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

Addressing the challenges to successful recruitment and retention in Alzheimer's disease clinical trials

Among the key challenges in Alzheimer's disease drug development is the timely completion of clinical trials. Unfortunately, clinical trials often suffer from slow or insufficient enrollment. Successful clinical trial recruitment describes a balance between expeditiously achieving full enrollment and ensuring an appropriate study sample. Investigators face a number of challenges to the successful negotiation of this balance. The failure to address these challenges means that drug development may take more time and money and that trial results may not adequately represent drug efficacy or may not be applicable beyond the study. We review the challenges to recruitment and retention in Alzheimer's disease clinical trials and present a framework to address them.

[Treatment of Alzheimer's disease and future approaches]

The progressive neuronal loss in Alzheimer's disease leads to neurochemical abnormalities which provide the basis for symptomatic treatments. Four cholinesterase inhibitors were released in this indication. Meta-analyses have confirmed a beneficial effect on cognitive functioning and activities of daily living. The NMDA receptor antagonist, memantine, was also approved for the treatment of moderate to severe and may be associated. Progress in the patho-physiology of the disease offers some hope of new treatments acting on the cerebral lesions. The amyloid hypothesis allowed the emergence of active or passive immunotherapies, and of secretase inhibitors or modulators. Recent studies have targeted the P tau protein. The brain plasticity and the uses of stem cells offer more distant hope.

Memantine shows promise in reducing gambling severity and cognitive inflexibility in pathological gambling: a pilot study

RATIONALE

Although pathological gambling (PG) is relatively common, pharmacotherapy research for PG is limited. Memantine, an N-methyl D-aspartate receptor antagonist, appears to reduce glutamate excitability and improve impulsive decision making, suggesting it may help individuals with PG.

OBJECTIVE

This study sought to examine the safety and efficacy of Memantine in PG.

METHODS

Twenty-nine subjects (18 females) with DSM-IV PG were enrolled in a 10-week open-label treatment study of memantine (dose ranging from 10 to 30 mg/day). Subjects were enrolled from January 2009 until April 2010. Change from baseline to study endpoint on the Yale Brown Obsessive Compulsive Scale Modified for Pathological Gambling (PG-YBOCS) was the primary outcome measure. Subjects underwent pre- and post-treatment cognitive assessments using the stop-signal task (assessing response impulsivity) and the intra-dimensional/extra-dimensional (ID/ED) set shift task (assessing cognitive flexibility).

RESULTS

Twenty-eight of the 29 subjects (96.6%) completed the 10-week study. PG-YBOCS scores decreased from a mean of 21.8 ± 4.3 at baseline to 8.9 ± 7.1 at study endpoint (p < 0.001). Hours spent gambling per week and money spent gambling both decreased significantly (p < 0.001). Subjects also demonstrated a significant improvement in ID/ED total errors (p = 0.037) at study endpoint. The mean effective dose of memantine was 23.4 ± 8.1 mg/day. The medication was well-tolerated. Memantine treatment was associated with diminished gambling and improved cognitive flexibility.

CONCLUSIONS

These findings suggest that pharmacological manipulation of the glutamate system may target both gambling and cognitive deficits in PG. Placebo-controlled, double-blind studies are warranted in order to confirm these preliminary findings in a controlled design.

Memantine benefits functional abilities in moderate to severe Alzheimer's disease

OBJECTIVE

Functional abilities are severely impacted in Alzheimer's disease (AD). Loss of the ability to perform complex (instrumental) and basic activities of daily living (ADL), leads to decreased independence and increased caregiver burden. This post-hoc analysis investigated the effect of memantine (20 mg/day) on ADLs, as measured by Alzheimer's Disease Cooperative Study-Activities of Daily Living 19-item (ADCS-ADL19) and 23-item (ADCS-ADL23) scales, in patients with moderate-to-severe AD.

DESIGN

Data were pooled from six multicenter, randomized, placebo-controlled, double-blind, 6-month studies of memantine 20 mg/day.

PARTICIPANTS

Male and female patients aged ≥ 50 years at baseline with a Mini Mental State Examination (MMSE) score < 20.

MEASUREMENTS

ADCS-ADL19 and ADCS-ADL23 scales were pooled, and 14 shared items, with a score range of 0-45, were identified and included in the analysis (ADL14). Basic ADLs (BADLs) were defined as: eating, walking, toileting, bathing, and grooming. Instrumental ADLs (IADLs) were defined as: using a telephone, watching television, conversing, clearing a table, finding belongings, obtaining a beverage, disposing of household rubbish, travelling outside the house, and being left alone. Changes from baseline on single-item, BADL (range: 0-15), IADL (range: 0-30), and total ADL14 scores were analysed for observed cases using ANCOVA, with study, center and treatment as categorical explanatory variables and score at baseline as a covariate.

RESULTS

959 patients were treated with memantine and 867 patients received placebo. Memantine-treated patients had less decline from baseline on the ADL14 total score, compared with placebo (p < 0.001) at study end. Memantine also showed lower reductions in BADLs (p < 0.05) and IADLs (p < 0.001), for observed cases, compared with placebo. Memantine-treated patients showed less worsening than placebo recipients for the ADL items: toileting (p < 0.01), grooming (p < 0.01), finding belongings (p < 0.01), and travelling outside the house (p < 0.05).

CONCLUSION

Compared with placebo, memantine shows benefits for both basic and instrumental ADLs in patients with moderate-to-severe AD, suggesting that memantine treatment may lead to a more interactive and dignified life for patients with moderate-to-severe AD.

Dependence as a unifying construct in defining Alzheimer's disease severity

This article reviews measures of Alzheimer's disease (AD) progression in relation to patient dependence and offers a unifying conceptual framework for dependence in AD. Clinicians typically characterize AD by symptomatic impairments in three domains: cognition, function, and behavior. From a patient's perspective, changes in these domains, individually and in concert, ultimately lead to increased dependence and loss of autonomy. Examples of dependence in AD range from a need for reminders (early AD) to requiring safety supervision and assistance with basic functions (late AD). Published literature has focused on the clinical domains as somewhat separate constructs and has given limited attention to the concept of patient dependence as a descriptor of AD progression. This article presents the concept of dependence on others for care needs as a potential method for translating the effect of changes in cognition, function, and behavior into a more holistic, transparent description of AD progression.

The pharmacoeconomics of cognitive enhancers in moderate to severe Alzheimer's disease

Alzheimer's disease is associated with a substantial economic impact on patients, their caregivers and society. Due to the current rise in the aging population, the prevalence and impact of Alzheimer's disease are expected to increase greatly. The cost of caring for someone with Alzheimer's disease is magnified in the more severe stages of the disease. There are four cognitive enhancers commonly used for the treatment of Alzheimer's disease: three cholinesterase inhibitors (donepezil, rivastigmine and galantamine) and one NMDA receptor antagonist (memantine). Of these, donepezil and memantine have been approved in many countries as pharmacological treatments for moderate to severe Alzheimer's disease, while donepezil, rivastigmine and galantamine are approved treatments for mild to moderate Alzheimer's disease. While cost effectiveness has been well studied in mild to moderate Alzheimer's disease, the cost-benefit information for drug therapy in moderate to severe Alzheimer's disease is less clear. This article reviews the pharmacoeconomic data available on these four drugs, with a specific focus on moderate to severe Alzheimer's disease, including economic burden, cost drivers, clinical outcomes and pharmacoeconomic studies. A key driver of the cost of Alzheimer's disease is the severity of the disease, indicating that the ability to stabilize the disease state is a potential source of cost savings. Drug therapies that can limit increases in behavioural problems and cognitive and functional impairment, and postpone institutionalization without an increase in longevity may serve to reduce the economic burden on Alzheimer's disease patients. The data suggest that, while the available, approved agents offer only modest improvements in clinical outcomes, they could be cost-effective treatments for moderate to severe Alzheimer's disease when viewed from the societal perspective. For memantine and donepezil, data are available that suggest that the cost of these drugs is offset by the clinical and societal benefits provided by slowing the progression of Alzheimer's disease. While there are few head-to-head comparison trials, the similarity in costs of the treatments and efficacy against placebo suggest that cost effectiveness will not be substantially different among treatments. More studies that examine longitudinal resource utilization and its relationship to drug treatment in the moderate to severe stages are needed to clarify cost benefit in this population and possibly differentiate between individual medications.

Characterization of Acetylcholinesterase Inhibitory Constituents from Annona glabra Assisted by HPLC Microfractionation

The active fraction of the EtOH extract of the stem of Annona glabra against acetylcholinesterase (AChE) was analyzed by combining HPLC microfractionation with a bioassay. The analytical-scale sample was fractionated by HPLC-DAD into 96-well microplates, which, after evaporation, were assayed against AChE. The active subfractions were scaled up by separation over semipreparative HPLC to give 20 compounds. Four of these, (7S,14S)-(-)-N-methyl-10-O-demethylxylopinine salt (3), S-(-)-7,8-didehydro-10-O-demethylxylopininium salt (10), S-(-)-7,8-didehydrocorydalminium salt (11), and 5-O-methylmarcanine D (17), were assigned as new natural products. In addition, compounds 10 and 11 represent the first natural occurrence of 7,8-didehydroprotoberberines. Compound 3, pseudocolumbamine (12), palmatine (15), and pseudopalmatine (16) showed anti-AChE IC50 values of 8.4, 5.0, 0.4, and 1.8 μM, respectively.

The ACTION study: methodology of a trial to evaluate safety and efficacy of a higher dose rivastigmine transdermal patch in severe Alzheimer's disease

BACKGROUND

Two sizes of rivastigmine patch (5 cm(2) and 10 cm(2)) are currently approved in the US and Europe, while a 20 cm(2) rivastigmine patch has also been tested. A 15 cm(2) rivastigmine patch may provide an optimal balance between efficacy and safety. Earlier studies have demonstrated the efficacy of rivastigmine in severe Alzheimer's disease (AD), and supported the use of a higher dose patch in AD.

OBJECTIVE

The ACTION (ACTivities of daily living and cognitION) trial (Study CENA713DUS44) is designed to evaluate the efficacy and safety of low-dose versus high-dose rivastigmine transdermal patch in patients with severe AD.

METHODS

ACTION is a prospective, randomized, parallel-group, double-blind, multicenter study of patients (aged ≥50 years) with severe AD and a Mini-Mental State Examination score of 3-12. Novartis began recruitment in July 2009 and is conducting the trial in the United States. Patients are randomized to receive either a 5 cm(2) (4.5 mg/24 h) or a 15 cm(2) rivastigmine patch (13.3 mg/24 h) for 24 weeks. Patients receiving the 15 cm(2) patch will be up-titrated over 8 weeks, via 5 and 10 cm(2) patches. The primary efficacy outcomes include activities of daily living (ADLs), assessed with the Alzheimer's Disease Cooperative Study - Activities of Daily Living - Severe Impairment Version (ADCS-ADL-SIV), and cognition, assessed with the Severe Impairment Battery (SIB). Secondary outcomes include behavior (Neuropsychiatric Inventory), global functioning (Alzheimer's Disease Cooperative Study - Clinical Global Impression of Change), response rates, and safety.

CONCLUSIONS

The ACTION trial examines the efficacy and tolerability of a 15 cm(2) rivastigmine patch over a 24-week period in patients with severe AD. This is a novel trial in the development of rivastigmine, as it uses a design that does not include a placebo arm, is recruiting patients with severe AD, and includes an ADL measure as a co-primary efficacy variable. CLINICAL REGISTRATION NUMBER: CENA713D US44.

Donepezil: A Review of Pharmacological Characteristics and Role in the Management of Alzheimer Disease

Donepezil is a potent, selective, noncompetitive, and rapidly reversible inhibitor of acetylcholinesterase (AChEI) licensed for the treatment of Alzheimer disease (AD); and is the first and only AChEI licensed for the treatment of severe AD. Its efficacy as monotherapy, or in combination with the NMDA-agonist, memantine, has been documented in several randomised double-blind, placebo-controlled, short-term clinical trials, as well as long-term extension trials and observational studies. Donepezil is a well tolerated drug that is generally safe as demonstrated even in patients with multiple co-morbidities receiving polypharmacy. It has been shown that donepezil improves cognition and global function in patients with mild-to-moderate AD; and long-term efficacy is maintained for up to 50 weeks. There is a dose-response relationship, with higher doses more likely to produce symptomatic benefit. Furthermore, donepezil-treated patients may improve cognitively and show global clinical improvement in all disease stages, including severe AD. Less consistent results in all disease stages were obtained on measures of function and behavior, and observations of mood. No effect on transition to AD has been found in long-term, randomized clinical trials in mild cognitive impairment (MCI). Cost-effectiveness of the treatment has been questioned by one long-term open-label societal study of 2-years duration. This study reported modest improvement of cognition but no statistically significant benefits during donepezil treatment as compared to placebo, in terms of rates of institutionalization and progression toward greater disability. However, there is a need for further research on clinically meaningful outcomes and treatment benefits favored by patients and caregivers, which are traditionally not defined as outcomes in clinical trials. Likewise, we need to know how to select responders, what is an optimal AChE inhibition particularly during the long-term treatment, in which patients the dosage should be increased for a sustained benefit, what is the optimal duration of treatment and when is meaningful to stop the treatment. After almost two decades of donepezil use in everyday clinical practice these issues are still unresolved.

Severe dementia: A review about diagnoses, therapeutic management and ethical issues

North American data show that in the year 2000 around 4.5 million people had a diagnosis of dementia and more than a half were at moderate or severe stages of the disease. There is inevitable cognitive and functional decline caused by all etiologies of irreversible dementia as well as many behavioral symptoms that compromise the quality of life of both patients and caregivers. Few published studies have investigated issues concerning severe dementia such as predictors of mortality and life expectancy, nutrition, end of life issues and palliative care in terminal dementia, as well as best pharmacological and non-pharmacological treatments. Due to the complexity that characterizes advanced dementia, it is important that this discussion starts as early as possible allowing some decisions to be taken, preferably when the patients can still express their opinion.

HIV-associated neurocognitive disorder: pathogenesis and therapeutic opportunities

Human immunodeficiency virus type 1 (HIV) infection presently affects more that 40 million people worldwide, and is associated with central nervous system (CNS) disruption in at least 30% of infected individuals. The use of highly active antiretroviral therapy has lessened the incidence, but not the prevalence of mild impairment of higher cognitive and cortical functions (HIV-associated neurocognitive disorders) as well as substantially reduced a more severe form dementia (HIV-associated dementia). Furthermore, improving neurological outcomes will require novel, adjunctive therapies that are targeted towards mechanisms of HIV-induced neurodegeneration. Identifying such molecular and pharmacological targets requires an understanding of the events preceding irreversible neuronal damage in the CNS, such as actions of neurotoxins (HIV proteins and cellular factors), disruption of ion channel properties, synaptic damage, and loss of adult neurogenesis. By considering the specific mechanisms and consequences of HIV neuropathogenesis, unified approaches for neuroprotection will likely emerge using a tailored, combined, and non-invasive approach.

Latrepirdine for Alzheimer’s disease: trials and tribulations

Robust preclinical in vitro and in vivo data indicate that latrepirdine has a protective effect against neurotoxic changes, increasing the survival of neurons, inhibiting mitochondrial permeability and reducing mitochondrial instability. The drug has been shown to increase neurite outgrowth, cortical neuron process and branch length and mitochondrial concentration. Nevertheless, a clearly defined mechanism of action has yet to be defined. Speculation regarding its mechanism of action include a preservative effect on mitochondria resulting in neural preservation and it appears to be unrelated to inhibition of acetylcholinesterases and N-methyl-D-aspartic acid-receptor antagonism. Phase I–III studies show demonstrable safety and minimal toxicity in subjects treated with latrepirdine. A Phase II study demonstrated statistically significant cognitive and behavioral improvement in the treatment group and cognitive and behavioral decline from baseline in the placebo group in Russian Alzheimer’s disease subjects. However, the Phase III monotherapy multinational study failed to reproduce a robust clinical efficacy signal. The reasons for treatment failure are most likely due to the placebo group failing to decline as expected, the proposed mechanism of action maybe not having an effect on the Alzheimer’s disease process and the data in Phase II being incongruous owing to significant disparities in the populations recruited in the Phase II compared with the Phase III trial.

Antinociceptive Effect of Memantine and Morphine on Vincristine-induced Peripheral Neuropathy in Rats

Background

Vincristine-induced peripheral neuropathy is a major dose limiting side effect and thus effective therapeutic strategy is required. In this study, we investigated the antinociceptive effect of memantine and morphine on a vincristine-induced peripheral neuropathy model in rats.

Methods

Male Sprague-Dawley rats weighing 220-240 g were used in all experiments. Rats subsequently received daily intraperitoneal injections of either vincristine sulfate (0.1 ml/kg/day) or saline (0.1 ml/kg/day) over 12 days, immediately following behavioral testing. For assessment of mechanical allodynia, mechanical stimuli using von Frey filament was applied to the paw to measure withdrawal threshold. The effects of N-methyl-D-aspartate receptors antagonist (memantine; 2.5, 5, 10 mg/kg intraperitoneal), opioid agonist (morphine; 2.5, 5, 10 mg/kg intraperitoneal) and vehicle (saline) on vicristine-induced neuropathy were evaluated.

Results

Mechanical allodynia developed over the course of ten daily injections of vincristine relative to groups receiving saline at the same time. Morphine abolished the reduction in paw withdrawal threshold compared to vehicle and produced dose-responsiveness. Only the highest dose of memantine (10 mg/kg) was able to increase paw withdrawal threshold compared to vehicle.

Conclusions

Systemic morphine and memantine have an antinociceptive effect on the vincristine-induced peripheral neuropathy model in rats. These results suggest morphine and memantine may be an alternative approach for the treatment of vincristine-induced peripheral neuropathic pain.

Memantine preferentially blocks extrasynaptic over synaptic NMDA receptor currents in hippocampal autapses

Glutamate is the major excitatory neurotransmitter in the brain. The NMDA subtype of glutamate receptors (NMDAR) is known to mediate many physiological neural functions. However, excessive activation of NMDARs contributes to neuronal damage in various acute and chronic neurological disorders. To avoid unwanted adverse side effects, blockade of excessive NMDAR activity must therefore be achieved without affecting its physiological function. Memantine, an adamantane derivative, has been used for the treatment of Alzheimer's disease with an excellent clinical safety profile. We previously showed that memantine preferentially blocked neurotoxicity mediated by excessive NMDAR activity while relatively sparing normal neurotransmission, in part because of its uncompetitive antagonism with a fast off-rate. Here, using rat autaptic hippocampal microcultures, we show that memantine at therapeutic concentrations (1-10 microM) preferentially blocks extrasynaptic rather than synaptic currents mediated by NMDARs in the same neuron. We found that memantine blocks extrasynaptic NMDAR-mediated currents induced by bath application of 100 microM NMDA/10 microM glycine with a twofold higher potency than its blockade of the NMDAR component of evoked EPSCs (EPSCs(NMDAR)); this effect persists under conditions of pathological depolarization in the presence of 1 mm extracellular Mg(2+). Thus, our findings provide the first unequivocal evidence to explain the tolerability of memantine based on differential extrasynaptic/synaptic receptor blockade. At therapeutic concentrations, memantine effectively blocks excessive extrasynaptic NMDAR-mediated currents, while relatively sparing normal synaptic activity.

Alzheimer's disease: clinical trials and drug development

Alzheimer's disease is the most common cause of dementia in elderly people. Research into Alzheimer's disease therapy has been at least partly successful in terms of developing symptomatic treatments, but has also had several failures in terms of developing disease-modifying therapies. These successes and failures have led to debate about the potential deficiencies in our understanding of the pathogenesis of Alzheimer's disease and potential pitfalls in diagnosis, choice of therapeutic targets, development of drug candidates, and design of clinical trials. Many clinical and experimental studies are ongoing, but we need to acknowledge that a single cure for Alzheimer's disease is unlikely to be found and that the approach to drug development for this disorder needs to be reconsidered. Preclinical research is constantly providing us with new information on pieces of the complex Alzheimer's disease puzzle, and an analysis of this information might reveal patterns of pharmacological interactions instead of single potential drug targets. Several promising randomised controlled trials are ongoing, and the increased collaboration between pharmaceutical companies, basic researchers, and clinical researchers has the potential to bring us closer to developing an optimum pharmaceutical approach for the treatment of Alzheimer's disease.

Memantine ER, a once-daily formulation for the treatment of Alzheimer's disease

IMPORTANCE OF THE FIELD

Alzheimer's disease is a progressive, degenerative brain disease. As the disease progresses, patients and caregivers face increasing problems with medication adherence. Given its relentlessly progressive nature, newer and more effective therapies for Alzheimer's disease are needed. Memantine 10 mg twice daily is the FDA-approved regimen for the treatment of moderate to severe Alzheimer's disease.

AREAS COVERED IN THIS REVIEW

The goal of this article is to review the once-daily memantine ER 28 mg formulation for the treatment of Alzheimer's disease, which, by simplifying the dosage regimen, decreases the problems of medication adherence. A new extended-release formulation has been developed to improve adherence and possibly efficacy without compromising an excellent tolerability and safety profile. There is also a possibility of dose-dependent improvement/superiority in cognitive, global and behavioral measures as well as in verbal fluency with higher-dose (28 mg/day) memantine.

WHAT THE READER WILL GAIN

Readers will become knowledgeable about this new dose and preparation of memantine. However, these advantages remain provisional and more research is needed to evaluate patient adherence, outcomes and caregiver burden related to twice-daily versus once-daily administration in patients with moderate to severe Alzheimer's disease.

TAKE HOME MESSAGE

A new, once-daily, higher-dose preparation of memantine seems to be well tolerated and may provide additional benefits for selected patients with Alzheimer's disease.

Differences in medication use in the Alzheimer's disease neuroimaging initiative: analysis of baseline characteristics

INTRODUCTION

The ADNI (Alzheimer's Disease Neuroimaging Initiative) is a large longitudinal study of patients with probable Alzheimer's disease (AD), patients with mild cognitive impairment (MCI) and healthy elderly controls followed for at least 2-3 years. Many participants in the ADNI are being treated with medications, and these may have beneficial or deleterious effects.

OBJECTIVE

The goal of the study was to characterize baseline medication use in the ADNI.

METHODS

Diagnosis, demographics, medication status, psychometric data and MRI measures of hippocampal volume and entorhinal cortex thickness were obtained for 818 participants from the ADNI cohort. Total number of medications, Beers list (potentially dangerous) medications and AD treatments were also tabulated. ANOVA and logistic regression were used to assess associations between baseline pharmacotherapy and diagnosis, demographics, and selected clinical and MRI variables.

RESULTS

Of the 818 enrolled ADNI participants, 809 were available for analysis in the present study, including 184 patients with AD, 399 patients with MCI and 226 healthy elderly controls. Significant gender differences in recruitment were observed in the MCI group. The average number of medications per participant was 8 (SD 4) and 22% reported treatment with one or more Beers list medications. For symptomatic treatment of MCI or AD, donepezil and memantine were the most commonly reported drugs. As expected, MCI and AD patients with more severe impairment were more likely to be treated. Men received treatment more frequently than women. Older subjects and those with less education were less likely to receive treatment.

CONCLUSIONS

AD and MCI participants from the ADNI cohort were being treated with polypharmacy and many were also taking one or more medications with the potential for adverse effects. Off-label use of cholinesterase inhibitors and/or memantine for MCI was common, with more severely affected patients most likely to receive treatment. Differences in the frequency of symptomatic treatment were also observed as a function of age, years of education, gender and disease severity.

Turning principles into practice in Alzheimer's disease

The prevalence of dementia is reaching epidemic proportions globally, but there remain a number of issues that prevent people with dementia, their families and caregivers, from taking control of their condition. In 2008, Alzheimer's Disease International (ADI) launched a Global Alzheimer's Disease Charter, which comprises six principles that underscore the urgency for a more ambitious approach to diagnosis, treatment and care. This review highlights some of the most important aspects and challenges of dementia diagnosis and treatment. These issues are reviewed in light of the six principles of the recent ADI Charter: promoting dementia awareness and understanding; respecting human rights; recognizing the key role of families and caregivers; providing access to health and social care; stressing the importance of optimal diagnosis and treatment; and preventing dementia through improvements in public health. The authors continue to hope that, one day, a cure for Alzheimer's disease will be found. Meanwhile, healthcare professionals need to unite in rising to the challenge of managing all cases of dementia, using the tools available to us now to work toward improved patient care.

Assessing physician attitudes and perceptions of Alzheimer's disease across Europe

Given the important role that physicians play in clinical care, disease advocacy, national health policy making and clinical research, the IMPACT survey sought to assess the attitudes and perceptions of physicians in 3 general categories: diagnosis and treatment of Alzheimer's disease (AD); caregivers and families of patients with AD; and the role of government in dealing with this disease and its consequences. Survey respondents comprised a total of 250 generalists and 250 specialists (neurologists, geriatricians, neuro-psychiatrists, psychiatrists and psychogeriatricians) from France, Germany, Italy, Spain and the United Kingdom. Physicians were aged 25 to 69 years, in practice for between 5 and 30 years and currently spending more than 50% of their time in direct patient care. Results showed that a sizable majority of physicians throughout Europe, specialists and generalists alike, agree that: 1) AD is underdiagnosed and undertreated; 2) patients and families are not prepared to recognise the early symptoms of the disease; 3) early treatment can help to slow the progression of the disease; and 4) more effective treatments are needed. Attitudes were statistically significantly different between some groups of physicians regarding disclosure of the diagnosis of AD, the benefits of lifestyle modification, and the value of AD-specific medication in patients whose symptoms are worsening. Differences in attitudes and perceptions of AD between specialists and generalists were limited; differences between countries were more common and of greater magnitude, particularly with respect to barriers to the use of prescription medications.

A brief instrument to assess treatment response in the patient with advanced Alzheimer disease

The availability of effective treatments for severe Alzheimer disease (AD) has accentuated the need for brief, simple tools to evaluate treatment response in busy clinical settings for patients with advanced dementia. To develop such a tool, data on 875 patients from 4 double-blind-randomized studies of donepezil in severe AD [Mini-Mental State Examination (MMSE) 0 to 12 inclusive] were pooled and analyzed to identify Severe Impairment Battery (SIB) items, which are sensitive to change over time. Eight of the 51 SIB items were chosen based on effect sizes and relative ease of administration. The resulting SIB-8 was then applied to a validation data set (not used to generate the short form) to characterize its usefulness. The items, Month, Months of Year, Write Name, Sentence, Fluency, Confrontational Naming-Spoon, Using Spoon-Photograph, and Digit Span, were sensitive to change with treatment (P<0.0001) and easy to administer. Baseline SIB-8 scores were correlated with baseline MMSE and full-scale SIB scores, and provided a good distribution of scores in patients at the lower end of the MMSE. The SIB-8 is a brief (< or =3 min) assessment for patients with severe AD that is sensitive to change and able to detect treatment response.

Anti-aging herbal medicine--how and why can they be used in aging-associated neurodegenerative diseases?

Aging is a universal biological process that leads to progressive and deleterious changes in organisms. From ancient time, mankind has already interested in preventing and keeping ourselves young. Anti-aging study is certainly not a new research area. Nowadays, the meaning of anti-aging has been changed from simply prolonging lifespan to increasing health span, which emphasizes more on the quality of life. This is the concept of healthy aging and prevention of pathological aging, which is associated with diseases. Keeping our brain functions as in young age is an important task for neuroscientists to prevent aging-associated neurological disorders, such as Alzheimer's diseases (AD) and Parkinson's disease (PD). The causes of these diseases are not fully understood, but it is believed that these diseases are affected by multiple factors. Neurodegenerative diseases can be cross-linked with a number of aging-associated conditions. Based on this, a holistic approach in anti-aging research seems to be more reasonable. Herbal medicine has a long history in Asian countries. It is believed that many of the medicinal herbs have anti-aging properties. Recent studies have shown that some medicinal herbs are effective in intervention or prevention of aging-associated neurological disorders. In this review, we use wolfberry and ginseng as examples to elaborate the properties of anti-aging herbs. The characteristics of medicinal herbs, especially their applications in different disease stages (prevention and intervention) and multi-targets properties, allow them to be potential anti-aging intervention in prevention and treatment of the aging-associated neurological disorders.

Effect of memantine treatment on regional cortical metabolism in Alzheimer's disease

OBJECTIVES

Cortical systems involved in the response to medication treatment for Alzheimer's disease (AD) are poorly understood. Preclinical studies have demonstrated the effect of memantine on neuroreceptors and cell physiology, although the impact of treatment on cortical activity in vivo is not known.

DESIGN

F-fluorodeoxyglucose positron emission tomography (PET) imaging and clinical assessment before and after open-label memantine treatment.

PARTICIPANTS/SETTING

Seventeen outpatients with probable AD on stable cholinesterase inhibitor medication.

INTERVENTION

Memantine up to 10 mg twice daily for 10 weeks.

MEASUREMENTS

Voxel-based analyses of change in cortical metabolic activity; Mattis Dementia Rating Scale (DRS), and Neurobehavioral Rating Scale (NRS).

RESULTS

: Mean age was 81 years; mean Mini-Mental State Examination score was 19.4. Compared with baseline, metabolic activity was significantly higher after 10 weeks memantine treatment in two cortical regions bilaterally: the inferior temporal gyrus (BA 20) and the angular gyrus/supramarginal gyrus (BA 39, 40). There was no significant relationship between change in DRS score and change in cortical metabolism, although change in NRS score was associated with the extent of metabolic change in the right parietal and temporal cortex.

CONCLUSION

Metabolic activity in bilateral inferior parietal and temporal cortex increases during 10 weeks of memantine treatment in patients with AD. PET imaging can reveal functional effects of medications on neural activity and may help to define critical mechanisms involved in drug treatment.

Effectiveness and tolerability of high-dose (23 mg/d) versus standard-dose (10 mg/d) donepezil in moderate to severe Alzheimer's disease: A 24-week, randomized, double-blind study

BACKGROUND

Currently approved Alzheimer's disease (AD) treatments have been reported to provide symptomatic benefit, without proven impact on clinical progression. We hypothesized that the loss of initial therapeutic benefit over time may be mitigated by higher doses of a cholinesterase inhibitor.

OBJECTIVE

The aim of this study was to determine the effectiveness and tolerability of increasing donepezil from 10 to 23 mg/d in patients with moderate to severe AD.

METHODS

This randomized, double-blind study was conducted at 219 sites in Asia, Europe, Australia, North America, South Africa, and South America from June 6, 2007, to March 27, 2009. Patients aged 45 to 90 years with probable AD, Mini-Mental State Examination score 0 to 20 (moderate to severe impairment), and who were receiving donepezil 10 mg once daily for > or =12 weeks before the start of the study were eligible. Patients (n = 1467) were randomly assigned to receive high-dose donepezil (23 mg once daily) or standard-dose donepezil (10 mg once daily) for 24 weeks. Coprimary effectiveness measures were changes in cognition and global functioning, as assessed using least squares mean changes from baseline (LSM [SE] A) scores (last observation carried forward) on the Severe Impairment Battery (SIB; cognition) and the Clinician's Interview-Based Impression of Change Plus Caregiver Input scale (CIBIC+; global function rating) overall change score (mean [SD]) at week 24. Treatment-emergent adverse events (TEAEs) were assessed using spontaneous patient/caregiver reporting and open-ended questioning; clinical laboratory testing (hematology, biochemistry, and urinalysis panels analyzed by a central laboratory); 12-lead ECG; and physical and neurologic examinations, including vital sign measurements.

RESULTS

The effectiveness analyses included 1371 patients (mean age, 73.8 years; 62.8% female; 73.5% white; weight range, 34.0-138.7 kg). A total of 296 of 981 patients (30.2%) withdrew from the donepezil 23-mg/d group; 87 of 486 patients (17.9%) withdrew from the donepezil 10-mg/d group. At study end (week 24), the LSM (SE) Delta in SIB score was significantly greater with donepezil 23 mg/d than with donepezil 10 mg/d (+2.6 [0.58] vs +0.4 [0.66], respectively; difference, 2.2; P < 0.001). The between-treatment difference in CIBIC+ score was nonsignificant (4.23 [1.07] vs 4.29 [1.07]). In post hoc analysis, LSM Delta in SIB score and CIBIC+ treatment effect at end point were greater with donepezil 23 mg/d than 10 mg/d in patients with more advanced AD compared with less impaired patients (SIB, +1.6 [0.78] vs -1.5 [0.88], respectively [P < 0.001]; CIBIC+, 4.31 [1.09] vs 4.42 [1.10] [P = 0.028]). TEAEs were reported in 710 of 963 patients (73.7%) who received donepezil 23 mg/d and in 300 of 471 patients (63.7%) who received donepezil 10 mg/d. With donepezil 23 mg/d, mild, moderate, and severe TEAEs were reported in 297 (30.8%), 332 (34.5%), and 81 (8.4%) patients, respectively; with donepezil 10 mg/d, these proportions were 147 (31.2%), 119 (25.3%), and 34 (7.2%). The 3 most common severe AEs reported with the 23-mg/d dose were nausea (9 patients [0.9%] vs 1 [0.2%] with the 10-mg/d dose), dizziness (7 [0.7%] vs 1 [0.2%]), and vomiting (6 [0.6%] vs 0). The most commonly reported TEAEs considered probably related to treatment with the 23-mg/d dose were nausea (59 patients [6.1%] vs 9 [1.9%] with the 10-mg/d dose), vomiting (48 [5.0%] vs 4 [0.8%]), and diarrhea (31 [3.2%] vs 7 [1.5%]).Thirteen deaths were reported during the study or within 30 days of study discontinuation (23 mg/d, 8 patients [0.8%]; 10 mg/d, 5 patients [1.1%]); all were considered unrelated to the study medication.

CONCLUSIONS

In this study in patients with moderate to severe AD, donepezil 23 mg/d was associated with greater benefits in cognition compared with donepezil 10 mg/d. The between-treatment difference in global functioning was not significant in the overall population. Patients with more advanced AD appeared to benefit from donepezil 23 mg/d on the assessment of global functioning, but this observation requires additional studies for confirmation. ClinicalTrials.gov identifier: NCT00478205.

Pharmacodynamics of memantine: an update

Memantine received marketing authorization from the European Agency for the Evaluation of Medicinal Products (EMEA) for the treatment of moderately severe to severe Alzheimer s disease (AD) in Europe on 17(th) May 2002 and shortly thereafter was also approved by the FDA for use in the same indication in the USA. Memantine is a moderate affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist with strong voltage-dependency and fast kinetics. Due to this mechanism of action (MOA), there is a wealth of other possible therapeutic indications for memantine and numerous preclinical data in animal models support this assumption. This review is intended to provide an update on preclinical studies on the pharmacodynamics of memantine, with an additional focus on animal models of diseases aside from the approved indication. For most studies prior to 1999, the reader is referred to a previous review [196].In general, since 1999, considerable additional preclinical evidence has accumulated supporting the use of memantine in AD (both symptomatic and neuroprotective). In addition, there has been further confirmation of the MOA of memantine as an uncompetitive NMDA receptor antagonist and essentially no data contradicting our understanding of the benign side effect profile of memantine.

The role of dopamine in symptoms and treatment of apathy in Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is characterized by a number of serious and debilitating behavioral and psychological symptoms of dementia (BPSD). The most common of these BPSD is apathy, which represents a major source of morbidity and premature institutionalization in the AD population. Many studies have identified discrete changes to the dopaminergic (DAergic) system in patients with AD. The DAergic system is closely related to the brain reward system (BRS) and some studies have suggested that dysfunction in the DAergic system may account for symptoms of apathy in the AD population.

METHOD

Changes to the dopamine (DA) system in AD will be reviewed, and evidence supporting the involvement of the DAergic system in the development of apathy will be examined. Additionally, some pharmacological interventions with DA activity have been identified. The utility of these treatments in the AD population will be reviewed, with a focus on apathy as an outcome.

RESULTS

Evidence presented in this review suggests that DA dysfunction in discrete brain areas is an important correlate of apathy in AD and that the DAergic system may be a rational target for pharmacological treatment of apathy.

Memantine for cognitive impairment in multiple sclerosis: a randomized placebo-controlled trial

BACKGROUND

Memantine, an NMDA antagonist, is effective for moderate to severe Alzheimer's disease.

OBJECTIVE

Determine whether memantine improves cognitive performance (CP) among subjects with multiple sclerosis (MS) and cognitive impairment (CI).

METHODS

This double-blind, randomized, placebo-controlled trial (Clinicaltrials.gov NCT00300716) compared memantine 10 mg twice a day (4 week titration followed by 12 weeks on the highest tolerated dose) with placebo. The primary outcome was the change from baseline to exit on the Paced Auditory Serial Addition Test (PASAT) and the California Verbal Learning Test-II (CVLT-II) Long Delay Free Recall (LDFR). Secondary outcomes included additional neuropsychological tests; self-report measures of quality of life, fatigue, and depression; and family/caregiver reports of subjects' CI and neuropsychiatric symptoms.

RESULTS

The differences between the groups on the change on the PASAT (placebo-memantine = 0.0 correct responses, 95% CI 3.4, 3.4; p = 0.9) and on CVLT-II LDFR (placebo-memantine =-0.6 words, 95% CI -2.1, 0.8; p = 0.4) as well as on the other cognitive tests were not significant. Subjects on memantine had no serious adverse events (AEs) but had more fatigue and neurological AEs as well as, per family members' reports, less cognitive improvement and greater neuropsychiatric symptoms than subjects on placebo.

CONCLUSION

Memantine 10 mg twice a day does not improve CP in subjects with MS, ages 18-65, without major depression, who have subjective cognitive complaints and perform worse than one SD below the mean on the PASAT or on the California Verbal Learning Test-II (total recall or delayed free recall).

Neuroprotective herbs and foods from different traditional medicines and diets

Plant secondary metabolites include an array of bioactive constituents form both medicinal and food plants able to improve human health. The exposure to these phytochemicals, including phenylpropanoids, isoprenoids and alkaloids, through correct dietary habits, may promote health benefits, protecting against the chronic degenerative disorders mainly seen in Western industrialized countries, such as cancer, cardiovascular and neurodegenerative diseases. In this review, we briefly deal with some plant foods and herbs of traditional medicines and diets, focusing on their neuroprotective active components. Because oxidative stress and neuroinflammation resulting from neuroglial activation, at the level of neurons, microglial cells and astrocytes, are key factors in the etiopathogenesis of both neurodegenerative and neurological diseases, emphasis will be placed on the antioxidant and anti-inflammatory activity exerted by specific molecules present in food plants or in remedies prescribed by herbal medicines.

Daily medication use in nursing home residents with advanced dementia

OBJECTIVES

To describe the pattern and factors associated with daily medication use in nursing home (NH) residents with advanced dementia.

DESIGN

Prospective cohort study.

SETTING

Twenty-two Boston-area NHs.

PARTICIPANTS

NH residents with advanced dementia (N=323).

MEASUREMENTS

Data from residents' records were used to determine the number or daily medications, specific drugs prescribed, and use of drugs deemed "never appropriate" in patients with advanced dementia. Resident characteristics associated with the use of more daily medications and drugs deemed inappropriate were examined.

RESULTS

Residents were prescribed a mean of 5.9 +/- 3.0 daily medications, and 37.5% received at least one medication considered "never appropriate" in advanced dementia. Acetylcholinesterase inhibitors (15.8%) and lipid-lowering agents (12.1%) were the most common inappropriate drugs. Twenty-eight percent of residents took antipsychotics daily. Modest reductions in most daily medications occurred only during the last week of life. Factors independently associated with taking more daily medications included older age, male sex, non-white race, dementia not due to Alzheimer's disease, better cognition, cardiovascular disease, acute illness, and hospice referral. Factors independently associated with greater likelihood of taking inappropriate medications included being male, shorter NH stay, better functional status, and diabetes mellitus, whereas a do-not-hospitalize order was associated with a lower likelihood.

CONCLUSION

Questionably beneficial medications are common in advanced dementia, even as death approaches. Several characteristics can help identify residents at risk for greater medication burden. Medication use in advanced dementia should be tailored to the goals of care.

Current therapeutic targets for the treatment of Alzheimer's disease

Alzheimer's disease is a progressive neurodegenerative disease for which no cure exists. There is a substantial need for new therapies that offer improved symptomatic benefit and disease-slowing capabilities. In recent decades there has been substantial progress in understanding the molecular and cellular changes associated with Alzheimer's disease pathology. This has resulted in identification of a large number of new drug targets. These targets include, but are not limited to, therapies that aim to prevent production of or remove the amyloid-beta protein that accumulates in neuritic plaques; to prevent the hyperphosphorylation and aggregation into paired helical filaments of the microtubule-associated protein tau; and to keep neurons alive and functioning normally in the face of these pathologic challenges. We provide a review of these targets for drug development.

Management of behavioral problems in Alzheimer's disease

Alzheimer's disease (AD) is a complex progressive brain degenerative disorder that has effects on multiple cerebral systems. In addition to cognitive and functional decline, diverse behavioral changes manifest with increasing severity over time, presenting significant management challenges for caregivers and health care professionals. Almost all patients with AD are affected by neuropsychiatric symptoms at some point during their illness; in some cases, symptoms occur prior to diagnosis of the dementia syndrome. Further, behavioral factors have been identified, which may have their origins in particular neurobiological processes, and respond to particular management strategies. Improved clarification of causes, triggers, and presentation of neuropsychiatric symptoms will guide both research and clinical decision-making. Measurement of neuropsychiatric symptoms in AD is most commonly by means of the Neuropsychiatric Inventory; its utility and future development are discussed, as are the limitations and difficulties encountered when quantifying behavioral responses in clinical trials. Evidence from clinical trials of both non-pharmacological and pharmacological treatments, and from neurobiological studies, provides a range of management options that can be tailored to individual needs. We suggest that non-pharmacological interventions (including psychosocial/psychological counseling, interpersonal management and environmental management) should be attempted first, followed by the least harmful medication for the shortest time possible. Pharmacological treatment options, such as antipsychotics, antidepressants, anticonvulsants, cholinesterase inhibitors and memantine, need careful consideration of the benefits and limitations of each drug class.

Spotlight on memantine in moderate to severe Alzheimer's disease

Memantine (Axura, Ebixa, Namenda) is an uncompetitive, moderate-affinity NMDA receptor antagonist that is indicated for the treatment of moderate to severe Alzheimer's disease. In well designed trials in patients with moderate to severe Alzheimer's disease, oral memantine monotherapy improved outcomes in the area of functional ability more than placebo in one trial, but in a second trial, treatment differences did not reach significance. Memantine has a distinct mode of action compared with that of acetylcholinesterase (AChE) inhibitors, and in a well designed study, combination therapy with memantine plus donepezil improved outcomes more than donepezil plus placebo in all four domains (function, cognition, behaviour and global change). Memantine is generally well tolerated, with adverse events occurring with a similar incidence to that reported with placebo. In modelled cost-effectiveness analyses, memantine was dominant to no therapy in regard to cost per quality-adjusted life-year (QALY) gained, and the combination of memantine plus donepezil was dominant to donepezil therapy alone in regard to QALYs gained when treatment periods exceeded 1 year in patients with moderate to severe disease. Thus, in the management of patients with moderate to severe Alzheimer's disease, memantine provides an effective treatment option. To date, clinical trial support is greater for memantine use in combination with an AChE inhibitor, while more data are needed to confirm its efficacy as monotherapy.

Safety and tolerability of rivastigmine capsule with memantine in patients with probable Alzheimer's disease: a 26-week, open-label, prospective trial (Study ENA713B US32)

OBJECTIVE

Rivastigmine, a dual cholinesterase inhibitor (ChEI), is widely approved for the symptomatic treatment of both mild-to-moderate Alzheimer's disease (AD) and Parkinson's disease dementia. Orally administered ChEIs may be associated with gastrointestinal (GI) side effects and add-on therapy with memantine, an N-methyl-d-aspartate receptor antagonist, approved for moderate-to-severe AD, may ameliorate such side effects. This was a 26-week, prospective, multicenter, single-arm, open-label pilot study to assess the safety and tolerability of rivastigmine capsules plus memantine in patients with moderate AD.

METHODS

The primary objective was to assess the safety and tolerability of rivastigmine capsules 6-12 mg/day plus memantine (5-20 mg/day) as measured by the incidences of vomiting and nausea compared with those reported in the rivastigmine United States Prescribing Information (US PI). A total of 117 patients were enrolled with 116 receiving at least one dose of study medication.

RESULTS

The incidences of nausea and vomiting (30% and 13%, respectively) observed in patients who received 6-12 mg/day rivastigmine plus memantine were lower than those stated in the US PI for rivastigmine monotherapy 6-12 mg/day (47% and 31%, respectively). The most common adverse events were nausea, vomiting, and dizziness.

CONCLUSION

Results from this study suggest the combination of rivastigmine capsule and memantine in patients with moderate AD is safe and tolerable. A greater reduction in the GI tolerability of rivastigmine has been established with rivastigmine transdermal patch.

Alzheimer's disease: visual system review

BACKGROUND

Ten million baby boomers in the United States will get Alzheimer's disease. Optometrists can benefit from understanding the impact the Alzheimer's disease process has on the visual system. This can result in more effective management of the condition and in more effective communication with members of the Alzheimer's disease multidisciplinary team.

METHODS

This is a review of the literature but by no means a completely exhaustive review. Alzheimer's disease is a complex disease. A rapidly expanding body of knowledge covers multiple disciplines.

RESULTS

The visual system shows deficits early in the degenerative process of Alzheimer's disease. Biomarkers through the visual system such as nerve fiber deficits, lens opacities, and functional losses in the magnocellular pathway, such as contrast sensitivity and temporal processing, may prove to not only help detect Alzheimer's disease early but also detect it before there are the classic cognitive and memory losses.

CONCLUSIONS

The effects of Alzheimer's disease are devastating. Optometrists, as primary care clinicians, can make critical contributions in the diagnosis, treatment, and management of this neurodegenerative disease.

Novel phage peptides attenuate beta amyloid-42 catalysed hydrogen peroxide production and associated neurotoxicity

Amyloid-beta (Abeta) peptides play a central role in the pathogenesis of Alzheimer's disease. There is accumulating evidence that supports the notion that the toxicity associated with human Abeta (both 40 and 42) is dependent on its superoxide dismutase (SOD)-like activity. We developed a novel screening method involving phage display technology to identify novel peptides capable of inhibiting Abeta's neurotoxicity. Two random peptide libraries containing 6-mer and 15-mer peptide inserts were used and resulted in the identification of 25 peptides that bound human Abeta (40 or 42). Here, we show that two of the three most enriched peptides obtained significantly reduced Abeta42's SOD-like activity. A 15-mer peptide reduced Abeta42 neurotoxicity in a dose-dependent manner as evidenced by a reduction in LDH release. These findings were confirmed in the independent MTT assay. Furthermore, comparative analysis of the 15-mer peptide with Clioquinol, a known inhibitor of Abeta's metal-mediated redox activity, showed the 15-mer peptide to be equipotent to this metal chelator, under the same experimental conditions. These agents represent novel peptides that selectively target and neutralise Abeta-induced neurotoxicity and thus provide promising leads for rational drug development.

S 24795 limits beta-amyloid-alpha7 nicotinic receptor interaction and reduces Alzheimer's disease-like pathologies

BACKGROUND

Beta-amyloid (Abeta) enables Alzheimer's disease (AD) plaque and neurofibrillary pathogenesis. Soluble Abeta promotes intraneuronal Abeta aggregates and tau phosphorylation by interacting with alpha7 nicotinic receptors (alpha7nAChRs). The current study assessed whether the novel alpha7nAChR partial agonist 2-(2-(4-bromophenyl)-2-oxoethyl)-1-methyl pyridinium (S 24795) could reduce AD-like pathologies by interfering with Abeta-alpha7nAChR interaction.

METHODS

We compared the in vitro effect of S 24795, memantine, galantamine, and Abeta(12-28) on Abeta(42)-alpha7nAChR interaction in rat hippocampal synaptosomes. We further evaluated the effect of S 24795 on Abeta(42)-induced tau phosphorylation with rat hippocampal synaptosomes in vitro. Effects of S 24795 on Abeta(42) immunostaining, Abeta(42)-alpha7nAChR interaction, and/or Abeta(42)-mediated reduction of calcium (Ca(2+)) influx through alpha7nAChR and N-methyl-d-aspartate receptor (NMDAR) were assessed in Abeta(42)-incubated organotypic brain slices and intracerebroventricularly (ICV) Abeta(42)-injected mouse brain.

RESULTS

Preincubation with S 24795 in vitro reduces Abeta(42)-alpha7nAChR interaction and Abeta(42)-induced tau phosphorylation. In organotypic brain slice cultures and in an ICV Abeta(42) injection in vivo model, S 24795 reduces Abeta(42)-alpha7nAChR association and Abeta(42) immunostaining. S 24795 also normalizes Ca(2+) fluxes through both alpha7nAChR and NMDAR channels in Abeta(42)-infused mouse brains and Abeta(42)-exposed organotypic cortical slices. Unlike S 24795 and Abeta(12-28), galantamine or memantine minimally affect Abeta(42)-alpha7nAChR coupling and Abeta(42)-mediated reduction of alpha7nAChR- and NMDAR-mediated Ca(2+) influx.

INTERPRETATION

Drugs like S 24795 that disrupt Abeta(42)-alpha7nAChR interaction might alleviate Abeta(42)-mediated synaptic dysfunction and block AD-like pathologies.

Novel mechanisms of central nervous system damage in HIV infection

Human immunodeficiency virus-1 infection of the central nervous system is an early event after primary infection, resulting in motor and cognitive defects in a significant number of individuals despite successful antiretroviral therapy. The pathology of the infected brain is characterized by enhanced leukocyte infiltration, microglial activation and nodules, aberrant expression of inflammatory factors, neuronal dysregulation and loss, and blood–brain barrier disruption. Months to years following the primary infection, these central nervous system insults result in a spectrum of motor and cognitive dysfunction, ranging from mild impairment to frank dementia. The mechanisms that mediate impairment are still not fully defined. In this review we discuss the cellular and molecular mechanisms that facilitate impairment and new data that implicate intercellular communication systems, gap junctions and tunneling nanotubes, as mediators of human immunodeficiency virus-1 toxicity and infection within the central nervous system. These data suggest potential targets for novel therapeutics.

A systematic review and meta-analysis of ethnic differences in use of dementia treatment, care, and research

The number of people with dementia from minority ethnic (ME) groups in western countries is projected to rise dramatically, and they may be less able to access dementia services. To compare the use of health and social services, treatments for dementia and dementia research between different ethnic groups. A systematic review of 33 articles fitting predetermined criteria. Compatible results were pooled in a meta-analysis. ME people with dementia were more cognitively impaired, and Hispanic people reported a longer duration of memory loss than non-ME people, at the time of referral to diagnostic dementia services in the United States and Australia {pooled weighted mean difference on Mini-Mental State Examination = 3.48 (95% confidence interval [CI]: 2.87-4.09); z = 11.19, p <0.0001; N = 2,090}. These differences remained after controlling for premorbid level of education. The use of community social services did not vary between ME and non-ME people with dementia, but African Americans were 30% less likely to be prescribed cholinesterase inhibitors {odds ratio (OR) 0.7 [0.6-0.9]; z = -3.1, p = 0.002; N = 175}, and ME groups were underrepresented in U.S. dementia drug trials. ME people with dementia were 40% less likely to enter 24-hour care (pooled hazard ratio 0.59 [95% CI: 0.52-0.69]; z = -7.15, p <0.0001; N = 12,053). The authors found consistent evidence, mostly from the United States, that ME people accessed diagnostic services later in their illness, and once they received a diagnosis, were less likely to access antidementia medication, research trials, and 24-hour care. Increasing community engagement and specific recruitment strategies for ME groups might help address inequalities, and these need to be evaluated. More research is also needed to evaluate ME access to dementia services outside the United States.

Update on the pharmacological treatment of Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disorder. Worldwide prevalence of the disease is estimated at more than 24 million cases. With aging of populations, this number will likely increase to more than 80 million cases by the year 2040. The annual incidence worldwide is estimated at 4.6 million cases which is the equivalent of one new case every seven seconds! The pathophysiology of AD is complex and largely misunderstood. It is thought to start with the accumulation of beta-amyloid (αβ) that leads to deposition of insoluble neuritic or senile plaques. Secondary events in this "amyloid cascade" include hyperphosphorylation of the protein tau into neurofibrillary tangles, inflammation, oxidation, and excitotoxicity that eventually cause activation of apoptotis, cell death and neurotransmitter deficits. This review will briefly summarize recent advances in the pathophysiology of AD and focus on the pharmacological treatment of the cognitive and functional symptoms of AD. It will discuss the roles of vascular prevention, cholinesterase inhibitors and an NMDA-antagonist in the management of AD. It will address the issues thought to be related to the lack of persistence or discontinuation of therapy with cholinesterase inhibitors shown in recent studies and some of the solutions proposed. These include setting realistic expectations in light of a neurodegenerative condition and available symptomatic treatments, slowly titrating medications, and using alternate routes of administration. Finally, it will introduce future therapeutic options currently under study.

Off-label medication use in frontotemporal dementia

OBJECTIVE

There are no Food and Drug Administration (FDA)-approved medications indicated for the treatment of frontotemporal dementia (FTD). We sought to determine the most commonly used drugs used to treat behavioral variant FTD (bvFTD) in specialized dementia clinics.

METHODS

Medication and demographic data from the Alzheimer's Disease Research Centers of California (ARCC) and a multicenter FTD natural history study (NHS) data set were compared in bvFTD and Alzheimer's disease (AD), and effects of demographic variables were assessed using logistic regression.

RESULTS

Overall, the percentage of patients taking one or more FDA-approved AD or psychiatric medications was similar in bvFTD and AD; however, after controlling for demographic variables, acetylcholinesterase inhibitor (AChI) use was less common in bvFTD, whereas memantine use remained similar in the 2 groups.

CONCLUSIONS

Despite lack of evidence for efficacy, the use of AChIs and memantine is common in bvFTD. Clinical trials should be pursued to determine the optimal therapeutic interventions for bvFTD.

Interventions for preventing falls in older people in nursing care facilities and hospitals

BACKGROUND

Falls in nursing care facilities and hospitals are common events that cause considerable morbidity and mortality for older people.

OBJECTIVES

To assess the effectiveness of interventions designed to reduce falls by older people in nursing care facilities and hospitals.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (January 2009); the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 2); MEDLINE, EMBASE, and CINAHL (all to November 2008); trial registers and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials of interventions to reduce falls in older people in nursing care facilities or hospitals. Primary outcomes were rate of falls and risk of falling.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Data were pooled where appropriate.

MAIN RESULTS

We included 41 trials (25,422 participants).In nursing care facilities, the results from seven trials testing supervised exercise interventions were inconsistent. This was the case too for multifactorial interventions, which overall did not significantly reduce the rate of falls (rate ratio (RaR) 0.82, 95% CI 0.62 to 1.08; 7 trials, 2997 participants) or risk of falling (risk ratio (RR) 0.93, 95% CI 0.86 to 1.01; 8 trials, 3271 participants). A post hoc subgroup analysis, however, indicated that where provided by a multidisciplinary team, multifactorial interventions reduced the rate of falls (RaR 0.60, 95% CI 0.51 to 0.72; 4 trials, 1651 participants) and risk of falling (RR 0.85, 95% CI 0.77 to 0.95; 5 trials, 1925 participants). Vitamin D supplementation reduced the rate of falls (RaR 0.72, 95% CI 0.55 to 0.95; 4 trials, 4512 participants), but not risk of falling (RR 0.98, 95% CI 0.89 to 1.09; 5 trials, 5095 participants).In hospitals, multifactorial interventions reduced the rate of falls (RaR 0.69, 95% CI 0.49 to 0.96; 4 trials, 6478 participants) and risk of falling (RR 0.73, 95% CI 0.56 to 0.96; 3 trials, 4824 participants). Supervised exercise interventions showed a significant reduction in risk of falling (RR 0.44, 95% CI 0.20 to 0.97; 3 trials, 131 participants).

AUTHORS' CONCLUSIONS

There is evidence that multifactorial interventions reduce falls and risk of falling in hospitals and may do so in nursing care facilities. Vitamin D supplementation is effective in reducing the rate of falls in nursing care facilities. Exercise in subacute hospital settings appears effective but its effectiveness in nursing care facilities remains uncertain.

An open-label study of memantine treatment in 3 subtypes of frontotemporal lobar degeneration

There are currently no Food and Drug Administration-approved treatments for frontotemporal lobar degeneration (FTLD). The objectives of this study were to explore the tolerability of memantine treatment in FTLD and to monitor for possible effects on behavior, cognition, and function. Forty-three individuals who met clinical criteria for FTLD [21 with frontotemporal dementia (FTD), 13 with semantic dementia (SD), and 9 with progressive nonfluent aphasia (PA)] received 26 weeks of open-label treatment with memantine at a target dose of 20 mg daily. Concurrent treatment with acetylcholinesterase inhibitors was prohibited. Cognitive and functional outcome measures included the Mini Mental State Examination, Alzheimer's Disease Assessment Scale-Cognitive (ADAS-cog), clinical dementia rating-sum of boxes, Neuropsychiatric Inventory (NPI), Frontal Behavior Inventory, Executive Interview (EXIT25), Texas Functional Living Scale (TFLS), Geriatric Depression Scale, and Unified Parkinson's Disease Rating Scale-motor scale. Most subjects were able to tolerate the target dose of memantine. A transient improvement was observed on the total NPI score primarily in the FTD group. Variable declines were observed on the ADAS-cog, EXIT25, Frontal Behavior Inventory, NPI, TFLS, and UPDRS scores. The FTD and SD groups declined on most of the cognitive and behavioral outcome measures, but remained stable on the UPDRS, whereas the progressive nonfluent aphasia group remained relatively stable on the ADAS-cog, NPI, and TFLS, but declined on the UPDRS. Memantine was well-tolerated in these subjects. Future placebo-controlled trials of memantine in FTLD are warranted and may have greater power to detect behavioral and cognitive effects if focused on the FTD and SD clinical syndromes.

Memantine lowers amyloid-beta peptide levels in neuronal cultures and in APP/PS1 transgenic mice

Memantine is a moderate-affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist that stabilizes cognitive, functional, and behavioral decline in patients with moderate to severe Alzheimer's disease (AD). In AD, the extracellular deposition of fibrillogenic amyloid-beta peptides (Abeta) occurs as a result of aberrant processing of the full-length Abeta precursor protein (APP). Memantine protects neurons from the neurotoxic effects of Abeta and improves cognition in transgenic mice with high brain levels of Abeta. However, it is unknown how memantine protects cells against neurodegeneration and affects APP processing and Abeta production. We report the effects of memantine in three different systems. In human neuroblastoma cells, memantine, at therapeutically relevant concentrations (1-4 muM), decreased levels of secreted APP and Abeta(1-40). Levels of the potentially amylodogenic Abeta(1-42) were undetectable in these cells. In primary rat cortical neuronal cultures, memantine treatment lowered Abeta(1-42) secretion. At the concentrations used, memantine treatment was not toxic to neuroblastoma or primary cultures and increased cell viability and/or metabolic activity under certain conditions. In APP/presenilin-1 (PS1) transgenic mice exhibiting high brain levels of Abeta(1-42), oral dosing of memantine (20 mg/kg/day for 8 days) produced a plasma drug concentration of 0.96 microM and significantly reduced the cortical levels of soluble Abeta(1-42). The ratio of Abeta(1-40)/Abeta(1-42) increased in treated mice, suggesting effects on the gamma-secretase complex. Thus, memantine reduces the levels of Abeta peptides at therapeutic concentrations and may inhibit the accumulation of fibrillogenic Abeta in mammalian brains. Memantine's ability to preserve neuronal cells against neurodegeneration, to increase metabolic activity, and to lower Abeta level has therapeutic implications for neurodegenerative disorders.

Memantine for AIDS dementia complex: open-label report of ACTG 301

OBJECTIVE

To evaluate the long-term safety and efficacy of memantine use as treatment of HIV-associated cognitive impairment.

BACKGROUND

The results of a 20-week, randomized, double-blind, placebo-controlled trial of memantine in HIV-infected participants with cognitive impairment (ACTG 301) were previously reported. We report the results of the up-to-60-week open-label phase following the double-blind phase.

METHOD

Participants received open-label memantine and were escalated to a 40 mg/day dose or their maximum tolerated dose in the double- blind phase. Adverse experiences were used to evaluate safety, and changes in the mean of eight neuropsychological test scores (NPZ-8) were used to evaluate efficacy.

RESULTS

Ninety-nine participants entered the initial 12-week open-label phase and 45 in the additional 48-week extension. Twenty-seven participants reported severe adverse experiences. During the initial 12-week open-label phase, participants randomized to memantine in the double-blind phase had a statistically significant higher improvement in NPZ-8 compared to those randomized to placebo in the double-blind phase. No statistically significant NPZ-8 changes were detected during the 48-week extension.

CONCLUSION

Long-term use of memantine appears safe and tolerable. Future randomized studies with longer follow-up are necessary to establish efficacy of memantine for the treatment of HIV-associated cognitive impairment.