Cognitive training and brain stimulation in prodromal Alzheimer’s disease (AD-Stim)—study protocol for a double-blind randomized controlled phase IIb (monocenter) trial

Abstract Background Given the growing older population worldwide, and the associated increase in age-related diseases, such as Alzheimer’s disease (AD), investigating non-invasive methods to ameliorate or even prevent cognitive decline in prodromal AD is highly relevant. Previous studies suggest transcranial direct current stimulation (tDCS) to be an effective method to boost cognitive performance, especially when applied in combination with cognitive training in healthy older adults. So far, no studies combining tDCS concurrent with an intense multi-session cognitive training in prodromal AD populations have been conducted. Methods The AD-Stim trial is a monocentric, randomized, double-blind, placebo-controlled study, including a 3-week tDCS-assisted cognitive training with anodal tDCS over left DLPFC (target intervention), compared to cognitive training plus sham (control intervention). The cognitive training encompasses a letter updating task and a three-stage Markov decision-making task. Forty-six participants with subjective cognitive decline (SCD) or mild cognitive impairment (MCI) will be randomized block-wise to either target or control intervention group and participate in nine interventional visits with additional pre- and post-intervention assessments. Performance in the letter updating task after training and anodal tDCS compared to sham stimulation will be analyzed as primary outcome. Further, performance on the second training task and transfer tasks will be investigated. Two follow-up visits (at 1 and 7 months post-training) will be performed to assess possible maintenance effects. Structural and functional magnetic resonance imaging (MRI) will be applied before the intervention and at the 7-month follow-up to identify possible neural predictors for successful intervention. Significance With this trial, we aim to provide evidence for tDCS-induced improvements of multi-session cognitive training in participants with SCD and MCI. An improved understanding of tDCS effects on cognitive training performance and neural predictors may help to develop novel approaches to counteract cognitive decline in participants with prodromal AD. Trial registration ClinicalTrials.gov, NCT04265378. Registered on 07 February 2020. Retrospectively registered. Protocol version: Based on BB 004/18 version 1.2 (May 17, 2019). Sponsor: University Medicine Greifswald.

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Smell identification test as a progression marker in Alzheimer's disease

European Psychiatry ◽

10.1016/s0924-9338(11)72209-x ◽

2011 ◽

Vol 26 (S2) ◽

pp. 502-502

Author(s):

L. Velayudhan ◽

M. Pritchard ◽

S. Lovestone

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Decline ◽

Late Onset ◽

Linear Regression Analysis ◽

Rapid Progressors ◽

Progression Marker ◽

Identification Test ◽

Smell Identification

IntroductionFactors influencing or predicting progression in Alzheimer's disease (AD) is not well understood. Olfactory dysfunction, impaired smell identification in particular, is known to occur in AD. Mesial temporal lobe, important for memory function is also critical for the processing of olfactory information. In view of the common anatomical substrate, we hypothesized that olfaction dysfunction worsens faster in people with AD with rapid cognitive decline compared to those with slower cognitive decline.AimsTo test whether smell identification test can be used as a predictor for illness progression in AD patients.MethodsForty one participants with late onset mild to moderate AD were recruited from mental health services for older adults. Subjects were classified as ‘Rapid Progressors’ defined on ‘a-priori’ with a loss of 2 or more points in Mini-Mental State Examination (MMSE) within six months. Assessments included MMSE, Neuropsychiatric Inventory, Bristol Activities of Daily Living, and the University of Pennsylvania Smell Identification Test (UPSIT), at baseline and after 3 months.ResultsTwenty subjects were ‘Rapid Progressors’, and had lower UPSIT scores compared to ‘Non-Rapid Progressors’ both at the baseline (p = 0.02) and at follow up after 3 months (p = 0.05). Baseline UPSIT correlated with follow up UPSIT (r = 0.5, p < 0.01) and MMSE (r = 0.4, p = 0.04). Also it was the baseline UPSIT score that best predicted (p < 0.05) the follow up smell and cognitive function on linear regression analysis.ConclusionsSmell identification function could be useful as a clinical measure to assess and predict progression in AD.

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Gantenerumab reduces amyloid-β plaques in patients with prodromal to moderate Alzheimer’s disease: a PET substudy interim analysis

Alzheimer s Research & Therapy ◽

10.1186/s13195-019-0559-z ◽

2019 ◽

Vol 11 (1) ◽

Cited By ~ 14

Author(s):

Gregory Klein ◽

Paul Delmar ◽

Nicola Voyle ◽

Sunita Rehal ◽

Carsten Hofmann ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Interim Analysis ◽

Human Monoclonal Antibody ◽

Amyloid Β ◽

Plaque Burden ◽

Ratio Method ◽

Double Blind ◽

Link Type ◽

Potential Clinical Benefit

Abstract Background We previously investigated low doses (105 or 225 mg) of gantenerumab, a fully human monoclonal antibody that binds and removes aggregated amyloid-β by Fc receptor-mediated phagocytosis, in the SCarlet RoAD (SR) and Marguerite RoAD (MR) phase 3 trials. Several lines of evidence suggested that higher doses may be necessary to achieve clinical efficacy. We therefore designed a positron emission tomography (PET) substudy to evaluate the effect of gantenerumab uptitrated to 1200 mg every 4 weeks on amyloid-β plaques as measured using florbetapir PET in patients with prodromal to moderate Alzheimer’s disease (AD). Methods A subset of patients enrolled in the SR and MR studies who subsequently entered the open-label extensions (OLEs) were included in this substudy. Patients were aged 50 to 90 years with a clinical diagnosis of probable prodromal to moderate AD and were included based on a visual read of the original screening scan in the double-blind phase. Patients were assigned to 1 of 5 titration schedules (ranging from 2 to 10 months) with a target gantenerumab dose of 1200 mg every 4 weeks. The main endpoint of this substudy was change in amyloid-β plaque burden from OLE baseline to week 52 and week 104, assessed using florbetapir PET. Florbetapir global cortical signal was calculated using a prespecified standard uptake value ratio method converted to the Centiloid scale. Results Sixty-seven of the 89 patients initially enrolled had ≥ 1 follow-up scan by August 15, 2018. Mean amyloid levels were reduced by 39 Centiloids by the first year and 59 Centiloids by year 2, a 3.5-times greater reduction than was seen after 2 years at 225 mg in SR. At years 1 and 2, 37% and 51% of patients, respectively, had amyloid-β plaque levels below the amyloid-β positivity threshold. Conclusion Results from this exploratory interim analysis of the PET substudy suggest that gantenerumab doses up to 1200 mg resulted in robust amyloid-β plaque removal at 2 years. PET amyloid levels were consistent with sparse-to-no neuritic amyloid-β plaques in 51% of patients after 2 years of therapy. Amyloid reductions were similar to those observed in other placebo-controlled studies that have suggested potential clinical benefit. Trial registration ClinicalTrials.gov, NCT01224106 (SCarlet RoAD) and NCT02051608 (Marguerite RoAD).

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Different patterns of cognitive decline related to normal or deteriorating EEG in a 3-year follow-up study of patients with Alzheimer's disease

Neurology ◽

10.1212/wnl.41.4.528 ◽

1991 ◽

Vol 41 (4) ◽

pp. 528-528 ◽

Cited By ~ 27

Author(s):

E-L. Helkala ◽

V. Laulumaa ◽

H. Soininen ◽

J. Partanen ◽

P. J. Riekkinen

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Decline ◽

Follow Up Study

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Automatic Prediction of Cognitive and Functional Decline Can Significantly Decrease the Number of Subjects Required for Clinical Trials in Early Alzheimer’s Disease

Journal of Alzheimer s Disease ◽

10.3233/jad-210664 ◽

2021 ◽

pp. 1-8

Author(s):

Neda Shafiee ◽

Mahsa Dadar ◽

Simon Ducharme ◽

D. Louis Collins ◽

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Clinical Trials ◽

Cognitive Decline ◽

Functional Decline ◽

Amyloid Β ◽

Cognitive Test ◽

Disease Heterogeneity ◽

Early Alzheimer’S Disease

Background: While both cognitive and magnetic resonance imaging (MRI) data has been used to predict progression in Alzheimer’s disease, heterogeneity between patients makes it challenging to predict the rate of cognitive and functional decline for individual subjects. Objective: To investigate prognostic power of MRI-based biomarkers of medial temporal lobe atrophy and macroscopic tissue change to predict cognitive decline in individual patients in clinical trials of early Alzheimer’s disease. Methods: Data used in this study included 312 patients with mild cognitive impairment from the ADNI dataset with baseline MRI, cerebrospinal fluid amyloid-β, cognitive test scores, and a minimum of two-year follow-up information available. We built a prognostic model using baseline cognitive scores and MRI-based features to determine which subjects remain stable and which functionally decline over 2 and 3-year follow-up periods. Results: Combining both sets of features yields 77%accuracy (81%sensitivity and 75%specificity) to predict cognitive decline at 2 years (74%accuracy at 3 years with 75%sensitivity and 73%specificity). When used to select trial participants, this tool yields a 3.8-fold decrease in the required sample size for a 2-year study (2.8-fold decrease for a 3-year study) for a hypothesized 25%treatment effect to reduce cognitive decline. Conclusion: When used in clinical trials for cohort enrichment, this tool could accelerate development of new treatments by significantly increasing statistical power to detect differences in cognitive decline between arms. In addition, detection of future decline can help clinicians improve patient management strategies that will slow or delay symptom progression.

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Effect of a Cognitive Training Program on the Platelet APP Ratio in Patients with Alzheimer’s Disease

International Journal of Molecular Sciences ◽

10.3390/ijms21145110 ◽

2020 ◽

Vol 21 (14) ◽

pp. 5110

Author(s):

Tiziana Casoli ◽

Cinzia Giuli ◽

Marta Balietti ◽

Paolo Fabbietti ◽

Fiorenzo Conti

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Synaptic Plasticity ◽

Cognitive Training ◽

Control Group ◽

Word Fluency ◽

Clinical Dementia Rating ◽

Cognitive Improvement ◽

App Ratio

In patients with Alzheimer’s disease (AD), synaptic plasticity seems to be involved in cognitive improvement induced by cognitive training. The platelet amyloid precursor protein (APP) ratio (APPr), i.e., the ratio between two APP isoforms, may be a useful peripheral biomarker to investigate synaptic plasticity pathways. This study evaluates the changes in neuropsychological/cognitive performance and APPr induced by cognitive training in AD patients participating in the “My Mind Project”. Neuropsychological/cognitive variables and APPr were evaluated in the trained group (n = 28) before a two-month experimental protocol, immediately after its termination at follow-up 1 (FU1), after 6 months at follow-up 2 (FU2), and after 24 months at follow-up 3 (FU3). The control group (n = 31) received general psychoeducational training for two months. Some memory and attention parameters were significantly improved in trained vs. control patients at FU1 and FU2 compared to baseline (Δ values). At FU3, APPr and Mini Mental State Examination (MMSE) scores decreased in trained patients. Δ APPr correlated significantly with the Δ scores of (i) MMSE at FU1, (ii) the prose memory test at FU2, and (iii) Instrumental Activities of Daily Living (IADL), the semantic word fluency test, Clinical Dementia Rating (CDR), and the attentive matrices test at FU3. Our data demonstrate that the platelet APPr correlates with key clinical variables, thereby proving that it may be a reliable biomarker of brain function in AD patients.

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A-5 Examining the Interactive Effects of Traumatic Brain Injury and Apolipoprotein E on Cognitive Decline in Alzheimer’s Disease

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acab062.23 ◽

2021 ◽

Vol 36 (6) ◽

pp. 1044-1044

Author(s):

Claire Alexander ◽

Julie Suhr

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Decline ◽

Apolipoprotein E ◽

Negative Impact ◽

Interactive Effects ◽

Decline Rate ◽

History Of ◽

Positive Effect

Abstract Objective Little research has focused on possible effects of TBI on cognitive decline rate after Alzheimer’s disease (ad) diagnosis. We examined whether Apolipoprotein E (APOE) status and TBI history interact to predict cognitive decline. Method We used data from the National Alzheimer’s Coordinating Centers (N = 463; 42.3% APOE e4 carriers, 7.8% with TBI history, mean baseline age 79.3). Inclusion criteria included normal cognition at baseline with diagnosis of ad at a follow-up visit; baseline age 50 or older; and at least 3 years of follow-up data. Mixed models (random intercept, random slope) were used, with TBI history, APOE status, and their interaction as predictors of interest. Education, race, and history of TIA, stroke, or hypertension were included as covariates. Cognitive measures included mental status exam scores and immediate/delayed story memory. Results After accounting for covariates, TBI history had a positive effect on cognitive decline rate on the screener and immediate memory measures. APOE status did not affect rate of cognitive decline on the screener, but presence of e4 predicted faster decline on immediate and delayed memory. TBI history and APOE status interacted to predict delayed memory decline, such that history of TBI was associated with a reduced rate of decline for e4 non-carriers but there was no effect of TBI for e4 carriers. Conclusion When examining cognitive decline trajectory, TBI history predicted slower decline (a positive effect) while APOE had either a negative impact or no effect, depending on the measure. Future study should examine cognitive decline in the context of demographic and genetic factors.

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