Journal of Alzheimer's Disease - Volume 42, issue 1

Authors: Alcolea, Daniel | Carmona-Iragui, María | Suárez-Calvet, Marc | Sánchez-Saudinós, M. Belén | Sala, Isabel | Antón-Aguirre, Sofía | Blesa, Rafael | Clarimón, Jordi | Fortea, Juan | Lleó, Alberto

Article Type: Research Article

Abstract: Background: Biomarkers in the cerebrospinal fluid (CSF) can track specific pathophysiological pathways underlying Alzheimer’s disease (AD). The connection between these biomarkers remains unclear. Objective: To study six CSF biomarkers in a clinical cohort of patients with different neurodegenerative conditions. Methods: We measured markers of amyloid-β protein precursor (AβPP) processing (Aβ42 , sAβPPβ, β-secretase activity), neuronal damage (total tau, p-tau), and inflammation (YKL-40) in CSF from 194 participants with the following diagnoses: subjective cognitive impairment or non-amnestic mild cognitive impairment (na-SCI, n = 44), amnestic mild cognitive impairment (aMCI, n = 45), dementia of the Alzheimer type …(DAT, n = 59), frontotemporal dementia (FTD, n = 22), and 24 cognitively normal controls. We compared biomarkers between clinical groups and CSF-profile groups, and we analyzed the correlation between biomarkers. Results: CSF levels of sAβPPβ were decreased in FTD patients compared to the other groups. YKL-40 was elevated in DAT and FTD, and also in aMCI patients. CSF Aβ42 correlated positively with β-secretase activity (RS = 0.262) and sAβPPβ (RS = 0.341). CSF YKL-40 correlated positively with total tau (RS = 0.467) and p-tau (RS = 0.429). CSF p-tau and sAβPPβ contributed significantly to distinguish DAT from FTD. Conclusions: CSF biomarkers of AβPP processing correlate with each other and are decreased in FTD. The inflammatory marker YKL-40 is increased in different neurodegenerative diseases, even in early stages, and it correlates with biomarkers of neurodegeneration. This suggests that inflammation is a common feature in AD and FTD. A combination of CSF biomarkers tracking distinct pathophysiological processes may be useful to classify subjects with neurodegenerative conditions. Show more

Keywords: Alzheimer's disease, amyloid-β protein precursor, β-secretase, biological markers, cerebrospinal fluid, frontotemporal dementia, inflammation, YKL-40

DOI: 10.3233/JAD-140240

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 157-167, 2014

Authors: Cure, Sandrine | Abrams, Keith | Belger, Mark | dell'agnello, Grazzia | Happich, Michael

Article Type: Research Article

Abstract: Background: Early diagnosis of Alzheimer’s disease (AD) is crucial to implement the latest treatment strategies and management of AD symptoms. Diagnostic procedures play a major role in this detection process but evidence on their respective accuracy is still limited. Objective: To conduct a systematic literature on the sensitivity and specificity of different test modalities to identify AD patients and perform meta-analyses on the test accuracy values of studies focusing on autopsy-confirmation as the standard of truth. Methods: The systematic review identified all English papers published between 1984 and 2011 on diagnostic imaging tests and cerebrospinal fluid …biomarkers including results on the newest technologies currently investigated in this area. Meta-analyses using bivariate fixed and random-effect models and hierarchical summary receiver operating curve (HSROC) random-effect model were applied. Results: Out of the 1,189 records, 20 publications were identified to report the accuracy of diagnostic tests in distinguishing autopsy-confirmed AD patients from other dementia types and healthy controls. Looking at all tests and comparator populations together, sensitivity was calculated at 85.4% (95% confidence interval [CI]: 80.9%–90.0%) and specificity at 77.7% (95% CI: 70.2%–85.1%). The area under the HSROC curve was 0.88. Sensitivity and specificity values were higher for imaging procedures, and slightly lower for CSF biomarkers. Test-specific random-effect models could not be calculated due to the small number of studies. Conclusion: The review and meta-analysis point to a slight advantage of imaging procedures in correctly detecting AD patients but also highlight the limited evidence on autopsy-confirmations and heterogeneity in study designs. Show more

Keywords: Alzheimer's disease, amyloid, biomarkers, diagnosis, emission tomography, magnetic resonance imaging, sensitivity and specificity, tomography

DOI: 10.3233/JAD-131559

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 169-182, 2014

Authors: Rusanen, Minna | Kivipelto, Miia | Levälahti, Esko | Laatikainen, Tiina | Tuomilehto, Jaakko | Soininen, Hilkka | Ngandu, Tiia

Article Type: Research Article

Abstract: Background: Many cardiovascular risk factors are shown to increase the risk of dementia and Alzheimer’s disease (AD), but the impact of heart disease on later development of dementia is still unclear. Objective: The aim of the study was to investigate the long-term risk of dementia and Alzheimer’s disease (AD) related to midlife and late-life atrial fibrillation (AF), heart failure (HF), and coronary artery disease (CAD) in a population-based study with a follow-up of over 25 years. Methods: Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study includes 2000 participants who were randomly selected from four separate, population-based …samples originally studied in midlife (1972, 1977, 1982, or 1987). Re-examinations were carried out in 1998 and 2005–2008. Altogether 1,510 (75.5%) persons participated in at least one re-examination, and 127 (8.4%) persons were diagnosed with dementia (of which 102 had AD). Results: AF in late-life was an independent risk factor for dementia (HR 2.61, 95% CI 1.05–6.47; p = 0.039) and AD (HR 2.54, 95% CI 1.04–6.16; p = 0.040) in the fully adjusted analyses. The association was even stronger among the apolipoprotein E (APOE) ε4 non-carriers. Late-life HF, but not CAD, tended to increase the risks as well. Heart diseases diagnosed at midlife did not increase the risk of later dementia and AD. Conclusion: Late-life heart diseases increase the subsequent risk of dementia and AD. Prevention and effective treatment of heart diseases may be important also from the perspective of brain health and cognitive functioning. Show more

Keywords: Alzheimer disease, atrial fibrillation, cohort studies, coronary artery disease, dementia, heart failure, risk factors

DOI: 10.3233/JAD-132363

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 183-191, 2014

Authors: Yang, Yuan-Han | Wang, Huali | Lam, Linda | Chan, Wai-Chi | Yu, Xin | Li, Tao | Wang, Wen-Fu | Chiu, Pai-Yi | Lin, Yu-Te | Hu, Chaur-Jong | Fuh, Jong-Ling | Morris, John C.

Article Type: Research Article

Abstract: In order to obtain data from patients with Alzheimer's disease dementia and their informants in a uniform manner and to foster further research among the Chinese and other races, we have conducted an international study to recruit patients diagnosed with Alzheimer's disease (AD) from Taiwan, Hong Kong, and Beijing. The Uniform Data Set was translated into Chinese and administrated to AD patients and their informants. A total of 1,107 AD dementia patients were recruited, including 691 from Taiwan, 244 from Beijing, and 172 from Hong Kong. There were differences in the AD patients: gender (p = 0.099), education (p < …0.001), age (p < 0.001), and handedness (p = 0.007). For informants, age (p = 0.679), gender (p = 0.117), education (p < 0.001), and living together or not (p < 0.001) differed in the three samples. Although three areas across the Taiwan Strait are ethnic Chinese, the clinical picture for patients and informants are very different. Further study is needed to clarify the significance of clinical characteristics in Chinese societies. Show more

Keywords: Alzheimer's disease, Beijing, Hong Kong, informant, Taiwan, uniform data set

DOI: 10.3233/JAD-140174

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 193-200, 2014

Authors: Kumfor, Fiona | Hodges, John R. | Piguet, Olivier

Article Type: Research Article

Abstract: Background: Events which are imbued with emotion are typically remembered vividly and with more confidence than similar non-emotional events. The extent that emotional enhancement of memory is compromised in neurodegenerative disorders is unclear, despite differential effects of dementia on emotion processing ability. Objective: To examine emotional enhancement of memory using an ecologically valid task in progressive nonfluent aphasia (PNFA), an expressive language subtype of frontotemporal dementia, in comparison to Alzheimer’s disease (AD) and matched-controls. Methods: Twenty-five dementia patients (13 PNFA, 12 AD) and 10 controls viewed either an emotionally arousing or a closely matched non-emotional story. …Multiple-choice recognition memory was tested after a 1-hour delay. The alternate story was presented two weeks later. Results: PNFA showed a similar level of memory for the emotional and neutral story, whereas both controls and AD remembered significantly more details from the emotional than the neutral story. Correlation analyses indicated that in PNFA, emotional story memory correlated with reduced emotion recognition, whereas in AD, neutral story memory correlated with visual recall memory performance only. Furthermore, in PNFA, reduced emotional memory enhancement was associated with increased carer stress and depression. Conclusion: Emotional memory enhancement is absent in PNFA, whereas emotion facilitates memory for real-life events in AD. Disrupted emotional memory enhancement in PNFA is associated with reduced emotion recognition ability, suggesting that widespread emotion processing dysfunction is present in this disease. Crucially, loss of emotional enhancement influences carer wellbeing, which represents an important avenue for future studies to examine. Show more

Keywords: Carer, depression, emotion, episodic memory, frontotemporal dementia, hippocampus, insula, stress

DOI: 10.3233/JAD-140351

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 201-210, 2014

Authors: Amadoro, Giuseppina | Corsetti, Veronica | Sancesario, Giulia Maria | Lubrano, Adele | Melchiorri, Gaia | Bernardini, Sergio | Calissano, Pietro | Sancesario, Giuseppe

Article Type: Research Article

Abstract: Truncation at N-terminal domain of tau protein is early associated with neurofibrillary pathology in several human tauopathies, including Alzheimer's disease (AD). In affected subjects, the monitoring of total (t-tau) and/or phosphorylated tau (p-tau) levels in cerebrospinal fluid (CSF) provides a reliable, indirect evaluation of cellular changes occurring in vivo and the identification of additional CSF biomarkers would better assist with the clinical practice, allowing a broader profile of underlying ongoing neurodegeneration. Here we show that a 20–22 kDa NH2 -truncated form of human tau (i.e., NH2 htau), a neurotoxic fragment of the full length protein (htau40) that we previously found …in synapses from subjects affected by different tauopathies: (i) is not a normal constituent of CSF, unlike t-tau and p-tau, being exceptionally detected in patients without cognitive impairment; (ii) discriminates, with a weak specificity of 65% but a high sensitivity of 85%, patients carrying a large spectrum of neurodegenerative diseases associated with cognitive deterioration (i.e., AD, frontotemporal lobar degeneration, Parkinson's disease with dementia, vascular dementia, mixed dementia, etc.) from subjects affected by other neurological disorders without mnesic disability; and (iii) is a neuronal injury biomarker as its levels in CSF are not related to the severity and progression of cognitive decline. The dynamic evaluation of NH2 htau in CSF might add some useful hints in the ordinary clinical practice as it provides a novel, general biomarker for human tauopathies and other neurodegenerative diseases associated with dementia. Show more

Keywords: Alzheimer's disease, biomarker, cerebrospinal fluid, tau truncation, tauopathies

DOI: 10.3233/JAD-140267

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 211-226, 2014

Authors: Maroof, Nazia | Ravipati, Srinivasarao | Pardon, Marie Christine | Barrett, David A. | Kendall, David A.

Article Type: Research Article

Abstract: Alterations in the endocannabinoid system (ECS) are thought to play a role in learning and memory impairments observed in Alzheimer's disease (AD). We aimed to determine the status of the brain ECS in the AβPPswe/PS1ΔE9 model of AD. The ECS comprises the neuromodulatory lipid endocannabinoids, anandamide and 2-arachidonoyl glycerol (2AG), which interact with the G protein-coupled type-1 and type-2 cannabinoid receptors. Using mass spectrometry, we quantified endocannabinoid levels and assessed lipidomic profiles of the frontal cortex, hippocampus, and striatum of 4-8 month old wildtype and AβPPswe/PS1ΔE9 mice to determine whether regional variations in endocannabinoids and lipid metabolism are observed with …age and disease progression. Additionally, open-field activity, performance in the contextual fear conditioning task, and various other tasks assessing spatial and recognition memory were examined to determine the influence of age and pathology on these parameters. At all ages, AβPPswe/PS1ΔE9 mice were significantly hyperactive in the open-field and acquired contextual fear as well as wildtype mice, reflecting intact associative learning. They, however, exhibited enhanced contextual fear memory and reduced contextual fear extinction regardless of age. Disturbances in striatal lipid metabolism were observed in 6 and 8 month old AβPPswe/PS1ΔE9 mice. Endocannabinoids increased significantly with age in the hippocampus and frontal cortex of both genotypes. 8 month old AβPPswe/PS1ΔE9 mice displayed significantly lower levels of striatal 2AG than wildtype mice, but greater cannabinoid receptor/effector coupling. This study shows that alterations in lipid metabolism and endocannabinoid signaling develop with age in AβPPswe/PS1ΔE9 mice, possibly contributing to the development of AD-like behavioral deficits. Show more

Keywords: AβPPswe/PS1ΔE9, Alzheimer's disease, contextual fear conditioning, endocannabinoids, learning and memory, lipidomics

DOI: 10.3233/JAD-131961

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 227-245, 2014

Authors: Suszyńska-Zajczyk, Joanna | Łuczak, Magdalena | Marczak, Łukasz | Jakubowski, Hieronim

Article Type: Research Article

Abstract: Homocysteine (Hcy) is a risk factor for Alzheimer's disease (AD). Paraoxonase 1 (Pon1) participates in Hcy metabolism and is also linked to AD. The inactivation of the Pon1 gene in mice causes the accumulation of Hcy-thiolactone in the brain and increases the susceptibility to Hcy-thiolactone-induced seizures. To gain insight into the brain-related Pon1 function, we used two-dimensional IEF/SDS-PAGE gel electrophoresis and MALDI-TOF/TOF mass spectrometry to study brain proteomes of Pon1−/− and Pon1+/+ mice fed with a hyperhomocysteinemic high-methionine (Met) or a control diet. We found that: 1) proteins involved in brain-specific function (Nrgn), antioxidant defenses (Sod1, DJ-1), and …cytoskeleton assembly (Tbcb, CapZa2) were differentially expressed in brains of Pon1-null mice; 2) proteins involved in brain-specific function (Ncald, Nrgn, Stmn1), antioxidant defenses (Prdx2, DJ-1), energy metabolism (Ak1), cell cycle (GDI1, Ran), cytoskeleton assembly (Tbcb), and unknown function (Hdhd2) showed differential expression in brains of Pon1-null fed with a hyperhomocysteinemic high-Met diet; 3) most proteins regulated by the Pon1−/− genotype were also regulated by the high-Met diet; 4) the proteins differentially expressed in Pon1-null mouse brains play important roles in neural development, learning, plasticity, and aging and are linked to neurodegenerative diseases, including AD. Taken together, our findings suggest that Pon1 interacts with diverse cellular processes from energy metabolism and anti-oxidative defenses to cell cycle, cytoskeleton dynamics, and synaptic plasticity essential for normal brain homeostasis and that these interactions are modulated by hyperhomocysteinemia and account for the involvement of Hcy and Pon1 in AD. Show more

Keywords: Alzheimer's disease, brain proteome, dietary hyperhomocysteinemia, homocysteine, neurodegenerative diseases, paraoxonase 1, Pon1-null mouse

DOI: 10.3233/JAD-132714

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 247-260, 2014

Authors: Moreira, Helena S. | Lima, César F. | Vicente, Selene G.

Article Type: Research Article

Abstract: Background: The Institute of Cognitive Neurology (INECO) Frontal Screening (IFS) is a brief neuropsychological tool recently devised for the evaluation of executive dysfunction in neurodegenerative conditions. Objective: In this study we present a cross-cultural validation of the IFS for the Portuguese population, provide normative values from a healthy sample, determine how age and education affect performance, and inspect its clinical utility in the context of Alzheimer’s disease (AD). A comparison with the Frontal Assessment Battery (FAB) was undertaken, and correlations with other well-established executive functions measures were examined. Methods: The normative sample included 204 participants varying …widely in age (20–85 years) and education (3–21 years). The clinical sample (n = 21) was compared with a sample of age- and education-matched controls (n = 21). Healthy participants completed the IFS and the Mini-Mental State Examination (MMSE). In addition to these, the patients (and matched controls) completed the FAB and a battery of other executive tests. Results: IFS scores were positively affected by education and MMSE, and negatively affected by age. Patients underperformed controls on the IFS, and correlations were found with the Clock Drawing Test, Stroop test, and the Zoo Map and Rule Shift Card tests of the Behavioral Assessment of the Dysexecutive Syndrome. A cut-off of 17 optimally differentiated patients from controls. While 88% of the IFS sub-tests discriminated patients from controls, only 67% of the FAB sub-tests did so. Conclusion: Age and education should be taken into account when interpreting performance on the IFS. The IFS is useful to detect executive dysfunction in AD, showing good discriminant and concurrent validities. Show more

Keywords: Alzheimer's disease, cognition, executive dysfunction, INECO Frontal Screening (IFS), Portuguese norms, screening tests

DOI: 10.3233/JAD-132348

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 261-273, 2014

Authors: Bondi, Mark W. | Edmonds, Emily C. | Jak, Amy J. | Clark, Lindsay R. | Delano-Wood, Lisa | McDonald, Carrie R. | Nation, Daniel A. | Libon, David J. | Au, Rhoda | Galasko, Douglas | Salmon, David P. | for the Alzheimer's Disease Neuroimaging Initiative

Article Type: Research Article

Abstract: We compared two methods of diagnosing mild cognitive impairment (MCI): conventional Petersen/Winblad criteria as operationalized by the Alzheimer's Disease Neuroimaging Initiative (ADNI) and an actuarial neuropsychological method put forward by Jak and Bondi designed to balance sensitivity and reliability. 1,150 ADNI participants were diagnosed at baseline as cognitively normal (CN) or MCI via ADNI criteria (MCI: n = 846; CN: n = 304) or Jak/Bondi criteria (MCI: n = 401; CN: n = 749), and the two MCI samples were submitted to cluster and discriminant function analyses. Resulting cluster groups were then compared and further examined for APOE allelic frequencies, …cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarker levels, and clinical outcomes. Results revealed that both criteria produced a mildly impaired Amnestic subtype and a more severely impaired Dysexecutive/Mixed subtype. The neuropsychological Jak/Bondi criteria uniquely yielded a third Impaired Language subtype, whereas conventional Petersen/Winblad ADNI criteria produced a third subtype comprising nearly one-third of the sample that performed within normal limits across the cognitive measures, suggesting this method's susceptibility to false positive diagnoses. MCI participants diagnosed via neuropsychological criteria yielded dissociable cognitive phenotypes, significant CSF AD biomarker associations, more stable diagnoses, and identified greater percentages of participants who progressed to dementia than conventional MCI diagnostic criteria. Importantly, the actuarial neuropsychological method did not produce a subtype that performed within normal limits on the cognitive testing, unlike the conventional diagnostic method. Findings support the need for refinement of MCI diagnoses to incorporate more comprehensive neuropsychological methods, with resulting gains in empirical characterization of specific cognitive phenotypes, biomarker associations, stability of diagnoses, and prediction of progression. Refinement of MCI diagnostic methods may also yield gains in biomarker and clinical trial study findings because of improvements in sample compositions of ‘true positive’ cases and removal of ‘false positive’ cases. Show more

Keywords: Alzheimer's disease, Alzheimer's Disease Neuroimaging Initiative, biomarker, cluster analysis, dementia, mild cognitive impairment, neuropsychology, progression

DOI: 10.3233/JAD-140276

Citation: Journal of Alzheimer's Disease, vol. 42, no. 1, pp. 275-289, 2014