Long-term associations between cholinesterase inhibitors and memantine use and health outcomes among patients with Alzheimer's disease

Patterns of use of symptomatic treatments for Alzheimer's disease dementia (AD)

BACKGROUND

Symptomatic treatment for Alzheimer's disease (AD) dementia could temporarily slow symptom worsening and improve the quality of life for both AD dementia patients and their caregivers. A comprehensive evaluation of symptomatic treatment patterns using recent data for newly diagnosed AD dementia has not been performed and compared across different countries.

METHODS

The drug name, time to the first therapy, duration, discontinuation or switches were described in newly diagnosed AD dementia patients in two databases (a major U.S. health plan [US] and UK-Clinical Practice Research Datalink [CPRD GOLD]). This analysis included patients with newly diagnosed AD dementia in 2018-2019, who initiated symptomatic AD drug therapy, with ≥ 1 year baseline period and ≥ 1 year of follow-up.

RESULTS

Over median follow-ups of 698 and 645 days, 63% and 65% of AD dementia patients used symptomatic treatments, with 34% and 77% newly initiating therapy, constituting analytic samples of 7637 patients in the US database and 4470 patients in the CPRD, respectively. The median time to the first therapy was 14 days for US and 49 days for CPRD; donepezil ranked the as most frequently used (69% vs 61%), followed by memantine (19% vs 28%) in the US database and CPRD, respectively. Median time on first therapy was 213 and 334 days, and 30% and 12% of patients proceeded to a second treatment in the US and CPRD databases, respectively.

CONCLUSION

Approximately two thirds of newly diagnosed AD dementia patients utilized approved symptomatic treatment. Time on first therapy was relatively short (< 1 year) and the majority did not move to a second therapy, highlighting the need for better adherence and persistence to existing AD symptomatic therapies and the need for additional therapies to alleviate the significant burden of AD dementia.

Compensatory remodeling of a septo-hippocampal GABAergic network in the triple transgenic Alzheimer's mouse model

BACKGROUND

Alzheimer's disease (AD) is characterized by a progressive loss of memory that cannot be efficiently managed by currently available AD therapeutics. So far, most treatments for AD that have the potential to improve memory target neural circuits to protect their integrity. However, the vulnerable neural circuits and their dynamic remodeling during AD progression remain largely undefined.

METHODS

Circuit-based approaches, including anterograde and retrograde tracing, slice electrophysiology, and fiber photometry, were used to investigate the dynamic structural and functional remodeling of a GABAergic circuit projected from the medial septum (MS) to the dentate gyrus (DG) in 3xTg-AD mice during AD progression.

RESULTS

We identified a long-distance GABAergic circuit that couples highly connected MS and DG GABAergic neurons during spatial memory encoding. Furthermore, we found hyperactivity of DG interneurons during early AD, which persisted into late AD stages. Interestingly, MS GABAergic projections developed a series of adaptive strategies to combat DG interneuron hyperactivity. During early-stage AD, MS-DG GABAergic projections exhibit increased inhibitory synaptic strength onto DG interneurons to inhibit their activities. During late-stage AD, MS-DG GABAergic projections form higher anatomical connectivity with DG interneurons and exhibit aberrant outgrowth to increase the inhibition onto DG interneurons.

CONCLUSION

We report the structural and functional remodeling of the MS-DG GABAergic circuit during disease progression in 3xTg-AD mice. Dynamic MS-DG GABAergic circuit remodeling represents a compensatory mechanism to combat DG interneuron hyperactivity induced by reduced GABA transmission.

Effect of Cholinesterase Inhibitors on Mortality in Patients With Dementia: A Systematic Review of Randomized and Nonrandomized Trials

BACKGROUND AND OBJECTIVES

Cholinesterase inhibitors (ChEIs) have cardiovascular effects in addition to their neurologic activity and might alter mortality. We wanted to know whether treatment with ChEIs modifies mortality in patients with dementia.

METHODS

We searched PubMed, Embase, Cochrane CENTRAL, ClinicalTrials.gov, and ICRTP, from their inception to November 2021, and screened bibliographies of reviews, guidelines, and included studies. We included randomized controlled trials (RCTs) and nonrandomized controlled studies at lower risk of bias comparing ChEI treatment with placebo or usual treatment, for 6 months or longer, in patients with dementia of any type. Two investigators independently assessed studies for inclusion, assessed their risk of bias, and extracted data using predefined forms. Any discordance between investigators was solved by discussion and consensus. Data on all-cause and cardiovascular mortality, measured as either crude death rates or multivariate adjusted hazard ratios (HRs), were pooled using a random-effect model. Information size achieved was assessed using trial sequential analysis (TSA). We followed Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.

RESULTS

Twenty-four studies (12 RCTs, 12 cohorts, mean follow-up 6-120 months), cumulating 79,153 patients with Alzheimer (13 studies), Parkinson (1), vascular (1), or any type (9) dementia, fulfilled inclusion criteria. Pooled all-cause mortality in control patients was 15.1 per 100 person-years. Treatment with ChEIs was associated with lower all-cause mortality (unadjusted risk ratio [RR] 0.74, 95% CI 0.66-0.84; adjusted HR 0.77, 95% CI 0.70-0.84, moderate-quality to high-quality evidence). This result was consistent between randomized and nonrandomized studies and in several sensitivity analyses. No difference appeared between subgroups by type of dementia, age, individual drug, or dementia severity. Less data were available for cardiovascular mortality (3 RCTs, 2 cohorts, 9,182 patients, low-quality to moderate-quality evidence), which was also lower in patients treated with ChEIs (unadjusted RR 0.61, 95% CI 0.40-0.93, adjusted HR 0.47, 95% CI 0.32-0.68). In TSA analysis, the results for all-cause mortality were conclusive but not those for cardiovascular mortality.

DISCUSSION

There is moderate-quality to high-quality evidence of a consistent association between long-term treatment with ChEIs and a reduction in all-cause mortality in patients with dementia. These findings may influence decisions to prescribe ChEIs in those patients.

TRIAL REGISTRATION INFORMATION

This systematic review was registered in the PROSPERO international prospective register of systematic reviews with the number CRD42021254458 (June 11, 2021).

Predictors of response to acetylcholinesterase inhibitors in dementia: A systematic review

Background

The mainstay of therapy for many neurodegenerative dementias still relies on acetylcholinesterase inhibitors (AChEI); however, there is debate on various aspects of such treatment. A huge body of literature exists on possible predictors of response, but a comprehensive review is lacking. Therefore, our aim is to perform a systematic review of the predictors of response to AChEI in neurodegenerative dementias, providing a categorization and interpretation of the results.

Methods

We conducted a systematic review of the literature up to December 31st, 2021, searching five different databases and registers, including studies on rivastigmine, donepezil, and galantamine, with clearly defined criteria for the diagnosis of dementia and the response to AChEI therapy. Records were identified through the string: predict * AND respon * AND (acetylcholinesterase inhibitors OR donepezil OR rivastigmine OR galantamine). The results were presented narratively.

Results

We identified 1,994 records in five different databases; after exclusion of duplicates, title and abstract screening, and full-text retrieval, 122 studies were finally included.

Discussion

The studies show high heterogeneity in duration, response definition, drug dosage, and diagnostic criteria. Response to AChEI seems associated with correlates of cholinergic deficit (hallucinations, fluctuating cognition, substantia innominate atrophy) and preserved cholinergic neurons (faster alpha on REM sleep EEG, increased anterior frontal and parietal lobe perfusion after donepezil); white matter hyperintensities in the cholinergic pathways have shown inconsistent results. The K-variant of butyrylcholinesterase may correlate with better response in late stages of disease, while the role of polymorphisms in other genes involved in the cholinergic system is controversial. Factors related to drug availability may influence response; in particular, low serum albumin (for donepezil), CYP2D6 variants associated with reduced enzymatic activity and higher drug doses are the most consistent predictors, while AChEI concentration influence on clinical outcomes is debatable. Other predictors of response include faster disease progression, lower serum cholesterol, preserved medial temporal lobes, apathy, absence of concomitant diseases, and absence of antipsychotics. Short-term response may predict subsequent cognitive response, while higher education might correlate with short-term good response (months), and long-term poor response (years). Age, gender, baseline cognitive and functional levels, and APOE relationship with treatment outcome is controversial.

Subjective short-term memory difficulties at ages 50-75 predict dementia risk in a community-based cohort followed over 17 years

INTRODUCTION

Subjective cognitive decline (SCD) is an established precursor of dementia. However, the relationship between SCD and dementia has been mostly studied among people aged 65+. We aimed to assess the association between subjective memory difficulties at ages 50-75 with all-cause dementia and dementia-subtypes in a community-based cohort with long-term follow-up.

METHODS

6,190 individuals (51% female) aged 50-75 years (median age, 62) attending a general health examination (by a total of 684 general practitioners) in Saarland, Germany, in 2000-2002 were recruited for a community-based cohort study. Subjective difficulties regarding short-term and long-term memory were assessed at baseline with two simple yes/no questions. Associations with dementia (-subtypes) diagnoses during 17 years of follow-up were estimated by Cox proportional hazards models.

RESULTS

492 participants were diagnosed with dementia during 17 years of follow-up. Participants with short-term memory difficulties were at higher risk to receive incident all-cause dementia and vascular dementia diagnoses both within 0-9 years (age and sex adjusted hazard ratios (aHR), 1.80 and 2.00, respectively) and within 0-17 years (aHR 1.55 and 1.78, respectively) from recruitment (P < 0.05 in all cases). For clinical Alzheimer's disease, a significant association was only seen within the initial 6 years. There were no associations of long-term memory difficulties with any type of dementia.

CONCLUSIONS

Subjective difficulties in short-term memory predict both intermediate and long-term risk of vascular and all-cause dementia even among late middle-age adults. These results underline the importance of cardiovascular disease prevention efforts well before old age for maintaining cognitive health.

Development and Biological Characterization of a Novel Selective TrkA Agonist with Neuroprotective Properties against Amyloid Toxicity

Neurotrophins are growth factors that exert important neuroprotective effects by preventing neuronal death and synaptic loss. Nerve Growth Factor (NGF) acts through the activation of its high-affinity, pro-survival TrkA and low-affinity, pro-apoptotic p75^NTR receptors. NGF has been shown to slow or prevent neurodegenerative signals in Alzheimer’s Disease (AD) progression. However, its low bioavailability and its blood–brain-barrier impermeability limit the use of NGF as a potential therapeutic agent against AD. Based on our previous findings on synthetic dehydroepiandrosterone derivatives, we identified a novel NGF mimetic, named ENT-A013, which selectively activates TrkA and exerts neuroprotective, anti-amyloid-β actions. We now report the chemical synthesis, in silico modelling, metabolic stability, CYP-mediated reaction phenotyping and biological characterization of ENT-A013 under physiological and neurodegenerative conditions. We show that ENT-A013 selectively activates the TrkA receptor and its downstream kinases Akt and Erk1/2 in PC12 cells, protecting these cells from serum deprivation-induced cell death. Moreover, ENT-A013 promotes survival of primary Dorsal Root Ganglion (DRG) neurons upon NGF withdrawal and protects hippocampal neurons against Amyloid β-induced apoptosis and synaptic loss. Furthermore, this neurotrophin mimetic partially restores LTP impairment. In conclusion, ENT-A013 represents a promising new lead molecule for developing therapeutics against neurodegenerative disorders, such as Alzheimer’s Disease, selectively targeting TrkA-mediated pro-survival signals.

A Review of Techniques for Biodelivery of Nerve Growth Factor (NGF) to the Brain in Relation to Alzheimer's Disease

Age-dependent progressive neurodegeneration and associated cognitive dysfunction represent a serious concern worldwide. Currently, dementia accounts for the fifth highest cause of death, among which Alzheimer's disease (AD) represents more than 60% of the cases. AD is associated with progressive cognitive dysfunction which affects daily life of the affected individual and associated family. The cognitive dysfunctions are at least partially due to the degeneration of a specific set of neurons (cholinergic neurons) whose cell bodies are situated in the basal forebrain region (basal forebrain cholinergic neurons, BFCNs) but innervate wide areas of the brain. It has been explicitly shown that the delivery of the neurotrophic protein nerve growth factor (NGF) can rescue BFCNs and restore cognitive dysfunction, making NGF interesting as a potential therapeutic substance for AD. Unfortunately, NGF cannot pass through the blood-brain barrier (BBB) and thus peripheral administration of NGF protein is not viable therapeutically. NGF must be delivered in a way which will allow its brain penetration and availability to the BFCNs to modulate BFCN activity and viability. Over the past few decades, various methodologies have been developed to deliver NGF to the brain tissue. In this chapter, NGF delivery methods are discussed in the context of AD.

Withdrawal or continuation of cholinesterase inhibitors or memantine or both, in people with dementia

BACKGROUND

Dementia is a progressive syndrome characterised by deterioration in memory, thinking and behaviour, and by impaired ability to perform daily activities. Two classes of drug - cholinesterase inhibitors (donepezil, galantamine and rivastigmine) and memantine - are widely licensed for dementia due to Alzheimer's disease, and rivastigmine is also licensed for Parkinson's disease dementia. These drugs are prescribed to alleviate symptoms and delay disease progression in these and sometimes in other forms of dementia. There are uncertainties about the benefits and adverse effects of these drugs in the long term and in severe dementia, about effects of withdrawal, and about the most appropriate time to discontinue treatment.

OBJECTIVES

To evaluate the effects of withdrawal or continuation of cholinesterase inhibitors or memantine, or both, in people with dementia on: cognitive, neuropsychiatric and functional outcomes, rates of institutionalisation, adverse events, dropout from trials, mortality, quality of life and carer-related outcomes.

SEARCH METHODS

We searched the Cochrane Dementia and Cognitive Improvement Group's Specialised Register up to 17 October 2020 using terms appropriate for the retrieval of studies of cholinesterase inhibitors or memantine. The Specialised Register contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources.

SELECTION CRITERIA

We included all randomised, controlled clinical trials (RCTs) which compared withdrawal of cholinesterase inhibitors or memantine, or both, with continuation of the same drug or drugs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed citations and full-text articles for inclusion, extracted data from included trials and assessed risk of bias using the Cochrane risk of bias tool. Where trials were sufficiently similar, we pooled data for outcomes in the short term (up to 2 months after randomisation), medium term (3-11 months) and long term (12 months or more). We assessed the overall certainty of the evidence for each outcome using GRADE methods.

MAIN RESULTS

We included six trials investigating cholinesterase inhibitor withdrawal, and one trial investigating withdrawal of either donepezil or memantine. No trials assessed withdrawal of memantine only. Drugs were withdrawn abruptly in five trials and stepwise in two trials. All participants had dementia due to Alzheimer's disease, with severities ranging from mild to very severe, and were taking cholinesterase inhibitors without known adverse effects at baseline. The included trials randomised 759 participants to treatment groups relevant to this review. Study duration ranged from 6 weeks to 12 months. There were too few included studies to allow planned subgroup analyses. We considered some studies to be at unclear or high risk of selection, performance, detection, attrition or reporting bias. Compared to continuing cholinesterase inhibitors, discontinuing treatment may be associated with worse cognitive function in the short term (standardised mean difference (SMD) -0.42, 95% confidence interval (CI) -0.64 to -0.21; 4 studies; low certainty), but the effect in the medium term is very uncertain (SMD -0.40, 95% CI -0.87 to 0.07; 3 studies; very low certainty). In a sensitivity analysis omitting data from a study which only included participants who had shown a relatively poor prior response to donepezil, inconsistency was reduced and we found that cognitive function may be worse in the discontinuation group in the medium term (SMD -0.62; 95% CI -0.94 to -0.31). Data from one longer-term study suggest that discontinuing a cholinesterase inhibitor is probably associated with worse cognitive function at 12 months (mean difference (MD) -2.09 Standardised Mini-Mental State Examination (SMMSE) points, 95% CI -3.43 to -0.75; moderate certainty). Discontinuation may make little or no difference to functional status in the short term (SMD -0.25, 95% CI -0.54 to 0.04; 2 studies; low certainty), and its effect in the medium term is uncertain (SMD -0.38, 95% CI -0.74 to -0.01; 2 studies; very low certainty). After 12 months, discontinuing a cholinesterase inhibitor probably results in greater functional impairment than continuing treatment (MD -3.38 Bristol Activities of Daily Living Scale (BADLS) points, 95% CI -6.67 to -0.10; one study; moderate certainty). Discontinuation may be associated with a worsening of neuropsychiatric symptoms over the short term and medium term, although we cannot exclude a minimal effect (SMD - 0.48, 95% CI -0.82 to -0.13; 2 studies; low certainty; and SMD -0.27, 95% CI -0.47 to -0.08; 3 studies; low certainty, respectively). Data from one study suggest that discontinuing a cholinesterase inhibitor may result in little to no change in neuropsychiatric status at 12 months (MD -0.87 Neuropsychiatric Inventory (NPI) points; 95% CI -8.42 to 6.68; moderate certainty). We found no clear evidence of an effect of discontinuation on dropout due to lack of medication efficacy or deterioration in overall medical condition (odds ratio (OR) 1.53, 95% CI 0.84 to 2.76; 4 studies; low certainty), on number of adverse events (OR 0.85, 95% CI 0.57 to 1.27; 4 studies; low certainty) or serious adverse events (OR 0.80, 95% CI 0.46 to 1.39; 4 studies; low certainty), and on mortality (OR 0.75, 95% CI 0.36 to 1.55; 5 studies; low certainty). Institutionalisation was reported in one trial, but it was not possible to extract data for the groups relevant to this review.

AUTHORS' CONCLUSIONS

This review suggests that discontinuing cholinesterase inhibitors may result in worse cognitive, neuropsychiatric and functional status than continuing treatment, although this is supported by limited evidence, almost all of low or very low certainty. As all participants had dementia due to Alzheimer's disease, our findings are not transferable to other dementia types. We were unable to determine whether the effects of discontinuing cholinesterase inhibitors differed with baseline dementia severity. There is currently no evidence to guide decisions about discontinuing memantine. There is a need for further well-designed RCTs, across a range of dementia severities and settings. We are aware of two ongoing registered trials. In making decisions about discontinuing these drugs, clinicians should exercise caution, considering the evidence from existing trials along with other factors important to patients and their carers.

Does Treatment Response With Antidementia Drugs After 6 Months in Alzheimer's Disease Predict Long-term Treatment Outcome?

BACKGROUND

Alzheimer's disease (AD) is a chronic, progressive disorder that causes declines in cognitive and physical functions. This condition places severe burdens on families and caregivers. Delaying progressive declines in cognitive function and reducing their burden are thus important. Relationships between early treatment response and subsequent outcomes of schizophrenia and major depressive disorder have been reported. We thus aimed to investigate the relationships between treatment response to antidementia drugs in AD after 6 months (M) and subsequent outcomes.

METHODS

Eligible individuals comprised 194 patients diagnosed with presumed AD. Of these, 110 patients who received antidementia drugs for the first time and were assessed using the Mini-Mental State Examination (MMSE) at 6 M, 12 M, and 24 M were categorized as responders (n = 84) or nonresponders (n = 26). Responders were defined as showing a change in MMSE after 6 M the same as or lower than that in the natural course according to previously reported data.

RESULTS

No significant differences in baseline characteristics (age, sex, education, or comorbidities) were seen between groups. Mean MMSE score at baseline was significantly lower in responders (18.0) than in nonresponders (20.7; P = 0.008). Mean change from baseline MMSE was significantly smaller in responders than in nonresponders at both 12 M (-0.46 vs -2.5; P = 0.04) and 24 M (-0.78 vs -4.4; P = 0.001).

CONCLUSIONS

Treatment response with antidementia drugs after 6 M predicted better outcomes at 12 M and 24 M. Treatment response should be assessed every 6 M, and treatment should be reconsidered accordingly.

Anti-amyloid-β protein agents for the treatment of Alzheimer's disease: an update on emerging drugs

INTRODUCTION

Currently available Alzheimer's disease (AD) therapeutics are only symptomatic, targeting cholinergic and glutamatergic neurotransmissions. Several putative disease-modifying drugs in late-stage clinical development target amyloid-β (Aβ) peptide and tau protein, the principal neurophatological hallmarks of the disease.

AREAS COVERED

Phase III randomized clinical trials of anti-Aβ drugs for AD treatment were searched in US and EU clinical trial registries and principal biomedical databases until May 2020.

EXPERT OPINION

At present, compounds in Phase III clinical development for AD include four  anti-Ab monoclonal antibodies (solanezumab, gantenerumab, aducanumab, BAN2401), the combination of cromolyn sodium and ibuprofen (ALZT-OP1), and two small molecules (levetiracetam, GV-971). These drugs are mainly being tested in subjects during early AD phases or at preclinical stage of familial AD or even in asymptomatic subjects at high risk of developing AD. The actual results support the hypothesis that elevated Aβ represents an early stage in the AD continuum and demonstrate the feasibility of enrolling these high-risk participants in secondary prevention trials to slow cognitive decline during the AD preclinical stages. However, a series of clinical failures may question further development of Aβ-targeting drugs and the findings from current ongoing Phase III trials will hopefully give light to this critical issue.

Improving Anti-Neurodegenerative Benefits of Acetylcholinesterase Inhibitors in Alzheimer's Disease: Are Irreversible Inhibitors the Future?

Decades of research have produced no effective method to prevent, delay the onset, or slow the progression of Alzheimer's disease (AD). In contrast to these failures, acetylcholinesterase (AChE, EC 3.1.1.7) inhibitors slow the clinical progression of the disease and randomized, placebo-controlled trials in prodromal and mild to moderate AD patients have shown AChE inhibitor anti-neurodegenerative benefits in the cortex, hippocampus, and basal forebrain. CNS neurodegeneration and atrophy are now recognized as biomarkers of AD according to the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria and recent evidence shows that these markers are among the earliest signs of prodromal AD, before the appearance of amyloid. The current AChE inhibitors (donepezil, rivastigmine, and galantamine) have short-acting mechanisms of action that result in dose-limiting toxicity and inadequate efficacy. Irreversible AChE inhibitors, with a long-acting mechanism of action, are inherently CNS selective and can more than double CNS AChE inhibition possible with short-acting inhibitors. Irreversible AChE inhibitors open the door to high-level CNS AChE inhibition and improved anti-neurodegenerative benefits that may be an important part of future treatments to more effectively prevent, delay the onset, or slow the progression of AD.

Risk for Health Events After Deprescribing Acetylcholinesterase Inhibitors in Nursing Home Residents With Severe Dementia

BACKGROUND/OBJECTIVE

Reevaluation of the appropriateness of acetylcholinesterase inhibitors (AChEIs) is recommended in older adults with severe dementia, given the lack of strong evidence to support their continued effectiveness and risk for medication-induced adverse events. We sought to evaluate the impact of deprescribing AChEIs on risk of all-cause events (hospitalizations, emergency department visits, and mortality) and serious falls or fractures in older nursing home (NH) residents with severe dementia.

DESIGN

Analysis of 2015 to 2016 data from Medicare claims, Part D prescriptions, Minimum Data Set (MDS) version 3.0, Area Health Resource File, and Nursing Home Compare. Marginal structural models with inverse probability of treatment weights were used to evaluate the association of deprescribing AChEIs and all-cause negative events as well as serious falls or fractures.

SETTING

US Medicare-certified NHs.

PARTICIPANTS

Nonskilled NH residents, aged 65 years and older, with severe dementia receiving AChEIs within the first 14 days of an MDS assessment in 2016 (n = 37 106).

RESULTS

The sample was primarily white (78.7%), female (75.5%), and aged 80 years or older (77.4%). Deprescribing AChEIs was associated with an increased likelihood of all-cause negative events in unadjusted models (odds ratio [OR] = 1.17; 95% confidence interval [CI] = 1.11-1.23; P < .01), but not in fully adjusted models (adjusted OR [aOR] = 1.00; 95% CI = 0.94-1.06; P = .94). By contrast, deprescribing was associated with a reduced likelihood of serious falls or fractures in unadjusted models (OR = 0.59; 95% CI = 0.52-0.66; P < .001) and remained significant in adjusted models (aOR = 0.64; 95% CI = 0.56-0.73; P < .001).

CONCLUSION

Deprescribing AChEIs was not associated with a significant increase in the likelihood for all-cause negative events and was associated with a reduced likelihood of falls and fractures in older NH residents with dementia. Our findings suggest that deprescribing AChEIs is a reasonable approach to reduce the risk of serious falls or fractures without increasing the risk for all-cause events. J Am Geriatr Soc 68:699-707, 2020.

Therapeutic noninvasive brain stimulation in Alzheimer's disease and related dementias

PURPOSE OF REVIEW

Alzheimer's disease is a progressive neurodegenerative disease without effective pharmacological treatment. Noninvasive brain stimulation (NIBS) techniques, such as repetitive transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES), are increasingly being investigated for their potential to ameliorate the symptoms of Alzheimer's disease and related dementias (ADRD).

RECENT FINDINGS

A comprehensive literature review for primary research reports that investigated the ability of TMS/tES to improve cognition in ADRD patients yielded a total of 20 reports since 2016. Eight studies used repetitive TMS and 12 used transcranial direct current stimulation, the most common form of tES. Eight of the studies combined NIBS with cognitive training. Promising results should encourage continued investigation, however there is currently insufficient evidence to support widespread adoption of NIBS-based clinical treatments for ADRD.

SUMMARY

NIBS remains an active area of investigation for treatment of ADRD, though the predominance of small, heterogeneous, proof-of-principle studies precludes definitive conclusions. We propose the establishment of a consortium to achieve the benefits of large-scale, controlled studies using biomarker-based diagnostic characterization of participants, development of neurophysiological markers to verify target engagement, and standardization of parameters.

Alzheimer's disease medication and outcomes of hospitalisation among patients with dementia

AIMS

The use of Alzheimer disease medication for the treatment of dementia symptoms has shown significant benefits with regards to functional and cognitive outcomes as well as nursing home placement (NHP) and mortality. Hospitalisations in these patient groups are characterised by extended length of stays (LOS), frequent readmissions, frequent NHP and high-mortality rates. The impact of Alzheimer disease medication on the aforementioned outcomes remains still unknown. This study assessed the association of Alzheimer disease medication with outcomes of hospitalisation among patients with Alzheimer disease and other forms of dementia.

METHODS

A dynamic retrospective cohort study from 2004 to 2015 was conducted which claims data from a German health insurance company. People with dementia (PWD) were identified using ICD-10 codes and diagnostic measures. The main predictor of interest was the use of Alzheimer disease medication. Hospitalisation outcomes included LOS, readmissions, NHP and mortality during and after hospitalisation across four hospitalisations. Confounding was addressed using a propensity score throughout all analyses.

RESULTS

A total of 1380 users of Alzheimer disease medication and 6730 non-users were identified. The use of Alzheimer disease medication was associated with significantly shorter LOS during the first hospitalisations with estimates for the second, third and fourth showed a tendency towards shorter hospital stays. In addition, current users of Alzheimer disease medication had a lower risk of hospital readmission after the first two hospitalisations. These associations were not significant for the third and fourth hospitalisations. Post-hospitalisation NHP and mortality rates also tended to be lower among current users than among non-users but differences did not reach statistical significance.

CONCLUSIONS

Our results indicate that Alzheimer disease medication might contribute to a reduction of the LOS and the number of readmissions in PWD.

Circuit Mechanisms of Neurodegenerative Diseases: A New Frontier With Miniature Fluorescence Microscopy

Neurodegenerative diseases (NDDs), such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD), are devastating age-associated brain disorders. Significant efforts have been made to uncover the molecular and cellular pathogenic mechanisms that underlie NDDs. However, our understanding of the neural circuit mechanisms that mediate NDDs and associated symptomatic features have been hindered by technological limitations. Our inability to identify and track individual neurons longitudinally in subcortical brain regions that are preferentially targeted in NDDs has left gaping holes in our knowledge of NDDs. Recent development and advancement of the miniature fluorescence microscope (miniscope) has opened up new avenues for examining spatially and temporally coordinated activity from hundreds of cells in deep brain structures in freely moving rodents. In the present mini-review, we examine the capabilities of current and future miniscope tools and discuss the innovative applications of miniscope imaging techniques that can push the boundaries of our understanding of neural circuit mechanisms of NDDs into new territories.

Behavioral and Psychiatric Symptoms of Dementia and Rate of Decline in Alzheimer's Disease

Alzheimer’s disease causes both cognitive and non-cognitive symptoms. There is increasing evidence that the presentation and course of Alzheimer’s disease is highly heterogenous. This heterogeneity presents challenges to patients, their families, and clinicians due to the difficulty in prognosticating future symptoms and functional impairment. Behavioral and psychiatric symptoms are emerging as a significant contributor to this clinical heterogeneity. These symptoms have been linked to multiple areas of neurodegeneration, which may suggest that they are representative of network-wide dysfunction in the brain. However, current diagnostic criteria for Alzheimer’s disease focus exclusively on the cognitive aspects of disease. Behavioral and psychiatric symptoms have been found in multiple studies to be related to disease severity and to contribute to disease progression over time. A better understanding of how behavioral and psychiatric symptoms relate to cognitive aspects of Alzheimer’s disease would help to refine the models of disease and hopefully lead to improved ability to develop therapeutic options for this devastating disease.

Are antidementia drugs associated with reduced mortality after a hospital emergency admission in the population with dementia aged 65 years and older?

Introduction

People with dementia experience poor outcomes after hospital admission, with mortality being particularly high. There is no cure for dementia; antidementia medications have been shown to improve cognition and function, but their effect on mortality in real-world settings is little known. This study examines associations between treatment with antidementia medication and mortality in older people with dementia after an emergency admission.

Methods

The design is a retrospective cohort study of people aged ≥65 years, with a diagnosis of dementia and an emergency hospital admission between 01/01/2010 and 31/12/2016. Two classes of antidementia medication were considered: the acetylcholinesterase inhibitors and memantine. Mortality was examined using a Cox proportional hazards model with time-varying covariates for the prescribing of antidementia medication before or on admission and during one-year follow-up, adjusted for demographics, comorbidity, and community prescribing including anticholinergic burden. Propensity score analysis was examined for treatment selection bias.

Results

There were 9142 patients with known dementia included in this study, of which 45.0% (n = 4110) received an antidementia medication before or on admission; 31.3% (n = 2864) were prescribed one of the acetylcholinesterase inhibitors, 8.7% (n = 798) memantine, and 4.9% (n = 448) both. 32.9% (n = 1352) of these patients died in the year after admission, compared to 42.7% (n = 2148) of those with no antidementia medication on admission. The Cox model showed a significant reduction in mortality in patients treated with acetylcholinesterase inhibitors (hazard ratio [HR] = 0.78, 95% CI 0.72–0.85) or memantine (HR = 0.75, 95% CI 0.66–0.86) or both (HR = 0.76, 95% CI 0.68–0.94). Sensitivity analysis by propensity score matching confirmed the associations between antidementia prescribing and reduced mortality.

Discussion

Treatment with antidementia medication is associated with a reduction in risk of death in the year after an emergency hospital admission. Further research is required to determine if there is a causal relationship between treatment and mortality, and whether “symptomatic” therapy for dementia does have a disease-modifying effect.

•

Mortality in older people admitted with dementia is very high after an emergency hospital admission with about 40% of them dying within one year from admission.

•

Less than half of patients admitted with dementia are in receipt of antidementia treatment on admission.

•

Risk of death is reduced in patients treated with antidementia medication at the time of acute admission, which is not explained by their age, sex, comorbidities, or other drug prescribing.

Decline in mortality in patients with dementia: Results from a nationwide cohort of 44 258 patients in the Netherlands during 2000 to 2008

OBJECTIVE

To investigate whether mortality and readmission risk have changed over the last decade.

METHODS

Prospective hospital-based cohort of 44 258 patients with dementia admitted to hospital or visiting a day clinic between 2000 and 2008. Absolute risks (ARs) of 1- and 3-year mortality and 1-year hospital readmission were quantified and stratified by type of care (day clinic or inpatient care). Cox models were used to compare hazard ratios (HRs), adjusted for age, sex, comorbidity, of death, and readmission across the years using 2000 as the reference group.

RESULTS

One-year mortality declined among men visiting a day clinic (AR in 2008 versus 2000: 13.0%, 29.9%; HR 0.41, 95% CI, 0.30-0.55). Among inpatients, these ARs were 48.7%, 53.0% (HR 0.85, 95% CI, 0.77-0.94). Three-year mortality also declined (AR for men visiting a day clinic: 37.5%, 58.4%, HR 0.53, 95% CI, 0.43-0.64; for inpatients: 74.4%, 78.9%, HR 0.80, 95% CI, 0.73-0.88). Whereas 1-year readmission risk decreased among men visiting a day clinic (AR 44.1%, 65.9%, HR 0.52, 95% CI, 0.43-0.63), the risk increased among inpatients (AR 36.9%, 27.6%, HR 1.48, 95% CI, 1.28-1.72).

CONCLUSION

One- and 3-year mortality remarkably declined. One-year hospital readmission risk increased among inpatients and decreased among patients visiting a day clinic. The results should raise awareness for the increased survival with dementia, as this has direct consequences for patients and (in)formal caregivers, and probably also for health care costs.

Postoperative cognitive dysfunction - current preventive strategies

Improving trends in global health care have resulted in a steady increase in the geriatric population. However, as the population ages, surgery is being performed more frequently in progressively older patients and those with higher prevalence of comorbidities. A significant percentage of elderly patients experience transient postoperative delirium following surgery or long-term postoperative cognitive dysfunction (POCD). Increasing age, educational level, pre-existing mental health, and comorbidities are contributory factors. Comprehensive geriatric assessment provides an objective evaluation on overall medical, social, mental, and functional well-being with scope for preoperative optimization. Preventive strategies for POCD target the surgical and patient-related factors as well as the utilization of the concept of stress-free anesthesia and surgery, that is, Enhanced Recovery After Surgery. This includes care bundles and protocols for the perioperative period which improves outcomes in the elderly. Research on biomarkers of neural injury in POCD is gaining momentum. Pharmacologic agents such as acetylcholine esterase inhibitors promise to have a vital role in the management of POCD but exhibit undesired side effects. Interventions to reduce oxidative stress and neuroinflammation could prove beneficial. Preventive strategies, early recognition, and management of perioperative risk factors seems to be, by far, the best modality to deal with POCD till further progress in therapeutic interventions evolve.

The Impact of a Long-Term Rivastigmine and Donepezil Treatment on All-Cause Mortality in Patients With Alzheimer's Disease

Cholinesterase inhibitors (ChEIs) are the mainstays of symptomatic treatment of Alzheimer's disease (AD); however, their efficacy is limited, and their use was associated with deaths in some groups of patients. The aim of the current study was to assess the impact of the long-term use of ChEIs on mortality in patients with AD. This observational, longitudinal study included 1171 adult patients with a diagnosis of AD treated with donepezil or rivastigmine. Each patient was observed for 24 months or until death. The cognitive and functional assessments, the use of ChEIs, memantine, antipsychotics, antidepressants, and anxiolytics were recorded. The total number of deaths at the end of the observational period was 99 (8.45%). The patients who had received rivastigmine treatment were at an increased risk of death in the follow-up period. The higher risk of death in the rivastigmine group remained significant in multivariate Cox regression models.

Impact of cholinesterase inhibitors or memantine on survival in adults with Down syndrome and dementia: clinical cohort study

BACKGROUND

There is little evidence to guide pharmacological treatment in adults with Down syndrome and Alzheimer's disease. Aims To investigate the effect of cholinesterase inhibitors or memantine on survival and function in adults with Down syndrome and Alzheimer's disease.

METHOD

This was a naturalistic longitudinal follow-up of a clinical cohort of 310 people with Down syndrome diagnosed with Alzheimer's disease collected from specialist community services in England.

RESULTS

Median survival time (5.59 years, 95% CI 4.67-6.67) for those on medication (n = 145, mainly cholinesterase inhibitors) was significantly greater than for those not prescribed medication (n = 165) (3.45 years, 95% CI 2.91-4.13, log-rank test P<0.001). Sequential assessments demonstrated an early effect in maintaining cognitive function.

CONCLUSIONS

Cholinesterase inhibitors appear to offer benefit for people with Down syndrome and Alzheimer's disease that is comparable with sporadic Alzheimer's disease; a trial to test the effect of earlier treatment (prodromal Alzheimer's disease) in Down syndrome may be indicated. Declaration of interest A.S. has undertaken consulting for Ono Pharmaceuticals, outside the submitted work. Z.W. has received a consultancy fee and grant from GE Healthcare, outside the submitted work.

Clinical Management of Episodic Memory Changes in Dementia

PURPOSE OF REVIEW

The purpose of this review was to discuss therapeutic options available for the treatment of memory difficulties in dementia.

RECENT FINDINGS

Because of the lack of progress in the availability of new medications, there has been an increased interest in focusing on non-pharmacological means to management cognitive symptoms related to dementia. The clinical management of memory loss should focus both on pharmacological and non-pharmacological approaches. Treatment with medications should usually begin with a cholinesterase inhibitor and then followed by addition of memantine if there is a decline. In addition to medication management, emphasis should be placed on the importance of maintaining a healthy lifestyle that encompasses physical activities, cognitive stimulation, and a healthy diet.

Association of Antidementia Drugs and Mortality in Community-Dwelling Frail Older Patients With Dementia: The Role of Mortality Risk Assessment

OBJECTIVE

To evaluate whether treatment with antidementia drugs is associated with reduced mortality in older patients with different mortality risk at baseline.

DESIGN

Retrospective.

SETTING

Community-dwelling.

PARTICIPANTS

A total of 6818 older people who underwent a Standardized Multidimensional Assessment Schedule for Adults and Aged Persons (SVaMA) evaluation to determine accessibility to homecare services or nursing home admission from 2005 to 2013 in the Padova Health District, Italy were included.

MEASUREMENTS

Mortality risk at baseline was calculated by the Multidimensional Prognostic Index (MPI), based on information collected with the SVaMA. Participants were categorized to have mild (MPI-SVaMA-1), moderate (MPI-SVaMA-2), and high (MPI-SVaMA-3) mortality risk. Propensity score-adjusted hazard ratios (HR) of 2-year mortality were calculated according to antidementia drug treatment.

RESULTS

Patients treated with antidementia drugs had a significant lower risk of death than untreated patients (HR 0.82; 95% confidence interval [CI] 0.73-0.92 and 0.56; 95% CI 0.49-0.65 for patients treated less than 2 years and more than 2 years treatment, respectively). After dividing patients according to their MPI-SVaMA grade, antidementia treatment was significantly associated with reduced mortality in the MPI-SVaMA-1 mild (HR 0.71; 95% CI 0.54-0.92) and MPI-SVaMA-2 moderate risk (HR 0.61; 95% CI 0.40-0.91, matched sample), but not in the MPI-SVaMA-3 high risk of death.

CONCLUSIONS

This large community-dwelling patient study suggests that antidementia drugs might contribute to increased survival in older adults with dementia with lower mortality risk.

Molecular and Cellular Basis of Neurodegeneration in Alzheimer's Disease

The most common form of senile dementia is Alzheimer's disease (AD), which is characterized by the extracellular deposition of amyloid β-peptide (Aβ) plaques and the intracellular formation of neurofibrillary tangles (NFTs) in the cerebral cortex. Tau abnormalities are commonly observed in many neurodegenerative diseases including AD, Parkinson's disease, and Pick's disease. Interestingly, tau-mediated formation of NFTs in AD brains shows better correlation with cognitive impairment than Aβ plaque accumulation; pathological tau alone is sufficient to elicit frontotemporal dementia, but it does not cause AD. A growing amount of evidence suggests that soluble Aβ oligomers in concert with hyperphosphorylated tau (pTau) serve as the major pathogenic drivers of neurodegeneration in AD. Increased Aβ oligomers trigger neuronal dysfunction and network alternations in learning and memory circuitry prior to clinical onset of AD, leading to cognitive decline. Furthermore, accumulated damage to mitochondria in the course of aging, which is the best-known nongenetic risk factor for AD, may collaborate with soluble Aβ and pTau to induce synapse loss and cognitive impairment in AD. In this review, I summarize and discuss the current knowledge of the molecular and cellular biology of AD and also the mechanisms that underlie Aβ-mediated neurodegeneration.

Neuropsychological Assessments of Cognitive Aging in Monolingual and Bilingual Older Adults

Standardized neuropsychological tests are routinely used as diagnostic criteria in aging populations and are an important piece of evidence for the identification of clinical pathology and neurodegenerative conditions such as Alzheimer's disease. Tests include such measures as the Mini Mental Status Exam, Delis-Kaplan Executive Function System, Montreal Cognitive Assessment, and others. These tests cover a range of functions including working memory, verbal fluency, prospective memory, and task switching. Interpretation of test results is based on comparison of the participant's score to standard scores that have been normed on a population database. However, a growing body of research has shown that the skills underlying these tests may be significantly different in monolingual and bilingual older adults, especially for those experiencing cognitive impairment, yet the standardized test scores do not account for such differences. Therefore, results of neuropsychological tests may be different for bilingual populations than for monolinguals, and those differences may be misinterpreted. The issue is important because the consequences of these interpretative errors may be over- or under- diagnosis of cognitive impairment. The present study examined the neuropsychological test scores of monolingual and bilingual older adults who were experiencing healthy aging or cognitive impairment to establish patterns in these scores that can more accurately guide the interpretation for bilingual older adults by considering group differences in the underlying abilities.

Discontinuation, Efficacy, and Safety of Cholinesterase Inhibitors for Alzheimer's Disease: a Meta-Analysis and Meta-Regression of 43 Randomized Clinical Trials Enrolling 16 106 Patients

Background

We investigated the effect of cholinesterase inhibitors on all-cause discontinuation, efficacy and safety, and the effects of study design-, intervention-, and patient-related covariates on the risk-benefit of cholinesterase inhibitors for Alzheimer's disease.

Methods

A systematic review and meta-analysis of randomized placebo-controlled clinical trials comparing cholinesterase inhibitors and placebo was performed. The effect of covariates on study outcomes was analysed by means of meta-regression using a Bayesian framework.

Results

Forty-three randomized placebo-controlled clinical trials involving 16106 patients were included. All-cause discontinuation was higher with cholinesterase inhibitors (OR = 1.66), as was discontinuation due to adverse events (OR=1.75). Cholinesterase inhibitors improved cognitive function (standardized mean difference = 0.38), global symptomatology (standardized mean difference=0.28) and functional capacity (standardized mean difference=0.16) but not neuropsychiatric symptoms. Rivastigmine was associated with a poorer outcome on all-cause discontinuation (Diff OR = 1.66) and donepezil with a higher efficacy on global change (Diff standardized mean difference = 0.41). The proportion of patients with serious adverse events decreased with age (Diff OR = -0.09). Mortality was lower with cholinesterase inhibitors than with placebo (OR = 0.65).

Conclusion

While cholinesterase inhibitors show a poor risk-benefit relationship as indicated by mild symptom improvement and a higher than placebo all-cause discontinuation, a reduction of mortality was suggested. Intervention- and patient-related factors modify the effect of cholinesterase inhibitors in patients with Alzheimer's disease.

A Real-world Analysis of Treatment Patterns for Cholinesterase Inhibitors and Memantine among Newly-diagnosed Alzheimer's Disease Patients

Introduction

Alzheimer’s disease (AD) is the most common neurodegenerative form of dementia. Pharmacological therapies for symptomatic treatment, such as acetylcholinesterase inhibitors (AChEIs) and memantine, have been available in the USA since 2000. Over the past decade, few studies have analyzed real-world anti-dementia treatment patterns in the USA. This study evaluated monotherapy AChEIs and memantine treatment patterns among newly diagnosed AD patients.

Methods

A retrospective cohort study was conducted using Medicare data and the Minimum Data Set from 2008 to 2012. Patients aged 65–100 years with newly diagnosed AD (ICD-9 code: 331.0) and monotherapy AChEI or memantine treatment initiated after diagnosis were included. Descriptive treatment pattern analyses, including discontinuation and switch, were undertaken. Kaplan–Meier curves were developed to examine the treatment duration.

Results

A total of 9812 newly diagnosed AD patients were identified, with 56.7% (n = 5567) first receiving anti-dementia treatment after the initial AD diagnosis. Among patients initiating monotherapy AChEIs or memantine after AD diagnosis (N = 5200), 51.6% continued index treatment during the entire follow-up period (mean follow-up: 659.7 days) and 21.7% discontinued treatment. Of those who initiated monotherapy treatment with an AChEI, 11.1% received adjunct therapy with memantine. Among patients with ≥1 year of continuous treatment (mean follow-up: 834 days), 75.6% remained on the index drug, 10.2% discontinued during the remaining follow-up period, and 9.5% of the AD patients initiating AChEIs received adjunct memantine therapy during the remaining follow-up period.

Conclusion

In the USA Medicare population, about 50% of the patients who initiated treatment with AChEI or memantine after diagnosis continued the index treatment, and more than 20% discontinued and were untreated afterwards over the observation period. AD patients initiating AChEIs or memantine were more likely to remain on their treatment if they were persistently treated for the first year.

Electronic supplementary material

The online version of this article (doi:10.1007/s40120-017-0067-7) contains supplementary material, which is available to authorized users.

Network pharmacology-based study on the mechanism of action for herbal medicines in Alzheimer treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD), as the most common type of dementia, has brought a heavy economic burden to healthcare system around the world. However, currently there is still lack of effective treatment for AD patients. Herbal medicines, featured as multiple herbs, ingredients and targets, have accumulated a great deal of valuable experience in treating AD although the exact molecular mechanisms are still unclear.

MATERIALS AND METHODS

In this investigation, we proposed a network pharmacology-based method, which combined large-scale text-mining, drug-likeness filtering, target prediction and network analysis to decipher the mechanisms of action for the most widely studied medicinal herbs in AD treatment.

RESULTS

The text mining of PubMed resulted in 10 herbs exhibiting significant correlations with AD. Subsequently, after drug-likeness filtering, 1016 compounds were remaining for 10 herbs, followed by structure clustering to sum up chemical scaffolds of herb ingredients. Based on target prediction results performed by our in-house protocol named AlzhCPI, compound-target (C-T) and target-pathway (T-P) networks were constructed to decipher the mechanism of action for anti-AD herbs.

CONCLUSIONS

Overall, this approach provided a novel strategy to explore the mechanisms of herbal medicine from a holistic perspective.

The road to restoring neural circuits for the treatment of Alzheimer's disease

Alzheimer's disease is a progressive loss of memory and cognition, for which there is no cure. Although genetic studies initially suggested a primary role for amyloid-in Alzheimer's disease, treatment strategies targeted at reducing amyloid-have failed to reverse cognitive symptoms. These clinical findings suggest that cognitive decline is the result of a complex pathophysiology and that targeting amyloid-alone may not be sufficient to treat Alzheimer's disease. Instead, a broad outlook on neural-circuit-damaging processes may yield insights into new therapeutic strategies for curing memory loss in the disease.

Association between acetylcholinesterase inhibitors and risk of stroke in patients with dementia

Patients with dementia are at increased risk of stroke. Acetylcholinesterase inhibitors (AChEIs) have endothelial function protection effects and anti-inflammatory properties. We investigated the ischemic stroke risk in AChEIs use in dementia patients without stroke history. Using Taiwan National Health Insurance Database from 1999 to 2008, 37,352 dementia patients over 50 years old without stroke history were eligible. The results were analyzed by propensity score–matched Cox proportional hazard models with competing risk adjustment. AChEIs users had lower incidence of ischemic stroke (160.3/10,000 person-years), compared to the propensity score–matched reference (240.8/10,000 person-years). The adjusted hazard ratio for ischemic stroke based on propensity score–matched Cox proportional hazard model was 0.508 (95% confidence interval, 0.434–0.594; P < 0.001). There was no significant difference in all-cause mortality between AChEIs users and nonusers. In conclusion, among dementia patients without previous ischemic stroke history, AChEIs treatment was associated with a decreased risk of ischemic stroke but not greater survival.

Aging in two languages: Implications for public health

With the population aging and a dramatic increase in the number of senior citizens, public health systems will be increasingly burdened with the need to deal with the care and treatment of individuals with dementia. We review evidence demonstrating how a particular experience, bilingualism, has been shown to protect cognitive function in older age and delay onset of symptoms of dementia. This paper describes behavioral and brain studies that have compared monolingual and bilingual older adults on measures of cognitive function or brain structure and reviews evidence demonstrating a protective effect of bilingualism against symptoms of dementia. We conclude by presenting some data showing the potential savings in both human costs in terms of demented patients and economic considerations in terms of public money if symptoms of dementia could be postponed.

Longitudinal Associations between Survival in Alzheimer's Disease and Cholinesterase Inhibitor Use, Progression, and Community-Based Services

BACKGROUND/AIMS

Factors including rate of disease progression, different aspects of cholinesterase inhibitor (ChEI) treatment, and use of community-based services might affect the longitudinal outcome of Alzheimer's disease (AD). Whether these factors alter life expectancy in AD is unclear. We therefore examined the association between long-term ChEI therapy and survival.

METHODS

The present study included 1,021 patients with a clinical diagnosis of AD and a Mini-Mental State Examination score of 10-26 at baseline from a 3-year, prospective, multicenter study of ChEI therapy in clinical practice. The relationship of potential predictors with mortality was analyzed using Cox regression models.

RESULTS

After up to 16 years of follow-up, 841 (82%) of the participants had died. In the Alzheimer's Disease Assessment Scale-cognitive subscale, a mean decline of ≥ 4 points/year or ≥ 2 points/year on the Physical Self-Maintenance Scale was a risk factor for an earlier death. In the multivariate models, longer survival was associated with higher ChEI dose and longer duration of treatment. Users of community-based services at baseline exhibited a 1-year shorter mean life expectancy than nonusers.

CONCLUSION

A longer survival time can be anticipated for AD patients with slower deterioration who receive and tolerate higher ChEI doses and a longer duration of treatment.

Impact of acetylcholinesterase inhibitors on the occurrence of acute coronary syndrome in patients with dementia

The study aimed to investigate the association of acetylcholinesterase inhibitors (AChEIs) use with the risk of acute coronary syndrome (ACS). We conducted a population-based retrospective cohort study of dementia patients during 1 January 1999 to 31 December 2008 using the National Health Insurance Database in Taiwan. New AChEI users during the study period were matched with AChEI nonusers in age-matched and gender-matched cohorts. The risk of ACS associated with use of AChEIs was analyzed using modified Kaplan-Meier analysis and Cox proportional hazard models after adjustment for competing death risk. Use of AChEIs was associated with a lower incidence of ACS (212.8/10,000 person-years) compared to the matched reference cohort (268.7/10,000 person-years). The adjusted hazard ratio for ACS in patients with dementia treated with AChEIs was 0.836 (95% confidence interval, 0.750–0.933; P < 0.001). Further sensitivity analysis of different study populations demonstrated consistent results. A statistical dose–response relationship for AChEI use and ACS risk was significant for the patients with dementia. In patients with dementia, AChEI treatment was associated with decreased risk of ACS.

Surgical outcomes of hip and knee arthroplasties for primary osteoarthritis in patients with Alzheimer's disease: a nationwide registry-based case-controlled study

We compared the length of hospitalisation, rate of infection, dislocation of the hip and revision, and mortality following primary hip and knee arthroplasty for osteoarthritis in patients with Alzheimer's disease (n = 1064) and a matched control group (n = 3192). The data were collected from nationwide Finnish health registers. Patients with Alzheimer's disease had a longer peri-operative hospitalisation (median 13 days vs eight days, p < 0.001) and an increased risk for hip revision with a hazard ratio (HR) of 1.76 (95% confidence interval (CI) 1.03 to 3.00). Dislocation was the leading indication for revision. There was no difference in the rates of infection, dislocation of the hip, knee revision and short-term mortality. In long-term follow-up, patients with Alzheimer's disease had a higher mortality (HR 1.43; 95% CI 1.22 to 1.70), and only one third survived ten years post-operatively. Increased age and comorbidity were associated with longer peri-operative hospitalisation in patients with Alzheimer's disease.

Survival and early recourse to care for dementia: A population based study

BACKGROUND

A large proportion of dementia cases are still undiagnosed. Although early dementia care has been hypothesized to benefit both patients and families, evidence-based benefits are lacking. Thus, investigating the benefits for newly demented persons according to their recourse to care in the "real life" appears critical.

METHODS

We examined the relation between initial care recourse care and demented individuals' survival in a large cohort of incident dementia cases screened in a prospective population-based cohort, the Three-City Study. We assessed recourse to care for cognitive complaint at the early beginning of dementia when incident cases were screened. We classified patients in three categories: no care recourse, general practitioner consultation or specialist consultation. We used proportional hazard regression models to test the association between recourse to care and mortality, adjusting on socio-demographical and clinical characteristics.

RESULTS

Two hundred and fifty-three incident dementia participants were screened at the 2 year or 4 year follow-up. One third of the incident demented individuals had not consulted a physician for cognitive problems. Eighty-six (34.0%) individuals had reported a cognitive problem only to their general practitioner (GP) and 80 (31.6%) had consulted a specialist. Mean duration of follow-up after incident dementia was 5.1 years, during which 146 participants died. After adjustment on potential confounders, participants who had consulted a specialist early in the disease course presented a poorer survival than those who did not consult any physician (hazard ratio = 1.64, 95% confidence interval 1.03-2.62). There was a trend but no significant differential survival profile between participants who complained to their GP and those without any care recourse.

CONCLUSION

Neither recourse to a specialist nor recourse to GP improve survival of new dementia cases. Those who had consulted a specialist early in the disease course even reported a worse life expectancy than those who did not.

Cost effective community based dementia screening: a markov model simulation

Background. Given the dementia epidemic and the increasing cost of healthcare, there is a need to assess the economic benefit of community based dementia screening programs. Materials and Methods. Markov model simulations were generated using data obtained from a community based dementia screening program over a one-year period. The models simulated yearly costs of caring for patients based on clinical transitions beginning in pre dementia and extending for 10 years. Results. A total of 93 individuals (74 female, 19 male) were screened for dementia and 12 meeting clinical criteria for either mild cognitive impairment (n = 7) or dementia (n = 5) were identified. Assuming early therapeutic intervention beginning during the year of dementia detection, Markov model simulations demonstrated 9.8% reduction in cost of dementia care over a ten-year simulation period, primarily through increased duration in mild stages and reduced time in more costly moderate and severe stages. Discussion. Community based dementia screening can reduce healthcare costs associated with caring for demented individuals through earlier detection and treatment, resulting in proportionately reduced time in more costly advanced stages.

Pharmacogenomics of Alzheimer's disease: novel therapeutic strategies for drug development

Alzheimer's disease (AD) is a major problem of health and disability, with a relevant economic impact on our society. Despite important advances in pathogenesis, diagnosis, and treatment, its primary causes still remain elusive, accurate biomarkers are not well characterized, and the available pharmacological treatments are not cost-effective. As a complex disorder, AD is a polygenic and multifactorial clinical entity in which hundreds of defective genes distributed across the human genome may contribute to its pathogenesis. Diverse environmental factors, cerebrovascular dysfunction, and epigenetic phenomena, together with structural and functional genomic dysfunctions, lead to amyloid deposition, neurofibrillary tangle formation, and premature neuronal death, the major neuropathological hallmarks of AD. Future perspectives for the global management of AD predict that genomics and proteomics may help in the search for reliable biomarkers. In practical terms, the therapeutic response to conventional drugs (cholinesterase inhibitors, multifactorial strategies) is genotype-specific. Genomic factors potentially involved in AD pharmacogenomics include at least five categories of gene clusters: (1) genes associated with disease pathogenesis; (2) genes associated with the mechanism of action of drugs; (3) genes associated with drug metabolism (phase I and II reactions); (4) genes associated with drug transporters; and (5) pleiotropic genes involved in multifaceted cascades and metabolic reactions. The implementation of pharmacogenomic strategies will contribute to optimize drug development and therapeutics in AD and related disorders.