| | | | | | | |
Collapse
|
33
|
Mielke MM, Leoutsakos JM, Tschanz JT, Green RC, Tripodis Y, Corcoran CD, Norton MC, Lyketsos CG. Interaction between vascular factors and the APOE ε4 allele in predicting rate of progression in Alzheimer's disease. J Alzheimers Dis 2012; 26:127-34. [PMID: 21593560 DOI: 10.3233/jad-2011-110086] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Vascular factors have been shown to affect the rate of Alzheimer's disease (AD) progression. However, the effect of the APOE ε4 allele on rate of progression has been ambiguous. Little research to date has examined an interaction between vascular factors and the APOE ε4 allele in predicting decline among AD patients. 216 participants with incident AD from a population of elderly persons in Cache County, Utah, were followed for a mean of 3.3 years and 4.2 follow-up visits. A history of vascular risk factors and conditions and anti-hypertensive use was assessed at the diagnostic visit. Linear mixed effects models tested interactions between the vascular factors, APOE ε4, and time as predictors of clinical progression on the Mini-Mental State Exam (MMSE) and Clinical Dementia Rating-Sum of Boxes (CDR-SB). Multiple comparisons were corrected using the Holm-Bonferroni method. There was a 3-way interaction between stroke, APOE ε4 and time in predicting MMSE decline (LR χ² = 10.32, 2 df, p = 0.006). For the CDR-SB, there were 3-way interactions between the APOE ε4, time and either myocardial infarction (LR χ² = 17.83, 2 df, p = 0.0001) or stroke (LR χ² = 11.48, 2 df, p = 0.003. Results suggest a complex relationship between the APOE ε4 and vascular factors in predicting cognitive and functional progression. Among individuals with a history of stroke or myocardial infarction at baseline, progression of AD is influenced by APOE ε4 carrier status and varies by time after AD diagnosis.
Collapse
Affiliation(s)
- Michelle M Mielke
- Department of Psychiatry, Division of Geriatric Psychiatry and Neuropsychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Molecular insights into the pathogenesis of Alzheimer's disease and its relationship to normal aging. PLoS One 2011; 6:e29610. [PMID: 22216330 PMCID: PMC3247273 DOI: 10.1371/journal.pone.0029610] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 12/01/2011] [Indexed: 11/19/2022] Open
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder that diverges from the process of normal brain aging by unknown mechanisms. We analyzed the global structure of age- and disease-dependent gene expression patterns in three regions from more than 600 brains. Gene expression variation could be almost completely explained by four transcriptional biomarkers that we named BioAge (biological age), Alz (Alzheimer), Inflame (inflammation), and NdStress (neurodegenerative stress). BioAge captures the first principal component of variation and includes genes statistically associated with neuronal loss, glial activation, and lipid metabolism. Normally BioAge increases with chronological age, but in AD it is prematurely expressed as if some of the subjects were 140 years old. A component of BioAge, Lipa, contains the AD risk factor APOE and reflects an apparent early disturbance in lipid metabolism. The rate of biological aging in AD patients, which cannot be explained by BioAge, is associated instead with NdStress, which includes genes related to protein folding and metabolism. Inflame, comprised of inflammatory cytokines and microglial genes, is broadly activated and appears early in the disease process. In contrast, the disease-specific biomarker Alz was selectively present only in the affected areas of the AD brain, appears later in pathogenesis, and is enriched in genes associated with the signaling and cell adhesion changes during the epithelial to mesenchymal (EMT) transition. Together these biomarkers provide detailed description of the aging process and its contribution to Alzheimer's disease progression.
Collapse
|
35
|
Freitas C, Mondragón-Llorca H, Pascual-Leone A. Noninvasive brain stimulation in Alzheimer's disease: systematic review and perspectives for the future. Exp Gerontol 2011; 46:611-27. [PMID: 21511025 PMCID: PMC3589803 DOI: 10.1016/j.exger.2011.04.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/31/2011] [Accepted: 04/06/2011] [Indexed: 11/25/2022]
Abstract
BACKGROUND A number of studies have applied transcranial magnetic stimulation (TMS) to physiologically characterize Alzheimer's disease (AD) and to monitor effects of pharmacological agents, while others have begun to therapeutically use TMS and transcranial direct current stimulation (tDCS) to improve cognitive function in AD. These applications are still very early in development, but offer the opportunity of learning from them for future development. METHODS We performed a systematic search of all studies using noninvasive stimulation in AD and reviewed all 29 identified articles. Twenty-four focused on measures of motor cortical reactivity and (local) plasticity and functional connectivity, with eight of these studies assessing also effects of pharmacological agents. Five studies focused on the enhancement of cognitive function in AD. RESULTS Short-latency afferent inhibition (SAI) and resting motor threshold are significantly reduced in AD patients as compared to healthy elders. Results on other measures of cortical reactivity, e.g. intracortical inhibition (ICI), are more divergent. Acetylcholine-esterase inhibitors and dopaminergic drugs may increase SAI and ICI in AD. Motor cortical plasticity and connectivity are impaired in AD. TMS/tDCS can induce acute and short-duration beneficial effects on cognitive function, but the therapeutic clinical significance in AD is unclear. Safety of TMS/tDCS is supported by studies to date. CONCLUSIONS TMS/tDCS appears safe in AD, but longer-term risks have been insufficiently considered. TMS holds promise as a physiologic biomarker in AD to identify therapeutic targets and monitor pharmacologic effects. In addition, TMS/tDCS may have therapeutic utility in AD, though the evidence is still very preliminary and cautious interpretation is warranted.
Collapse
Affiliation(s)
- Catarina Freitas
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Helena Mondragón-Llorca
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Alvaro Pascual-Leone
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Institut Guttmann, Universitat Autonoma Barcelona, Spain
| |
Collapse
|
36
|
Allan CL, Ebmeier KP. The influence of ApoE4 on clinical progression of dementia: a meta-analysis. Int J Geriatr Psychiatry 2011; 26:520-6. [PMID: 20845403 DOI: 10.1002/gps.2559] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 04/29/2010] [Indexed: 11/05/2022]
Abstract
OBJECTIVE ApoE4 is a risk factor for the development of Alzheimer's disease, and has a functional role suggesting its importance in the neuropathology of dementia. We present a meta-analysis to investigate whether ApoE4 also affects the clinical progression of dementia in terms of cognitive decline or mortality. METHODS We searched Medline, Embase and PsychINFO from 1990 until April 2009, for case control or cohort studies which investigated the effect of ApoE4 on progression of dementia. We identified 427 studies; 17 were suitable for inclusion. In total, there were 1733 participants with dementia at baseline, of whom 975 were heterozygous or homozygous for ApoE4. RESULTS There was no significant difference in cognitive decline (random-model effect size = 0.02; 95% C.-I.: -0.09 to 0.14; p = 0.67) or mortality (random-model pooled odds ratio = 0.74; 95% C.-I.: 0.36 to 1.53; p = 0.41) based on the presence of ApoE4. There was no significant heterogeneity between studies using cognitive decline as an outcome. In meta-regressions of cognitive decline, duration of symptoms, age, gender and frequency of participants with ApoE4 in the samples did not contribute to outcome. CONCLUSION Different ApoE alleles do not modify the speed of clinical progression of dementia in a way that would be detectable in a sample of 1700 patients.
Collapse
|
37
|
Kume K, Hanyu H, Sato T, Hirao K, Shimizu S, Kanetaka H, Sakurai H, Iwamoto T. Vascular risk factors are associated with faster decline of Alzheimer disease: a longitudinal SPECT study. J Neurol 2011; 258:1295-303. [PMID: 21327852 DOI: 10.1007/s00415-011-5927-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 01/07/2011] [Accepted: 01/17/2011] [Indexed: 01/15/2023]
Abstract
We investigated the effects of cardiovascular risk factors, such as hypertension, diabetes mellitus, and hypercholesterolemia, on longitudinal regional cerebral blood flow (rCBF) changes in Alzheimer's disease (AD). We followed 68 outpatients with probable AD for an average of 40 months. They were divided into three groups based on no (n = 24), single (n = 27), and multiple (n = 17) vascular risk factors. We assessed longitudinal changes on the Mini-Mental State Examination, Functional Assessment Staging scores, and in rCBF deficits using repeated single photon emission computed tomography (SPECT) using N-isopropyl-p-[(123)I] iodoamphetamine. During follow-up, the multiple vascular risk factor group showed faster cognitive and functional decline than the no and single vascular risk factor groups. When compared with the initial SPECT, the follow-up SPECT showed a significant rCBF reduction in widespread regions, including the parietotemporal, frontal, and limbic lobes, in the multiple and single vascular risk factor groups, while there was rCBF reduction in small scattered regions of the temporoparietal lobe in the no vascular risk factor group. Multiple vascular risk factors are associated with a greater rate of decline in cognition, function, and rCBF in patients with AD. Our results highlight the contribution of vascular risk factors on the progression of AD.
Collapse
Affiliation(s)
- Kazumasa Kume
- Department of Geriatric Medicine, Tokyo Medical University, 6-7-1 Nishishinjuku Shinjuku-ku, Tokyo 160-0023, Japan
| | | | | | | | | | | | | | | |
Collapse
|
38
|
van der Flier WM, Pijnenburg YA, Fox NC, Scheltens P. Early-onset versus late-onset Alzheimer's disease: the case of the missing APOE ɛ4 allele. Lancet Neurol 2010; 10:280-8. [PMID: 21185234 DOI: 10.1016/s1474-4422(10)70306-9] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Some patients with early-onset Alzheimer's disease (AD) present with a distinct phenotype. Typically, the first and most salient characteristic of AD is episodic memory impairment. A few patients, however, present with focal cortical, non-memory symptoms, such as difficulties with language, visuospatial, or executive functions. These presentations are associated with specific patterns of atrophy and frequently with a young age at onset. Age is not, however, the only determinant of phenotype; underlying factors, especially genetic factors, seem also to affect phenotype and predispose patients to younger or older age at onset. Importantly, patients with atypical early-onset disease seldom carry the APOE ɛ4 allele, which is the most important risk factor for lowering the age of onset in patients with AD. Additionally, theAPOE ɛ4 genotype seems to predispose patients to vulnerability in the medial temporal areas, which leads to memory loss. Conversely, patients negative for the APOE ɛ4 allele and with early-onset AD are more likely to be predisposed to vulnerability of cerebral networks beyond the medial temporal lobes. Other factors are probably involved in determining the pattern of atrophy, but these are currently unknown.
Collapse
Affiliation(s)
- Wiesje M van der Flier
- Alzheimer Centre, Department of Neurology, VU University Medical Centre, Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
39
|
McGuinness B, Carson R, Barrett SL, Craig D, Passmore AP. Apolipoprotein ɛ4 and neuropsychological performance in Alzheimer's disease and vascular dementia. Neurosci Lett 2010; 483:62-6. [DOI: 10.1016/j.neulet.2010.07.063] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2010] [Revised: 06/23/2010] [Accepted: 07/23/2010] [Indexed: 11/16/2022]
|
40
|
Zdanys KF, Kleiman TG, Zhang H, Ozbay F, MacAvoy MG, Gelernter J, van Dyck CH. BDNF variants, premorbid educational attainment, and disease characteristics in Alzheimer's disease: an exploratory study. J Alzheimers Dis 2010; 17:887-98. [PMID: 19542613 DOI: 10.3233/jad-2009-1106] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin that promotes neuronal survival, growth, and differentiation. The role of BDNF in learning and memory suggests that it may also modulate the clinical course of Alzheimer's disease (AD). This study aimed to determine whether BDNF genetic variants are related to premorbid educational attainment, progression of cognitive and functional decline, and associated neuropsychiatric symptoms in AD patients. A sample of AD subjects (N = 341) was genotyped for the BDNF polymorphisms: Val66Met, C270T, and G-712A. Subjects received tests of cognition and daily function at baseline and at multiple subsequent time points. They were also characterized for the frequency and severity of neuropsychiatric symptoms. There was a significant effect of Val66Met genotype on educational attainment (F = 7.49, df = 2,329, P = 0.00066), with Met/Met homozygotes having significantly lower education than both the Val/Met and Val/Val groups. No association was observed between any BDNF polymorphism and measures of cognitive or functional decline. The T-allele of the C270T polymorphism was associated with a higher prevalence of neuropsychiatric symptoms and specifically with the presence of hallucinations. The effect of the Val66Met polymorphism on premorbid educational attainment is intriguing and should be verified in a larger sample.
Collapse
Affiliation(s)
- Kristina F Zdanys
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06510, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
BACKGROUND Late-onset Alzheimer disease (LOAD) is a clinically heterogeneous complex disease defined by progressively disabling cognitive impairment. Psychotic symptoms which affect approximately one-half of LOAD subjects have been associated with more rapid cognitive decline. However, the variety of cognitive trajectories in LOAD, and their correlates, have not been well defined. We therefore used latent class modeling to characterize trajectories of cognitive and behavioral decline in a cohort of AD subjects. METHODS 201 Caucasian subjects with possible or probable Alzheimer's disease (AD) were evaluated for cognitive and psychotic symptoms at regular intervals for up to 13.5 years. Cognitive symptoms were evaluated serially with the Mini-mental State Examination (MMSE), and psychotic symptoms were rated using the CERAD behavioral rating scale (CBRS). Analyses undertaken were latent class mixture models of quadratic trajectories including a random intercept with initial MMSE score, age, gender, education, and APOE 4 count modeled as concomitant variables. In a secondary analysis, psychosis status was also included. RESULTS AD subjects showed six trajectories with significantly different courses and rates of cognitive decline. The concomitant variables included in the best latent class trajectory model were initial MMSE and age. Greater burden of psychotic symptoms increased the probability of following a trajectory of more rapid cognitive decline in all age and initial MMSE groups. APOE 4 was not associated with any trajectory. CONCLUSION Trajectory modeling of longitudinal cognitive and behavioral data may provide enhanced resolution of phenotypic variation in AD.
Collapse
|
42
|
Cantero JL, Atienza M, Gomez-Herrero G, Cruz-Vadell A, Gil-Neciga E, Rodriguez-Romero R, Garcia-Solis D. Functional integrity of thalamocortical circuits differentiates normal aging from mild cognitive impairment. Hum Brain Mapp 2010; 30:3944-57. [PMID: 19449329 DOI: 10.1002/hbm.20819] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Resonance in thalamocortical networks is critically involved in sculpting oscillatory behavior in large ensembles of neocortical cells. Neocortical oscillations provide critical information about the integrity of thalamocortical circuits and functional connectivity of cortical networks, which seem to be significantly disrupted by the neuronal death and synapse loss characterizing Alzheimer's disease (AD). By applying a novel analysis methodology to overcome volume conduction effects between scalp electroencephalographic (EEG) measurements, we were able to estimate the temporal activation of EEG-alpha sources in the thalamus and parieto-occipital regions of the cortex. We found that synaptic flow underlying the lower alpha band (7.5-10 Hz) was abnormally facilitated in patients with mild cognitive impairment (MCI) as compared to healthy elderly individuals, particularly from thalamus to cortex (approximately 38% higher). In addition, the thalamic generator of lower alpha oscillations was also abnormally activated in patients with MCI. Regarding the upper alpha subdivision (10.1-12.5 Hz), both controls and patients with MCI showed a bidirectional decrease of thalamocortical synaptic transmission, which was age-dependent only in the control group. Altogether, our results suggest that functional dynamics of thalamocortical networks differentiate individuals at high risk of developing AD from healthy elderly subjects, supporting the hypothesis that neurodegeneration mechanisms are active years before the patient is clinically diagnosed with dementia.
Collapse
Affiliation(s)
- Jose L Cantero
- Laboratory of Functional Neuroscience, Network for Biomedical Research in Neurodegenerative Diseases (CIBERNED), University Pablo de Olavide, Seville, Spain.
| | | | | | | | | | | | | |
Collapse
|
43
|
Reitz C, Mayeux R. Use of genetic variation as biomarkers for mild cognitive impairment and progression of mild cognitive impairment to dementia. J Alzheimers Dis 2010; 19:229-51. [PMID: 20061642 PMCID: PMC2908485 DOI: 10.3233/jad-2010-1255] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cognitive impairment is prevalent in the elderly. The high estimates of conversion to dementia have spurred the interest in identification of genetic risk factors associated with development of cognitive impairment and or its progression. However, despite notable achievements in human genetics over the years, in particular technological advances in gene mapping and in statistical methods that relate genetic variants to disease, to date only a small proportion of the genetic contribution to late-life cognitive impairment can be explained. A likely explanation for the difficulty in gene identification is that it is a multifactorial disorder with both genetic and environmental components, in which several genes with small effects each are likely to contribute to the quantitative traits associated with the disease. The motivation for identifying the underlying genetic risk factors elderly is clear. Not only could it shed light on disease pathogenesis, but it may also provide potential targets for effective treatment, screening, and prevention. In this article we review the current knowledge on underlying genetic variants and the usefulness of genetic variation as diagnostic tools and biomarkers. In addition, we discuss the potentials and difficulties researchers face in designing appropriate studies for gene discovery.
Collapse
Affiliation(s)
- Christiane Reitz
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY
- Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Richard Mayeux
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY
- Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Epidemiology, Joseph P. Mailman School of Public Health, Columbia University, New York, NY
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY
| |
Collapse
|
44
|
Hanyu H, Sato T, Hirao K, Kanetaka H, Iwamoto T, Koizumi K. The progression of cognitive deterioration and regional cerebral blood flow patterns in Alzheimer's disease: a longitudinal SPECT study. J Neurol Sci 2009; 290:96-101. [PMID: 19931870 DOI: 10.1016/j.jns.2009.10.022] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 10/29/2009] [Accepted: 10/30/2009] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND PURPOSE The progression of cognitive deterioration in patients with Alzheimer's disease (AD) is considerably variable. The ability to predict the progression rate is important for clinicians to treat and manage patients with AD. We examined the possible relationship between the rate of cognitive deterioration and regional cerebral blood flow (rCBF) patterns in patients with AD. METHODS We followed 48 patients with AD for an average of 37 months. They were subsequently divided into the rapidly progressing group (n=24) and slowly progressing group (n=24) based on an annual Mini-Mental State Examination (MMSE) score change. Initial and follow-up rCBF were assessed using single photon emission CT (SPECT) and the SPECT data were analyzed by 3D-stereotactic surface projections. RESULTS At initial evaluation, the rapidly progressing group had greater rCBF deficits mainly in the parietotemporal and frontal regions, and left posterior cingulate than did the slowly progressing group. When compared with initial SPECT, follow-up SPECT showed a significant rCBF reduction in widespread regions, including parietotemporal and frontal lobes, of the rapidly progressing group, while showed in the scattered and small regions of hemispheres of the slowly progressing group. CONCLUSION Our longitudinal SPECT study suggests a significant association between rCBF deficits in the parietotemporal, posterior cingulate, and frontal regions and subsequent rapid cognitive and rCBF deterioration.
Collapse
Affiliation(s)
- Haruo Hanyu
- Department of Geriatric Medicine, Tokyo Medical University, Tokyo, Japan.
| | | | | | | | | | | |
Collapse
|
45
|
van der Vlies AE, Koedam ELGE, Pijnenburg YAL, Twisk JWR, Scheltens P, van der Flier WM. Most rapid cognitive decline in APOE epsilon4 negative Alzheimer's disease with early onset. Psychol Med 2009; 39:1907-1911. [PMID: 19335933 DOI: 10.1017/s0033291709005492] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND We aimed to compare the rate of cognitive decline in patients with early and late onset Alzheimer's disease (AD) and to investigate the potentially modifying influence of the apolipoprotein E (APOE) genotype. METHOD We included 99 patients with early onset AD (age 65 years) and 192 patients with late onset AD (age >65 years) who had at least two scores on the Mini-Mental State Examination (MMSE) (range 2-14) obtained at least 1 year apart. Linear mixed models were performed to investigate the rate of cognitive decline dependent on age at onset (AAO) and APOE genotype. RESULTS The mean (S.D.) age for patients with early onset AD was 57.7 (4.5) years, and 74.5 (5.1) years for patients with late onset AD. AAO was not associated with baseline MMSE [beta (S.E.)=0.8 (0.5), p=0.14]. However, patients with early onset showed a faster decline on the MMSE [beta (S.E.)=2.4 (0.1) points/year] than those with late onset [beta (S.E.)=1.7 (0.1) points/year, p=0.00]. After stratification according to APOE genotype, APOE epsilon4 non-carriers with early onset showed faster cognitive decline than non-carriers with late onset [2.4 (0.3) v. 1.3 (0.3) points/year, p=0.01]. In APOE epsilon4 carriers, no difference in rate of cognitive decline was found between patients with early and late onset [beta (S.E.)=0.2 (0.2), p=0.47]. CONCLUSION Patients with early onset AD show more rapid cognitive decline than patients with late onset, suggesting that early onset AD follows a more aggressive course. Furthermore, this effect seems to be most prominent in patients with early onset who do not carry the genetic APOE epsilon4 risk factor for AD.
Collapse
Affiliation(s)
- A E van der Vlies
- Department of Neurology and Alzheimer Centre, VU University Medical Centre, Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
SummaryThis review discusses the role that the APOE gene plays in cognitive dysfunction both in demented and non-demented elderly people. The increasing problem of cognitive impairment in developed countries makes finding new and effective treatments a research priority. Understanding the biological basis of this impairment is therefore paramount. APOE has received much attention in the field of cognitive genetics due to it being a major susceptibility gene for Alzheimer's disease, which itself is characterized by a rapid and irreversible loss in memory function. Over the past 14 years this has generated a considerable number of publications that have produced conflicting findings, making it difficult for the reader to interpret whether the APOE gene regulates cognition or not. This review attempts to summarize the mass of information on this gene in relation to cognition, by weighting the pros and cons of the methodologies used, and offers suggestions for future study designs.
Collapse
|
47
|
The FAS gene, brain volume, and disease progression in Alzheimer's disease. Alzheimers Dement 2009; 6:118-24. [PMID: 19766542 DOI: 10.1016/j.jalz.2009.05.663] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 05/04/2009] [Accepted: 05/04/2009] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We sought to identify single-nucleotide polymorphisms (SNPs) associated with Alzheimer's disease (AD) progression and brain volume. METHODS Ninety-seven SNPs were genotyped in 243 subjects from a longitudinal study of healthy aging. Subjects who received a diagnosis of cognitive impairment (CI) at any study visit (before their most recent visit) and had DNA in the study's DNA bank were included. Progression of AD was defined as the duration from onset of CI to diagnosis of AD. Association of each of the 97 SNPs with AD progression was tested via Cox model. Those SNPs meeting a criterion of nominal significance (P < 0.05) for association with AD progression were reassessed to account for multiple testing by repeating the marker selection process in 10,000 random permutations. Next, the association between the one SNP that survived the multiple-testing adjustment and brain volume was determined by multiple regression analysis in a subgroup of subjects for whom magnetic-resonance imaging (MRI)-derived brain-volume data were available. Brain volumes were adjusted for age at MRI, gender, and time from MRI to onset of CI. RESULTS The minor allele of rs1468063 in the FAS gene, which is member 6 of the tumor necrosis factor receptor superfamily, was significantly associated with faster AD progression after adjustment for multiple testing (P(permutation) = 0.049). The same allele in rs1468063 was associated with smaller brain volumes and larger ventricular volumes (P = 0.02 and 0.04, respectively). CONCLUSIONS The FAS gene, which plays a role in apoptosis, may be associated with AD by modulating the apoptosis and neuronal loss secondary to AD neuropathology.
Collapse
|
48
|
Fu BY, Ma SL, Tang NLS, Tam CWC, Lui VWC, Chiu HFK, Lam LCW. Cholesterol 24-hydroxylase (CYP46A1) polymorphisms are associated with faster cognitive deterioration in Chinese older persons: a two-year follow up study. Int J Geriatr Psychiatry 2009; 24:921-6. [PMID: 19212968 DOI: 10.1002/gps.2196] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES We previously found that the polymorphisms of cholesterol 24-hydroxylase (CYP46A1) gene were associated with the risk of Alzheimer's disease (AD) in Chinese. However, its effect in predicting progression of cognitive decline remains unknown. METHODS Two hundred and eighty-one Chinese subjects (121 cognitively intact, 101 with mild cognitive impairment and 59 with mildly dementia) were followed-up with a mean (SD) duration of 25.22(5.74) months. Association between the CYP46A1 gene polymorphisms and 2-year cognitive deterioration were evaluated. RESULTS At follow-up, 225(80.0%) subjects were reassessed. Sixty-three subjects were diagnosed as AD, 68 were MCI and 94 were cognitively intact. Among them, 158 had improved or remained stable while 67 deteriorated. The 'deteriorated' group was older than 'improved or stable' group (t-test, t = -2.87, p < 0.001). IVS2-150 polymorphism was associated with a higher risk of cognitive deterioration. Subjects with T allele were more likely to deteriorate compared with those without T allele (Pearson chi(2) = 8.98, df 2, p = 0.011). IVS3-128 CC genotype was higher in 'improved or stable' group (Likelihood Ratio = 6.55, df 2, p = 0.038), suggesting a protective role for this allele. The two other polymorphisms, IVS1-192 and IVS4-122, did not show any significant association with cognitive function. CONCLUSION CYP46A1 gene may act to modulate the course of cognitive deterioration in late life.
Collapse
Affiliation(s)
- Brenda Yan Fu
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | | | | | | | | | | | | |
Collapse
|
49
|
Small GW, Siddarth P, Burggren AC, Kepe V, Ercoli LM, Miller KJ, Lavretsky H, Thompson PM, Cole GM, Huang SC, Phelps ME, Bookheimer SY, Barrio JR. Influence of cognitive status, age, and APOE-4 genetic risk on brain FDDNP positron-emission tomography imaging in persons without dementia. ACTA ACUST UNITED AC 2009; 66:81-7. [PMID: 19124691 DOI: 10.1001/archgenpsychiatry.2008.516] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Amyloid senile plaques and tau neurofibrillary tangles are neuropathological hallmarks of Alzheimer disease that accumulate in the brains of people without dementia years before they develop dementia. Positron emission tomography (PET) scans after intravenous injections of 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile (FDDNP), which binds to plaques and tangles in vitro, demonstrate increased cerebral binding in patients with Alzheimer disease compared with cognitively intact controls. Here we investigated whether known risk factors for Alzheimer disease and dementia are associated with FDDNP-PET binding. OBJECTIVE To determine if impaired cognitive status, older age, apolipoprotein E-4 (APOE-4) genetic risk for Alzheimer disease, family history of dementia, and less education are associated with increased regional cerebral FDDNP-PET binding. DESIGN Cross-sectional clinical study. SETTING A university research institute. PARTICIPANTS Volunteer sample of 76 middle-aged and older persons without dementia (mean age, 67 years) including 36 with mild cognitive impairment. Of the 72 subjects with genetic data, 34 were APOE-4 carriers. MAIN OUTCOME MEASURES The FDDNP-PET signal in brain regions of interest, including medial and lateral temporal, posterior cingulate, parietal, and frontal. RESULTS For all regions studied, cognitive status was associated with increased FDDNP binding (P < .02 to .005). Older age was associated with increased lateral temporal FDDNP binding. Carriers of APOE-4 demonstrated higher frontal FDDNP binding than noncarriers. In the mild cognitive impairment group, age was associated with increased medial and lateral temporal FDDNP binding, and APOE-4 carriers had higher medial temporal binding than noncarriers. CONCLUSIONS Impaired cognitive status, older age, and APOE-4 carrier status are associated with increased brain FDDNP-PET binding in persons without dementia, consistent with previous clinical and postmortem studies associating these risk factors with amyloid plaque and tau tangle accumulation. Stratifying subject groups according to APOE-4 carrier status, age, and cognitive status may therefore be an informative strategy in future clinical trials using FDDNP-PET.
Collapse
Affiliation(s)
- Gary W Small
- Semel Institute, 760 Westwood Plaza, Ste 88-201, Los Angeles, CA 90024, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
Dementia of the Alzheimer type is a progressive, fatal neurodegenerative condition characterized by deterioration in cognition and memory, progressive impairment in the ability to carry out activities of daily living, and a number of neuropsychiatric symptoms. This narrative review summarizes the literature regarding descriptive epidemiology, clinical course, and characteristic neuropathological changes of dementia of the Alzheimer type. Although there are no definitive imaging or laboratory tests, except for brain biopsy, for diagnosis, brief screening instruments and neuropsychiatric test batteries used to assess the disease are discussed. Insufficient evidence exists for the use of biomarkers in clinical practice for diagnosis or disease management, but promising discoveries are summarized. Optimal treatment requires both nonpharmacological and pharmacological interventions, yet none have been shown to modify the disease's clinical course. This review describes the current available options and summarizes promising new avenues for treatment. Issues related to the care of persons with dementia of the Alzheimer type, including caregiver burden, long-term care, and the proliferation of dementia special care units, are discussed. Although advances have been made, more research is needed to address the gaps in our understanding of the disease.
Collapse
Affiliation(s)
- Jessica J Jalbert
- Department of Community Health - Epidemiology, Warren Alpert School of Medicine at Brown University, 121 South Main, Box G, Providence, RI 02912, USA.
| | | | | |
Collapse
|