Journal of Alzheimer's Disease - Volume Pre-press, issue Pre-press

Authors: Reed, Marilyn | Freedman, Morris | Mark Fraser, Amy E. | Bromwich, Matthew | Santiago, Anna Theresa | Gallucci, Christina Elizabeth | Frank, Andrew

Article Type: Research Article

Abstract: Background: Hearing loss is the largest potentially modifiable risk factor for dementia and is highly prevalent among older adults, yet it goes largely unreported, unidentified, and untreated, at great cost to health and quality of life. Hearing screening is a proven cost-effective solution to overcome delays in its identification and management yet is not typically recommended by physicians for older adults. Objective: To demonstrate the feasibility and value of hearing screening for older adults at risk for dementia in order to enhance physicians’ awareness of hearing loss and improve access to timely hearing care. Methods: Patients …referred to two academic medical clinics for memory disorders were offered hearing screening as part of clinic protocol. Patients with hearing loss were recruited to the study if they consented to a post-appointment telephone interview and chart review. Memory Clinic physicians were surveyed about the usefulness of the screening information and referral of patients with hearing loss to audiology. Results: Hearing loss was reliably detected in Memory Clinic patients with both in-office and online screening tools. Physicians reported that screening enhanced their awareness of hearing loss and increased the referral rate to audiology. Conclusion: Hearing screening in Memory Clinic patients is a useful component of clinic protocol that facilitates timely access to management and addresses an important risk factor for dementia. Show more

Keywords: Dementia, hearing loss, memory clinic, older adults, screening

DOI: 10.3233/JAD-215377

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-12, 2022

Authors: McNerney, M. Windy | Heath, Alesha | Narayanan, Sindhu | Yesavage, Jerome

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is a debilitating disorder involving the loss of plasticity and cholinergic neurons in the cortex. Pharmaceutical treatments are limited in their efficacy, but brain stimulation is emerging as a treatment for diseases of cognition. More research is needed to determine the biochemical mechanisms and treatment efficacy of this technique. Objective: We aimed to determine if forebrain repetitive transcranial magnetic stimulation can improve cortical BDNF gene expression and cholinergic signaling in the 3xTgAD mouse model of AD. Methods: Both B6 wild type mice and 3xTgAD mice aged 12 months were given daily treatment …sessions for 14 days or twice weekly for 6 weeks. Following treatment, brain tissue was extracted for immunological stains for plaque load, as well as biochemical analysis for BDNF gene expression and cholinergic signaling via acetylcholinesterase and choline acetyltransferase ELISA assays. Results: For the 3xTgAD mice, both 14 days and 6 weeks treatment regimens resulted in an increase in BDNF gene expression relative to sham treatment, with a larger increase in the 6-week group. Acetylcholinesterase activity also increased for both treatments in 3xTgAD mice. The B6 mice only had an increase in BDNF gene expression for the 6-week group. Conclusion: Brain stimulation is a possible non-invasive and nonpharmaceutical treatment option for AD as it improves both plasticity markers and cholinergic signaling in an AD mouse model. Show more

Keywords: Acetylcholinesterase, brain-derived neurotrophic factor, cortex, mouse, transcranial magnetic stimulation

DOI: 10.3233/JAD-215361

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-9, 2022

Authors: Levy, Boaz | Priest, Amanda | Delaney, Tyler | Hogan, Jacqueline | Herrawi, Farahdeba

Article Type: Research Article

Abstract: Background: Preventing dementia warrants the pragmatic engagement of primary care. Objective: This study predicted conversion to dementia 12 months before diagnosis with indicators that primary care can utilize within the practical constraints of routine practice. Methods: The study analyzed data from the Alzheimer’s Disease Neuroimaging Initiative (Total sample = 645, converting participants = 54). It predicted the conversion from biological (plasma neurofilament light chain), cognitive (Trails Making Test– B), and functional (Functional Activities Questionnaire) measures, in addition to demographic variables (age and education). Results: A Gradient Booster Trees classifier effectively predicted the conversion, based on a Synthetic Minority …Oversampling Technique (n  = 1,290, F1 Score = 92, AUC = 94, Recall = 87, Precision = 97, Accuracy = 92). Subsequent analysis indicated that the MCI False Positive group (i.e., non-converting participants with cognitive impairment flagged by the model for prospective conversion) scored significantly lower on multiple cognitive tests (Montreal Cognitive Assessment, p  < 0.002; ADAS-13, p  < 0.0004; Rey Auditory Verbal Learning Test, p  < 0.002/0.003) than the MCI True Negative group (i.e., correctly classified non-converting participants with cognitive impairment). These groups also differed in CSF tau levels (p  < 0.04), while consistent effect size differences emerged in the all-pairwise comparisons of hippocampal volume and CSF Aβ1 - 42 . Conclusion: The model effectively predicted 12-month conversion to dementia and further identified non-converting participants with MCI, in the False Positive group, at relatively higher neurocognitive risk. Future studies may seek to extend these results to earlier prodromal phases. Detection of dementia before diagnosis may be feasible and practical in primary care settings, pending replication of these findings in diverse clinical samples. Show more

Keywords: Alzheimer’s disease, dementia, pre-diagnostic detection, prevention, primary care, screening

DOI: 10.3233/JAD-215242

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-12, 2022

Authors: Josephs, Kennedy A. | Pham, Nha Trang Thu | Graff-Radford, Jonathan | Machulda, Mary M. | Lowe, Val J. | Whitwell, Jennifer L.

Article Type: Research Article

Abstract: Background: It has been hypothesized that medial temporal sparing may be related to preserved posterior cingulate metabolism and the cingulate island sign (CIS) on [18 F]fluorodeoxyglucose (FDG) PET in posterior cortical atrophy (PCA). Objective: To assess the severity of medial temporal atrophy in PCA and determine whether the presence of a CIS is related to medial temporal sparing. Methods: Fifty-five PCA patients underwent MRI and FDG-PET. The degree and symmetry of medial temporal atrophy on MRI was visually assessed using a five-point scale for both hemispheres. Visual assessments of FDG-PET coded the presence/absence of a CIS …and whether the CIS was symmetric or asymmetric. Hippocampal volumes and a quantitative CIS were also measured. Results: Medial temporal atrophy was most commonly mild or moderate, was symmetric in 55% of patients, and when asymmetric was most commonly worse on the right (76%). Older age and worse memory performance were associated with greater medial temporal atrophy. The CIS was observed in 44% of the PCA patients and was asymmetric in 50% of these. The patients with a CIS showed greater medial temporal asymmetry, but did not show lower medial temporal atrophy scores, compared to those without a CIS. Hippocampal volumes were not associated with quantitative CIS. Conclusion: Mild medial temporal atrophy is a common finding in PCA and is associated with memory impairment. However, medial temporal sparing was not related to the presence of a CIS in PCA. Show more

Keywords: Cingulate island sign, FDG-PET, hippocampus, MRI, visual assessment

DOI: 10.3233/JAD-215263

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-8, 2022

Authors: Kuksa, Pavel P. | Liu, Chia-Lun | Fu, Wei | Qu, Liming | Zhao, Yi | Katanic, Zivadin | Clark, Kaylyn | Kuzma, Amanda B. | Ho, Pei-Chuan | Tzeng, Kai-Teh | Valladares, Otto | Chou, Shin-Yi | Naj, Adam C. | Schellenberg, Gerard D. | Wang, Li-San | Leung, Yuk Yee

Article Type: Research Article

Abstract: Background: Recent Alzheimer’s disease (AD) genetics findings from genome-wide association studies (GWAS) span progressively larger and more diverse populations and outcomes. Currently, there is no up-to-date resource providing harmonized and searchable information on all AD genetic associations found by GWAS, nor linking the reported genetic variants and genes with functional and genomic annotations. Objective: Create an integrated/harmonized, and literature-derived collection of population-specific AD genetic associations. Methods: We developed the Alzheimer’s Disease Variant Portal (ADVP), an extensive collection of associations curated from >200 GWAS publications from Alzheimer’s Disease Genetics Consortium and other consortia. Genetic associations were systematically …extracted, harmonized, and annotated from both the genome-wide significant and suggestive loci reported in these publications. To ensure consistent representation of AD genetic findings, all the extracted genetic association information was harmonized across specifically designed publication, variant, and association categories. Results: ADVP V1.0 (February 2021) catalogs 6,990 associations related to disease-risk, expression quantitative traits, endophenotypes, or neuropathology. This extensive harmonization effort led to a catalog containing >900 loci, >1,800 variants, >80 cohorts, and 8 populations. Besides, ADVP provides investigators with a seamless integration of genomic and publicly available functional annotations across multiple databases per harmonized variant and gene records, thus facilitating further understanding and analyses of these genetics findings. Conclusion: ADVP is a valuable resource for investigators to quickly and systematically explore high-confidence AD genetic findings and provides insights into population-specific AD genetic architecture. ADVP is continually maintained and enhanced by NIAGADS and is freely accessible at https://advp.niagads.org . Show more

Keywords: AD GWAS literature curation, Alzheimer’s disease, data curation, database, genome-wide association studies, harmonization

DOI: 10.3233/JAD-215055

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-17, 2022

Authors: Mukaetova-Ladinska, Elizabeta B. | Abdullah, Shahbaz | Critchfield, Mathew | Maltby, John

Article Type: Research Article

Abstract: Background: Memory complaints are frequent among young adults presenting in general practice. Many of them will have reversable, functional cognitive impairment that can easily be mistaken for dementia. Its accurate and timely identification is warranted to prevent further escalation to overt dementia syndrome. Objective: To evaluate the recommended primary care screening cognitive tools for dementia for use in younger people. Methods: 2.5 years clinical data were collected during the course of ongoing patient care for all assessed face-to-face patients in a secondary care memory service for younger adults. Cognitive screening and assessment tests used in primary …[General Practice Assessment of Cognition (GPCOG)] and secondary [Addenbrooke’s Cognitive Examination-III (ACE-III), Rowland Universal Dementia Assessment Scale (RUDAS), Salzburg Dementia Test Prediction (SDTP)] care were analyzed for their accuracy to identify dementia and memory complaints. Area under the curve in receiver operating characteristic curves was used to measure predictive value of tests for a clinical diagnosis of dementia. Results: 348 young adults were assessed for cognitive impairment. Following comprehensive Memory Clinic assessments, 241 (69.25%) were diagnosed with memory complaints in the absence of relevant neuropathology and 107 with dementia. GPCOG, especially the informant part, and RUDAS had low accuracy to identify dementia (AUC = 0.465 and AUC = 0.698, respectively). In contrast, ACE-III and SDTP demonstrated the highest accuracy (AUC = 0.799 and AUC = 0.809/0.817, respectively). Conclusion: Dementia screening in younger people will benefit from SDTP incorporated as part of the screening cognitive toolset. The national guidance on dementia screening tools, diagnostic pathways, and management should also refer to younger adults. Show more

Keywords: Cognitive impairment, cognitive screening, dementia, primary health care, suspected dementia, young adults

DOI: 10.3233/JAD-215514

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-9, 2021

Authors: Sohn, Bo Kyung | Byun, Min Soo | Yi, Dahyun | Jeon, So Yeon | Lee, Jun Ho | Choe, Young Min | Lee, Dong Woo | Lee, Jun-Young | Kim, Yu Kyeong | Sohn, Chul-Ho | Lee, Dong Young | for the KBASE Research Group

Article Type: Research Article

Abstract: Background: Physical activities (PA) have been suggested to reduce the risk of Alzheimer‘s disease (AD) dementia. However, information on the neuropathological links underlying the relationship is limited. Objective: We investigated the role of midlife and late-life PA with in vivo AD neuropathologies in old adults without dementia. Methods: This study included participants from the Korean Brain Aging Study for Early diagnosis and prediction of Alzheimer’s disease (KBASE). The participants underwent comprehensive clinical and neuropsychological assessment, [11 C] Pittsburgh Compound B positron emission tomography (PET), [18 F] fluorodeoxyglucose PET, and magnetic resonance imaging. Using the multi-modal …brain imaging data, in vivo AD pathologies including global amyloid deposition, AD-signature region cerebral glucose metabolism (AD-CM), and AD-signature region cortical thickness (AD-CT) were quantified. Both midlife and late-life PA of participants were measured using the Lifetime Total Physical Activity Questionnaire. Results: This study was performed on 260 participants without dementia (195 with normal cognitive function and 65 with mild cognitive impairment). PA of neither midlife nor late-life showed direct correspondence with any neuroimaging biomarker. However, late-life PA moderated the relationship of brain amyloid-β (Aβ) deposition with AD-CM and AD-CT. Aβ positivity had a significant negative effect on both AD-CM and AD-CT in individuals with lower late-life PA, but those with higher late-life PA did not show such results. Midlife PA did not have such a moderation effect. Conclusion: The findings suggest that physically active lifestyle in late-life, rather than that in midlife, may delay AD-associated cognitive decline by decreasing Aβ-induced neurodegenerative changes in old adults. Show more

Keywords: Amyloid, cortical thickness, neurodegeneration, physical activity

DOI: 10.3233/JAD-215258

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-10, 2021

Authors: Premi, Enrico | Costa, Tommaso | Gazzina, Stefano | Benussi, Alberto | Cauda, Franco | Gasparotti, Roberto | Archetti, Silvana | Alberici, Antonella | van Swieten, John C. | Sanchez-Valle, Raquel | Moreno, Fermin | Santana, Isabel | Laforce, Robert | Ducharme, Simon | Graff, Caroline | Galimberti, Daniela | Masellis, Mario | Tartaglia, Carmela | Rowe, James B. | Finger, Elizabeth | Tagliavini, Fabrizio | de Mendonça, Alexandre | Vandenberghe, Rik | Gerhard, Alexander | Butler, Chris R. | Danek, Adrian | Synofzik, Matthis | Levin, Johannes | Otto, Markus | Ghidoni, Roberta | Frisoni, Giovanni | Sorbi, Sandro | Peakman, Georgia | Todd, Emily | Bocchetta, Martina | Rohrer, Johnathan D. | Borroni, Barbara | GENFI Consortium Members

Collaborators: Afonso, Sónia | Rosario Almeida, Maria | Anderl-Straub, Sarah | Andersson, Christin | Antonell, Anna | Arighi, Andrea | Balasa, Mircea | Barandiaran, Myriam | Bargalló, Nuria | Bartha, Robart | Bender, Benjamin | Benussi, Luisa | Bessi, Valentina | Binetti, Giuliano | Black, Sandra | Borrego-Ecija, Sergi | Bras, Jose | Bruffaerts, Rose | Caroppo, Paola | Cash, David | Castelo-Branco, Miguel | Convery, Rhian | Cope, Thomas | de Arriba, María | Di Fede, Giuseppe | Díaz, Zigor | Duro, Diana | Fenoglio, Chiara | Ferrari, Camilla | B. Ferreira, Catarina | Fox, Nick | Freedman, Morris | Fumagalli, Giorgio | Gabilondo, Alazne | Gauthier, Serge | Giaccone, Giorgio | Gorostidi, Ana | Greaves, Caroline | Guerreiro, Rita | Heller, Carolin | Hoegen, Tobias | Indakoetxea, Begoña | Jelic, Vesna | Jiskoot, Lize | Karnath, Hans-Otto | Keren, Ron | Langheinrich, Tobias | João Leitão, Maria | Lladó, Albert | Lombardi, Gemma | Loosli, Sandra | Maruta, Carolina | Mead, Simon | Meeter, Lieke | Miltenberger, Gabriel | van Minkelen, Rick | Mitchell, Sara | Moore, Katrina | Nacmias, Benedetta | Nicholas, Jennifer | Öijerstedt, Linn | Olives, Jaume | Panman, Jessica | Papma, Janne | Pievani, Michela | Pijnenburg, Yolande | Polito, Cristina | Prioni, Sara | Prix, Catharina | Rademakers [as London Ontario geneticist], Rosa | Redaelli, Veronica | Rittman, Tim | Rogaeva, Ekaterina | Rosa-Neto, Pedro | Rossi, Giacomina | Rossor, Martin | Santiago, Beatriz | Scarpini, Elio | Schönecker, Sonja | Semler, Elisa | Shafei, Rachelle | Shoesmith, Christen | Tábuas-Pereira, Miguel | Tainta, Mikel | Taipa, Ricardo | Tang-Wai, David | L Thomas, David | Thompson, Paul | Thonberg, Hakan | Timberlake, Carolyn | Tiraboschi, Pietro | Van Damme, Philip | Vandenbulcke, Mathieu | Veldsman, Michele | Verdelho, Ana | Villanua, Jorge | Warren, Jason | Wilke, Carlo | Woollacott, Ione | Wlasich, Elisabeth | Zetterberg, Henrik | Zulaica, Miren

Article Type: Research Article

Abstract: Background: Magnetic resonance imaging (MRI) measures may be used as outcome markers in frontotemporal dementia (FTD). Objectives: To predict MRI cortical thickness (CT) at follow-up at the single subject level, using brain MRI acquired at baseline in preclinical FTD. Methods: 84 presymptomatic subjects carrying Granulin mutations underwent MRI scans at baseline and at follow-up (31.2±16.5 months). Multivariate nonlinear mixed-effects model was used for estimating individualized CT at follow-up based on baseline MRI data. The automated user-friendly preGRN-MRI script was coded. Results: Prediction accuracy was high for each considered brain region (i.e., prefrontal region, …real CT at follow-up versus predicted CT at follow-up, mean error ≤1.87%). The sample size required to detect a reduction in decline in a 1-year clinical trial was equal to 52 subjects (power = 0.80, alpha = 0.05). Conclusion: The preGRN-MRI tool, using baseline MRI measures, was able to predict the expected MRI atrophy at follow-up in presymptomatic subjects carrying GRN mutations with good performances. This tool could be useful in clinical trials, where deviation of CT from the predicted model may be considered an effect of the intervention itself. Show more

Keywords: Frontotemporal dementia, granulin, magnetic resonance imaging, mutation, preclinical, presymptomatic

DOI: 10.3233/JAD-215447

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-14, 2021

Authors: Siddiqui, Fatima | Nistala, Kameswara Rishi Yeshayahu | Quek, Chrystie Wan Ning | Shi Ying Leong, Victoria | Ying Shan Tan, Amarinda | En Tan, Christopher Yu | Hilal, Saima

Article Type: Research Article

Abstract: Background: Dementia is the decline in cognitive function sufficient to impair one’s accustomed functioning. Countries with aging populations, such as Singapore, face rising rates of dementia. Dementia patients and their caregivers endure great financial and emotional stress. With the broad aim of minimizing these stresses, this study provides a cross-sectional view of the knowledge, attitudes, and perceptions (KAP) towards dementia in middle-aged Singaporean residents. Objective: We aim to examine 1) the associations between demographic correlates and KAP; and 2) the effect of dementia knowledge on attitudes and perceptions towards dementia. Methods: An online anonymous cross-sectional questionnaire …was administered to Singaporeans and Permanent Residents aged 45 to 65 years old in English, Mandarin, and Malay. Knowledge was evaluated across three domains: symptoms, risk factors, and management. Total and domain scores were dichotomized as good or poor knowledge using median cut-offs. Attitudes/perceptions across six domains were evaluated on Likert scales, and responses to each question were dichotomized into positive or negative attitudes/perceptions. Results: From 1,733 responses, 1,209 valid complete responses were accepted (mean age±SD 54.8±5.12 years old, females = 69.6%). Lower socioeconomic status was associated with poorer knowledge and greater barriers to risk-mitigating lifestyle modifications. Lack of personal experience with dementia and poor knowledge were also associated with erroneous attitudes/perceptions. Conclusion: Socioeconomic status and personal experience affect KAP towards dementia. Policy and education campaigns to address KAP towards dementia should account for baseline differences across demographics, for greater improvements in dementia incidence and support. Show more

Keywords: Attitudes, dementia, knowledge, middle age, practices

DOI: 10.3233/JAD-215262

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-14, 2021

Authors: Che, Bizhong | Chen, Haichang | Wang, Aili | Peng, Hao | Bu, Xiaoqing | Zhang, Jintao | Ju, Zhong | Xu, Tan | He, Jiang | Zhong, Chongke | Zhang, Yonghong

Article Type: Research Article

Abstract: Background: L-carnitine has been shown to exert neuroprotective effects on cerebral ischemia, mainly by improving mitochondrial function and reducing inflammation. L-carnitine supplementation has also been promoted to enhance cognitive function. However, the relationship between L-carnitine and cognitive impairment after ischemic stroke has seldom been studied. Objective: We aimed to evaluate the association between plasma L-carnitine and poststroke cognitive impairment. Methods: The study sample population was drawn from the China Antihypertensive Trial in Acute Ischemic Stroke. Plasma L-carnitine were measured at baseline in 617 patients with ischemic stroke using ultrahigh-performance liquid chromatography-tandem mass spectrometry. Cognitive function was …evaluated using the Montreal Cognitive Assessment at 3-month follow-up after ischemic stroke. Results: Plasma L-carnitine were inversely associated with cognitive impairment at 3 months after ischemic stroke, and the adjusted odds ratio (95% CI) for the highest versus lowest quartiles of L-carnitine was 0.60 (0.37, 0.98; p for trend = 0.04). Each 1-SD increase in log-transformed L-carnitine concentration was significantly associated with a 15% (95% CI: 1%, 29%) reduction in the risk of cognitive impairment after stroke. The addition of L-carnitine to the model including conventional risk factors significantly improved the risk reclassification for cognitive impairment (net reclassification improvement: 17.9%, integrated discrimination improvement: 0.8% ; both p  <  0.05). Furthermore, joint effects of L-carnitine and inflammation markers were observed, and patients with higher L-carnitine and a lower inflammatory status simultaneously had the lowest risk of poststroke cognitive impairment. Conclusion: The present study provided prospective evidence on the inverse association between plasma L-carnitine and cognitive impairment after ischemic stroke. Show more

Keywords: Acute ischemic stroke, cognitive impairment, inflammation, L-carnitine

DOI: 10.3233/JAD-215376

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-12, 2021