Different Doses of Pharmacological Treatments for Mild to Moderate Alzheimer's Disease: A Bayesian Network Meta-Analysis

Antidementia Medication Use in Nursing Home Residents

BACKGROUND

Antidementia medication can provide symptomatic improvements in patients with Alzheimer's disease, but there is a lack of consensus guidance on when to start and stop treatment in the nursing home setting.

METHODS

We describe utilization patterns of cholinesterase inhibitors (ChEI) and memantine for 3,50,197 newly admitted NH residents with dementia between 2011 and 2018.

RESULTS

Overall, pre-admission use of antidementia medications declined from 2011 to 2018 (ChEIs: 44.5% to 36.9%; memantine: 27.4% to 23.2%). Older age, use of a feeding tube, and greater functional dependency were associated with lower odds of ChEI initiation. Coronary artery disease, parenteral nutrition, severe aggressive behaviors, severe cognitive impairment, and high functional dependency were associated with discontinuation of ChEIs. Comparison of clinical factors related to anti-dementia drug treatment changes from pre to post NH admission in 2011 and 2018 revealed a change toward lower likelihood of initiation of treatment among residents with more functional dependency and those with indicators of more complex illness as well as a change toward higher likelihood of discontinuation in residents having 2 or more hospital stays.

CONCLUSIONS

These prescribing trends highlight the need for additional research on the effects of initiating and discontinuing antidementia medications in the NH to provide clear guidance for clinicians when making treatment decisions for individual residents.

A Potential Role for the Ketogenic Diet in Alzheimer's Disease Treatment: Exploring Pre-Clinical and Clinical Evidence

Given the remarkable progress in global health and overall quality of life, the significant rise in life expectancy has become intertwined with the surging occurrence of neurodegenerative disorders (NDs). This emerging trend is poised to pose a substantial challenge to the fields of medicine and public health in the years ahead. In this context, Alzheimer's disease (AD) is regarded as an ND that causes recent memory loss, motor impairment and cognitive deficits. AD is the most common cause of dementia in the elderly and its development is linked to multifactorial interactions between the environment, genetics, aging and lifestyle. The pathological hallmarks in AD are the accumulation of β-amyloid peptide (Aβ), the hyperphosphorylation of tau protein, neurotoxic events and impaired glucose metabolism. Due to pharmacological limitations and in view of the prevailing glycemic hypometabolism, the ketogenic diet (KD) emerges as a promising non-pharmacological possibility for managing AD, an approach that has already demonstrated efficacy in addressing other disorders, notably epilepsy. The KD consists of a food regimen in which carbohydrate intake is discouraged at the expense of increased lipid consumption, inducing metabolic ketosis whereby the main source of energy becomes ketone bodies instead of glucose. Thus, under these dietary conditions, neuronal death via lack of energy would be decreased, inasmuch as the metabolism of lipids is not impaired in AD. In this way, the clinical picture of patients with AD would potentially improve via the slowing down of symptoms and delaying of the progression of the disease. Hence, this review aims to explore the rationale behind utilizing the KD in AD treatment while emphasizing the metabolic interplay between the KD and the improvement of AD indicators, drawing insights from both preclinical and clinical investigations. Via a comprehensive examination of the studies detailed in this review, it is evident that the KD emerges as a promising alternative for managing AD. Moreover, its efficacy is notably enhanced when dietary composition is modified, thereby opening up innovative avenues for decreasing the progression of AD.

Repetitive transcranial magnetic stimulation may be superior to drug therapy in the treatment of Alzheimer's disease: A systematic review and Bayesian network meta-analysis

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation therapy that is primarily used to treat a variety of neuropsychiatric conditions. Recently, previous research reports stated that rTMS have the characteristics of neurorestorative in Alzheimer's disease (AD). However, the relevant clinical research evidence has not been fully summarized.

METHODS

This article performed a network meta-analysis of individual participant data from eligible studies searched in PubMed, Embase, and the Cochrane Library from inception to March 31, 2022. The drug treatments involved were acetylcholinesterase inhibitors (AChEIs), N-methyl-d-aspartate (NMDA), anti-amyloid-beta (Aβ), and some new targeted therapeutic drugs.

RESULTS

A total of 15, 548 individuals with AD disease in 57 randomized clinical trials (RCTs) were included in this meta-analysis. The results indicated that the patients who received rTMS treatment (standard mean difference [SMD]: 0.65; 95% confidence interval [CI]: 0.22-1.07) had a better MMSE score than placebo. Treatment outcome analysis showed that, compared with multiple pharmacological interventions, rTMS acquired the greatest probability rank with the best cognitive improvement in MMSE score [the surface under the cumulative ranking curve (SUCRA) 93.3%] and ADAS-cog score (SUCRA 86.7%). At the same time, rTMS treatment had the lowest rank in the adverse events (SUCRA 24.1%) except for the placebo group (SUCRA 19.1%).

CONCLUSION

Compared with the current clinical drug treatment, rTMS demonstrated better cognitive function improvement and fewer adverse events in AD patients. Therefore, rTMS shows broad prospects in the treatment of Alzheimer's disease, and it is worth being widely popularized in clinic.

Effectiveness and safety of ginkgo biloba preparations in the treatment of Alzheimer's disease: A systematic review and meta-analysis

Objective

To conduct a meta-analysis of the effectiveness and safety of ginkgo biloba preparations combined with donepezil hydrochloride vs. donepezil for the treatment of Alzheimer's disease (AD).

Methods

Three English databases (Cochrane Library, PubMed, EMBASE), and four Chinese databases [the China National Knowledge Infrastructure (CKNI), the Chinese Biomedical Literature database (CBM), the Chongqing VIP database, and WANFANG DATA)] were manually searched for literature published from the respective dates of inception of the databases to December 2022. The randomized controlled trials (RCTs) of ginkgo biloba preparations with donepezil hydrochloride vs. donepezil for the treatment of AD were included. Relevant literature was screened, and the data in the included studies were extracted for quality assessment according to the Risk of bias tool. The RevMan 5.3 software was used for meta-analysis.

Results

A total of 1,642 participants were enrolled in the 18 RCTs. Of these, 842 were in the experimental group (ginkgo biloba preparations combined with donepezil hydrochloride) and 800 were in the control group (donepezil). The overall methodological quality of the included RCTs is poor due to the high risks of blindness and allocation concealment. The meta-analysis results showed statistically significant differences in several outcomes including Risk Ratio (RR) in change for clinical effectiveness rate (1.23, 95% CI 1.13, 1.34, P < 0.00001), mean difference (MD) in change for Mini-Mental State Examination score (3.02, 95% CI 2.14, 3.89, P < 0.00001), Activity of Daily Living Scale score (-4.56, 95% CI -5.09, -4.03, P < 0.00001), Hasegawa Dementia Scale score (2.04, 95% CI 1.74, 2.34, P < 0.00001), Montreal Cognitive Assessment score (2.38, 95% CI 0.72, 4.06, P = 0.005), between the experimental and control groups. But there is no statistically significant difference in change for adverse reaction (0.91, 95% CI 0.58, 1.42, P = 0.69).

Conclusion

Ginkgo biloba preparations plus donepezil can improve clinical effectiveness rate and vocabulary memory outcomes. However, more relevant high-quality RCTs are needed in the future to validate these results.

Systematic review registration

Identifier CRD42022378970.

Donepezil inhibits neuromuscular junctional acetylcholinesterase and enhances synaptic transmission and function in isolated skeletal muscle

BACKGROUND AND PURPOSE

Donepezil, a piperidine inhibitor of acetylcholinesterase (AChE) prescribed for treatment of Alzheimer's disease, has adverse neuromuscular effects in humans, including requirement for higher concentrations of non-depolarising neuromuscular blockers during surgery. Here, we examined the effects of donepezil on synaptic transmission at neuromuscular junctions (NMJs) in isolated nerve-muscle preparations from mice.

EXPERIMENTAL APPROACH

We measured effects of therapeutic concentrations of donepezil (10 nM to 1 μM) on AChE enzymic activity, muscle force responses to repetitive stimulation, and spontaneous and evoked endplate potentials (EPPs) recorded intracellularly from flexor digitorum brevis muscles from CD01 or C57BlWld^S mice.

KEY RESULTS

Donepezil inhibited muscle AChE with an approximate IC₅₀ of 30 nM. Tetanic stimulation in sub-micromolar concentrations of donepezil prolonged post-tetanic muscle contractions. Preliminary Fluo4-imaging indicated an association of these contractions with an increase and slow decay of intracellular Ca²⁺ transients at motor endplates. Donepezil prolonged spontaneous miniature EPP (MEPP) decay time constants by about 65% and extended evoked EPP duration almost threefold. The mean frequency of spontaneous MEPPs was unaffected but the incidence of 'giant' MEPPs (gMEPPs), some exceeding 10 mV in amplitude, was increased. Neither mean MEPP amplitude (excluding gMEPPs), mean EPP amplitude, quantal content or synaptic depression during repetitive stimulation were significantly altered by concentrations of donepezil up to 1 μM.

CONCLUSION AND IMPLICATIONS

Adverse neuromuscular signs associated with donepezil therapy, including relative insensitivity to neuromuscular blockers, are probably due to inhibition of AChE at NMJs, prolonging the action of ACh on postsynaptic nicotinic acetylcholine receptors but without substantively impairing evoked ACh release.

A Synopsis of Multitarget Potential Therapeutic Effects of Huperzine A in Diverse Pathologies-Emphasis on Alzheimer's Disease Pathogenesis

Numerous challenges are confronted when it comes to the recognition of therapeutic agents for treating complex neurodegenerative diseases like Alzheimer's disease (AD). The perplexing pathogenicity of AD embodies cholinergic dysfunction, amyloid beta (Aβ) aggregation, neurofibrillary tangle formation, neuroinflammation, mitochondrial disruption along with vicious production of reactive oxygen species (ROS) generating oxidative stress. In this frame of reference, drugs with multi target components could prove more advantageous to counter complex pathological mechanisms that are responsible for AD progression. For as much as, medicinal plant based pharmaco-therapies are emerging as potential candidates for AD treatment keeping the efficacy and safety parameters in terms of toxicity and side effects into consideration. Huperzine A (Hup A) is a purified alkaloid compound extracted from a club moss called Huperzia serrata. Several studies have reported both cholinergic and non-cholinergic effects of this compound on AD with significant neuroprotective properties. The present review convenes cumulative demonstrations of neuroprotection provided by Hup A in in vitro, in vivo, and human studies in various pathologies. The underlying molecular mechanisms of its actions have also been discussed. However, more profound evidence would certainly promote the therapeutic implementation of this drug thus furnishing decisive insights into AD therapeutics and various other pathologies along with preventive and curative management.

Hypoxia-Induced Neuroinflammation in Alzheimer's Disease: Potential Neuroprotective Effects of Centella asiatica

Alzheimer's disease (AD) is a neurodegenerative disorder that is characterised by the presence of extracellular beta-amyloid fibrillary plaques and intraneuronal neurofibrillary tau tangles in the brain. Recurring failures of drug candidates targeting these pathways have prompted research in AD multifactorial pathogenesis, including the role of neuroinflammation. Triggered by various factors, such as hypoxia, neuroinflammation is strongly linked to AD susceptibility and/or progression to dementia. Chronic hypoxia induces neuroinflammation by activating microglia, the resident immune cells in the brain, along with an increased in reactive oxygen species and pro-inflammatory cytokines, features that are common to many degenerative central nervous system (CNS) disorders. Hence, interests are emerging on therapeutic agents and plant derivatives for AD that target the hypoxia-neuroinflammation pathway. Centella asiatica is one of the natural products reported to show neuroprotective effects in various models of CNS diseases. Here, we review the complex hypoxia-induced neuroinflammation in the pathogenesis of AD and the potential application of Centella asiatica as a therapeutic agent in AD or dementia.

Chemical update on the potential for serotonin 5-HT6 and 5-HT7 receptor agents in the treatment of Alzheimer's disease

Despite the better understanding of the mechanisms underlying Alzheimer's Disease (AD) and launched clinical trials, no AD-modifying treatment based on a synthetic drug has been introduced for almost twenty years. The serotonin 5-HT₆ and 5-HT₇ receptors turned out to be promising biological targets for modulation of central nervous system dysfunctions including cognitive impairment. Within this paper, we evaluate the pharmacological potency of both, 5-HT₆R and 5-HT₇R, agents in search for novel AD treatment. An overview of chemical structures of the 5-HTRs ligands with simultaneous procognitive action which have undergone preclinical and clinical studies within the last 10 years has been performed.

Effects of 6-Month Multimodal Physical Exercise Program on Bone Mineral Density, Fall Risk, Balance, and Gait in Patients with Alzheimer's Disease: A Controlled Clinical Trial

We aimed to determine the short- and medium-term effects of a multimodal physical exercise program (MPEP) on bone health status, fall risk, balance, and gait in patients with Alzheimer’s disease. A single-blinded, controlled clinical trial was performed where 72 subjects were allocated in a 3:1 ratio to an intervention group (IG; n = 53) and control group (CG; n = 19), where the IG’s subjects were admitted to live in a State Reference Center of Alzheimer’s disease, which offers the targeted exercise program, while the CG’s subjects resided in independent living. A multidisciplinary health team assessed all patients before allocation, and dependent outcomes were again assessed at one, three, and six months. During the study, falls were recorded, and in all evaluations, bone mineral density was measured using a calcaneal quantitative ultrasound densitometer; balance and gait were measured using the performance-oriented mobility assessment (POMA), the timed up and go test (TUG), the one-leg balance test (OLB), and the functional reach test (FR). There were no differences between groups at baseline for all outcome measures. The prevalence of falls was significantly lower in the IG (15.09%) than in the CG (42.11%) (χ² = 5.904; p = 0.015). We also found that there was a significant time*group interaction, with a post hoc Šidák test finding significant differences of improved physical function, especially in gait, for the IG, as assessed by POMA-Total, POMA-Gait, and TUG with a large effect size (ƞ²p = 0.185–0.201). In balance, we found significant differences between groups, regardless of time, and a medium effect size as assessed by POMA-Balance and the OLB (ƞ²p = 0.091–0.104). Clinically relevant effects were observed, although without significant differences in bone health, with a slowing of bone loss. These results show that a multimodal physical exercise program reduces fall risk and produces an improvement in gait, balance, and bone mineral density in the short and medium term in institutionalized patients with Alzheimer’s disease.

Repetitive Transcranial Magnetic Stimulation for Alzheimer's Disease Based on Apolipoprotein E Genotyping: Protocol for a Randomized Controlled Study

To date, there is a shortage of effective treatment strategies for Alzheimer's disease (AD), and although repetitive transcranial magnetic stimulation (rTMS) can improve AD cognitive function, there are obvious individual differences, which may be related to different apolipoprotein E (APOE) genotypes. As the risk and pathogenesis of AD varies greatly among different genotypes precise treatment strategies should be implemented depending upon genotype, which has not been proved by clinical studies. Apart from that, the published clinical studies are highly heterogeneous, and therefore, systematic and well-developed randomized controlled Trails (RCT) and demonstration of precise administration protocols are required. To verify this hypothesis, this project designed a RCT study, and randomly divided apoE4 carrier AD and non-carrier AD into high-frequency rTMS (HF-rTMS) or low-frequency rTMS (LF-rTMS) treatment groups. Specifically, 80 patients with AD, namely 48 APOE4 carriers and 32 non-APOE4 carriers will be included in the study. After that, based on different stimulation frequencies of rTMS, they will be divided into the HF-rTMS group and the LF-rTMS group, when patients with AD will be randomly assigned to different treatment groups. After AD patients are involved in the study, their memory, cognition, anxiety, depression and activities of daily living will be tested before and during 2 weeks of rTMS. Furthermore, peripheral blood will be collected before and after treatment to detect changes in pathological indexes via MSD platform (Meso Scale Discovery), while 32-channel EEG data will be also collected to detect and analyze changes in gamma oscillation. In addition, these patients will be followed up for 6 months and their neuropsychological scale was also evaluated every month. At present, our study has included 18 AD patients (10 APOE4 carriers; 8 non-carriers). Our study is still in progress. The grouping has not been unblinded. But the preliminary data demonstrated that non-carriers had better MoCA score improvement than APOE4 carriers. The results indicated that the two populations of AD patients should be treated differently. Thus, this project will provide direction for precision rTMS in AD and also promotes a shift in relevant treatment philosophy. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [ChiCTR2100041625].