Memantine treatment in patients with moderate to severe Alzheimer disease already receiving donepezil: a randomized controlled trial

Association between chronic stress and Alzheimer's disease: Therapeutic effects of Saffron

Chronic stress and high levels of glucocorticoids produce functional and structural changes in brain and especially in the hippocampus, an important limbic system structure that plays a key role in cognitive functions including learning and memory. Alzheimer's disease (AD) is a chronic neurodegenerative disease that usually starts slowly and worsens over time. Indeed, cognitive dysfunction, neuronal atrophy, and synaptic loss are associated with both AD and chronic stress. Recent preclinical and clinical studies have highlighted a possible link between chronic stress, cognitive decline and the development of AD. It is suggested that Tau protein is an essential mediator of the neurodegenerative effects of stress and glucocorticoids towards the development of AD pathology. Recent findings from animal and humans studies demonstrated that saffron and its main constitutive crocin are effective against chronic stress-induced cognitive dysfunction and oxidative stress and slowed cognitive decline in AD. The inhibitory actions on acetylcholinesterase activity, aggregation of beta-amyloid protein into amyloid plaques and tau protein into neurofibrillary tangles, and also the antioxidant, anti-inflammatory, and the promotion of synaptic plasticity effects are among the possible mechanisms to explain the neuroprotective effects of saffron. New evidences demonstrate that saffron and its main component crocin might be a promising target for cognition improvement in AD and stress-related disorders.

Reliability and validity of the severe impairment battery in Taiwanese patients with moderate to severe Alzheimer's disease

BACKGROUND

The severe impairment battery (SIB) was developed to evaluate cognitive functions in moderate to severe dementia patients. We aimed to examine the reliability and validity of the Taiwanese version of the SIB (T-SIB) in patients with moderate to severe Alzheimer's disease (AD).

METHODS

AD patients with clinical dementia rating (CDR) stage 2 (n = 79) or 3 (n = 21) and scores <15 on the Taiwanese version of mini mental state examination (T-MMSE) were recruited from six hospitals in Taiwan. Cronbach's alpha was used to evaluate the internal consistency of the T-SIB. The CDR and functional assessment staging (FAST) scores were used to assess dementia severity.

RESULTS

We recruited 100 AD patients (73 women and 27 men; mean T-SIB score, 56.4 ± 24.8). The mean T-SIB total score for patients with CDR 2 and 3 were 60.3 ± 23.3 and 41.2 ± 24.9, respectively. The internal consistency of the T-SIB was 0.96. The T-SIB was moderately correlated with the T-MMSE (Pearson's correlation coefficient = 0.76). The areas under the curve for discriminating between CDR 2 and CDR 3 were 0.81 (95% CI = 0.91-0.71) and 0.72 (95% CI = 0.84-0.61), respectively. Using a cut-off score of 59, the T-SIB had a sensitivity of 80% and specificity of 61% for discriminating between CDR 2 and CDR 3. Using a cut-off score of 45, the T-SIB had a sensitivity of 83.3% and specificity of 73.1% for discriminating between the FAST stage 7c.

CONCLUSION

T-SIB is a reliable and valid instrument for measuring cognition of severely demented Taiwanese AD patients.

Hydrolytic Stability of New Amino Acids Analogues of Memantine

In the present work, the hydrolytic stability of new memantine analogues modified with amino acids, at different pH corresponding to the human biological liquids and organs, was evaluated. Memantine is an uncompetitive N-methyl-d-aspartate receptor antagonist with low-to moderate-affinity. In addition, it is the first representative of a novel class of Alzheimer’s disease (AD) medications acting on the glutamatergic system by blocking N-methyl-D-aspartate receptors. Generally, prodrugs are compounds aiming to improve stability of active fragment and to facilitate transportation across the cell membranes or lipid barriers. The investigated series of prodrugs include modified memantine with the following amino acids: alanine, β-alanine, glycine, phenylalanine, and valine. Hydrolytic stability was determined at two different pH values 2.0 and 7.4 at 37 °C, similar to those in the human stomach and blood plasma. Specially developed UV-VIS spectrophotometric method for quantification of the concentrations of unchanged compounds was applied in the kinetic studies. Val-MEM is the most stable in neutral medium and at 37 °C compound with t1/2 = 50.2 h. The compound Phe-MEM has also very good hydrolytic stability with t1/2 = 29.6 h. The order of other compounds is: Val-MEM ≫ Phe-MEM ≫ Ala-MEM ≈ Val-MEM > β-Ala-MEM. Ala-MEM and Gly-MEM are the most stable compounds at acid condition with almost identical values for t1/2 = 17.8 h and t1/2 = 16.3 h, respectively. The stability of tested compounds in acid conditions are relatively less than in neutral one. They are ordered as follows: Ala-MEM ≈ Gly-MEM > Val-MEM ≈ Phe-MEM ≈ β-Ala-MEM. All compounds have relatively good hydrolytic stability of more than 10 h at both neutral and acid conditions, which is quite enough in order to pass in the blood circulation and to be used as a potential antimicrobial agent.

A randomized, controlled clinical trial of plasma exchange with albumin replacement for Alzheimer's disease: Primary results of the AMBAR Study

Introduction

This phase 2b/3 trial examined the effects of plasma exchange (PE) in patients with mild‐to‐moderate Alzheimer's disease (AD).

Methods

Three hundred forty‐seven patients (496 screened) were randomized (1:1:1:1) into three PE treatment arms with different doses of albumin and intravenous immunoglobulin replacement (6‐week period of weekly conventional PE followed by a 12‐month period of monthly low‐volume PE), and placebo (sham).

Results

PE‐treated patients performed significantly better than placebo for the co‐primary endpoints: change from baseline of Alzheimer's Disease Cooperative Study–Activities of Daily Living (ADCS‐ADL; P = .03; 52% less decline) with a trend for Alzheimer's Disease Assessment Scale–Cognitive Subscale (ADAS‐Cog; P = .06; 66% less decline) scores at month 14. Moderate‐AD patients (baseline Mini‐Mental State Examination [MMSE] 18‐21) scored better on ADCS‐ADL (P = .002) and ADAS‐Cog (P = .05), 61% less decline both. There were no changes in mild‐AD patients (MMSE 22‐26). PE‐treated patients scored better on the Clinical Dementia Rating Sum of Boxes (CDR‐sb) (P = .002; 71% less decline) and Alzheimer's Disease Cooperative Study‐Clinical Global Impression of Change (ADCS‐CGIC) (P < .0001; 100% less decline) scales.

Discussion

This trial suggests that PE with albumin replacement could slow cognitive and functional decline in AD, although further studies are warranted.

Stress-Induced Spatial Memory Deficit Reversed by Basolateral Amygdala NMDA Receptor Inhibition in Male Wistar Rats

INTRODUCTION

The present study investigated the role of the Basolateral Amygdala (BLA) N-methyl-D-aspartate (NMDA) receptors in stress-induced spatial memory disturbance among the male Wistar rats.

METHODS

The male Wistar rats (Average weight =200 g) were cannulated bilaterally in the BLA, and entered the study (n=6-8) after one week. They received seven electro-foot-shock stress sessions on seven consecutive days. Memantine (0.1, 1, and 5 μg/rat) or saline (0.5 μL/ rat) was injected into the BLA, five minutes before each stress session. The control groups received the same doses of memantine and no stress. After the end of the stress sessions, blood samples were taken from all animals to evaluate their plasma corticosterone. Also, the spatial learning and memory of the study animals were evaluated using the Barnes maze method. The animals experienced five consecutive days of training on the maze for spatial learning. On the sixth day, their spatial memory was evaluated on the maze. Time, distance, the number of errors, and the taking strategy for reaching the target hole were considered as the parameters for the spatial learning and memory evaluation.

RESULTS

Stress increases the plasma corticosterone level, while memantine preadministration reduces the stress effects. Besides, stress increases the time and distance to the target hole and the number of errors. Stress changed the animals' strategy from serial to random type. However, the intra-BLA memantine reversed all the disturbances induced by the stress.

CONCLUSION

This study indicated that the BLA glutamate NMDA receptors modulate the effect of stress on spatial learning and memory deficit.

An Ecologically Valid, Longitudinal, and Unbiased Assessment of Treatment Efficacy in Alzheimer Disease (the EVALUATE-AD Trial): Proof-of-Concept Study

Background

The current clinical trial assessment methodology relies on a combination of self-report measures, cognitive and physical function tests, and biomarkers. This methodology is limited by recall bias and recency effects in self-reporting and by assessments that are brief, episodic, and clinic based. Continuous monitoring of ecologically valid measures of cognition and daily functioning in the community may provide a more sensitive method to detect subtle, progressive changes in patients with cognitive impairment and dementia.

Objective

This study aimed to present an alternative trial approach using a home-based sensing and computing system to detect changes related to common treatments employed in Alzheimer disease (AD). This paper introduces an ongoing study that aims to determine the feasibility of capturing sensor-based data at home and to compare the sensor-based outcomes with conventional outcomes. We describe the methodology used in the assessment protocol and present preliminary results of feasibility measures and examples of data related to medication-taking behavior, activity levels, and sleep.

Methods

The EVALUATE-AD (Ecologically Valid, Ambient, Longitudinal and Unbiased Assessment of Treatment Efficacy in Alzheimer’s Disease) trial is a longitudinal naturalistic observational cohort study recruiting 30 patients and 30 spouse coresident care partners. Participants are monitored continuously using a home-based sensing and computing system for up to 24 months. Outcome measures of the automated system are compared with conventional clinical outcome measures in AD. Acceptance of the home system and protocol are assessed by rates of dropout and protocol adherence. After completion of the study monitoring period, a composite model using multiple functional outcome measures will be created that represents a behavioral-activity signature of initiating or discontinuing AD-related medications, such as cholinesterase inhibitors, memantine, or antidepressants.

Results

The home-based sensing and computing system has been well accepted by individuals with cognitive impairment and their care partners. Participants showed good adherence to the completion of a weekly web-based health survey. Daily activity, medication adherence, and total time in bed could be derived from algorithms using data from the sensing and computing system. The mean monitoring time for current participants was 14.6 months. Medication adherence, as measured with an electronic pillbox, was 77% for participants taking AD-related medications.

Conclusions

Continuous, home-based assessment provides a novel approach to test the impact of new or existing dementia treatments generating objective, clinically meaningful measures related to cognition and everyday functioning. Combining this approach with the current clinical trial methodology may ultimately reduce trial durations, sample size needs, and reliance on a clinic-based assessment.

International Registered Report Identifier (IRRID)

DERR1-10.2196/17603

Benefits and Harms of Prescription Drugs and Supplements for Treatment of Clinical Alzheimer-Type Dementia

BACKGROUND

Effects of drug treatment of clinical Alzheimer-type dementia (CATD) are uncertain.

PURPOSE

To summarize evidence on the effects of prescription drugs and supplements for CATD treatment.

DATA SOURCES

Electronic bibliographic databases (inception to November 2019), ClinicalTrials.gov (to November 2019), and systematic review bibliographies.

STUDY SELECTION

English-language trials of prescription drug and supplement treatment in older adults with CATD that report cognition, function, global measures, behavioral and psychological symptoms of dementia (BPSD), or harms. Minimum treatment was 24 weeks (≥2 weeks for selected BPSD).

DATA EXTRACTION

Studies with low or medium risk of bias (ROB) were analyzed. Two reviewers rated ROB. One reviewer extracted data; another verified extraction accuracy.

DATA SYNTHESIS

Fifty-five studies reporting non-BPSD outcomes (most ≤26 weeks) and 12 reporting BPSD (most ≤12 weeks) were analyzed. Across CATD severity, mostly low-strength evidence suggested that, compared with placebo, cholinesterase inhibitors produced small average improvements in cognition (median standardized mean difference [SMD], 0.30 [range, 0.24 to 0.52]), no difference to small improvement in function (median SMD, 0.19 [range, -0.10 to 0.22]), no difference in the likelihood of at least moderate improvement in global clinical impression (median absolute risk difference, 4% [range, 2% to 4%]), and increased withdrawals due to adverse events. In adults with moderate to severe CATD receiving cholinesterase inhibitors, low- to insufficient-strength evidence suggested that, compared with placebo, add-on memantine inconsistently improved cognition and improved global clinical impression but not function. Evidence was mostly insufficient about prescription drugs for BPSD and about supplements for all outcomes.

LIMITATION

Most drugs had few trials without high ROB, especially for supplements, active drug comparisons, BPSD, and longer trials.

CONCLUSION

Cholinesterase inhibitors and memantine slightly reduced short-term cognitive decline, and cholinesterase inhibitors slightly reduced reported functional decline, but differences versus placebo were of uncertain clinical importance. Evidence was mostly insufficient on drug treatment of BPSD and on supplements for all outcomes.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (PROSPERO: CRD42018117897).

The CITIMEM study: A pilot study. Optimizing pharmacological treatment in dementia

INTRODUCTION

Citicoline can have beneficial effects both in degenerative and in vascular cognitive decline; it works through an increase in acetylcholine intrasynaptic levels and promoting phospholipid synthesis, (chiefly phosphatidylcholine), cellular function, and neuronal repair. Memantine is an N-methyl-D-aspartate (NMDA) receptor antagonist used for the treatment of mild to moderate Alzheimer's disease (AD). When co-administered they could have a synergistic action in patients affected with AD and mixed dementia (MD) too.

SCOPE

The aim of the present study was to show the effectiveness of oral citicoline plus memantine in patients affected with AD and MD.

PATIENTS AND METHODS

This was a retrospective study between 2015 and 2017 on 126 patients aged 65 years old or older affected with AD or MD (mean age 80.7 ± 5.2 years old). The study involved four different centers for dementia all over Italy. Diagnosis of AD was made according to clinical symptoms, neuropsychological tests and brain imaging. Diagnosis of MD was made when symptoms typical of AD such as memory loss were associated to symptoms due to cerebrovascular deficits, i.e., impaired judgement, ability to make decisions, plan or organize, and brain imaging. 58 patients were treated with memantine (group A), 68 patients with memantine plus citicoline 1 g/day given orally (group B). In both groups memantine dosage was 10-20 mg/day according to its tolerability. 24 patients of group A and 29 patients of group B were affected with MD. Cognitive functions were assessed by MMSE, daily life functions by ADL and IADL, behavioral symptoms by NPI, comorbidities by CIRS, and mood by GDS-short form. Tests were administered at baseline (T0), after 6 (T1), and 12 months (T2). The primary outcomes were the effects of combined treatment versus memantine alone on cognitive functions assessed by MMSE. The secondary outcomes were the possible side effects or adverse events of combination therapy versus memantine alone, influence on daily life functions and behavioral symptoms.

RESULTS AND CONCLUSIONS

Patients treated with citicoline plus memantine showed an increase in MMSE between T0 and T1 (16.6 ± 2.9 vs 17.4 ± 2.7) and between T1 and T2 (17.4 ± 2.7 vs 17.7 ± 2.8). The difference in MMSE score was significant when comparing the two groups, both at T1 (p = 0.003) and T2 (p = 0.000). Since it is important to maximize the pharmacological means in AD and MD, the present study encourages the role of combined administration of memantine plus citicoline in disease management and in slowing down the progression of disease.

Combination Drug Therapy for the Management of Alzheimer's Disease

Alzheimer's disease (AD) is the leading cause of dementia worldwide. Even though the number of AD patients is rapidly growing, there is no effective treatment for this neurodegenerative disorder. At present, implementation of effective treatment approaches for AD is vital to meet clinical needs. In AD research, priorities concern the development of disease-modifying therapeutic agents to be used in the early phases of AD and the optimization of the symptomatic treatments predominantly dedicated to the more advanced AD stages. Until now, available therapeutic agents for AD treatment only provide symptomatic treatment. Since AD pathogenesis is multifactorial, use of a multimodal therapeutic intervention addressing several molecular targets of AD-related pathological processes seems to be the most practical approach to modify the course of AD progression. It has been demonstrated through numerous studies, that the clinical efficacy of combination therapy (CT) is higher than that of monotherapy. In case of AD, CT is more effective, mostly when started early, at slowing the rate of cognitive impairment. In this review, we have covered the major studies regarding CT to combat AD pathogenesis. Moreover, we have also highlighted the safety, tolerability, and efficacy of CT in the treatment of AD.

Acute and chronic effects of single dose memantine after controlled cortical impact injury in adult rats

BACKGROUND

Altered glutamatergic neurotransmission after traumatic brain injury (TBI) contributes to excitotoxic cell damage and death. Prevention or suppression of such changes is a desirable goal for treatment of TBI. Memantine (3,5-dimethyl-1-adamantanamine), an uncompetitive NMDA receptor antagonist with voltage-dependent open channel blocking kinetics, was reported to be neuroprotective in preclinical models of excitotoxicity, brain ischemia, and in TBI when administered prophylactically, immediately, or within minutes after injury.

METHODS

The current study examined effects of memantine administered by single intraperitoneal injection to adult male rats at a more clinically relevant delay of one hour after moderate-severe controlled cortical impact (CCI) injury or sham surgery. Histopathology was assessed on days 1, 7, 21, and 90, vestibulomotor function (beam balance and beam walk) was assessed on days 1-5 and 71-75, and spatial memory (Morris water maze test, MWM) was assessed on days 14-21 and 83-90 after CCI injury or sham surgery.

RESULTS

When administered at 10 mg/kg, but not 2.5 or 5 mg/kg, memantine preserved cortical tissue and reduced neuronal degeneration 1 day after injury, and attenuated loss of synaptophysin immunoreactivity in the hippocampus 7 days after injury. No effects of 10 mg/kg memantine were observed on histopathology at 21 and 90 days after CCI injury or sham surgery, or on vestibulomotor function and spatial memory acquisition assessed during any of the testing periods. However, 10 mg/kg memantine resulted in trends for improved search strategy in the MWM memory retention probe trial.

CONCLUSIONS

Administration of memantine at a clinically-relevant delay after moderate-severe CCI injury has beneficial effects on acute outcomes, while more significant improvement on subacute and chronic outcomes may require repeated drug administration or its combination with another therapy.

Considerations and Current Trends in the Management of the Geriatric Patient on a Consultation-Liaison Service

PURPOSE OF REVIEW

To provide consultation-liaison psychiatrists with an updated resource that can assist in the treatment and management of geriatric patients.

RECENT FINDINGS

The current available literature has not shown any differences in efficacy between haloperidol and second-generation antipsychotics in patients with delirium. When considering relative advantages of forms of antipsychotic administration, there is no support for a superior safety profile of oral compared to intramuscular or intravenous administration. A recent meta-analysis of four randomized controlled trials concluded that when melatonin was administered to older age patients on medical wards, it significantly prevented the incidence of delirium when compared with the control group. While suvorexant administered nightly to elderly patients in acute care settings may lower the incidence of delirium, larger studies are needed to confirm this finding. Despite the black box warning of increased mortality risk in older patients with dementia, antipsychotics may be used with caution by the consultation-liaison (CL) psychiatrist to treat the neuropsychologic symptoms of dementia including hallucinations and psychosis in the hospital setting. While antidepressant studies have focused primarily on citalopram and escitalopram in the treatment of agitation in the setting of dementia, these two medications have not been adequately compared directly to other SSRIs for this condition. It is therefore not clear whether citalopram and escitalopram are more efficacious in treating agitation in the setting of dementia when compared to other SSRIs. While the evidence supporting trazodone's use is limited, it is generally well tolerated and is an option as a PRN for irritability and agitation in patients with Alzheimer's and mixed dementia. While there is some evidence to support the use of acetylcholinesterase inhibitors for treating cognitive impairments and hallucinations in Lewy body dementia, the usefulness of these agents in other forms of dementia is not well studied, and those studies did not show any benefit in the management of acute agitation. It is important to note that memantine can cause or exacerbate agitation and may be the cause of behavioral dysregulation. There is no evidence to support the routine use of benzodiazepines for behavioral improvement in patients with dementia. Escitalopram and citalopram do have a unique pharmacokinetic properties in the sense that they have been found to have 50-56% plasma protein binding, compared to sertraline, fluoxetine, and paroxetine (95% or more). Pooled analyses suggest that antidepressants are more effective than placebo in reducing the symptoms of post-stroke depression. SSRIs are considered first-line antidepressants in stroke patients, who are often elderly with underlying cardiovascular problems. Although treatment with SSRIs is recommended for post-stroke depression, there are no studies providing conclusive data on the superiority of a specific drug. Older age is associated with a better outcome from ECT, with remission rates of approximately 73% to 90% in patients over 65 years. ECT is the treatment of choice for patients with psychotic depression, and elderly patients with psychotic depression have been shown to have a higher remission rate and faster time to response than depressed patients without psychotic symptoms. With the average life expectancy increase, it is projected that 19 million people will reach the age of 85 or higher, an increase from 5.5 million in 2010. With an increasing older population, psychiatric consultation in the management of geriatric patients is becoming more necessary. Psychiatrists must be aware of the unique considerations in elderly patients. In this article, we provide evidence-based guidance to the CL psychiatrist on major issues relating to the older age patient, highlighting recent trends in treatment. First, we provide background on the evaluation of the medically hospitalized geriatric patient. As rates of medical and psychiatric illnesses increase with advancing age, elderly patients are more likely to be taking a higher number of medications as compared to younger patients, and physicians must pay special attention to polypharmacy, including side effects and drug interactions in this group. Next, we focus on the diagnosis, management, and unique needs of the geriatric patient presenting with common clinical syndromes of delirium, dementia, and depression. Delirium and dementia are among the most common causes of cognitive impairment in clinical settings yet are often either unrecognized or misdiagnosed as they may have similar signs and symptoms. In addition, depression is prevalent in older adults, especially in those with comorbid medical illness. Depression can be fatal as the rates of suicide are higher in later life than in any other age group. Consultation can improve the management of elderly patients and prevent unnecessary nursing home placement.

Gene Expressions, Hippocampal Volume Loss, and MMSE Scores in Computation of Progression and Pharmacologic Therapy Effects for Alzheimer's Disease

We build personalized relevance parameterization method (prep-ad) based on artificial intelligence (ai) techniques to compute Alzheimer's disease (ad) progression for patients at the mild cognitive impairment (mci) stage. Expressions of ad related genes, mini mental state examination (mmse) scores, and hippocampal volume measurements of mci patients are obtained from the Alzheimer's Disease Neuroimaging Initiative (adni) database. In evaluation of cognitive changes under pharmacological therapies, patients are grouped based on available clinical measurements and the type of therapy administered, namely donepezil monotherapy and polytherapy of donepezil with memantine. Average leave one out cross validation (loocv) error rates are calculated for prep-ad results as less than 8 percent when mmse scores are used to compute disease progression for a 60 month period, and 3 percent with hippocampal volume measurements for 12 months. Statistical significance is calculated as p = 0.003 for using ad related genes in disease progression and as for the results computed by prep-ad. These relatively small average loocv errors and p-values suggest that our prep-ad methods employing gene expressions, mmse scores and hippocampal volume loss measurements can be useful in supporting pharmacologic therapy decisions during early stages of ad.

Alzheimer's Treatment: Real-World Physician Behavior Across Countries

OBJECTIVE

Timely initiation of Alzheimer's disease (AD)-specific treatment may postpone cognitive deterioration and preserve patient independence. We explored real-world physician behavior in the treatment of AD.

METHODS

Online questionnaires and patient record forms (PRFs) were completed by participating physicians. The physicians included general practitioners, neurologists, geriatricians and psychiatrists, recruited from France, Germany, Japan, the UK and the USA. Physicians completed an online interview and two to three PRFs based on selected records of their patients with AD. Data on treatment algorithms and key drivers for therapy were captured.

RESULTS

A total of 3346 PRFs were submitted and 1086 physicians interviewed. Overall, 44% of patients with mild cognitive impairment/prodromal AD, 71% of patients with mild disease and 76% of patients with moderate disease had already received therapy. The most common reasons for not prescribing therapy were patient refusal (35%) and early disease stage (26%). Except in the USA, the majority of physicians preferred to prescribe monotherapy. Almost 30% of patients at any stage of the disease did not receive AD-specific pharmacotherapy immediately after diagnosis.

CONCLUSIONS

Physicians' attitudes toward AD treatment could be driven by limited awareness regarding the benefits of early intervention and the modest efficacy of currently available therapies. Efficacious therapies for AD, especially early AD, which could be used alone or in combination with current medications to maximize treatment benefit, are still needed. The availability of more efficacious therapies may improve time to treatment initiation, treatment rates and acceptance of treatment by patients, caregivers and physicians.

Oligomers Are Promising Targets for Drug Development in the Treatment of Proteinopathies

Currently, there is no effective treatment of proteinopathies, as well as their diagnosis in the early stages of the disease until the first clinical symptoms appear. The proposed model of fibrillation of the Aβ peptide and its fragments not only describes molecular rearrangements, but also offers models of processes that occur during the formation of amyloid aggregates. Since this model is also characteristic of other proteins and peptides, a new potential target for drug development in the treatment of Alzheimer’s disease (AD) and other proteinopathies is proposed on the basis of this model. In our opinion, it is oligomers that are promising targets for innovative developments in the treatment of these diseases.

Revisiting the intersection of amyloid, pathologically modified tau and iron in Alzheimer's disease from a ferroptosis perspective

The complexity of Alzheimer's disease (AD) complicates the search for effective treatments. While the key roles of pathologically modified proteins has occupied a central role in hypotheses of the pathophysiology, less attention has been paid to the potential role for transition metals overload, subsequent oxidative stress, and tissue injury. The association of transition metals, the major focus heretofore iron and amyloid, the same can now be said for the likely pathogenic microtubular associated tau (MAPT). This review discusses the interplay between iron, pathologically modified tau and oxidative stress, and connects many related discoveries. Basic principles of the transition to pathological MAPT are discussed. Iron, its homeostatic mechanisms, the recently described phenomenon of ferroptosis and purported, although still controversial roles in AD are reviewed as well as considerations to overcome existing hurdles of iron-targeted therapeutic avenues that have been attempted in AD. We summarize the involvement of multiple pathological pathways at different disease stages of disease progression that supports the potential for a combinatorial treatment strategy targeting multiple factors.

Alzheimer's Disease Therapeutic Approaches

Alzheimer's disease (AD) was first described and diagnosed by Dr. Alois Alzheimer in 1906 (Hippius and Neundorfer, Dialogues Clin Neurosc 5:101-108, 2003). According to World Health Organization (WHO), AD is the most common cause of dementia, accounting for as many as 60-70% of senile dementia cases and affecting 47.5 million people worldwide (data from 2015) (Dementia Fact Sheet No 362. http://who.int/mediacentre/factsheets/fs362/en/ ). The median survival time after the onset of dementia ranges from 3.3 to 11.7 years (Todd et al. Int J Geriatr Psychiatry 28:1109-1124, 2013). AD is characterized as a severe, chronic, incurable, and progressive neurodegenerative disorder, associated with memory loss and cognition impairment accompanied by abnormal behavior and personality changes (Godyn et al. Pharmacol Rep 68:127-138, 2016). AD is characterized by neuronal death, which usually correlates with the appearance of key neuropathological changes, including acetylcholine deficiency, glutamate excitotoxicity, extracellular deposition of β-amyloid (Aβ plaques), intracellular neurofibrillary tangles by hyperphosphorylated tau protein deposits, neuroinflammation, and widespread neuronal loss (Godyn et al. Pharmacol Rep 68:127-138, 2016; Graham et al. Annu Rev. Med 68:413-430, 2017). The discovery of the degeneration of cholinergic neurons and the reduction of acetylcholine levels in postmortem studies of patients resulted in the use of drugs that leads to the increase of acetylcholine levels in brain (Dubois et al. Lacet Neurol 13:614-629, 2014). At present there is no preventative or curative treatment that interferes with the development of the disease. However, in recent years progress was made in the development of cholinergic drugs which have a positive effect on disease progression. Nowadays, specific drugs that can inhibit the enzyme that degrades acetylcholine are used. The development of new effective drugs involves a difficult and time-consuming process, accompanied by a very high failure rate. In the absence of effective therapies, the estimated number of people with dementia will reach 115 to 131, five million by 2050 (Dubois et al. Lacet Neurol 13:614-629, 2014; Cummings et al. Alzheimers Res Ther 6:37, 2014). Novel therapies and new targets required for developing more effective drugs for the treatment of AD patients are urgently needed.

Cognitive symptoms of Alzheimer's disease: clinical management and prevention

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by the accumulation of amyloid β in the form of extracellular plaques and by intracellular neurofibrillary tangles, with eventual neurodegeneration and dementia. There is currently no disease-modifying treatment though several symptomatic medications exist with modest benefit on cognition. Acetylcholinesterase inhibitors have a consistent benefit across all stages of dementia; their benefit in mild cognitive impairment and prodromal AD is unproven. Memantine has a smaller benefit on cognition overall which is limited to the moderate to severe stages, and the combination of a cholinesterase inhibitor and memantine may have additional efficacy. Evidence for the efficacy of vitamin E supplementation and medical foods is weak but might be considered in the context of cost, availability, and safety in individual patients. Apparently promising disease-modifying interventions, mostly addressing the amyloid cascade hypothesis of AD, have recently failed to demonstrate efficacy so novel approaches must be considered.

Changes in metabolites in the brain of patients with fibromyalgia after treatment with an NMDA receptor antagonist

The aims of this work were to evaluate whether the treatment of patients with fibromyalgia with memantine is associated with significant changes in metabolite concentrations in the brain, and to explore any changes in clinical outcome measures. Magnetic resonance spectroscopy was performed of the right anterior and posterior insula, both hippocampi and the posterior cingulate cortex. Questionnaires on pain, anxiety, depression, global function, quality of life and cognitive impairment were used. Ten patients were studied at baseline and after three months of treatment with memantine. Significant increases were observed in the following areas: N-acetylaspartate (4.47 at baseline vs. 4.71 at three months, p = 0.02) and N-acetylaspartate+N-acetylaspartate glutamate in the left hippocampus (5.89 vs. 5.98; p = 0.007); N-acetylaspartate+N-acetylaspartate glutamate in the right hippocampus (5.31 vs 5.79; p = 0.01) and the anterior insula (7.56 vs. 7.70; p = 0.033); glutamate+glutamine/creatine ratio in the anterior insula (2.03 vs. 2.17; p = 0.022) and the posterior insula (1.77 vs. 2.00; p = 0.004); choline/creatine ratio in the posterior cingulate (0.18 vs. 0.19; p = 0.023); and creatine in the right hippocampus (3.60 vs. 3.85; p = 0.007). At the three-month follow-up, memantine improved cognitive function assessed by the Cognition Mini-Exam (31.50, SD = 2.95 vs. 34.40, SD = 0.6; p = 0.005), depression measured by the Hamilton Depression Scale (7.70, SD = 0.81 vs. 7.56, SD = 0.68; p = 0.042) and severity of illness measured by the Clinical Global Impression severity scale (5.79, SD = 0.96 vs. 5.31, SD = 1.12; p = 0.007). Depression, clinical global impression and cognitive function showed improvement with memantine. Magnetic resonance spectroscopy could be useful in monitoring response to the pharmacological treatment of fibromyalgia.

Unmet Needs in Pharmacological Treatment of Apathy in Alzheimer's Disease: A Systematic Review

Background: Apathy is one of the most prevalent neuropsychiatric symptoms encountered in Alzheimer’s disease (AD) and may be an early sign in the development of dementia persisting over the disease course. It has been associated with poor disease outcome, impaired daily functioning, and significant caregiver distress. Early diagnosis and timely treatment of apathy in AD are of great importance. However, approved agents for apathy are still missing.

Methods: Within this context, we conducted an extensive electronic search in the databases included in the National Library of Medicine, PsychInfo, and Google Scholar for studies that have investigated the effect of pharmacological treatments in apathy in AD. There were no limitations regarding study design and all care settings were considered for inclusion. Structured measures for level of evidence and study quality were employed to evaluate the results.

Results: A total of 1,607 records were identified; 1,483 records remained after the removal of duplicates and were screened; 166 full-text articles were selected and assessed for eligibility and a remaining 90 unique studies and relevant reviews were included in the qualitative synthesis. Acetylcholinesterase inhibitors, gingko biloba, and methylphenidate were found to be successful in reducing apathy in patients with AD. Methodological heterogeneity in the studies and the small amount of studies where apathy was the primary outcome are limiting factors to assess for group effects.

Conclusions: Pharmacological treatment of apathy in AD is an underexplored field. Standardized and systematic efforts are needed to establish a possible treatment benefit. Elucidating the pathophysiology of apathy and its components or subtypes will inform disease models and mechanistic drug studies that can quantify a benefit from specific agents for specific AD groups.

The "rights" of precision drug development for Alzheimer's disease

There is a high rate of failure in Alzheimer's disease (AD) drug development with 99% of trials showing no drug-placebo difference. This low rate of success delays new treatments for patients and discourages investment in AD drug development. Studies across drug development programs in multiple disorders have identified important strategies for decreasing the risk and increasing the likelihood of success in drug development programs. These experiences provide guidance for the optimization of AD drug development. The "rights" of AD drug development include the right target, right drug, right biomarker, right participant, and right trial. The right target identifies the appropriate biologic process for an AD therapeutic intervention. The right drug must have well-understood pharmacokinetic and pharmacodynamic features, ability to penetrate the blood-brain barrier, efficacy demonstrated in animals, maximum tolerated dose established in phase I, and acceptable toxicity. The right biomarkers include participant selection biomarkers, target engagement biomarkers, biomarkers supportive of disease modification, and biomarkers for side effect monitoring. The right participant hinges on the identification of the phase of AD (preclinical, prodromal, dementia). Severity of disease and drug mechanism both have a role in defining the right participant. The right trial is a well-conducted trial with appropriate clinical and biomarker outcomes collected over an appropriate period of time, powered to detect a clinically meaningful drug-placebo difference, and anticipating variability introduced by globalization. We lack understanding of some critical aspects of disease biology and drug action that may affect the success of development programs even when the "rights" are adhered to. Attention to disciplined drug development will increase the likelihood of success, decrease the risks associated with AD drug development, enhance the ability to attract investment, and make it more likely that new therapies will become available to those with or vulnerable to the emergence of AD.

Antiapoptosis effect of ZiShen prescription to increase learning and memory abilities of compound Alzheimer's disease model rats

Alzheimer's disease (AD) is a neurodegenerative disease characterized progressive memory loss and cognitive impairment. In previous studies, the activities of extracts of Chinese medicinal herbs to treat brain function disorders caused by AD have already been reported. ZiShen prescription was a traditional Chinese medicine (TCM) compound prescription reformed for AD disease based on the basic theory of TCM. To explore the effect of ZiShen (kidney-reinforcing) prescription on the learning and memory abilities, we made compound AD model rats by injecting d-galactose and ibotenic acid into the abdominal cavity to damage both sides of the nucleus basalis of Meynert with ibotenic acid. The trisected Y-maze was used to test the learning and memory abilities of AD model rats before and after treatment by ZiShen prescription and Piracetam. To investigate the mechanism of ZiShen prescription, the expressions of apoptosis-related genes (Bcl-2/Bax) in the cortex and hippocampus of compound AD model rats were detected in the cortex and hippocampus. The results show that, comparing with Piracetam, a clinical medicine to promote the thinking and memory for AD patients, ZiShen prescription significantly increased the learning and memory abilities of the compound AD model rats. After the treatment of ZiShen prescription, the expression of Bcl-2 was upregulated, along with a downregulation of Bax in the cortex and hippocampus of compound AD model rats. And the results indicated that the clinical benefits of ZiShen prescription were slightly better than Piracetam. Still, further well-designed studies are required to ensure the clinical effect of ZiShen.

Memantine ameliorates learning and memory disturbance and the behavioral and psychological symptoms of dementia in thiamine-deficient mice

Several studies have reported on the beneficial effects of memantine on behavioral and psychological symptoms of dementia (BPSD) in patients with Alzheimer's disease. However, the effects of memantine on BPSD-like behaviors in animals have not been well addressed. Here, the effects of memantine on memory disturbance and BPSD-like behaviors were evaluated in thiamine-deficient (TD) mice. Memantine (3 and 10 mg/kg, b.i.d.) was orally administered to ddY mice fed a TD diet for 22 days. During the treatment period, the forced swimming test, elevated plus-maze test, passive avoidance test, and locomotor activity test were performed. Neurotransmitter levels in the brain were analyzed after the treatment period. Daily oral administration of memantine ameliorated the memory disturbances, anxiety-like behavior, and depression-like behavior observed in TD mice. Memantine did not have a significant effect on monoamine levels, but increased glutamate levels in the hippocampus in TD mice. These results suggest that memantine prevents or suppresses the progression of BPSD-like behaviors that develop due to TD. This effect may be mediated in part by the enhancement of glutamatergic neuron activity in the hippocampus.

Neuromodulatory potential of phenylpropanoids; para-methoxycinnamic acid and ethyl-p-methoxycinnamate on aluminum-induced memory deficit in rats

Para-methoxycinnamic acid (PMCA) and Ethyl-p-methoxycinnamate (EPMC) are reported to possess neuroprotective effect in reversing an acute memory deficit. However, there is a dearth of evidence for their therapeutic effect in chronic memory deficit. Thus, there is a scope to study these derivatives against the chronic model of cognitive dysfunction. The present study was aimed to determine the cognitive enhancing activity of PMCA and EPMC in aluminum-induced chronic dementia. Cognitive enhancing property of PMCA and EPMC was assessed using Morris water maze by analyzing spatial memory parameters such as escape latency, D-quadrant latency, and island entries. To find a possible mechanism, the effect of test compounds on altered acetylcholinesterase (AChE) activity and oxidative stress was determined in the hippocampus and frontal cortex of rats. Docking interaction of these derivatives with acetylcholinesterase enzyme and glutamate receptors was also studied. Treatment with PMCA and EPMC showed a significant improvement in spatial memory markers and altered hippocampal AChE activity in rats with cognitive dysfunction. The implication of hippocampal and cortical oxidative stress in memory impairment was confirmed with decreased catalase/increased thiobarbituric acid reactive substances (TBARS) in rats. PMCA and EPMC reversed the oxidative stress in the brain by negatively affecting TBARS levels. Against depleted catalase levels, PMCA was more effective than EPMC in raising the depleted catalase levels. In silico analysis revealed poor affinity of EPMC and PMCA with AChE enzyme and glutamate receptor. To conclude, PMCA and EPMC exerted cognitive enhancing property independent of direct AChE and glutamate receptor inhibition.

The Role of N-Methyl-D-Aspartate Receptor Neurotransmission and Precision Medicine in Behavioral and Psychological Symptoms of Dementia

While the world's population is aging, the prevalence of dementia and the associated behavioral and psychological symptoms of dementia (BPSD) rises rapidly. BPSD are associated with worsening of cognitive function and poorer prognosis. No pharmacological treatment has been approved to be beneficial for BPSD to date. Dysfunction of the N-methyl-D-aspartate receptor (NMDAR)-related neurotransmission leads to cognitive impairment and behavioral changes, both of which are core symptoms of BPSD. Memantine, an NMDAR partial antagonist, is used to treat moderate to severe Alzheimer's disease (AD). On the other hand, a D-amino acid oxidase inhibitor improved early-phase AD. Whether to enhance or to attenuate the NMDAR may depend on the phases of dementia. It will be valuable to develop biomarkers indicating the activity of NMDAR, particularly in BPSD. In addition, recent reports suggest that gender difference exists in the treatment of dementia. Selecting subpopulations of patients with BPSD who are prone to improvement with treatment would be important. We reviewed literatures regarding the treatment of BPSD, focusing on the NMDAR-related modulation and precision medicine. Future studies examining the NMDAR modulators with the aid of potential biomarkers to tailor the treatment for individualized patients with BPSD are warranted.

[The efficacy of pharmacological approaches to therapy of the apathy syndrome in dementia disorders (the review)]

The article presents a literature review of psychopharmacological methods of treatment of the apathy syndrome, which is common in neurocognitive disorders. The review provides recommendations for the management of such patients, taking into account evidence-based medicine.

Meta-Analysis of Randomized Controlled Trials on the Efficacy and Safety of Donepezil, Galantamine, Rivastigmine, and Memantine for the Treatment of Alzheimer's Disease

To study the impact of donepezil, rivastigmine, galantamine, and memantine on cognitive, functional, behavioral, global changes and adverse effects in patients with mild, moderate and severe Alzheimer’s disease (AD), we screened the literature published before September 2017 in the Pubmed, Embase, Cochrane library and Web of Science Electronic databases according to the inclusion criteria. Thirty-six studies were finally determined from 1560 preliminary screened articles. The AD Assessment Scale-cognitive Subscale (ADAS-cog), AD Cooperative Study-Activities of Daily Living (ADCS-ADL), Neuropsychiatric Inventory (NPI), and Clinician’s Interview-Based Impression of Change Plus Caregiver Input scale (CIBIC+) were used as valid endpoints. Of the 36 trials included, meta-analyses of these placebo-control trials showed that there were significant differences between the donepezil, rivastigmine and placebo groups using ADAS-cog, ADCS-ADL, and CIBIC+. Meta-analyses of these placebo-controlled trials showed that there were significant differences between the galantamine and placebo groups using ADAS-cog, ADCS-ADL, NPI, and CIBIC+. These observations suggest that memantine is beneficial for stabilizing or slowing the decline in ADAS-cog and ADCS-ADL₁₉ changes in AD patients. However, there was no significant effect according to the ADCS-ADL₂₃, NPI, and CIBIC+ tests, which indicated that memantine treatment has no significant effect on these cognitive aspects of AD patients. Different effects of donepezil, rivastigmine, galantamine, or memantine on AD were found in this study. According to the results, we conclude that galantamine is effective in treating all aspects of AD and is the first choice for the treatment of AD. However, due to limited data, we should consider additional data to obtain more stable results.

Alignment of European Regulatory and Health Technology Assessments: A Review of Licensed Products for Alzheimer's Disease

Aims: To facilitate regulatory learning, we evaluated similarities and differences in evidence requirements between regulatory and health technology assessment (HTA) bodies of Alzheimer's disease (AD) approved products. Methods: The European marketing authorisation application dossiers and European public assessment reports (EPARs) of the licensed AD drugs were screened to identify the phase III randomised controlled trials (RCTs) and outcomes used. We also screened the assessment reports of the National Institute of Health and Care Excellence (NICE, England) and the National Health Care Institute (ZiN, the Netherlands) to identify the studies and outcomes used in HTA assessments. Results: The application dossiers of donepezil, galantamine, rivastigmine, and memantine contained 16 phase III RCTs in total. These trials were also included in HTA assessments except that NICE excluded studies that were not published (n = 2) or trials that included patients with other types of dementia (n = 3). In the regulatory assessments the focus was on cognitive and global outcomes, and to some extent on function. In the HTA assessments of clinical effectiveness other domains were also covered including: function, behaviour and mood, and, occasionally, quality of life. In the economic analyses of NICE the domains cognition, function, and quality of life were included. Conclusion: There was a large overlap in inclusion of trials in regulatory and HTA assessments, although the focus on specific outcomes slightly differed. Understanding the methods and perceptions of both authorities can stimulate regulatory and HTA cross-talk and further alignment, and therefore more rapid patient access to new treatments.

A Systematic Review and Meta-Analysis of Nonpharmacological Interventions for Moderate to Severe Dementia

OBJECTIVE

Due to limited efficacy of medications, non-pharmacological interventions (NPI) are frequently co-administered to people with moderate to severe dementia (PWMSD). This systematic review and meta-analysis investigated the effects of NPI on activities of daily living (ADL), behavioral and psychological symptoms of dementia (BPSD), and cognition and quality of life (QoL) of PWMSD.

METHODS

A literature search was conducted in the following databases: Cochrane CENTRAL, EMBASE, Medline, CIHNAL, PsycINFO, KoreaMED, KMbase, and KISS. We conducted a meta-analysis on randomized controlled trials and used the generic inverse variance method with a fixed-effects model to calculate the standardized mean difference (SMD). The protocol had been registered (CRD42017058020).

RESULTS

Ten randomized controlled trials met the inclusion criteria of the current meta-analysis. NPI were effective in improving ADL [SMD=0.28, 95% confidence interval (CI)=0.11-0.45] and reducing depression (SMD=-0.44, 95% CI=-0.70- -0.19). However, NPI were not effective in reducing agitation, anxiety, or overall, or improving cognitive function. In a subgroup analysis, music therapy was effective in reducing overall BPSD (SMD=-0.52, 95% CI=-0.90- -0.13).

CONCLUSION

Albeit the number of studies was limited, NPI improved ADL and depression in PWMSD.

An Acquaintance with An Aging Society

Low birth rates and higher life expectancy have been ravaging Japanese society. This article summarizes some of the latest medical knowledge and assistive activities, with a nod toward one nonprofit organization’s efforts to deliver better home healthcare to the elderly through housing and technologies, in the world’s first super-aging society. The response to the transforming society requires a combination of familiar customs and new technologies that create a favorable environment for mobility and continuous learning that are key to elderly health. As other countries will face similar issues, further international interdisciplinary knowledge-building will be necessary to face the challenges of super-aging societies.

Toward a Glutamate Hypothesis of Frontotemporal Dementia

Frontotemporal dementia (FTD) is a heterogenous neurodegenerative disorder, characterized by diverse clinical presentations, neuropathological characteristics and underlying genetic causes. Emerging evidence has shown that FTD is characterized by a series of changes in several neurotransmitter systems, including serotonin, dopamine, GABA and, above all, glutamate. Indeed, several studies have now provided preclinical and clinical evidence that glutamate is key in the pathogenesis of FTD. Animal models of FTD have shown a selective hypofunction in N-methyl D-aspartate (NMDA) and α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, while in patients, glutamatergic pyramidal neurons are depleted in several areas, including the frontal and temporal cortices. Recently, a selective involvement of the AMPA GluA3 subunit has been observed in patients with autoimmune anti-GluA3 antibodies, which accounted for nearly 25% of FTD patients, leading to a decrease of the GluA3 subunit synaptic localization of the AMPA receptor and loss of dendritic spines. Other in vivo evidence of the involvement of the glutamatergic system in FTD derives from non-invasive brain stimulation studies using transcranial magnetic stimulation, in which specific stimulation protocols have indirectly identified a selective and prominent impairment in glutamatergic circuits in patients with both sporadic and genetic FTD. In view of limited disease modifying therapies to slow or revert disease progression in FTD, an important approach could consist in targeting the neurotransmitter deficits, similarly to what has been achieved in Parkinson’s disease with dopaminergic therapy or Alzheimer’s disease with cholinergic therapy. In this review, we summarize the current evidence concerning the involvement of the glutamatergic system in FTD, suggesting the development of new therapeutic strategies.

Memantine for dementia

BACKGROUND

Memantine is a moderate affinity uncompetitive antagonist of glutamate NMDA receptors. It is licensed for use in moderate and severe Alzheimer's disease (AD); in the USA, it is also widely used off-label for mild AD.

OBJECTIVES

To determine efficacy and safety of memantine for people with dementia. To assess whether memantine adds benefit for people already taking cholinesterase inhibitors (ChEIs).

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's register of trials (http://www.medicine.ox.ac.uk/alois/) up to 25 March 2018. We examined clinical trials registries, press releases and posters of memantine manufacturers; and the web sites of the FDA, EMEA and NICE. We contacted authors and companies for missing information.

SELECTION CRITERIA

Double-blind, parallel group, placebo-controlled, randomised trials of memantine in people with dementia.

DATA COLLECTION AND ANALYSIS

We pooled and analysed data from four clinical domains across different aetiologies and severities of dementia and for AD with agitation. We assessed the impact of study duration, severity and concomitant use of ChEIs. Consequently, we restricted analyses to the licensed dose (20 mg/day or 28 mg extended release) and data at six to seven months duration of follow-up, and analysed separately results for mild and moderate-to-severe AD.We transformed results for efficacy outcomes into the difference in points on particular outcome scales.

MAIN RESULTS

Across all types of dementia, data were available from almost 10,000 participants in 44 included trials, most of which were at low or unclear risk of bias. For nearly half the studies, relevant data were obtained from unpublished sources. The majority of trials (29 in 7885 participants) were conducted in people with AD.1. Moderate-to-severe AD (with or without concomitant ChEIs). High-certainty evidence from up to 14 studies in around 3700 participants consistently shows a small clinical benefit for memantine versus placebo: clinical global rating (CGR): 0.21 CIBIC+ points (95% confidence interval (CI) 0.14 to 0.30); cognitive function (CF): 3.11 Severe Impairment Battery (SIB) points (95% CI 2.42 to 3.92); performance on activities of daily living (ADL): 1.09 ADL19 points (95% CI 0.62 to 1.64); and behaviour and mood (BM): 1.84 Neuropsychiatric Inventory (NPI) points (95% CI 1.05 to 2.76). There may be no difference in the number of people discontinuing memantine compared to placebo: risk ratio (RR) 0.93 (95% CI 0.83 to 1.04) corresponding to 13 fewer people per 1000 (95% CI 31 fewer to 7 more). Although there is moderate-certainty evidence that fewer people taking memantine experience agitation as an adverse event: RR 0.81 (95% CI 0.66 to 0.99) (25 fewer people per 1000, 95% CI 1 to 44 fewer), there is also moderate-certainty evidence, from three additional studies, suggesting that memantine is not beneficial as a treatment for agitation (e.g. Cohen Mansfield Agitation Inventory: clinical benefit of 0.50 CMAI points, 95% CI -3.71 to 4.71) .The presence of concomitant ChEI does not impact on the difference between memantine and placebo, with the possible exceptions of the BM outcome (larger effect in people taking ChEIs) and the CF outcome (smaller effect).2. Mild AD (Mini Mental State Examination (MMSE) 20 to 23): mainly moderate-certainty evidence based on post-hoc subgroups from up to four studies in around 600 participants suggests there is probably no difference between memantine and placebo for CF: 0.21 ADAS-Cog points (95% CI -0.95 to 1.38); performance on ADL: -0.07 ADL 23 points (95% CI -1.80 to 1.66); and BM: -0.29 NPI points (95% CI -2.16 to 1.58). There is less certainty in the CGR evidence, which also suggests there may be no difference: 0.09 CIBIC+ points (95% CI -0.12 to 0.30). Memantine (compared with placebo) may increase the numbers of people discontinuing treatment because of adverse events (RR 2.12, 95% CI 1.03 to 4.39).3. Mild-to-moderate vascular dementia. Moderate- and low-certainty evidence from two studies in around 750 participants indicates there is probably a small clinical benefit for CF: 2.15 ADAS-Cog points (95% CI 1.05 to 3.25); there may be a small clinical benefit for BM: 0.47 NOSGER disturbing behaviour points (95% CI 0.07 to 0.87); there is probably no difference in CGR: 0.03 CIBIC+ points (95% CI -0.28 to 0.34); and there may be no difference in ADL: 0.11 NOSGER II self-care subscale points (95% CI -0.35 to 0.54) or in the numbers of people discontinuing treatment: RR 1.05 (95% CI 0.83 to 1.34).There is limited, mainly low- or very low-certainty efficacy evidence for other types of dementia (Parkinson's disease and dementia Lewy bodies (for which CGR may show a small clinical benefit; four studies in 319 people); frontotemporal dementia (two studies in 133 people); and AIDS-related Dementia Complex (one study in 140 people)).There is high-certainty evidence showing no difference between memantine and placebo in the proportion experiencing at least one adverse event: RR 1.03 (95% CI 1.00 to 1.06); the RR does not differ between aetiologies or severities of dementia. Combining available data from all trials, there is moderate-certainty evidence that memantine is 1.6 times more likely than placebo to result in dizziness (6.1% versus 3.9%), low-certainty evidence of a 1.3-fold increased risk of headache (5.5% versus 4.3%), but high-certainty evidence of no difference in falls.

AUTHORS' CONCLUSIONS

We found important differences in the efficacy of memantine in mild AD compared to that in moderate-to-severe AD. There is a small clinical benefit of memantine in people with moderate-to-severe AD, which occurs irrespective of whether they are also taking a ChEI, but no benefit in people with mild AD.Clinical heterogeneity in AD makes it unlikely that any single drug will have a large effect size, and means that the optimal drug treatment may involve multiple drugs, each having an effect size that may be less than the minimum clinically important difference.A definitive long-duration trial in mild AD is needed to establish whether starting memantine earlier would be beneficial over the long term and safe: at present the evidence is against this, despite it being common practice. A long-duration trial in moderate-to-severe AD is needed to establish whether the benefit persists beyond six months.

Effects of Memantine in a Mouse Model of Postoperative Cognitive Dysfunction

Persistent impairment in cognitive functioning postoperatively is reported by clinical and animal studies, and is labeled as postoperative cognitive dysfunction (POCD). Evidence points to an exaggerated neuroinflammatory response resulting from peripheral systemic inflammation after surgery, with subsequent cytokine-induced glutamatergic excitotoxicity and synaptic impairment. These immunological changes, among many others, are also observed in Alzheimer’s disease. Memantine is an N-methyl-D-aspartate receptor (NMDAR) antagonist commonly used to treat Alzheimer’s disease. Surprisingly, little research exists on the role of memantine in preventing POCD. The purpose of this study is to investigate the effects of memantine on a spectrum of cognitive functions postoperatively. Mice were divided into 3 groups and each received treatment for 4 weeks. Placebo groups received a placebo then underwent either a sham procedure or a laparotomy procedure. The memantine group received memantine hydrochloride then underwent a laparotomy procedure. Cognitive tests were performed on postoperative days (POD) 1 and 7. Compared to sham-operated mice, placebo groups that underwent a laparotomy procedure showed impaired memory in the Morris water maze test, higher anxiety-like behavior in the open field and the elevated plus maze tests, increased depression-like behavior in the tail suspension test, and lack of preference for social novelty in the three-chamber test. On the other hand, memantine-treated mice that underwent a laparotomy procedure showed enhanced memory on POD7, improved depression-like behavior on POD1 and POD7, enhanced preference for social novelty on POD1, and no improvement in anxiety-like behavior. These findings suggest a potential protective effect of memantine in mice postoperatively on memory, depression-like behavior, and preference for social novelty.

Association of Antidementia Therapies With Time to Skilled Nursing Facility Admission and Cardiovascular Events Among Elderly Adults With Alzheimer Disease

Importance

To date, no study has compared time to skilled nursing facility (SNF) admission and cardiovascular events across medications available to treat Alzheimer disease.

Objective

To compare time to SNF admission and cardiovascular events between acetylcholinesterase inhibitor (AChEI) monotherapy, memantine hydrochloride monotherapy, and combination therapy with an AChEI and memantine in treating elderly adults with Alzheimer disease.

Design, Setting, and Participants

This retrospective cohort study uses January 1, 2006, to December 31, 2014, claims data from a 5% random sample of Medicare beneficiaries who had received a new diagnosis of Alzheimer disease between January 1, 2007, and December 31, 2013, and who initiated AChEI monotherapy, memantine monotherapy, or combination therapy with an AChEI and memantine (N = 73 475). Patients were followed up until discontinuation of treatment, switch of treatment, death, or the end of the study period. Statistical analysis was conducted from February 15, 2018, to June 15, 2018.

Exposures

Acetylcholinesterase inhibitor monotherapy (n = 44 424), memantine monotherapy (n = 11 809), and combination therapy with an AChEI and memantine (n = 17 242).

Main Outcomes and Measures

Primary outcomes were time to SNF admission and the composite of the following cardiovascular events: acute myocardial infarction, bradycardia, syncope, atrioventricular block, QT interval prolongation, and ventricular tachycardia. Cox proportional hazards regression models were constructed to compare outcomes between each pair of treatment groups, controlling for a comprehensive list of patient characteristics.

Results

The study population included 73 475 participants (53 068 women and 20 407 men; mean [SD] age, 81.8 [8.3] years); 25.5% of the participants initiating AChEI monotherapy, 25.6% of participants initiating memantine monotherapy, and 29.7% of participants initiating combination therapy with an AChEI and memantine were admitted to an SNF. Similarly, 22.2% of the participants initiating AChEI monotherapy, 20.0% of those initiating memantine monotherapy, and 24.5% of those initiating combination therapy experienced at least 1 cardiovascular event. No difference in time to SNF admission was found across the 3 treatment groups. The risk of the composite measure of any cardiovascular event did not differ between the combination therapy and AChEI monotherapy groups (adjusted hazard ratio [aHR], 0.99; 95% CI, 0.96-1.03); however, it was higher for both AChEI monotherapy (aHR, 1.07; 95% CI, 1.02-1.12) and combination therapy (aHR, 1.07; 95% CI, 1.01-1.12), relative to memantine monotherapy. This result was mainly driven by the lower risk of bradycardia and syncope observed for the memantine monotherapy group relative to both AChEI monotherapy (bradycardia: aHR, 0.88; 95% CI, 0.82-0.95; and syncope: aHR, 0.92; 95% CI, 0.86-0.97) and combination therapy (bradycardia: aHR, 0.89; 95% CI, 0.82-0.97; and syncope: aHR, 0.87; 95% CI, 0.83-0.94).

Conclusions and Relevance

Time to SNF admission did not differ across treatment groups, but memantine monotherapy was associated with a lower risk of cardiovascular events compared with both AChEI monotherapy and combination therapy with an AChEI and memantine.

The Alzheimer's Disease Clinical Spectrum: Diagnosis and Management

Alzheimer's disease (AD) care requires timely diagnosis and multidisciplinary management. Evaluation involves structured patient and caregiver history and symptom-function reviews, examination, and testing (laboratory and neuroimaging) to delineate impairment level, determine the cognitive-behavioral syndrome, and diagnose cause. Clinical biomarkers are available to aid high confidence in etiologic diagnosis. Management uses psychoeducation, shared goal setting, and patient-caregiver dyad decision making. When combined, pharmacologic and nonpharmacologic therapies mitigate symptoms and reduce clinical progression and care burden. AD biopathologic processes develop over decades before symptoms manifest; this period is increasingly targeted in research as an opportunity to best delay or prevent AD dementia.

Brain Delivery of Curcumin Using Solid Lipid Nanoparticles and Nanostructured Lipid Carriers: Preparation, Optimization, and Pharmacokinetic Evaluation

Curcumin is a multitherapeutic agent with great therapeutic potential in central nervous system (CNS) diseases. In the current study, curcumin was encapsulated in solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) for the purpose of increasing brain accumulation. The preparation processes have been optimized using experimental design and multiobjective optimization methods. Entrapment efficiency of curcumin in SLNs and NLCs was found to be 82% ± 0.49 and 94% ± 0.74, respectively. The pharmacokinetic studies showed that the amount of curcumin available in the brain was significantly higher in curcumin-loaded NLCs (AUC_0-t = 505.76 ng/g h) compared to free curcumin (AUC_0-t = 0.00 ng/g h) and curcumin-loaded SLNs (AUC_0-t = 116.31 ng/g h) ( P < 0.005), after intravenous (IV) administration of 4 mg/kg dose of curcumin in rat. The results of differential scanning calorimetry and X-ray diffraction showed that curcumin has been dispersed as amorphous in the nanocarriers. Scanning electron microscopy images confirmed the nanoscale size and spherical shape of the nanoparticles. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging study indicated that preparation processes do not have any significant effect on the antioxidant activity of curcumin. The results of this study are promising for the use of curcumin-loaded NLCs in more studies and using curcumin in the treatment of CNS diseases.

Radiation-induced cognitive toxicity: pathophysiology and interventions to reduce toxicity in adults

Radiotherapy is ubiquitous in the treatment of patients with both primary brain tumors as well as disease which is metastatic to the brain. This therapy is not without cost, however, as cognitive decline is frequently associated with cranial radiation, particularly with whole brain radiotherapy (WBRT). The precise mechanisms responsible for radiation-induced morbidity remain incompletely understood and continue to be an active area of ongoing research. In this article, we review the hypothetical means by which cranial radiation induces cognitive decline as well as potential therapeutic approaches to prevent, minimize, or reverse treatment-induced cognitive deterioration. We additionally review advances in imaging modalities that can potentially be used to identify site-specific radiation-induced anatomic or functional changes in the brain and their correlation with clinical outcomes.

The effect of memantine in adult patients with attention deficit hyperactivity disorder

BACKGROUND

Hyperactivity disorder and attention deficit are common neurological disorders in children and adolescents. The symptoms of hyperactivity are decreased in adults, and attention deficit is more noticeable. This study was carried out to evaluate the effect of memantine on adult patients with attention deficit hyperactivity disorder (ADHD).

MATERIALS AND METHODS

In a double-blind clinical trial study, 40 patients aged 18 to 45 years with ADHD were selected on the basis on the Diagnosis and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria, and randomly assigned memantine or placebo. Before starting the treatment, Conners' screening questionnaire was completed for each patient, and the subjects were entered the study after acquiring minimum acceptable score in the questionnaire.

RESULTS

The mean age of patients who were receiving memantine and placebo was about 34.7 ± 4.48 and 31.5 ± 7.4 years, respectively. The results have shown a significant difference in the behavior and attention deficit between the two groups treated with memantine and placebo during 6 weeks (p < 0.001). Also, there was a significant difference in the third and sixth weeks between treatment groups in hyperactivity and attention deficit index (p = 0.001).

CONCLUSION

The results of this study indicated that memantine was effective in reducing symptoms of Inattention/Memory Problems, Hyperactivity/Restlessness, Impulsivity/Emotional Lability.

Monotherapy Is Good Enough for Patients with Mild-to-Moderate Alzheimer's Disease: A Network Meta-analysis of 76 Randomized Controlled Trials

Memantine and the Acetylcholinesterase inhibitors (AChEIs) are two classes of drugs that are used to treat patients with Alzheimer's disease. We conducted a network meta-analysis of randomized controlled trials to compare the treatment effectiveness of monotherapy or combination therapy A total of 23,707 AD patients in 76 randomized trials were identified. In patients with mild-to-moderate AD, monotherapy with donepezil, galantamine or rivastigmine were superior to placebo in enhancing cognitive functions and activities of daily living (ADL), whereas monotherapy with donepezil or memantine were superior to placebo in improving behavioral symptoms. However, combination therapy with AChEIs and memantine did not show additional benefit than monotherapy. In patients with moderate-to-severe AD, neither monotherapy nor combination therapy were superior to placebo in any domain measurement. Combination therapy with memantine and AChEIs is confirmed to have no additional benefits over monotherapy. This article is protected by copyright. All rights reserved.

Two Year Outcomes, Cognitive and Behavioral Markers of Decline in Healthy, Cognitively Normal Older Persons with Global Deterioration Scale Stage 2 (Subjective Cognitive Decline with Impairment)

BACKGROUND

Little is known with respect to behavioral markers of subjective cognitive decline (SCD), a condition initially described in association with Global Deterioration Scale (GDS) stage 2.

OBJECTIVE

Two-year interval behavioral markers were investigated herein.

METHODS

Subjects from a published 7-year outcome study of GDS stage 2 subjects were selected. This study had demonstrated a hazard ratio of 4.5 for progression of GDS stage 2, in comparison with GDS stage 1 (no subjective or objective cognitive decline) subjects, after controlling for demographic and temporal variables. Because GDS 2 subjects have previously demonstrated impairment in comparison with healthy persons free of complaints, we herein suggest the terminology "SCD(I)" for these persons. 98 SCD(I) persons, 63 women and 35 men, mean baseline age, 67.12±8.75 years, with a mean educational background of 15.55±2.60 years, and mean baseline MMSE scores of 28.9±1.24 were followed for 2.13±0.30 years.

RESULTS

Observed annual decline on the GDS was 6.701% per annum, very close to a 1986 published estimate. At follow up, the MMSE, and 7 of 8 psychometric tests did not decline significantly. Of 21 Hamilton Depression Scale items, 2 improved and the remainder were unchanged. Anxieties declined from multiple perspectives. The Brief Cognitive Rating Scale (BCRS) declined significantly (p < 0.001), with component declines in Remote memory (p < 0.01), and Functioning/self-care (p = 0.01).

CONCLUSION

SCD(I) persons decline at an annual rate of approximately 6.7% /year from several recent studies. The BCRS assessments and the Digit Symbol Substitution Test can be sensitive measures for future studies of progression mitigation.

Present Algorithms and Future Treatments for Alzheimer's Disease

An estimated 47 million people live with Alzheimer's disease (AD) and other forms of dementia worldwide. Although no disease-modifying treatments are currently available for AD, earlier diagnosis and proper management of the disease could have considerable impact on patient and caregiver quality of life and functioning. Drugs currently approved for AD treat the cognitive, behavioral, and functional symptoms of the disease and consist of three cholinesterase inhibitors (ChEIs) and the N-methyl-D-aspartate receptor antagonist memantine. Treatment of patients with mild to moderate AD is generally initiated with a ChEI. Patients who show progression of symptoms while on ChEI monotherapy may be switched to another ChEI and/or memantine can be added to the treatment regimen. In recent years, putative disease-modifying therapies have emerged that aim to slow the progression of AD instead of only addressing its symptoms. However, many therapies have failed in clinical trials in patients with established AD, suggesting that, once developed, disease-modifying agents may need to be deployed earlier in the course of illness. The goal of this narrative literature review is to discuss present treatment algorithms and potential future therapies in AD.

Brain Iron Metabolism and CNS Diseases

Iron is the most abundant trace element in the human body. It is well known that iron is an important component of hemoglobin involved in the transport of oxygen. As a component of various enzymes, it participates in the tricarboxylic acid cycle and oxidative phosphorylation. Iron in the nervous system is also involved in the metabolism of catecholamine neurotransmitters and is involved in the formation of myelin. Therefore, iron metabolism needs to be strictly regulated. Previous studies have shown that iron deficiency in the brain during infants and young children causes mental retardation, such as delayed development of language and body balance, and psychomotor disorders. However, if the iron is excessively deposited in the aged brain, it is closely related to the occurrence of various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Friedreich's ataxia. Therefore, it is important to fully study and understand the mechanism of brain iron metabolism and its regulation. On this basis, exploring the relationship between brain iron regulation and the occurrence of nervous system diseases and discovering new therapeutic targets related to iron metabolism have important significance for breaking through the limitation of prevention and treatment of nervous system diseases. This review discusses the complete research history of iron and its significant role in the pathogenesis of the central nervous system (CNS) diseases.

Pathogenic Feed-Forward Mechanisms in Alzheimer's and Parkinson's Disease Converge on GSK-3

Alzheimer's disease (AD) and Parkinson's disease (PD) share many commonalities ranging from signaling deficits such as altered cholinergic activity, neurotrophin and insulin signaling to cell stress cascades that result in proteinopathy, mitochondrial dysfunction and neuronal cell death. These pathological processes are not unidirectional, but are intertwined, resulting in a series of feed-forward loops that worsen symptoms and advance disease progression. At the center of these loops is glycogen synthase kinase-3 (GSK-3), a keystone protein involved in many of the multidirectional biological processes that contribute to AD and PD neuropathology. Here, a unified overview of the involvement of GSK-3 in the major processes involved in these diseases will be presented. The mechanisms by which these processes are linked will be discussed and the feed-forward pathways identified. In this regard, this review will put forth the notion that combination therapy, targeting these multiple facets of AD or PD neuropathology is a necessary next step in the search for effective therapies.

Does memantine improve memory in subjects with focal-onset epilepsy and memory dysfunction? A randomized, double-blind, placebo-controlled trial

OBJECTIVE

Excitotoxic injury involving N-methyl-d-aspartate (NMDA) receptor hyperactivity contributes to epilepsy-related memory dysfunction (ERMD). Current treatment strategies for ERMD have limited efficacy and fail to target the underlying pathophysiology. The present pilot study evaluated the efficacy of memantine, an NMDA receptor antagonist, for the treatment of ERMD in adults with focal-onset seizures.

METHODS

Subjects underwent cognitive testing at baseline, after a 13-week randomized, parallel-group, double-blinded phase (of memantine titrated to 10 mg bid or placebo), and following a 13-week open-label extension phase (of memantine titrated to 10 mg bid). The selective reminding test (SRT) continuous long-term retrieval (CLTR) score and 7/24 Spatial Recall Test learning score served as the primary outcome measures. Secondary measures included tests of attention span, fluency, visual construction, and response inhibition, as well as assessments of quality of life, depression, sleepiness, and side effects.

RESULTS

Seventeen subjects contributed data to the blinded phase (n = 8 memantine, n = 9 placebo). No significant differences were seen between groups on the primary or secondary outcome measures. Pooled data at the end of the open-label phase from 10 subjects (initially randomized to memantine n = 3 or placebo n = 7) demonstrated statistically significant improvement from baseline in CLTR score, memory-related quality of life, spatial span, and response inhibition. No significant changes were evident in depression, sleepiness, side effects, or seizure frequency throughout the trial.

SIGNIFICANCE

Results demonstrated no significant effect of memantine on cognition when assessed at the end of the blinded period. Pooled data at the end of the open-label phase showed significant improvement over baseline performance in measures of verbal memory, frontal-executive function, and memory-related quality of life. These improvements, however, may be due to practice effects and should be interpreted cautiously. Findings suggest a favorable safety profile of memantine in the setting of epilepsy.

NMDA receptors mediate synaptic depression, but not spine loss in the dentate gyrus of adult amyloid Beta (Aβ) overexpressing mice

Amyloid beta (Aβ)-mediated synapse dysfunction and spine loss are considered to be early events in Alzheimer’s disease (AD) pathogenesis. N-methyl-D-aspartate receptors (NMDARs) have previously been suggested to play a role for Amyloid beta (Aβ) toxicity. Pharmacological block of NMDAR subunits in cultured neurons and mice suggested that NMDARs containing the GluN2B subunit are necessary for Aβ-mediated changes in synapse number and function in hippocampal neurons. Interestingly, NMDARs undergo a developmental switch from GluN2B- to GluN2A-containing receptors. This indicates different functional roles of NMDARs in young mice compared to older animals. In addition, the lack of pharmacological tools to efficiently dissect the role of NMDARs containing the different subunits complicates the interpretation of their specific role. In order to address this problem and to investigate the specific role for Aβ toxicity of the distinct NMDAR subunits in dentate gyrus granule cells of adult mice, we used conditional knockout mouse lines for the subunits GluN1, GluN2A and GluN2B. Aβ-mediated changes in synaptic function and neuronal anatomy were investigated in several-months old mice with virus-mediated overproduction of Aβ and in 1-year old 5xFAD mice. We found that all three NMDAR subunits contribute to the Aβ-mediated decrease in the number of functional synapses. However, NMDARs are not required for the spine number reduction in dentate gyrus granule cells after chronic Aβ-overproduction in 5xFAD mice. Furthermore, the amplitude of synaptic and extrasynaptic NMDAR-mediated currents was reduced in dentate gyrus granule of 5xFAD mice without changes in current kinetics, suggesting that a redistribution or change in subunit composition of NMDARs does not play a role in mediating Amyloid beta (Aβ) toxicity. Our study indicates that NMDARs are involved in AD pathogenesis by compromising synapse function but not by affecting neuron morphology.