Wczesne leczenie cholinergiczne w zapobieganiu zmianom neuropatologicznym w chorobie Alzheimera

Wyróżnienie obszarów mózgu, w obrębie których odchodzi do zmian neuropatologicznych przyczyniających się do rozwoju choroby Alzheimera (AD, Alzheimer’s disease), umożliwi w przyszłości lepsze zrozumienie patofizjologii tego schorzenia. Dodatkowo wiedza ta pozwoli na skuteczną kontrolę skutków prowadzonego w AD leczenia pod kątem oceny zmian obserwowanych we wspomnianych wyżej obszarach. Utrata funkcji poznawczych we wczesnej fazie AD o łagodnym nasileniu w pierwszej kolejności dotyczy pamięci epizodycznej oraz orientacji przestrzennej. Badania kliniczne oraz eksperymentalne wskazują, że zaburzenia pamięci we wczesnych fazach AD są spowodowane uszkodzeniami mózgu w rejonie hipokampa oraz przyśrodkowej części płatów skroniowych. Czy można zapobiec rozwojowi patologii w tych obszarach mózgu? Działanie neuroprotekcyjne inhibitorów cholinesterazy (ChEI, cholinesterase inhibitor) wykazano w wielu badaniach na modelach zwierzęcych AD prowadzonych u myszy transgenicznych. Udowodniono działanie protekcyjne ChEI względem neuronów kory mózgowej w modelu zahamowania dopływu glukozy i tlenu oraz ekspozycji na toksyczne działanie glutaminianu, a także względem skutków zaburzeń mitochondrialnych komórek hipokampa. Wnioski z powyższych badań przedklinicznych znajdują odzwierciedlenie w wynikach wielu badań klinicznych, które wskazują jednoznacznie na celowość jak najwcześniejszego podjęcia farmakoterapii donepezilem oraz sugerują, że działanie tego leku może wykazywać również inny niż tylko objawowy mechanizm działania

Generic quality of life assessment in dementia patients: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Quality of life (QoL) is increasingly used to characterize the impact of disease and the efficacy of interventions.</p> <p>Methods</p> <p>Prospective cohort study in patients' and proxies' homes with137 patients with dementia (age 52 to 88; Mini-Mental Status Examination (MMSE) 3 to 28) and their proxies (age 43 to 90). MMSE, Behave-AD, Geriatric Depression Scale (GDS), and Bayer-ADL scale (B-ADL), and the Euroqol (EQ-5D; patient self-rating, proxy self-rating, and proxy-rating of patient).</p> <p>Results</p> <p>B-ADL impairment and Behave-AD total score increased with dementia severity (Kruskal-Wallis p < 0.001 and p = 0.023, respectively). Patients' self-rated QoL and proxies' self-rated QoL were unrelated to dementia severity (p = 0.148 and p = 0.414, respectively). The difference between patients' self- and proxies'-rating of the patient's QoL correlated with the patient's MMSE (Spearman's rho = -0.434; p < 0.001), even if analysis was constrained to patients with mild AD (rho = -0.328; p = 0.019). The proxies' rating of the patients QoL was not only correlated with cognitive and behavioral symptoms of the patient but also with mood (GDS-score; rho = 0.317; p < 0.001) and cognitive abilities (verbal fluency; rho = 0.209; p < 0.018) of the proxy.</p> <p>Conclusion</p> <p>Proxies' assessment of the patients' QoL is related to the proxies' health, and the difference of patient's and proxie's QoL-rating is correlated with dementia severity even in mild dementia stages. QOL measures use ratings of the individual to assess the impact of symptoms and disorders on everyday life. In dementia patients, however, this impact is not captured since patients' and proxies' self-assessment of their own QoL do not reflect severity of disease whatsoever. Patients' and proxies' influencing variables render the score obtained with generic quality of life assessment meaningless in capturing the impact of dementia. Decisions on initiation or discontinuation of treatment or allocation of other resources for patients with dementia therefore need not depend on generic assessment of quality of life.</p

Quantitative analysis of regional distribution of tau pathology with 11C-PBB3-PET in a clinical setting.

PURPOSE The recent developments of tau-positron emission tomography (tau-PET) enable in vivo assessment of neuropathological tau aggregates. Among the tau-specific tracers, the application of 11C-pyridinyl-butadienyl-benzothiazole 3 (11C-PBB3) in PET shows high sensitivity to Alzheimer disease (AD)-related tau deposition. The current study investigates the regional tau load in patients within the AD continuum, biomarker-negative individuals (BN) and patients with suspected non-AD pathophysiology (SNAP) using 11C-PBB3-PET. MATERIALS AND METHODS A total of 23 memory clinic outpatients with recent decline of episodic memory were examined using 11C-PBB3-PET. Pittsburg compound B (11C-PIB) PET was available for 17, 18F-flurodeoxyglucose (18F-FDG) PET for 16, and cerebrospinal fluid (CSF) protein levels for 11 patients. CSF biomarkers were considered abnormal based on Aβ42 ( 450 ng/L). The PET biomarkers were classified as positive or negative using statistical parametric mapping (SPM) analysis and visual assessment. Using the amyloid/tau/neurodegeneration (A/T/N) scheme, patients were grouped as within the AD continuum, SNAP, and BN based on amyloid and neurodegeneration status. The 11C-PBB3 load detected by PET was compared among the groups using both atlas-based and voxel-wise analyses. RESULTS Seven patients were identified as within the AD continuum, 10 SNAP and 6 BN. In voxel-wise analysis, significantly higher 11C-PBB3 binding was observed in the AD continuum group compared to the BN patients in the cingulate gyrus, tempo-parieto-occipital junction and frontal lobe. Compared to the SNAP group, patients within the AD continuum had a considerably increased 11C-PBB3 uptake in the posterior cingulate cortex. There was no significant difference between SNAP and BN groups. The atlas-based analysis supported the outcome of the voxel-wise quantification analysis. CONCLUSION Our results suggest that 11C-PBB3-PET can effectively analyze regional tau load and has the potential to differentiate patients in the AD continuum group from the BN and SNAP group

Additive scales in degenerative disease - calculation of effect sizes and clinical judgment

<p>Abstract</p> <p>Background</p> <p>The therapeutic efficacy of an intervention is often assessed in clinical trials by scales measuring multiple diverse activities that are added to produce a cumulative global score. Medical communities and health care systems subsequently use these data to calculate pooled effect sizes to compare treatments. This is done because major doubt has been cast over the clinical relevance of statistically significant findings relying on <it>p </it>values with the potential to report chance findings. Hence in an aim to overcome this pooling the results of clinical studies into a meta-analyses with a statistical calculus has been assumed to be a more definitive way of deciding of efficacy.</p> <p>Methods</p> <p>We simulate the therapeutic effects as measured with additive scales in patient cohorts with different disease severity and assess the limitations of an effect size calculation of additive scales which are proven mathematically.</p> <p>Results</p> <p>We demonstrate that the major problem, which cannot be overcome by current numerical methods, is the complex nature and neurobiological foundation of clinical psychiatric endpoints in particular and additive scales in general. This is particularly relevant for endpoints used in dementia research. 'Cognition' is composed of functions such as memory, attention, orientation and many more. These individual functions decline in varied and non-linear ways. Here we demonstrate that with progressive diseases cumulative values from multidimensional scales are subject to distortion by the limitations of the additive scale. The non-linearity of the decline of function impedes the calculation of effect sizes based on cumulative values from these multidimensional scales.</p> <p>Conclusions</p> <p>Statistical analysis needs to be guided by boundaries of the biological condition. Alternatively, we suggest a different approach avoiding the error imposed by over-analysis of cumulative global scores from additive scales.</p

Quality of Life as an outcome in Alzheimer's disease and other dementias- obstacles and goals

<p>Abstract</p> <p>Background</p> <p>The number of individuals at risk for dementia will probably increase in ageing societies as will the array of preventive and therapeutic options, both however within limited economic resources. For economic and medical purposes valid instruments are required to assess disease processes and the efficacy of therapeutic interventions for different forms and stages of illness. In principal, the impact of illness and success of an intervention can be assessed with biomedical variables, e.g. severity of symptoms or frequency of complications of a disease. However, this does not allow clear judgement on clinical relevance or comparison across different diseases.</p> <p>Discussion</p> <p>Outcome model variables such as quality of life (QoL) or health care resource utilization require the patient to appraise their own well-being or third parties to set preferences. In Alzheimer's disease and other dementias the evaluation process performed by the patient is subject to the disease process itself because over progress of the disease neuroanatomical structures are affected that mediate evaluation processes.</p> <p>Summary</p> <p>Published research and methodological considerations thus lead to the conclusion that current QoL-instruments, which have been useful in other contexts, are ill-suited and insufficiently validated to play a major role in dementia research, decision making and resource allocation. New models integrating biomedical and outcome variables need to be developed in order to meet the upcoming medical and economic challenges.</p

Potentially inappropriate medication use in older adults with mild-moderate Alzheimer's disease:Prevalence and associations with adverse events

Aim: Potentially inappropriate medication (PIM) use is prevalent in older adults and is associated with adverse events, hospitalisation and mortality. We assessed the patterns and associations of PIM use in older adults with mild-to-moderate Alzheimer's Disease (AD), who may represent a particularly vulnerable group. Design: Analysis of data from NILVad, an 18-month Randomised Control Trial of Nilvadapine in mild-to-moderate AD. The v2 STOPP criteria were applied in duplicate to identify PIM use. Associations between PIM use and adverse events/unscheduled healthcare visits in addition to the associations between PIM use and AD progression were evaluated. Setting and Participants: 448 older adults with mild-to-moderate AD from 23 centres in nine European countries. Results: Of 448 participants (mean age: 72.56 ± 8.19 years), over half (55.8%) were prescribed a PIM with 30.1% being prescribed 2+ PIMs. The most frequent PIMs were (i) long-term benzodiazepines (11.6% N = 52/448), (ii) selective serotonin reuptake inhibitors without appropriate indication (11.1% N = 50/448), and (iii) Proton-Pump Inhibitors (PPIs) without appropriate indication (10.7% N = 48/448). Increasing number of PIMs was associated with a greater risk of adverse events (IRR 1.17, 1.13-1.19, P &lt; 0.001), serious adverse events (IRR 1.27; 1.17-1.37, P &lt; 0.001), unscheduled hospitalisations (IRR 1.16, 1.03-1.30, P = 0.016) and GP visits (IRR 1.22, 1.15-1.28, P &lt; 0.001). PIM use was not associated with dementia progression. Conclusions and Implications: PIM use is highly prevalent in mild-to-moderate AD and is associated with adverse events and unscheduled healthcare utilisation. Further attention to de-prescribing in this vulnerable group is warranted

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570