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Bransby L, Rosenich E, Maruff P, Lim YY. How Modifiable Are Modifiable Dementia Risk Factors? A Framework for Considering the Modifiability of Dementia Risk Factors. J Prev Alzheimers Dis 2024; 11:22-37. [PMID: 38230714 PMCID: PMC10995020 DOI: 10.14283/jpad.2023.119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/06/2023] [Indexed: 01/18/2024]
Abstract
Many risk factors for dementia, identified from observational studies, are potentially modifiable. This raises the possibility that targeting key modifiable dementia risk factors may reduce the prevalence of dementia, which has led to the development of dementia risk reduction and prevention strategies, such as intervention trials or dementia prevention guidelines. However, what has rarely been considered in the studies that inform these strategies is the extent to which modifiable dementia risk factors can (1) be identified by individuals, and (2) be readily modified by individuals. Characteristics of modifiable dementia risk factors such as readiness of identification and targeting, as well as when they should be targeted, can influence the design, or success of strategies for reducing dementia risk. This review aims to develop a framework for classifying the degree of modifiability of dementia risk factors for research studies. The extent to which these modifiable dementia risk factors could be modified by an individual seeking to reduce their dementia risk is determined, as well as the resources that might be needed for both risk factor identification and modification, and whether modification may be optimal in early-life (aged <45 years), midlife (aged 45-65 years) or late-life (aged >65 years). Finally, barriers that could influence the ability of an individual to engage in risk factor modification and, ultimately, dementia risk reduction are discussed.
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Affiliation(s)
- L Bransby
- Lisa Bransby, Turner Institute for Brain and Mental Health, 18 Innovation Walk, Clayton, VIC 3800, Australia;
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Feizpour A, Doré V, Doecke JD, Saad ZS, Triana-Baltzer G, Slemmon R, Maruff P, Krishnadas N, Bourgeat P, Huang K, Fowler C, Rainey-Smith SR, Bush AI, Ward L, Robertson J, Martins RN, Masters CL, Villemagne VL, Fripp J, Kolb HC, Rowe CC. Two-Year Prognostic Utility of Plasma p217+tau across the Alzheimer's Continuum. J Prev Alzheimers Dis 2023; 10:828-836. [PMID: 37874105 DOI: 10.14283/jpad.2023.83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
BACKGROUND Plasma p217+tau has shown high concordance with cerebrospinal fluid (CSF) and positron emission tomography (PET) measures of amyloid-β (Aβ) and tau in Alzheimer's Disease (AD). However, its association with longitudinal cognition and comparative performance to PET Aβ and tau in predicting cognitive decline are unknown. OBJECTIVES To evaluate whether p217+tau can predict the rate of cognitive decline observed over two-year average follow-up and compare this to prediction based on Aβ (18F-NAV4694) and tau (18F-MK6240) PET. We also explored the sample size required to detect a 30% slowing in cognitive decline in a 2-year trial and selection test cost using p217+tau (pT+) as compared to PET Aβ (A+) and tau (T+) with and without p217+tau pre-screening. DESIGN A prospective observational cohort study. SETTING Participants of the Australian Imaging, Biomarker and Lifestyle Flagship Study of Ageing (AIBL) and Australian Dementia Network (ADNeT). PARTICIPANTS 153 cognitively unimpaired (CU) and 50 cognitively impaired (CI) individuals. MEASUREMENTS Baseline p217+tau Simoa® assay, 18F-MK6240 tau-PET and 18F-NAV4694 Aβ-PET with neuropsychological follow-up (MMSE, CDR-SB, AIBL-PACC) over 2.4 ± 0.8 years. RESULTS In CI, p217+tau was a significant predictor of change in MMSE (β = -0.55, p < 0.001) and CDR-SB (β =0.61, p < 0.001) with an effect size similar to Aβ Centiloid (MMSE β = -0.48, p = 0.002; CDR-SB β = 0.43, p = 0.004) and meta-temporal (MetaT) tau SUVR (MMSE: β = -0.62, p < 0.001; CDR-SB: β = 0.65, p < 0.001). In CU, only MetaT tau SUVR was significantly associated with change in AIBL-PACC (β = -0.22, p = 0.008). Screening pT+ CI participants into a trial could lead to 24% reduction in sample size compared to screening with PET for A+ and 6-13% compared to screening with PET for T+ (different regions). This would translate to an 81-83% biomarker test cost-saving assuming the p217+tau test cost one-fifth of a PET scan. In a trial requiring PET A+ or T+, p217+tau pre-screening followed by PET in those who were pT+ would cost more in the CI group, compared to 26-38% biomarker test cost-saving in the CU. CONCLUSIONS Substantial cost reduction can be achieved using p217+tau alone to select participants with MCI or mild dementia for a clinical trial designed to slow cognitive decline over two years, compared to participant selection by PET. In pre-clinical AD trials, p217+tau provides significant cost-saving if used as a pre-screening measure for PET A+ or T+ but in MCI/mild dementia trials this may add to cost both in testing and in the increased number of participants needed for testing.
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Affiliation(s)
- A Feizpour
- Professor Christopher C Rowe, Department of Molecular Imaging and Therapy, Austin Health, 145 Studley Road, Heidelberg, VIC. 3084, Australia. Telephone: +61-3-9496 3321. Fax +61-3-9458 5023.
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Ashford MT, Eichenbaum J, Jin C, Neuhaus J, Aaronson A, Ulbricht A, Camacho MR, Fockler J, Flenniken D, Truran D, Mackin RS, Maruff P, Weiner MW, Nosheny RL. Associations between Participant Characteristics and Participant Feedback about an Unsupervised Online Cognitive Assessment in a Research Registry. J Prev Alzheimers Dis 2023; 10:607-614. [PMID: 37357303 PMCID: PMC10126538 DOI: 10.14283/jpad.2023.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/21/2023] [Indexed: 07/26/2023]
Abstract
BACKGROUND This study aims to understand whether and how participant characteristics (age, gender, education, ethnocultural identity) are related to their feedback about taking a remote, unsupervised, online cognitive assessment. METHODS The Brain Health Registry is a public online registry which includes cognitive assessments. Multivariable ordinal regressions assessed associations between participant characteristics and feedback responses of older (55+) participants (N=11,553) regarding their Cogstate Brief Battery assessment experience. RESULTS Higher age, secondary education or less, Latino identity, and female gender were associated with a poorer assessment experience; higher age and a non-White identity were associated with experiencing the assessment instructions as less clear; and higher age, non-White identity, and secondary education or less were associated with rating additional human support with the assessment as more useful. DISCUSSION Our findings highlight the importance of improving the design and instructions of unsupervised, remote, online cognitive assessments to better suit the needs of diverse communities.
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Affiliation(s)
- M T Ashford
- Miriam Ashford, NCIRE - Northern California Institute for Research and Education, 4150 Clement Street, San Francisco, CA 94121, USA, , Phone: 650-208-9267
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Lim YY, Kong J, Maruff P, Jaeger J, Huang E, Ratti E. Longitudinal Cognitive Decline in Patients With Mild Cognitive Impairment or Dementia Due to Alzheimer's Disease. J Prev Alzheimers Dis 2022; 9:178-183. [PMID: 35098989 DOI: 10.14283/jpad.2021.64] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sensitive cognitive assessments accurately detect and track cognitive decline in Alzheimer's disease. The Cogstate battery was used to measure cognitive change in cognitively normal participants and in individuals with mild cognitive impairment and mild Alzheimer's disease enrolled in the Australian Imaging, Biomarker and Lifestyle Rate of Change Substudy. Over 18 months, verbal episodic memory performance declined for mild cognitive impairment and mild Alzeheimer's disease groups when compared to cognitively normal participants. Frequent assessments of episodic memory may facilitate early detection of cognitive decline due to Alzheimer's disease.
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Affiliation(s)
- Y Y Lim
- Yen Ying Lim, Turner Institute for Brain and Mental Health, 18 Innovation Walk, Clayton VIC 3168, Australia, , Ph: +61 4 3387 3222
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Gaudet D, Ruzza A, Bridges I, Maruff P, Schembri A, Hamer A, Kurtz C, Mach F, Bergeron J, Gaudet I, St-Pierre J, Kastelein J, Hovingh G, Wiegman A, Raal F, Santos R. Effect of evolocumab on cognition in pediatric patients with familial hypercholesterolemia: Results from the HAUSER-RCT study. Atherosclerosis 2021. [DOI: 10.1016/j.atherosclerosis.2021.06.789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Banh T, Jin C, Neuhaus J, Mackin RS, Maruff P, Stricker N, Weiner MW, Nosheny RL. Unsupervised Performance of the CogState Brief Battery in the Brain Health Registry: Implications for Detecting Cognitive Decline. J Prev Alzheimers Dis 2021; 9:262-268. [PMID: 35542999 PMCID: PMC9101916 DOI: 10.14283/jpad.2021.68] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION: The feasibility and validity of unsupervised, longitudinal brief computerized cognitive batteries is unknown. METHODS: Participants aged 56–90 (N = 19476) from the Brain Health Registry (BHR) completed the CogState Brief Battery (CBB) at 6-month intervals over a period of 5 years. We used linear mixed-effects models to assess whether cross-sectional and longitudinal performance on CBB within BHR was associated with demographic and cognitive characteristics. We also defined a group of CBB decliners based on subject-specific slopes and estimated associations between decliner status and participant characteristics. RESULTS: We found weak associations between longitudinal change in CBB and participant characteristics. Cross-sectional CBB scores were significantly associated with participant characteristics such as age, gender, ethnicity, self-reported disease status, and memory concern. CBB decliners were more likely to self-report mild cognitive impairment (MCI) and memory concerns. DISCUSSION: Cross-sectional, remote CBB shows evidence of construct validity, but our results suggest that longitudinal assessment may not provide additional value for identifying those at risk for and with cognitive impairment.
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Affiliation(s)
- T Banh
- Tim Banh, University of California San Francisco, USA,
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Papp KV, Rentz DM, Maruff P, Sun CK, Raman R, Donohue MC, Schembri A, Stark C, Yassa MA, Wessels AM, Yaari R, Holdridge KC, Aisen PS, Sperling RA. The Computerized Cognitive Composite (C3) in an Alzheimer's Disease Secondary Prevention Trial. J Prev Alzheimers Dis 2021; 8:59-67. [PMID: 33336226 PMCID: PMC7755110 DOI: 10.14283/jpad.2020.38] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND Computerized cognitive assessments may improve Alzheimer's disease (AD) secondary prevention trial efficiency and accuracy. However, they require validation against standard outcomes and relevant biomarkers. OBJECTIVE To assess the feasibility and validity of the tablet-based Computerized Cognitive Composite (C3). DESIGN Cross-sectional analysis of cognitive screening data from the A4 study (Anti-Amyloid in Asymptomatic AD). SETTING Multi-center international study. PARTICIPANTS Clinically normal (CN) older adults (65-85; n=4486). MEASUREMENTS Participants underwent florbetapir-Positron Emission Tomography for Aβ+/- classification. They completed the C3 and standard paper and pencil measures included in the Preclinical Alzheimer's Cognitive Composite (PACC). The C3 combines memory measures sensitive to change over time (Cogstate Brief Battery-One Card Learning) and measures shown to be declining early in AD including pattern separation (Behavioral Pattern Separation Test- Object- Lure Discrimination Index) and associative memory (Face Name Associative Memory Exam- Face-Name Matching). C3 acceptability and completion rates were assessed using qualitative and quantitative methods. C3 performance was explored in relation to Aβ+/- groups (n=1323/3163) and PACC. RESULTS C3 was feasible for CN older adults to complete. Rates of incomplete or invalid administrations were extremely low, even in the bottom quartile of cognitive performers (PACC). C3 was moderately correlated with PACC (r=0.39). Aβ+ performed worse on C3 compared with Aβ- [unadjusted Cohen's d=-0.22 (95%CI: -0.31,-0.13) p<0.001] and at a magnitude comparable to the PACC [d=-0.32 (95%CI: -0.41,-0.23) p<0.001]. Better C3 performance was observed in younger, more educated, and female participants. CONCLUSIONS These findings provide support for both the feasibility and validity of C3 and computerized cognitive outcomes more generally in AD secondary prevention trials.
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Affiliation(s)
- K V Papp
- Kathryn V. Papp, Center for Alzheimer Research and Treatment; 60 Fenwood Road; Boston, MA 02115, Telephone: 617-643-5322; Fax: 857-5461, Email Address:
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Burnham SC, Coloma PM, Li QX, Collins S, Savage G, Laws S, Doecke J, Maruff P, Martins RN, Ames D, Rowe CC, Masters CL, Villemagne VL. Application of the NIA-AA Research Framework: Towards a Biological Definition of Alzheimer's Disease Using Cerebrospinal Fluid Biomarkers in the AIBL Study. J Prev Alzheimers Dis 2020; 6:248-255. [PMID: 31686097 DOI: 10.14283/jpad.2019.25] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND The National Institute on Aging and Alzheimer's Association (NIA-AA) have proposed a new Research Framework: Towards a biological definition of Alzheimer's disease, which uses a three-biomarker construct: Aß-amyloid, tau and neurodegeneration AT(N), to generate a biomarker based definition of Alzheimer's disease. OBJECTIVES To stratify AIBL participants using the new NIA-AA Research Framework using cerebrospinal fluid (CSF) biomarkers. To evaluate the clinical and cognitive profiles of the different groups resultant from the AT(N) stratification. To compare the findings to those that result from stratification using two-biomarker construct criteria (AT and/or A(N)). DESIGN Individuals were classified as being positive or negative for each of the A, T, and (N) categories and then assigned to the appropriate AT(N) combinatorial group: A-T-(N)-; A+T-(N)-; A+T+(N)-; A+T-(N)+; A+T+(N)+; A-T+(N)-; A-T-(N)+; A-T+(N)+. In line with the NIA-AA research framework, these eight AT(N) groups were then collapsed into four main groups of interest (normal AD biomarkers, AD pathologic change, AD and non-AD pathologic change) and the respective clinical and cognitive trajectories over 4.5 years for each group were assessed. In two sensitivity analyses the methods were replicated after assigning individuals to four groups based on being positive or negative for AT biomarkers as well as A(N) biomarkers. SETTING Two study centers in Melbourne (Victoria) and Perth (Western Australia), Australia recruited MCI individuals and individuals with AD from primary care physicians or tertiary memory disorder clinics. Cognitively healthy, elderly NCs were recruited through advertisement or via spouses of participants in the study. PARTICIPANTS One-hundred and forty NC, 33 MCI participants, and 27 participants with AD from the AIBL study who had undergone CSF evaluation using Elecsys® assays. INTERVENTION (if any): Not applicable. MEASUREMENTS Three CSF biomarkers, namely amyloid β1-42, phosphorylated tau181, and total tau, were measured to provide the AT(N) classifications. Clinical and cognitive trajectories were evaluated using the AIBL Preclinical Alzheimer Cognitive Composite (AIBL-PACC), a verbal episodic memory composite, an executive function composite, California Verbal Learning Test - Second Edition; Long-Delay Free Recall, Mini-Mental State Examination, and Clinical Dementia Rating Sum of Boxes scores. RESULTS Thirty-eight percent of the elderly NCs had no evidence of abnormal AD biomarkers, whereas 33% had biomarker levels consistent with AD or AD pathologic change, and 29% had evidence of non-AD biomarker change. Among NC participants, those with biomarker evidence of AD pathology tended to perform worse on cognitive outcome assessments than other biomarker groups. Approximately three in four participants with MCI or AD had biomarker levels consistent with the research framework's definition of AD or AD pathologic change. For MCI participants, a decrease in AIBL-PACC scores was observed with increasing abnormal biomarkers; and increased abnormal biomarkers were also associated with increased rates of decline across some cognitive measures. CONCLUSIONS Increasing biomarker abnormality appears to be associated with worse cognitive trajectories. The implementation of biomarker classifications could help better characterize prognosis in clinical practice and identify those at-risk individuals more likely to clinically progress, for their inclusion in future therapeutic trials.
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Affiliation(s)
- S C Burnham
- Samantha C. Burnham, CSIRO, 343 Royal Parade, Parkville, VIC 3052, Australia, , Tel.: +61399627162
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McMahon W, Ftouni S, Collet J, Diep C, Rajaratnam S, Maruff P, Drummond S, Anderson C. Task-dependent effects of the wake maintenance zone on cognition and alertness, with and without sleep loss. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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De Meijer L, Merlo D, Skibina O, Grobbee EJ, Gale J, Haartsen J, Maruff P, Darby D, Butzkueven H, Van der Walt A. Monitoring cognitive change in multiple sclerosis using a computerized cognitive battery. Mult Scler J Exp Transl Clin 2018; 4:2055217318815513. [PMID: 30559973 PMCID: PMC6293367 DOI: 10.1177/2055217318815513] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/11/2018] [Accepted: 11/01/2018] [Indexed: 11/15/2022] Open
Abstract
Background Cognitive monitoring that can detect short-term change in multiple sclerosis is challenging. Computerized cognitive batteries such as the CogState Brief Battery can rapidly assess commonly affected cognitive domains. Objectives The purpose of this study was to establish the acceptability and sensitivity of the CogState Brief Battery in multiple sclerosis patients compared to controls. We compared the sensitivity of the CogState Brief Battery to that of the Paced Auditory Serial Addition Test over 12 months. Methods Demographics, Expanded Disability Status Scale scores, depression and anxiety scores were compared with CogState Brief Battery and Paced Auditory Serial Addition Test performances of 51 patients with relapsing-remitting multiple sclerosis, 19 with secondary progressive multiple sclerosis and 40 healthy controls. Longitudinal data in 37 relapsing-remitting multiple sclerosis patients were evaluated using linear mixed models. Results Both the CogState Brief Battery and the Paced Auditory Serial Addition Test discriminated between multiple sclerosis and healthy controls at baseline (p<0.001). CogState Brief Battery tasks were more acceptable and caused less anxiety than the Paced Auditory Serial Addition Test (p<0.001). In relapsing-remitting multiple sclerosis patients, reaction time slowed over 12 months (p<0.001) for the CogState Brief Battery Detection (mean change -34.23 ms) and Identification (-25.31 ms) tasks. Paced Auditory Serial Addition Test scores did not change over this time. Conclusions The CogState Brief Battery is highly acceptable and better able to detect cognitive change than the Paced Auditory Serial Addition Test. The CogState Brief Battery could potentially be used as a practical cognitive monitoring tool in the multiple sclerosis clinic setting.
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Affiliation(s)
- L De Meijer
- Rijksuniversiteit, The Netherlands.,Erasmus MC Medical Center, The Netherlands
| | - D Merlo
- Eastern Health Clinical Research Unit, Monash University, Australia.,Department of Neuroscience, Monash University, Australia
| | - O Skibina
- Eastern Health Clinical Research Unit, Monash University, Australia.,Department of Neurology, Eastern Health, Australia.,Department of Neurology, Alfred Health, Australia
| | | | | | - J Haartsen
- Eastern Health Clinical Research Unit, Monash University, Australia.,Department of Neurology, Eastern Health, Australia
| | - P Maruff
- Department of Neuroscience, Monash University, Australia
| | - D Darby
- Department of Neurology, Eastern Health, Australia.,Florey Institute for Neuroscience and Mental Health, University of Melbourne, Australia
| | - H Butzkueven
- Eastern Health Clinical Research Unit, Monash University, Australia.,Department of Neuroscience, Monash University, Australia.,Department of Neurology, Eastern Health, Australia.,Department of Neurology, Alfred Health, Australia
| | - A Van der Walt
- Eastern Health Clinical Research Unit, Monash University, Australia.,Department of Neuroscience, Monash University, Australia.,Department of Neurology, Eastern Health, Australia.,Department of Neurology, Alfred Health, Australia.,These authors contributed equally
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McMahon WR, Ftouni S, Maruff P, Rajaratnam SM, Lockley SW, Drummond SP, Anderson C. 0256 IMPROVEMENT IN COGNITION DURING THE WAKE MAINTENANCE ZONE FOLLOWING SLEEP LOSS IS DEPENDENT ON COGNITIVE DOMAIN. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Lim YY, Villemagne VL, Laws SM, Pietrzak RH, Snyder PJ, Ames D, Ellis KA, Harrington K, Rembach A, Martins RN, Rowe CC, Masters CL, Maruff P. APOE and BDNF polymorphisms moderate amyloid β-related cognitive decline in preclinical Alzheimer's disease. Mol Psychiatry 2015; 20:1322-8. [PMID: 25288138 PMCID: PMC4759101 DOI: 10.1038/mp.2014.123] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/29/2014] [Accepted: 08/21/2014] [Indexed: 12/11/2022]
Abstract
Accumulation of β-amyloid (Aβ) in the brain is associated with memory decline in healthy individuals as a prelude to Alzheimer's disease (AD). Genetic factors may moderate this decline. We examined the role of apolipoprotein E (ɛ4 carrier[ɛ4(+)], ɛ4 non-carrier[ɛ4(-)]) and brain-derived neurotrophic factor (BDNF(Val/Val), BDNF(Met)) in the extent to which they moderate Aβ-related memory decline. Healthy adults (n=333, Mage=70 years) enrolled in the Australian Imaging, Biomarkers and Lifestyle study underwent Aβ neuroimaging. Neuropsychological assessments were conducted at baseline, 18-, 36- and 54-month follow-ups. Aβ positron emission tomography neuroimaging was used to classify participants as Aβ(-) or Aβ(+). Relative to Aβ(-)ɛ4(-), Aβ(+)ɛ4(+) individuals showed significantly faster rates of cognitive decline over 54 months across all domains (d=0.40-1.22), while Aβ(+)ɛ4(-) individuals showed significantly faster decline only on verbal episodic memory (EM). There were no differences in rates of cognitive change between Aβ(-)ɛ4(-) and Aβ(-)ɛ4(+) groups. Among Aβ(+) individuals, ɛ4(+)/BDNF(Met) participants showed a significantly faster rate of decline on verbal and visual EM, and language over 54 months compared with ɛ4(-)/BDNF(Val/Val) participants (d=0.90-1.02). At least two genetic loci affect the rate of Aβ-related cognitive decline. Aβ(+)ɛ4(+)/BDNF(Met) individuals can expect to show clinically significant memory impairment after 3 years, whereas Aβ(+)ɛ4(+)/BDNF(Val/Val) individuals can expect a similar degree of impairment after 10 years. Little decline over 54 months was observed in the Aβ(-) and Aβ(+) ɛ4(-) groups, irrespective of BDNF status. These data raise important prognostic issues in managing preclinical AD, and should be considered in designing secondary preventative clinical trials.
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Affiliation(s)
- Y Y Lim
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia,Department of Neurology, Warren Alpert School of Medicine, Brown University, Providence, RI, USA,Department of Neurology, Rhode Island Hospital, Providence, RI, USA
| | - V L Villemagne
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia,Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, VIC, Australia,Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
| | - S M Laws
- Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia,Sir James McCusker Alzheimer's Disease Research Unit, Hollywood Private Hospital, Perth, WA, Australia,Co-operative Research Centre for Mental Health
| | - R H Pietrzak
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - P J Snyder
- Department of Neurology, Warren Alpert School of Medicine, Brown University, Providence, RI, USA,Department of Neurology, Rhode Island Hospital, Providence, RI, USA
| | - D Ames
- Academic Unit for Psychiatry of Old Age, Department of Psychiatry, St. Vincent's Health, University of Melbourne, Kew, VIC, Australia,National Ageing Research Institute, Parkville, VIC, Australia
| | - K A Ellis
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia,National Ageing Research Institute, Parkville, VIC, Australia
| | - K Harrington
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - A Rembach
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - R N Martins
- Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia
| | - C C Rowe
- Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, VIC, Australia,Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
| | - C L Masters
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Kenneth Myer Building, Genetics Lane, Royal Parade, Melbourne, VIC 3000, Australia. E-mail:
| | - P Maruff
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia,CogState Ltd, Melbourne, VIC, Australia
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Shah T, Verdile G, Sohrabi H, Campbell A, Putland E, Cheetham C, Dhaliwal S, Weinborn M, Maruff P, Darby D, Martins RN. A combination of physical activity and computerized brain training improves verbal memory and increases cerebral glucose metabolism in the elderly. Transl Psychiatry 2014; 4:e487. [PMID: 25463973 PMCID: PMC4270308 DOI: 10.1038/tp.2014.122] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 09/19/2014] [Accepted: 10/05/2014] [Indexed: 11/09/2022] Open
Abstract
Physical exercise interventions and cognitive training programs have individually been reported to improve cognition in the healthy elderly population; however, the clinical significance of using a combined approach is currently lacking. This study evaluated whether physical activity (PA), computerized cognitive training and/or a combination of both could improve cognition. In this nonrandomized study, 224 healthy community-dwelling older adults (60-85 years) were assigned to 16 weeks home-based PA (n=64), computerized cognitive stimulation (n=62), a combination of both (combined, n=51) or a control group (n=47). Cognition was assessed using the Rey Auditory Verbal Learning Test, Controlled Oral Word Association Test and the CogState computerized battery at baseline, 8 and 16 weeks post intervention. Physical fitness assessments were performed at all time points. A subset (total n=45) of participants underwent [(18)F] fluorodeoxyglucose positron emission tomography scans at 16 weeks (post-intervention). One hundred and ninety-one participants completed the study and the data of 172 participants were included in the final analysis. Compared with the control group, the combined group showed improved verbal episodic memory and significantly higher brain glucose metabolism in the left sensorimotor cortex after controlling for age, sex, premorbid IQ, apolipoprotein E (APOE) status and history of head injury. The higher cerebral glucose metabolism in this brain region was positively associated with improved verbal memory seen in the combined group only. Our study provides evidence that a specific combination of physical and mental exercises for 16 weeks can improve cognition and increase cerebral glucose metabolism in cognitively intact healthy older adults.
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Affiliation(s)
- T Shah
- School of Psychiatry and Clinical
Neurosciences, University of Western Australia, Perth,
WA, Australia,The McCusker Alzheimer's Research
Foundation (Hollywood Private Hospital), Hollywood Medical Centre,
Perth, WA, Australia,Centre of Excellence for
Alzheimer's Disease Research and Care, School of Medical Sciences, Edith
Cowan University, Perth, WA, Australia
| | - G Verdile
- The McCusker Alzheimer's Research
Foundation (Hollywood Private Hospital), Hollywood Medical Centre,
Perth, WA, Australia,Centre of Excellence for
Alzheimer's Disease Research and Care, School of Medical Sciences, Edith
Cowan University, Perth, WA, Australia,School of Biomedical Sciences, Curtin
University, Perth, WA, Australia
| | - H Sohrabi
- School of Psychiatry and Clinical
Neurosciences, University of Western Australia, Perth,
WA, Australia,The McCusker Alzheimer's Research
Foundation (Hollywood Private Hospital), Hollywood Medical Centre,
Perth, WA, Australia,Centre of Excellence for
Alzheimer's Disease Research and Care, School of Medical Sciences, Edith
Cowan University, Perth, WA, Australia
| | - A Campbell
- Department of Nuclear Medicine, Royal
Perth Hospital, Perth, WA, Australia
| | - E Putland
- The McCusker Alzheimer's Research
Foundation (Hollywood Private Hospital), Hollywood Medical Centre,
Perth, WA, Australia
| | - C Cheetham
- Health Care Western Australia, Hollywood
Private Hospital, Perth, WA, Australia,School of Sports Science, Exercise and
Health, University of Western Australia, Perth, WA,
Australia
| | - S Dhaliwal
- School of Public Health, Curtin
University, Perth, WA, Australia
| | - M Weinborn
- The McCusker Alzheimer's Research
Foundation (Hollywood Private Hospital), Hollywood Medical Centre,
Perth, WA, Australia,School of Psychology, University of
Western Australia, Perth, WA, Australia
| | - P Maruff
- Mental Health Research Institute, The
University of Melbourne, Parkville, VIC,
Australia,CogState Ltd,
Melbourne, VIC, Australia
| | - D Darby
- Mental Health Research Institute, The
University of Melbourne, Parkville, VIC,
Australia,CogState Ltd,
Melbourne, VIC, Australia,Florey Neuroscience Institutes,
Carlton South, VIC, Australia
| | - R N Martins
- School of Psychiatry and Clinical
Neurosciences, University of Western Australia, Perth,
WA, Australia,The McCusker Alzheimer's Research
Foundation (Hollywood Private Hospital), Hollywood Medical Centre,
Perth, WA, Australia,Centre of Excellence for
Alzheimer's Disease Research and Care, School of Medical Sciences, Edith
Cowan University, Perth, WA, Australia,Centre of Excellence for Alzheimer's Disease Research
and Care, School of Medical Sciences, Edith Cowan University, 270
Joondalup Drive, Joondalup, Perth, WA
6027, Australia. E-mail:
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Brown BM, Bourgeat P, Peiffer JJ, Burnham S, Laws SM, Rainey-Smith SR, Bartres-Faz D, Villemagne VL, Taddei K, Rembach A, Bush A, Ellis KA, Macaulay SL, Rowe CC, Ames D, Masters CL, Maruff P, Martins RN. Influence of BDNF Val66Met on the relationship between physical activity and brain volume. Neurology 2014; 83:1345-52. [DOI: 10.1212/wnl.0000000000000867] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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15
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Louey AG, Cromer JA, Schembri AJ, Darby DG, Maruff P, Makdissi M, Mccrory P. Detecting Cognitive Impairment After Concussion: Sensitivity of Change From Baseline and Normative Data Methods Using the CogSport/Axon Cognitive Test Battery. Arch Clin Neuropsychol 2014; 29:432-41. [DOI: 10.1093/arclin/acu020] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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16
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Darby D, Fredrickson J, Pietrzak R, Maruff P, Woodward M, Brodtmann A. Reliability and usability of an internet-based computerized cognitive testing battery in community-dwelling older people. Computers in Human Behavior 2014. [DOI: 10.1016/j.chb.2013.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Lim YY, Jaeger J, Harrington K, Ashwood T, Ellis KA, Stoffler A, Szoeke C, Lachovitzki R, Martins RN, Villemagne VL, Bush A, Masters CL, Rowe CC, Ames D, Darby D, Maruff P. Three-Month Stability of the CogState Brief Battery in Healthy Older Adults, Mild Cognitive Impairment, and Alzheimer's Disease: Results from the Australian Imaging, Biomarkers, and Lifestyle-Rate of Change Substudy (AIBL-ROCS). Arch Clin Neuropsychol 2013; 28:320-30. [DOI: 10.1093/arclin/act021] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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18
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Lim YY, Ellis KA, Pietrzak RH, Ames D, Darby D, Harrington K, Martins RN, Masters CL, Rowe C, Savage G, Szoeke C, Villemagne VL, Maruff P. Stronger effect of amyloid load than APOE genotype on cognitive decline in healthy older adults. Neurology 2012; 79:1645-52. [DOI: 10.1212/wnl.0b013e31826e9ae6] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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19
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Rahimi-Golkhandan S, Maruff P, Darby D, Wilson P. Barriers to Repeated Assessment of Verbal Learning and Memory: A Comparison of International Shopping List Task and Rey Auditory Verbal Learning Test on Build-Up of Proactive Interference. Arch Clin Neuropsychol 2012; 27:790-5. [DOI: 10.1093/arclin/acs074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Murthy NV, Mahncke H, Wexler BE, Maruff P, Inamdar A, Zucchetto M, Lund J, Shabbir S, Shergill S, Keshavan M, Kapur S, Laruelle M, Alexander R. Computerized cognitive remediation training for schizophrenia: an open label, multi-site, multinational methodology study. Schizophr Res 2012; 139:87-91. [PMID: 22342330 DOI: 10.1016/j.schres.2012.01.042] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 01/19/2012] [Accepted: 01/30/2012] [Indexed: 10/28/2022]
Abstract
A recent single-site study (Fisher et al., 2009. Am J Psychiatry. 166 (7) 805-11) showed that repeated training with the Brain Fitness Program (BFP) improved performance on a battery of neuropsychological tasks. If replicated these data suggest an important non-pharmacological method for ameliorating cognitive impairment in schizophrenia. Our study evaluated the BFP training effects in an open-label, multi-site, multinational clinical trial. Fifty-five stable adult patients with schizophrenia on regular antipsychotic medication completed ≥ 32 BFP training sessions over 8-10 weeks. Training effects on cognitive performance and functional capacity outcome measures were measured using CogState® schizophrenia battery, UCSD Performance based Skills Assessment (UPSA-2) and Cognitive Assessment Interview (CAI). BFP training showed a large and significant treatment effect on a training exercise task (auditory processing speed), however this effect did not generalize to improved performance on independent CogState® assessment. There were no significant effects on UPSA-2 or CAI scores. Our study demonstrated the feasibility of implementing BFP training in a multi-site study. However, BFP training did not show significant treatment effects on cognitive performance or functional capacity outcome measures despite showing large and significant effects on a training exercise.
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Affiliation(s)
- N V Murthy
- Neurosciences CEDD, GlaxoSmithKline R&D, New Frontier Science Park, Harlow, UK.
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21
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Lim YY, Pietrzak RH, Snyder PJ, Darby D, Maruff P. Preliminary Data on the Effect of Culture on the Assessment of Alzheimer's Disease-Related Verbal Memory Impairment with the International Shopping List Test. Arch Clin Neuropsychol 2011; 27:136-47. [DOI: 10.1093/arclin/acr102] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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22
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Thompson TAC, Wilson PH, Snyder PJ, Pietrzak RH, Darby D, Maruff P, Buschke H. Sensitivity and Test-Retest Reliability of the International Shopping List Test in Assessing Verbal Learning and Memory in Mild Alzheimer's Disease. Arch Clin Neuropsychol 2011; 26:412-24. [DOI: 10.1093/arclin/acr039] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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23
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Lewis M, Snyder P, Pietrzak R, Darby D, Feldman R, Maruff P. The effect of acute increase in urge to void on cognitive function in healthy adults. Neurourol Urodyn 2010; 30:183-7. [DOI: 10.1002/nau.20963] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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24
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Thiyagarajan A, Garvey L, Pflugrad H, Maruff P, Scullard G, Main J, Taylor-Robinson S, Winston A. Cerebral function tests reveal differences in HIV-infected subjects with and without chronic HCV co-infection. Clin Microbiol Infect 2010; 16:1579-84. [DOI: 10.1111/j.1469-0691.2010.03176.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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25
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Fredrickson J, Maruff P, Woodward M, Moore L, Fredrickson A, Sach J, Darby D. Evaluation of the Usability of a Brief Computerized Cognitive Screening Test in Older People for Epidemiological Studies. Neuroepidemiology 2010; 34:65-75. [DOI: 10.1159/000264823] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 09/16/2009] [Indexed: 11/19/2022] Open
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26
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Evered L, Silbert B, Scott D, Maruff P, Laughton K, Volitakis I, Cowie T, Cherny R, Masters C, Li Q. Plasma amyloid β
42
and amyloid β
40
levels are associated with early cognitive dysfunction after cardiac surgery. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- L. Evered
- St Vincent's HospitalMelbourneVICAustralia
- University of MelbourneParkvilleVICAustralia
| | - B. Silbert
- St Vincent's HospitalMelbourneVICAustralia
- University of MelbourneParkvilleVICAustralia
| | - D. Scott
- St Vincent's HospitalMelbourneVICAustralia
- University of MelbourneParkvilleVICAustralia
| | - P. Maruff
- University of MelbourneParkvilleVICAustralia
| | - K. Laughton
- University of MelbourneParkvilleVICAustralia
| | | | - T. Cowie
- University of MelbourneParkvilleVICAustralia
| | - R. Cherny
- University of MelbourneParkvilleVICAustralia
| | - C. Masters
- University of MelbourneParkvilleVICAustralia
| | - Q. Li
- University of MelbourneParkvilleVICAustralia
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27
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Pietrzak RH, Maruff P, Snyder PJ. Methodological improvements in quantifying cognitive change in clinical trials: an example with single-dose administration of donepezil. J Nutr Health Aging 2009; 13:268-73. [PMID: 19262966 DOI: 10.1007/s12603-009-0071-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Change in cognitive function in response to a pharmacologic challenge can be observed with greater sensitivity by employing cognitive tests with optimal psychometric properties and a statistical approach that more accurately accounts for individual variability in performance. To demonstrate this approach we examined the cognitive effects of a single acute dose administration of an acetylcholinesterase inhibitor, donepezil, in healthy older adults and in older adults with mild Alzheimer's disease (AD). DESIGN Placebo-controlled crossover study with three separate testing days: baseline, placebo, and donepezil, with assessments at baseline, and 1-, 2-, 3-, 6-, and 8-hrs post-dosing on each day. SETTING Early phase I clinical trial. PARTICIPANTS 15 healthy older adults; 14 older adults with mild Alzheimer's disease. INTERVENTION Single acute dose of 5mg donepezil. MEASUREMENTS Performance on the Groton Maze Learning Test (GMLT), a computerized neuropsychological measure of spatial working memory and error monitoring. RESULTS A single acute dose of donepezil improved GMLT performance in healthy older adults (effect size: 0.83 at 6 hrs post-dosing) and older adults with mild AD (effect size: 0.58 at 3 hrs post-dosing). CONCLUSION The GMLT detected cognitive improvement following a single, acute dose administration of donepezil in healthy older adults and older adults with mild AD. The choice of cognitive tests designed for repeated administration, as well as an analytic approach that emphasizes individual-level change in cognitive function, provides a sensitive approach to detecting central nervous system drug penetration and activity of cognitive-enhancing agents.
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Affiliation(s)
- R H Pietrzak
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
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28
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Weaver Cargin J, Collie A, Masters C, Maruff P. The nature of cognitive complaints in healthy older adults with and without objective memory decline. J Clin Exp Neuropsychol 2009; 30:245-57. [PMID: 18938676 DOI: 10.1080/13803390701377829] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Cognitive and memory complaints were assessed in 100 healthy older adults on two occasions over 2.5 years as part of a 6-year study assessing cognition, mood, and general health factors. Diminished memory for names and actions and lapses in concentration were common complaints, regardless of the individuals' actual cognitive status. No change in cognitive complaints occurred over time, even for individuals whose memory had declined over 6 years. Cognitive complaints correlated with anxiety, depression, and general mental health but not with objectively measured memory or cognition, education or age. Complaints did not differ with gender, apolipoprotein E epsilon4 genotype, cardiovascular risk factors, or intake of sedating medications. Thus, cognitive complaints could not differentiate memory-declining older adults from cognitively normal older adults and were more closely associated with mood and general mental health than actual cognitive status, age, or potential risk factors for Alzheimer's disease. Thus, the evaluation of cognitive complaints must be broad and must consider the correspondence of complaints not only to relevant measurable cognitive abilities but also to the affect of the individual.
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Affiliation(s)
- J Weaver Cargin
- School of Psychological Science, LaTrobe University, Melbourne, Australia.
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29
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Abstract
Decline in memory function was detected in 30% of healthy community-dwelling elderly over 6 years using a task assessing delayed word list recall. Individuals with memory decline over time also demonstrated relative deficits on additional tasks of memory and learning, a task of working memory and executive function, and on a verbal (category) fluency task at their most recent assessment. These relative deficits in the performance of individuals with memory decline cannot be explained by age-related changes, education, intelligence, mood, health-related factors, or the individuals' APOE epsilon 4 status. Decline in memory performance did not result in greater complaints of cognitive difficulties when compared with normal elderly, nor did it limit overall participation in life activities. Although the significance of memory decline in the current study was not determined quantitatively, memory decline is consistent with the early deterioration characteristic of mild cognitive impairment and preclinical Alzheimer's disease and confirms the need to monitor individuals with objective memory decline, even when these individuals fall within normal limits for a given neuropsychological task.
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Affiliation(s)
- J Weaver Cargin
- School of Psychological Science, La Trobe University, Melbourne, Australia.
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30
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Currie J, Ramsden B, McArthur C, Lunch J, Maruff P, Benson E, Perdices M, Cooper D. Hochauflösende Augenmotilitätsmessungen bei der Untersuchung neurologischer Komplikationen der HIV-1-Infektion. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
OBJECTIVE The aim of the study was to investigate the impact of treatment-related clearance of hepatitis C virus (HCV) on cognitive function. METHODS A prospective study was conducted in 19 HCV-monoinfected and 15 HIV/HCV-coinfected individuals undergoing pegylated interferon alpha-2a and ribavirin therapy between April 2003 and August 2005. Neuropsychological, mood, and health-related quality of life (HRQOL) effects were assessed using computer-based battery, Trail Making Tests, Depression Anxiety Stress Scales and the Short Form-36 health survey. RESULTS Pretreatment cognitive function, mood status, and HRQOL were similar between the HCV patient groups. Sustained virological response (SVR) rates were similar between HCV-monoinfected (68%) and HIV/HCV-coinfected (73%) groups. SVR was associated with significant improvements in some measures of cognitive function, independent of HRQOL improvement. CONCLUSIONS Our findings provide evidence to support cognitive effects of HCV independent of mood status and HRQOL profiles.
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Affiliation(s)
- H H Thein
- National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales, Sydney, NSW, Australia
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32
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Villemagne VL, Pike KE, Darby D, Maruff P, Savage G, Ng S, Ackermann U, Cowie TF, Currie J, Chan SG, Jones G, Tochon-Danguy H, O'Keefe G, Masters CL, Rowe CC. Abeta deposits in older non-demented individuals with cognitive decline are indicative of preclinical Alzheimer's disease. Neuropsychologia 2008; 46:1688-97. [PMID: 18343463 DOI: 10.1016/j.neuropsychologia.2008.02.008] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2007] [Revised: 12/28/2007] [Accepted: 02/01/2008] [Indexed: 12/20/2022]
Abstract
Approximately 30% of healthy persons aged over 75 years show Abeta deposition at autopsy. It is postulated that this represents preclinical Alzheimer's disease (AD). We evaluated the relationship between Abeta burden as assessed by PiB PET and cognitive decline in a well-characterized, non-demented, elderly cohort. PiB PET studies and cognitive tests were performed on 34 elderly participants (age 73+/-6) from the longitudinal Melbourne Healthy Aging Study (MHAS). Subjects were classified as being cognitively 'stable' or 'declining' by an independent behavioural neurologist based on clinical assessment and serial word-list recall scores from the preceding 6-10 years. Decline was calculated from the slope of the word-list recall scores. Abeta burden was quantified using Standardized Uptake Value normalized to cerebellar cortex. Ten subjects were clinically classified as declining. At the time of the PET scans, three of the declining subjects had mild cognitive impairment, one had AD, and six were declining but remained within the normal range for age on cognitive tests. Declining subjects were much more likely to show cortical PiB binding than stable subjects (70% vs. 17%, respectively). Neocortical Abeta burden correlated with word-list recall slopes (r=-0.78) and memory function (r=-0.85) in the declining group. No correlations were observed in the stable group. Abeta burden correlated with incident memory impairment and the rate of memory decline in the non-demented ageing population. These observations suggest that neither memory decline nor Abeta deposition are part of normal ageing and likely represent preclinical AD. Further longitudinal observations are required to confirm this hypothesis.
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Affiliation(s)
- V L Villemagne
- Department of Nuclear Medicine, Centre for PET, Austin Health, 145 Studley Road, Heidelberg, VIC 3084, Australia.
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Thein H, Maruff P, Krahn M, Kaldor J, Koorey D, Brew B, Dore G. Cognitive function, mood and health-related quality of life in hepatitis C virus (HCV)-monoinfected and HIV/HCV-coinfected individuals commencing HCV treatment. HIV Med 2007; 8:192-202. [PMID: 17461864 DOI: 10.1111/j.1468-1293.2007.00452.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The aim of the study was to examine cognitive function, mood and health-related quality of life (HRQOL), and their interrelationships, among hepatitis C virus (HCV)-monoinfected and HIV/HCV-coinfected individuals. METHODS Baseline neuropsychological and HRQOL measures of HCV-monoinfected and HIV/HCV-coinfected individuals commencing HCV treatment were examined from a prospective cohort study conducted between April 2003 and August 2005 in Sydney, Australia. Participants' neuropsychological performance and HRQOL were measured using computer-based battery, Trail Making Tests (TMT), Depression Anxiety Stress Scales (DASS), the Hepatitis Quality of Life Questionnaire (HQLQ), and the Visual Analogue Scale (VAS). Neuropsychological measures of HCV-infected patient groups were compared with those of two control groups consisting of HIV-monoinfected and uninfected individuals. RESULTS Similar cognitive function, mood and HRQOL were found in HCV-monoinfected (n=19) and HIV/HCV-coinfected (n=15) individuals. When compared with the HIV-monoinfected (n=30) and uninfected control (n=30) groups, subtle cognitive impairment in attention was found in the HIV/HCV-coinfected group (P<0.05). Twenty-one percent of the HCV-monoinfected group were classified as having cognitive impairment compared with 10% or less in the other groups. Sociodemographic characteristics, mood, HRQOL and HCV indices did not correlate with cognitive function. CONCLUSIONS Our findings indicate no statistically significant difference in neuropsychological and HRQOL impairments between HIV/HCV-coinfected individuals with nonadvanced HIV disease and HCV-monoinfected individuals. This lack of significant difference may relate to the relatively small study population.
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Affiliation(s)
- Hh Thein
- National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales, Sydney, NSW, Australia
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34
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Rowe CC, Ng S, Ackermann U, Gong SJ, Pike K, Savage G, Cowie TF, Dickinson KL, Maruff P, Darby D, Smith C, Woodward M, Merory J, Tochon-Danguy H, O'Keefe G, Klunk WE, Mathis CA, Price JC, Masters CL, Villemagne VL. Imaging beta-amyloid burden in aging and dementia. Neurology 2007; 68:1718-25. [PMID: 17502554 DOI: 10.1212/01.wnl.0000261919.22630.ea] [Citation(s) in RCA: 759] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE To compare brain beta-amyloid (Abeta) burden measured with [(11)C]Pittsburgh Compound B (PIB) PET in normal aging, Alzheimer disease (AD), and other dementias. METHODS Thirty-three subjects with dementia (17 AD, 10 dementia with Lewy bodies [DLB], 6 frontotemporal dementia [FTD]), 9 subjects with mild cognitive impairment (MCI), and 27 age-matched healthy control subjects (HCs) were studied. Abeta burden was quantified using PIB distribution volume ratio. RESULTS Cortical PIB binding was markedly elevated in every AD subject regardless of disease severity, generally lower and more variable in DLB, and absent in FTD, whereas subjects with MCI presented either an "AD-like" (60%) or normal pattern. Binding was greatest in the precuneus/posterior cingulate, frontal cortex, and caudate nuclei, followed by lateral temporal and parietal cortex. Six HCs (22%) showed cortical uptake despite normal neuropsychological scores. PIB binding did not correlate with dementia severity in AD or DLB but was higher in subjects with an APOE-epsilon4 allele. In DLB, binding correlated inversely with the interval from onset of cognitive impairment to diagnosis. CONCLUSIONS Pittsburgh Compound B PET findings match histopathologic reports of beta-amyloid (Abeta) distribution in aging and dementia. Noninvasive longitudinal studies to better understand the role of amyloid deposition in the course of neurodegeneration and to determine if Abeta deposition in nondemented subjects is preclinical AD are now feasible. Our findings also suggest that Abeta may influence the development of dementia with Lewy bodies, and therefore strategies to reduce Abeta may benefit this condition.
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Affiliation(s)
- C C Rowe
- Department of Nuclear Medicine, Centre for PET, Austin Health, Heidelberg, Victoria, Australia.
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Abstract
BACKGROUND The concept that the neurotoxicity of amyloid beta protein could partly result from vascular effects that may be detected in peripheral microcirculation is new. METHODS We compared peripheral endothelial vascular responses of patients with early clinically confirmed Alzheimer's disease (AD) to that of people with normal cognition and those with other forms of dementia. Acetylcholine (ACh) was iontophoresed into the skin and the resultant vasodilator response was measured using laser Doppler flowmetery. RESULTS The ratio of ACh response to saline (ratio E/S) was determined. Mean +/- SEM of ratios E/S were 8.8 +/- 0.9 for controls (n=168), 1.4 +/- 0.1 for AD patients (n=80) and 3.1 +/- 0.5 for other dementia (n=84). Using the optimal cut-off point of E/S ratio of 1.9, an 80% diagnostic sensitivity and specificity for AD have been observed. When the control sample was filtered for those with cardiovascular diseases and with MMSE < 28, this improved the specificity to 90% (n=119). Furthermore, 15 subjects were randomly drawn from a longitudinal healthy ageing study. Five of those subjects met the criteria for mild cognitive impairment (MCI) after eight years of follow up using a battery of cognitive tests. When tested for their E/S ratio in a blind fashion, the skin test successfully identified those subjects. CONCLUSIONS The results support our hypothesis that endothelial alterations can be detected early in the course of the disease. We suggest that this simple skin test could potentially be applied as diagnostic adjunct in patients with mild cognitive symptoms or those with early clinical evidence of AD.
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Affiliation(s)
- Z Khalil
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne Victoria, Australia.
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Griffiths JD, McCutcheont C, Silbert BS, Maruff P. A prospective observational study of the effect of night duty on the cognitive function of anaesthetic registrars. Anaesth Intensive Care 2007; 34:621-8. [PMID: 17061638 DOI: 10.1177/0310057x0603400512] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The issue of fatigue in hospital medical staff represents a potential health and safety risk to both staff and patients, and is receiving worldwide interest. We aimed to characterize the cognitive performance of anaesthetic registrars before and after a series of night shifts. We enrolled nine full-time anaesthetic trainees in an Australian adult tertiary-referral hospital. We conducted a cross-over observational study which tested cognitive performance in participants before and after seven consecutive night shifts and compared this with performance before and after seven consecutive day shifts. Cognitive function was measured using a computerized assessment tool. Participants completed a mean of 62.5% of the requested testing (seven participants completed 87%). There was no significant change in performance before or after any day shift, nor at the commencement of each night shift. There was near perfect accuracy in performance in all tests at all times. There was a statistically significant deterioration in speed of performance for detection and identification tasks at the end of night shift as the week progressed. Anaesthetic registrars demonstrate a significant decline in cognitive performance after a series of night shifts.
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Affiliation(s)
- J D Griffiths
- Centre for Anaesthesia and Cognitive Function, Department of Anaesthesia, St Vincent's Health, Fitzroy, Victoria, Australia
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37
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Abstract
AIM This study aimed to test the internal modelling deficit (IMD) hypothesis using the mental rotation paradigm. BACKGROUND According to the IMD hypothesis, children with Developmental Coordination Disorder (DCD) have an impaired ability to internally represent action. Thirty-six children (18 DCD) completed four tasks: two versions of a single-hand rotation task (with and without explicit imagery instructions), a whole-body imagery task and an alphanumeric rotation task. RESULTS There was partial support for the hypothesis that children with DCD would display an atypical pattern of performance on the hand rotation task, requiring implicit use of motor imagery. Overall, there were no significant differences between the DCD and control groups when the hand task was completed without explicit instructions, on either response time or accuracy. However, when imagery instructions were introduced, the controls were significantly more accurate than the DCD group, indicating that children with DCD were unable to benefit from explicit cuing. As predicted, the controls were also significantly more accurate than the DCD group on the whole-body task, with the accuracy of the DCD group barely rising above chance. Finally, and as expected, there was no difference between the groups on the alphanumeric task, a measure of visual (or object-related) imagery. CONCLUSIONS The inability of the DCD group to utilize specific motor imagery instructions and to perform egocentric transformations lends some support to the IMD hypothesis. Future work needs to address the question of whether the IMD itself is subgroup-specific.
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Affiliation(s)
- J Williams
- Division of Psychology, School of Health Sciences, RMIT University, Melbourne, Vic., Australia
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38
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Vance A, Hall N, Bellgrove MA, Casey M, Karsz F, Maruff P. Visuospatial working memory deficits in adolescent onset schizophrenia. Schizophr Res 2006; 87:223-7. [PMID: 16793240 DOI: 10.1016/j.schres.2006.04.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 04/07/2006] [Accepted: 04/07/2006] [Indexed: 10/24/2022]
Abstract
This study determines that visuospatial working memory (VSWM) deficits are evident in adolescent-onset schizophrenia, while the spatial strategy and spatial span components of VSWM are spared. These findings imply that frontal-striatal-parietal neural networks are dysfunctional in adolescent-onset schizophrenia, while mid-dorsolateral and ventrolateral PFC functions remain intact: the current conceptualisation of schizophrenia as a progressive neurodevelopmental disorder is consistent with these results.
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Affiliation(s)
- A Vance
- Academic Child Psychiatry Unit, Department of Paediatrics, University of Melbourne and Royal Children's Hospital and Murdoch Childrens Research Institute, Parkville, 3052, Victoria, Australia.
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39
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Abstract
BACKGROUND Prolonged exposure to extreme environments may result in cognitive changes that may influence decision making ability and increasing risk of injury or death. OBJECTIVE To measure the cognitive performance of a healthy man as he completed a 17 day desert expedition. METHOD A computer based cognitive test battery, subjective cognitive rating scale, and measures of physical characteristics were used. Objective cognitive performance was compared with the performance of eight age matched men who remained in their own homes. RESULTS The speed of psychomotor, attentional, and executive functions decreased as the expedition progressed, but the accuracy of performance remained unaffected. Although some impairments were large, they resolved completely once the expedition was completed. Subjective ratings indicated that the subject had insight into his failing cognitive performance during the expedition. CONCLUSIONS Cognitive performance can be measured repeatedly throughout an expedition in an extreme environment. Cognitive impairment may occur.
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Affiliation(s)
- P Maruff
- CogState Ltd, Melbourne, Victoria, Australia.
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40
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Abstract
BACKGROUND Concussion is a common neurological injury occurring during contact sport. Current guidelines recommend that no athlete should return to play while symptomatic or displaying cognitive dysfunction. This study compared post-concussion cognitive function in recently concussed athletes who were symptomatic/asymptomatic at the time of assessment with that of non-injured (control) athletes. METHODS Prospective study of 615 male Australian Rules footballers. Before the season, all participants (while healthy) completed a battery of baseline computerised (CogSport) and paper and pencil cognitive tasks. Sixty one injured athletes (symptomatic = 25 and asymptomatic = 36) were reassessed within 11 days of being concussed; 84 controls were also reassessed. The serial cognitive function of the three groups was compared using analysis of variance. RESULTS The performance of the symptomatic group declined at the post-concussion assessment on computerised tests of simple, choice, and complex reaction times compared with the asymptomatic and control groups. The magnitude of changes was large according to conventional statistical criteria. On paper and pencil tests, the symptomatic group displayed no change at reassessment, whereas large improvements were seen in the other two groups. CONCLUSION Injured athletes experiencing symptoms of concussion displayed impaired motor function and attention, although their learning and memory were preserved. These athletes displayed no change in performance on paper and pencil tests in contrast with the improvement observed in asymptomatic and non-injured athletes. Athletes experiencing symptoms of concussion should be withheld from training and competition until both symptoms and cognitive dysfunction have resolved.
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Affiliation(s)
- A Collie
- Centre for Health, Exercise and Sports Medicine, University of Melbourne, Parkville, Victoria, Australia.
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41
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Weaver Cargin J, Maruff P, Collie A, Masters C. Mild memory impairment in healthy older adults is distinct from normal aging. Brain Cogn 2006; 60:146-55. [PMID: 16446021 DOI: 10.1016/j.bandc.2005.10.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 10/24/2005] [Accepted: 10/25/2005] [Indexed: 11/20/2022]
Abstract
Mild memory impairment was detected in 28% of a sample of healthy community-dwelling older adults using the delayed recall trial of a word list learning task. Statistical analysis revealed that individuals with memory impairment also demonstrated relative deficits on other measures of memory, and tests of executive function, processing speed and global cognition, as measured by the CERAD and CogState batteries and CANTAB paired associate learning task. These relative deficits cannot be explained by age-related changes, education, intelligence, mood, health-related factors, or the individuals' ApoEepsilon4 status. Memory-impaired individuals (n = 30) did not recognize the extent of their memory and cognitive difficulties beyond the general complaints expressed by normal elderly (n = 77) within the study and their apparent difficulties did not appear to impact on their participation in life activities. These findings suggest it is unlikely that the memory and cognitive difficulties demonstrated by individuals with mild memory impairment reflect normal aging. Rather it is possible that such impairment may signal early neurodegenerative processes worthy of further investigation.
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Affiliation(s)
- J Weaver Cargin
- School of Psychology, La Trobe University Melbourne, Australia.
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42
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Lewis MS, Maruff P, Silbert BS, Evered LA, Scott DA. The sensitivity and specificity of three common statistical rules for the classification of post-operative cognitive dysfunction following coronary artery bypass graft surgery. Acta Anaesthesiol Scand 2006; 50:50-7. [PMID: 16451151 DOI: 10.1111/j.1399-6576.2006.00893.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The application of statistical rules to determine post-operative cognitive dysfunction (POCD) has varied, and partially explains the wide range of reported incidences of POCD in the literature. The current study assessed the sensitivity and specificity of three commonly used statistical rules in a sample of coronary artery bypass graft (CABG) patients and healthy non-surgical controls. METHODS Two hundred and four CABG patients [mean age, 68.8 years; standard deviation (SD), 7.0 years] completed neuropsychological assessment pre-operatively (baseline) and 1 week and 3 months post-operatively. Ninety age- and gender-matched non-surgical controls (mean age, 67.8 years; SD, 7.9 years) completed the same tasks at the same time points. POCD was determined in each group using three rules: the 1SD decline on two or more tasks; the 20% decline on 20% of tasks rule; and a modified reliable change index. RESULTS The modified reliable change index demonstrated the greatest combination of sensitivity and specificity. The 20% decline on 20% of tasks rule detected the largest incidence of impairment in the CABG group, but showed large incidences of false positive classifications in the control group. The 1SD rule detected the lowest incidence of POCD in the CABG group, but detected a larger incidence of impairment in the control group. CONCLUSIONS The use of the modified reliable change index is recommended, given the sensitivity to change it displayed and the low rates of false positive classification in the control sample. The use of control groups in future research is also recommended.
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Affiliation(s)
- M S Lewis
- Centre for Anaesthesia and Cognitive Function, Department of Anaesthesia, St. Vincent's Hospital, and School of Psychological Science, La Trobe University, Melbourne, Vic., Australia.
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43
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Abstract
BACKGROUND Memory impairment is not considered a core cognitive feature of attention deficit hyperactivity disorder, combined type (ADHD-CT), although it is associated with impairments in attentional and executive functions. This study investigates visuospatial memory impairment, in particular encoding and retrieval aspects, in children with ADHD-CT who are stimulant-medication naive and medicated with stimulant medication. METHOD A cross-sectional study of visuospatial memory in 6- to 12-year-old children with stimulant-medication-naive ADHD-CT (n = 62) and medicated ADHD-CT (n = 58) compared to an age- and gender-matched healthy control group (n = 39) was completed. RESULTS Both medication-naive and medicated ADHD-CT groups demonstrated subtle yet significant impairment in visuospatial memory. The memory impairment was delay-independent, which, along with other factors, suggest dysfunction of the encoding rather than retrieval phase of visuospatial memory. CONCLUSIONS Careful study of large ADHD-CT samples does detect deficits in a visuospatial memory task, but these reflect attentional deficits rather than being specifically due to dysfunction of the medial temporal lobe explicit memory system. Children with ADHD-CT may benefit from cognitive and behavioural strategies focused on improving encoding of relevant information rather than retrieval strategies.
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44
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Maruff P, Wood SJ, Velakoulis D, Smith DJ, Soulsby B, Suckling J, Bullmore ET, Pantelis C. Reduced volume of parietal and frontal association areas in patients with schizophrenia characterized by passivity delusions. Psychol Med 2005; 35:783-789. [PMID: 15997599 DOI: 10.1017/s0033291704003113] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND In patients with schizophrenia, passivity delusions are characterized by a difficulty in determining the agency of purposive actions. Neuropsychological and functional neuroimaging data suggest that passivity delusions are associated with dysfunction of the parietal lobe association cortex. METHOD Cortical volume calculated from magnetic resonance imaging data in a group of 12 patients with schizophrenia characterized by motor passivity delusions was compared statistically with the cortical volume of 11 patients without passivity delusions. RESULTS Reduced cortical volume was observed in parietal and frontal association cortices in the passivity group. CONCLUSIONS These data provide direct evidence for the involvement of the parietal lobe in the pathophysiology of passivity delusions in schizophrenia.
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Affiliation(s)
- P Maruff
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Sunshine Hospital, St Albans, Melbourne, Australia
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45
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Collie A, Maruff P, Makdissi M, McStephen M, Darby DG, McCrory P. Statistical procedures for determining the extent of cognitive change following concussion. Br J Sports Med 2005; 38:273-8. [PMID: 15155425 PMCID: PMC1724830 DOI: 10.1136/bjsm.2003.000293] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Neuropsychological (NP) testing is now often used to help to determine if the cognitive function of a concussed athlete has declined. The NP test score after concussion is compared with the baseline test score. Many clinicians simply subtract one from the other and make a clinical decision about the significance or otherwise of the resulting "difference score". Such techniques are inadequate, as they fail to account for the many factors that may confound interpretation of serially acquired cognitive test scores. This is a review of a number of alternative approaches used in other areas of medicine for differentiating "true" changes from changes caused by these confounding factors. A case example is used to illustrate the effect that the statistical approach may have on clinical decision making.
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Affiliation(s)
- A Collie
- Center for Neuroscience, University of Melbourne, Parkville, Victoria, Australia.
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46
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Maruff P, Collie A, Darby D, Weaver-Cargin J, Masters C, Currie J. Subtle memory decline over 12 months in mild cognitive impairment. Dement Geriatr Cogn Disord 2005; 18:342-8. [PMID: 15316183 DOI: 10.1159/000080229] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/17/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Screening of normal older persons for progressive memory decline is a worthwhile strategy in the pursuit of the earliest possible stages of pre-clinical Alzheimer's disease (AD) or mild cognitive impairment (MCI). Reliable tests are needed to both detect MCI and measure the natural history of decline over months rather than years. We aimed to detect memory decline over 1 year in a group of older individuals with well-characterised amnestic MCI. METHODS The continuous learning task (CLT) from the CogState test battery was administered 8 times in 12 months to 15 individuals with MCI and 35 controls matched for age, education, IQ and gender. All subjects were recruited from an ongoing aging study. The rate of change in CLT performance over the year was compared between groups and also compared to that detected with a word list learning task and a computerised paired associate learning task. RESULTS At baseline, memory performance in the amnestic MCI group was significantly worse than controls on all memory tests. However, at 12 months the magnitude of the difference between the groups had increased significantly on the CLT due to decline in memory accuracy in the MCI group. No decline over 12 months was detectable on the routine memory tests. CONCLUSIONS Subtle memory decline is detectable in amnestic MCI using reliable and sensitive tests of memory. Such measures may assist in the early identification of AD and also in trials of putative disease-modifying therapies to be conducted over as little as 12 months.
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Affiliation(s)
- P Maruff
- Mental Health Research Institute of Victoria, Carlton, Australia.
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Wilson PH, Maruff P, Butson M, Williams J, Lum J, Thomas PR. Internal representation of movement in children with developmental coordination disorder: a mental rotation task. Dev Med Child Neurol 2004; 46:754-9. [PMID: 15540636 DOI: 10.1017/s001216220400129x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Recent studies show that children with developmental coordination disorder (DCD) have difficulties in generating an accurate visuospatial representation of an intended action, which are shown by deficits in motor imagery. This study sought to test this hypothesis further using a mental rotation paradigm. It was predicted that children with DCD would not conform to the typical pattern of responding when required to imagine movement of their limbs. Participants included 16 children with DCD and 18 control children; mean age for the DCD group was 10 years 4 months, and for controls 10 years. The task required children to judge the handedness of single-hand images that were presented at angles between 0 degrees and 180 degrees at 45 degrees intervals in either direction. Results were broadly consistent with the hypothesis above. Responses of the control children conformed to the typical pattern of mental rotation: a moderate trade-off between response time and angle of rotation. The response pattern for the DCD group was less typical, with a small trade-off function. Response accuracy did not differ between groups. It was suggested that children with DCD, unlike controls, do not automatically enlist motor imagery when performing mental rotation, but rely on an alternative object-based strategy that preserves speed and accuracy. This occurs because these children manifest a reduced ability to make imagined transformations from an egocentric or first-person perspective.
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Affiliation(s)
- P H Wilson
- Psychology and Disability Studies, School of Health Sciences, RMIT University, Victoria, Australia.
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48
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Cohn AC, Wilson WM, Yan B, Joshi SB, Heily M, Morley P, Maruff P, Grigg LE, Ajani AE. Analysis of clinical outcomes following in-hospital adult cardiac arrest. Intern Med J 2004; 34:398-402. [PMID: 15271173 DOI: 10.1111/j.1445-5994.2004.00566.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The outcome of in-hospital resuscitation following cardiac arrest depends on many factors related to the patient, the environment and the extent of resuscitation efforts. The aim of the present study was to determine predictors of successful resuscitation and survival to -hospital discharge following in-hospital cardiac arrest and to assess functional outcomes of survivors (cerebral performance scores). METHODS Medical records of adult patients sustaining in-hospital cardiac arrest between June 2001 and January 2003 were reviewed. Successful resuscitation was defined as the return of spontaneous circulation at the completion of resuscitative efforts, irrespective of degree of inotropic/vasopressor support. Thirty demographic and clinical variables were analysed to determine predictors of successful resuscitation and in-hospital survival. RESULTS In 105 patients with cardiac arrest, 46 patients (44%) were successfully resuscitated and 22 (21%) survived to hospital discharge. Predictors of successful resuscitation included a primary cardiac admission diagnosis, monitoring at the time of the arrest, a longer duration of resuscitation and the absence of the need for endotracheal intubation. Patients with ventricular tachycardia/fibrillation were more likely to survive to hospital discharge than those with asystolic or pulseless electrical activity (45 vs 12 vs 20%, P = 0.01). The sole independent predictor of survival to hospital discharge was the absence of the need for endotracheal intubation (odds ratio 0.14, 95% confidence interval 0.02-0.88, P < 0.01). The majority of survivors (73%) had normal cerebral performance scores. CONCLUSIONS Identification of predictors of successful resuscitation following cardiac arrest is important for risk stratification. Ongoing appraisal of in-hospital cardiac arrests through a multicentre registry could improve clinical outcomes.
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Affiliation(s)
- A C Cohn
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
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49
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Silbert BS, Maruff P, Evered LA, Scott DA, Kalpokas M, Martin KJ, Lewis MS, Myles PS. Detection of cognitive decline after coronary surgery: a comparison of computerized and conventional tests. Br J Anaesth 2004; 92:814-20. [PMID: 15064253 DOI: 10.1093/bja/aeh157] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Postoperative cognitive decline is a common complication after coronary artery bypass graft (CABG) surgery. Postoperative cognitive decline is defined on the basis of change in cognitive function detected with repeated assessments using neuropsychological tests. Therefore improvement in neuropsychological testing instruments may increase our understanding of postoperative cognitive decline. METHODS Fifty patients undergoing CABG surgery completed both a conventional and a computerized battery of tests before and 6 days after CABG surgery. Fifty age- and education-matched controls completed the same test batteries 6 days apart. The reliability and the sensitivity to postoperative cognitive decline were computed for each battery. RESULTS Both test batteries detected postoperative cognitive decline 6 days after CABG surgery. For the computerized battery, the reliability of the reaction times (intraclass correlation 0.89-0.92) was greater than for any test from the conventional battery (intraclass correlation 0.56-0.71), although accuracy measures were less reliable (intraclass correlation 0.61-0.89). The computerized battery detected all the cases of POCD identified by the conventional test battery and also five cases that were classified as normal by the conventional tests. CONCLUSION Computerized tests are suitable for measuring cognitive change after CABG surgery and may detect change in a greater proportion of patients 6 days after CABG surgery than conventional neuropsychological tests.
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Affiliation(s)
- B S Silbert
- Department of Anaesthesia, St Vincent's Hospital, Melbourne, Australia.
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50
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Pantelis C, Harvey CA, Plant G, Fossey E, Maruff P, Stuart GW, Brewer WJ, Nelson HE, Robbins TW, Barnes TRE. Relationship of behavioural and symptomatic syndromes in schizophrenia to spatial working memory and attentional set-shifting ability. Psychol Med 2004; 34:693-703. [PMID: 15099423 DOI: 10.1017/s0033291703001569] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Behavioural syndromes (thought disturbance, social withdrawal, depressed behaviour and antisocial behaviour) offer a different perspective from that of symptomatic syndromes on the disability that may be associated with schizophrenia. Few studies have assessed their relationship with neuropsychological deficits. We hypothesized that these syndromes may represent behavioural manifestations of frontal-subcortical impairments, previously described in schizophrenia. METHOD Long-stay inpatients (n=54) and community patients (n=43) with enduring schizophrenia were assessed, using measures of symptoms and behaviour and tests of executive functioning. The relationship between syndromes and neuropsychological function was assessed using multiple regression and logistic regression analyses. RESULTS Significant associations were found between performance on the spatial working memory task and the psychomotor poverty symptomatic syndrome, and between attentional set-shifting ability and both disorganization symptoms and the thought disturbance behavioural syndrome. These results were not explained by the effect of premorbid IQ, geographical location, length of illness or antipsychotic medication. Length of illness was an independent predictor of attentional set-shifting ability but not of working memory performance. CONCLUSION The specific relationship between negative symptoms and spatial working memory is consistent with involvement of the dorsolateral prefrontal cortex. The associations between difficulty with set-shifting ability and both disorganization symptoms and behaviours may reflect inability to generalize a rule that had been learned and impaired ability to respond flexibly. The specific relationship of illness duration to set-shifting ability may suggest progressive impairment on some executive tasks. The nature of these relationships and their neurobiological and rehabilitation implications are considered.
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Affiliation(s)
- C Pantelis
- Melbourne Neuropsychiatry Centre, The University of Melbourne, Parkville and Sunshine Hospital, St. Albans, Victoria, Australia.
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