Effects of rivastigmine on behavioral and psychological symptoms of dementia in Alzheimer's disease

Phytopharmaceuticals and Herbal Approaches to Target Neurodegenerative Disorders

Neurodegeneration is characterized as the continuous functional and structural loss of neurons, resulting in various clinical and pathological manifestations and loss of functional anatomy. Medicinal plants have been oppressed from ancient years and are highly considered throughout the world as a rich source of therapeutic means for the prevention, treatment of various ailments. Plant-derived medicinal products are becoming popular in India and other nations. Further herbal therapies shows good impact on chronic long term illnesses including degenerative conditions of neurons and brain. The use of herbal medicines continues to expand rapidly across the world. The active phytochemical constituents of individual plants are sometimes insufficient to achieve the desirable therapeutic effects. Combining the multiple herbs in a particular ratio (polyherbalism) will give a better therapeutic effect and reduce toxicity. Herbal-based nanosystems are also being studied as a way to enhance the delivery and bioavailability of phytochemical compounds for the treatment of neurodegenerative diseases. This review mainly focuses on the importance of the herbal medicines, polyherbalism and herbal-based nanosystems and its clinical significance for neurodegenerative diseases.

Targeting Sigma Receptors for the Treatment of Neurodegenerative and Neurodevelopmental Disorders

The sigma-1 receptor is a 223 amino acid-long protein with a recently identified structure. The sigma-2 receptor is a genetically unrelated protein with a similarly shaped binding pocket and acts to influence cellular activities similar to the sigma-1 receptor. Both proteins are highly expressed in neuronal tissues. As such, they have become targets for treating neurological diseases, including Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), multiple sclerosis (MS), Rett syndrome (RS), developmental and epileptic encephalopathies (DEE), and motor neuron disease/amyotrophic lateral sclerosis (MND/ALS). In recent years, there have been many pre-clinical and clinical studies of sigma receptor (1 and 2) ligands for treating neurological disease. Drugs such as blarcamesine, dextromethorphan and pridopidine, which have sigma-1 receptor activity as part of their pharmacological profile, are effective in treating multiple aspects of several neurological diseases. Furthermore, several sigma-2 receptor ligands are under investigation, including CT1812, rivastigmine and SAS0132. This review aims to provide a current and up-to-date analysis of the current clinical and pre-clinical data of drugs with sigma receptor activities for treating neurological disease.

Degenerative dementias: A question of syndrome or disease?

BACKGROUND

Neurologists refer to numerous "syndromes,‿ consisting of specific combinations of clinical manifestations, following a specific progression pattern, and with the support of blood analysis (without genomic-proteomic parameters) and neuroimaging findings (MRI, CT, perfusion SPECT, or 18F-FDG-PET scans). Neurodegenerative "diseases,‿ on the other hand, are defined by specific combinations of clinical signs and histopathological findings; these must be confirmed by a clinical examination and a histology study or evidence of markers of a specific disorder for the diagnosis to be made. However, we currently know that most genetic and histopathological alterations can result in diverse syndromes. The genetic or histopathological aetiology of each syndrome is also heterogeneous, and we may encounter situations with pathophysiological alterations characterising more than one neurodegenerative disease. Sometimes, specific biomarkers are detected in the preclinical stage.

DEVELOPMENT

We performed a literature review to identify patients whose histopathological or genetic disorder was discordant with that expected for the clinical syndrome observed, as well as patients presenting multiple neurodegenerative diseases, confirming the heterogeneity and overlap between syndromes and diseases. We also observed that the treatments currently prescribed to patients with neurodegenerative diseases are symptomatic.

CONCLUSIONS

Our findings show that the search for disease biomarkers should be restricted to research centres, given the lack of disease-modifying drugs or treatments improving survival. Moreover, syndromes and specific molecular or histopathological alterations should be managed independently of one another, and new "diseases‿ should be defined and adapted to current knowledge and practice.

Associated factors of suicidal ideation among older persons with dementia living at home in eight European countries

OBJECTIVES

This study aimed to investigate the occurrence of suicidal ideation and associated factors in older persons with dementia living at home in eight European countries, and its association with quality of life. Furthermore, changes in suicidal ideation over time were investigated.

METHODS

This cohort study (n = 1,223) was part of the European "RightTimePlaceCare" project conducted in 2010-2013. Participating countries were Estonia, Finland, France, Germany, the Netherlands, Spain, Sweden and the United Kingdom. Baseline and follow-up data were analysed using bivariate and multivariate logistic regression.

RESULTS

The occurrence of suicidal ideation in the participating countries varied between 6% and 24%. Factors significantly (p < 0.0018) associated with suicidal ideation using bivariate analysis were: nationality, depressive symptoms, delusions, hallucinations, agitation, anxiety, apathy, disinhibition, irritability, night-time behaviour disturbances, anxiolytics and anti-dementia medication. In the multivariate regression analysis, country of origin, moderate stage of the dementia, depressive and delusional symptoms, and anti-dementia medication were significantly associated with suicidal ideation (p < 0.05). Over time, suicidal ideation decreased from severe to mild or became absent in 54% of the persons with dementia.

CONCLUSION

It is essential that professionals identify older persons with dementia and suicidal ideation and depressive and other psychological symptoms in order to give them appropriate treatment and provide relief for their informal caregivers. We emphasize the importance of identifying suicidal ideation, irrespective of depressive symptoms, and specifically of paying attention to persons with moderate dementia. Living with the informal caregiver seems to be associated with staying stable without suicidal ideation.

Effects of Rivastigmine on Brain Functional Networks in Patients With Alzheimer Disease Based on the Graph Theory

OBJECTIVE

The aim of this study was to explore the effect of rivastigmine on brain function in Alzheimer disease (AD) by analyzing brain functional network based on the graph theory.

METHODS

We enrolled 9 patients with mild to moderate AD who received rivastigmine treatment and 9 healthy controls (HC). Subsequently, we used resting-state functional magnetic resonance imaging data to establish the whole-brain functional network using a graph theory-based analysis. Furthermore, we compared systemic and local network indicators between pre- and posttreatment.

RESULTS

Patients with AD exhibited a posttreatment increase in the Mini-Mental State Examination scores and a decrease in the Alzheimer's Disease Assessment Scale cognitive subscale scores and activities of daily living. The systemic network for HC and patients with AD had good pre- and posttreatment clustering coefficients. There was no change in the Cp, Lp, Gamma, Lambda, and Sigma in patients with AD. There were no significant between-group differences in the pre- and posttreatment systemic network measures. Regarding the regional network, patients with AD showed increased betweenness centrality in the bilateral caudate nucleus and right superior temporal pole after treatment with rivastigmine. However, there was no between-group difference in the pre- and posttreatment betweenness centrality of these regions. There were no significant correlations between regional network measure changes and clinical score alterations in patients with AD.

CONCLUSIONS

There are similar systemic network properties between patients with AD and HC. Rivastigmine cannot alter systemic network attributes in patients with AD. However, it improves the topological properties of regional networks and between-node information transmission in patients with AD.

Tackling N-Alkyl Imines with 3d Metal Catalysis: Highly Enantioselective Iron-Catalyzed Synthesis of α-Chiral Amines

A readily activated iron alkyl precatalyst effectively catalyzes the highly enantioselective hydroboration of N‐alkyl imines. Employing a chiral bis(oxazolinylmethylidene)isoindoline pincer ligand, the asymmetric reduction of various acyclic N‐alkyl imines provided the corresponding α‐chiral amines in excellent yields and with up to >99 % ee. The applicability of this base metal catalytic system was further demonstrated with the synthesis of the pharmaceuticals Fendiline and Tecalcet.

Brahmi (Bacopa monnieri): An ayurvedic herb against the Alzheimer's disease

Ayurveda is the medicinal science, dealing with utilization of naturally available plant products for treatment. A wide variety of neuroprotective herbs have been reported in Ayurveda. Brahmi, Bacopa monnieri is a nootropic ayurvedic herb known to be effective in neurological disorders from ancient times. Numerous approaches including natural and synthetic compounds have been applied against Alzheimer's disease. Amyloid-β and Tau are the hallmarks proteins of several neuronal dysfunctions resulting in Alzheimer's disease. Tau is a microtubule-associated protein known to be involved in progression of Alzheimer's disease. The generation of reaction oxygen species, increased neuroinflammation and neurotoxicity are the major physiological dysfunctions associated with Tau aggregates, which leads to dementia and behavioural deficits. Bacoside A, Bacoside B, Bacosaponins, Betulinic acid, etc; are the bioactive component of Brahmi belonging to various chemical families. Each chemical component known have its significant role in neuroprotection. The neuroprotective properties of Brahmi and its bioactive components including reduction of ROS, neuroinflammation, aggregation inhibition of Amyloid-β and improvement of cognitive and learning behaviour. Here on basis of earlier studies we hypothesize the inhibitory role of Brahmi against Tau-mediated toxicity. The overall studies have concluded that Brahmi can be used as a lead formulation for treatment of Alzheimer's disease and other neurological disorders.

Sialorrhoea associated with sertraline use

INTRODUCTION

Sialorrhoea, which has been defined as excessive amount of saliva in the mouth, can be a debilitating symptom. Psychoactive drugs may cause an increase or decrease in saliva secretion. Antidepressant drugs, especially tricyclic antidepressants and less often serotonin reuptake inhibitors, are often associated with a decrease in salivation and the complaint of dry mouth.

CASE PRESENTATION

A 46-year-old male patient with complaints of being depressed, lack of motivation, irritability and difficulty in falling asleep was started on sertraline treatment and had trouble with sialorrhoea after the dose increase, without other causes of hypersalivation.

DISCUSSION

We could not find report of any case with antidepressant-associated sialorrhoea in the literature. Future cases may support a relationship between sertraline and sialorrhoea.

Subchronic use of rivastigmine increases procognitive flexibility across multimodal behavioral tasks in healthy male rats

Rivastigmine (RVT) is a reversible inhibitor of cholinesterase approved worldwide for the treatment of cognitive dysfunctions, especially in Alzheimer's disease. Most previous pre-clinical studies have examined the effects of RVT treatment in a wide variety of pathological research models. Nonetheless, the effects of this drug on sensorimotor gating, memory, and learning tasks in healthy subjects remains unclear. In this study, we investigate the procognitive effects of RVT treatment in healthy rats through sensorimotor gating evaluations (measured as prepulse inhibition of the acoustic startle reflex), active avoidance learning, and spatial memory learning in a radial maze. There is an increase in the amplitude of the startle reflex in RVT-treated rats compared to the control groups, whereas the latency remained constant. Sensorimotor gating values were also incremented compared to those values from controls. In active avoidance, rats treated with RVT learned faster to successfully perform the task compared to controls, but afterwards all groups exhibited virtually identical results. During the sessions in the radial maze, RVT-treated rats committed fewer errors in both the working and reference memory compared to controls. All in all, our results support the hypothesis that RVT treatment may entail procognitive effects in healthy subjects.

Traditional Chinese medicine-based neurorestorative therapy for Alzheimer’s and Parkinson’s disease

The prevalence of multiple neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), has been dramatically increasing, particularly in the aging population. However, the currently available therapies merely alleviate the symptoms of these diseases and are unable to retard disease progression significantly. Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years for ameliorating symptoms or interfering with the pathogenesis of aging- associated diseases. Modern pharmacological studies have proved that TCM imparts disease-modifying therapeutic effects against these diseases, such as protection of neurons, clearance of protein aggregates, and regulation of neuroinflammation. This review summarizes the evidence from recent studies on AD and PD therapies regarding the neuroprotective activities and molecular mechanisms of a series of TCM formulations comprising herbs and their active ingredients. The findings of this review support the use of TCM as an alternative source of therapy for the treatment of neurodegenerative diseases.

Direct Asymmetric Hydrogenation of N-Methyl and N-Alkyl Imines with an Ir(III)H Catalyst

A novel cationic [IrH(THF)(P,N)(imine)] [BAr_F] catalyst containing a P-stereogenic MaxPHOX ligand is described for the direct asymmetric hydrogenation of N-methyl and N-alkyl imines. This is the first catalytic system to attain high enantioselectivity (up to 94% ee) in this type of transformation. The labile tetrahydrofuran ligand allows for effective activation and reactivity, even at low temperatures. Density functional theory calculations allowed the rationalization of the stereochemical course of the reaction.

Neurodegenerative Diseases: Regenerative Mechanisms and Novel Therapeutic Approaches

Regeneration refers to regrowth of tissue in the central nervous system. It includes generation of new neurons, glia, myelin, and synapses, as well as the regaining of essential functions: sensory, motor, emotional and cognitive abilities. Unfortunately, regeneration within the nervous system is very slow compared to other body systems. This relative slowness is attributed to increased vulnerability to irreversible cellular insults and the loss of function due to the very long lifespan of neurons, the stretch of cells and cytoplasm over several dozens of inches throughout the body, insufficiency of the tissue-level waste removal system, and minimal neural cell proliferation/self-renewal capacity. In this context, the current review summarized the most common features of major neurodegenerative disorders; their causes and consequences and proposed novel therapeutic approaches.

Features and outcomes of drugs for combination therapy as multi-targets strategy to combat Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD), a deleterious neurodegenerative disorder that impairs memory, cognitive functions and may lead to dementia in late stage of life. The pathogenic cause of AD remains incompletely understood and FDA approved drugs are partial inhibitors rather than curative. Most of drugs are synthetic or natural products as galanthamine is an alkaloid obtained from Galanthus spp. Huperzine A, an alkaloid found in Huperzia spp., gingkolides a diterpenoids from Gingko biloba and many ethnobotanicals like Withania somnifera (L.) Dunal., Physostigma venenosum Balf., Bacopa monnieri (L.) Wettst., Centella asiatica (L.) Urb. have been used by traditional Indian, Chinese, and European system of medicines in AD. Clinical significance opioid alkaloid in Papaver somniferum has shown another dimension to this study. Over exploitation of medicinal plants with limited bioactive principles has provided templates to design synthetic drugs in AD e.g. rivastigmine, phenserine, eptastigmine based on chemical structure of physostigmine of Physostigma venenosum Balf. Even ZT-1 a prodrug of Hup A and memogain a prodrug of galantamine has achieved new direction in drug development in AD. All these first-line cholinesterase-inhibitors are used as symptomatic treatments in AD. Single modality of "One-molecule-one-target" strategy for treating AD has failed and so future therapies on "Combination-drugs-multi-targets" strategy (CDMT) will need to address multiple aspects to block the progression of pathogenesis of AD. Besides, cholinergic and amyloid drugs, in this article we summarize proteinopathy-based drugs as AD therapeutics from a variety of biological sources. In this review, an attempt has been made to elucidate the molecular mode of action of various plant products, and synthetic drugs investigated in various preclinical and clinical tests in AD. It also discusses current attempts to formulate a comprehensive CDMT strategy to counter complex pathogenesis in AD.

MATERIALS AND METHODS

Information were collected from classical books on medicinal plants, pharmacopoeias and scientific databases like PubMed, Scopus, GoogleScholar, Web of Science and electronic searches were performed using Cochrane Library, Medline and EMBASE. Also published scientific literatures from Elsevier, Taylor and Francis, Springer, ACS, Wiley publishers and reports by government bodies and documentations were assessed.

RESULTS

60 no. of natural and synthetic drugs have been studied with their significant bioactivities. A decision matrix designed for evaluation of drugs for considering to the hypothetic "CDMT" strategy in AD. We have introduced the scoring pattern of individual drugs and based on scoring pattern, drugs that fall within the scoring range of 18-25 are considered in the proposed CDMT. It also highlights the importance of available natural products and in future those drugs may be considered in CDMT along with the qualified synthetic drugs.

CONCLUSION

A successful validation of the CDMT strategy may open up a debate on health care reform to explore other possibilities of combination therapy. In doing so, it should focus on clinical and molecular relationships between AD and CDMT. A better understanding of these relationships could inform and impact future development of AD-directed treatment strategies. This strategy also involves in reducing costs in treatment phases which will be affordable to a common man suffering from AD.

Treatment of psychosis in elderly people

Psychotic symptoms in elderly people can be seen in a variety of conditions. This article reviews treatment strategies (both pharmacological and non-pharmacological) for such symptoms in schizophrenia and neurodegenerative disorders in this population. Traditionally, antipsychotics have been the most commonly used treatment for psychotic symptoms. Their usefulness in treating schizophrenia, both chronic and late onset, is well established and the atypical antipsychotics, which have a better side-effect profile, are more suitable for elderly people. More recently, there have been increasing concerns about their safety in psychoses due to dementia. The debate about whether an absolute ban on their use is required is still ongoing, but it has highlighted the need for adopting and developing non-pharmacological interventions.

Pharmacological interventions to improve cognition and adaptive functioning in Down syndrome: Strides to date

Although an increasing number of clinical trials have been developed for cognition in Down syndrome, there has been limited success to date in identifying effective interventions. This review describes the progression from pre-clinical studies with mouse models to human clinical trials research using pharmacological interventions to improve cognition and adaptive functioning in Down syndrome. We also provide considerations for investigators when conducting human clinical trials and describe strategies for the pharmaceutical industry to advance the field in drug discovery for Down syndrome. Future research focusing on earlier pharmaceutical interventions, development of appropriate outcome measures, and greater collaboration between industry, academia, advocacy, and regulatory groups will be important for addressing limitations from prior studies and developing potential effective interventions for cognition in Down syndrome.

Effects of Renal Impairment on Steady-State Plasma Concentrations of Rivastigmine: A Population Pharmacokinetic Analysis of Capsule and Patch Formulations in Patients with Alzheimer's Disease

Introduction

The glomerular filtration rate (GFR), a measure of renal function, decreases by approximately 10 mL/min every 10 years after the age of 40 years, which could lead to the accumulation of drugs and/or renal toxicity. Pharmacokinetic studies of drugs excreted both renally and non-renally are desirable in patients with impaired renal function, defined by parameters including estimated GFR (eGFR) and creatinine clearance (CL_CR).

Objective

We describe here a population pharmacokinetic analysis of the possible effects of renal impairment on steady-state plasma concentrations of rivastigmine and its metabolite NAP226-90 after rivastigmine patch (5 cm² [4.6 mg/24 h], 10 cm² [9.5 mg/24 h], 15 cm² [13.3 mg/24 h], and 20 cm² [17.4 mg/24 h]) and capsule (1.5, 3, 4.5, and 6 mg/12 h) treatment in patients with Alzheimer’s disease.

Methods

The data used to conduct the current pharmacokinetic analysis were obtained from the pivotal phase III, 24-week, multicenter, randomized, double-blind, placebo- and active-controlled, parallel-group study (IDEAL). One blood sample was collected from each patient at steady-state to measure plasma concentrations of rivastigmine and NAP226-90 using a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. The steady-state plasma concentrations of rivastigmine and NAP226-90 were plotted against CL_CR and eGFR data, and boxplots were constructed after stratification by renal function.

Results

The two groups (mild/no renal impairment vs. moderate/severe/end-stage renal impairment) showed comparable demographic covariates for all patch sizes and capsule doses. No correlation was observed between CL_CR or eGFR and plasma concentrations of rivastigmine or NAP226-90. Boxplots of concentrations of rivastigmine or NAP226-90 for each dose largely overlapped for patch and capsule. Additionally, model-based estimates of plasma concentrations adjusted for body weight yielded similar results.

Conclusion

The results of this study show that renal function does not affect rivastigmine or NAP226-90 steady-state plasma concentrations, and no dose adjustment in patients with renal impairment is required.

ClinicalTrials.gov

NCT00099242.

Management of Neuropsychiatric Symptoms in Neurocognitive Disorders

Dementias, renamed neurocognitive disorders (NCDs) in the DSM-5, are defined by acquired decline in cognitive and functional abilities. DSM-5 now also includes mild NCD, which incorporates the previous diagnosis of mild cognitive impairment. DSM-5 recognizes the following etiologies for NCDs: NCD due to Alzheimer's disease, vascular NCD, NCD with Lewy bodies, frontotemporal NCD, substance-/medication-induced NCD, NCD due to traumatic brain injury, NCD due to Huntington's disease, NCD due to HIV infection, NCD due to prion disease, and NCD due to other medical conditions. In this review, the authors discuss a wide variety of interventions that have been studied for the treatment and management of neuropsychiatric symptoms of patients with NCDs. In addition to nonpharmacological interventions, several classes of medications-including antipsychotics, antidepressants, anticonvulsants, and cholinesterase inhibitors-have been studied for this indication.

Pharmacokinetic Modeling to Simulate the Concentration-Time Profiles After Dermal Application of Rivastigmine Patch

Rivastigmine is an inhibitor of acetylcholinesterases and butyrylcholinesterases for symptomatic treatment of Alzheimer disease and is available as oral and transdermal patch formulations. A dermal absorption pharmacokinetic (PK) model was developed to simulate the plasma concentration-time profile of rivastigmine to answer questions relative to the efficacy and safety risks after misuse of the patch (e.g., longer application than 24 h, multiple patches applied at the same time, and so forth). The model comprised 2 compartments which was a combination of mechanistic dermal absorption model and a basic 1-compartment model. The initial values for the model were determined based on the physicochemical characteristics of rivastigmine and PK parameters after intravenous administration. The model was fitted to the clinical PK profiles after single application of rivastigmine patch to obtain model parameters. The final model was validated by confirming that the simulated concentration-time curves and PK parameters (Cmax and area under the drug plasma concentration-time curve) conformed to the observed values and then was used to simulate the PK profiles of rivastigmine. This work demonstrated that the mechanistic dermal PK model fitted the clinical data well and was able to simulate the PK profile after patch misuse.

Synthesis and inhibitory properties of some carbamates on carbonic anhydrase and acetylcholine esterase

A series of carbamate derivatives were synthesized and their carbonic anhydrase I and II isoenzymes and acetylcholinesterase enzyme (AChE) inhibitory effects were investigated. All carbamates were synthesized from the corresponding carboxylic acids via the Curtius reactions of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The carbamates were determined to be very good inhibitors against for AChE and hCA I, and II isoenzymes. AChE inhibition was determined in the range 0.209-0.291 nM. On the other hand, tacrine, which is used in the treatment of Alzheimer's disease possessed lower inhibition effect (Ki: 0.398 nM). Also, hCA I and II isoenzymes were effectively inhibited by the carbamates, with inhibition constants (Ki) in the range of 4.49-5.61 nM for hCA I, and 4.94-7.66 nM for hCA II, respectively. Acetazolamide, which was clinically used carbonic anhydrase (CA) inhibitor demonstrated Ki values of 281.33 nM for hCA I and 9.07 nM for hCA II. The results clearly showed that AChE and both CA isoenzymes were effectively inhibited by carbamates at the low nanomolar levels.

Latrepirdine for Alzheimer's disease

BACKGROUND

Current treatments for Alzheimer's disease (AD) provide modest symptomatic relief but do not slow the progression of the disease. Latrepirdine may modulate several targets involved in AD pathology, including lipid peroxidation, mitochondrial permeability, voltage-gated calcium ion channels as well as neurotransmitter receptor activity, and thus potentially represents both a symptomatic and disease-modifying intervention. Several randomized, placebo-controlled trials have sought to evaluate the effect of latrepirdine on cognition, function and behaviour in patients with AD.

OBJECTIVES

To evaluate the efficacy and safety of latrepirdine for the treatment of AD.

SEARCH METHODS

We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 4 June 2014 using the terms: latrepirdine OR dimebon OR dimebolin OR 2,3,4,5-tetrahydro-2,8-dimethyl-5- (2-(6-methyl-3-pyridyl)ethyl)-1H-pyrido(4,3-b)indole.

SELECTION CRITERIA

We included all randomized, double-blind, placebo-controlled trials where latrepirdine was administered to patients with mild, moderate or severe AD.

DATA COLLECTION AND ANALYSIS

We assessed the quality of studies and two authors extracted data. We calculated mean difference (MD), risk ratio (RR) and 95% confidence interval (CI) on an intention-to-treat (ITT) basis for all relevant outcome measures.

MAIN RESULTS

Seven trials involving a total of 1697 participants were found and six were included in the quantitative analyses. No data were available from the seventh trial. Three trials involving 1243 patients were included in analyses of efficacy outcomes, and four trials involving 1034 patients were included in analyses of safety and tolerability outcomes. We judged five trials to be at high risk of bias due to selective outcome reporting and three to be at high risk of attrition bias. There was low quality evidence favouring latrepirdine on the Clinician's Interview - Based Impression of Change Plus Caregiver Input after 26 weeks (CIBIC-Plus) (MD -0.60, 95% CI -0.89 to -0.31, 1 study, P < 0.001). Due to imprecision in the results, it was not possible to determine whether latrepirdine had any effect on cognition measured with the Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-Cog) (MD -1.49, 95% CI -3.47 to 0.49, 3 studies, P = 0.14) or the Mini-Mental State Examination (MMSE) (MD 0.59, 95% CI -0.94 to 2.11, 3 studies, P = 0.45), or on function measured with the Alzheimer's Disease Co-operative Study - Activities of Daily Living scale (ADCS-ADL) (MD 1.00, 95% CI -1.15 to 3.15, 3 studies, P = 0.36) at study endpoint (26 or 52 weeks). We considered the evidence provided on these outcomes to be of overall low quality. However, there was some high quality evidence showing a very small benefit of latrepirdine on the Neuropsychiatric Inventory (NPI) (MD -1.77, 95% CI -3.09 to -0.45, 3 studies, P = 0.009) at study endpoint (26 or 52 weeks). Additionally, moderate quality evidence suggested that latrepirdine and placebo were comparable in adverse events (RR 1.03, 95% CI 0.93 to 1.14, P = 0.51), serious adverse events (RR 0.86, 95% CI 0.55 to 1.35, P = 0.52), dropouts (RR 0.91, 95% CI 0.65 to 1.27, P = 0.57) and dropouts due to adverse events (RR 0.98, 95% CI 0.57 to 1.67, P = 0.93).

AUTHORS' CONCLUSIONS

Our meta-analysis is limited by the small number of studies, imprecision, inconsistencies between studies and likelihood of bias. Nevertheless, the evidence to date suggests that while not associated with an increased risk of adverse events compared with placebo, there is no effect of latrepirdine on cognition and function in mild-to-moderate AD patients, though there appears to be a modest benefit for behaviour. Further studies should investigate the potential benefit of latrepirdine on neuropsychiatric symptoms in AD.

Salivary Secretory Disorders, Inducing Drugs, and Clinical Management

BACKGROUND

Salivary secretory disorders can be the result of a wide range of factors. Their prevalence and negative effects on the patient's quality of life oblige the clinician to confront the issue.

AIM

To review the salivary secretory disorders, inducing drugs and their clinical management.

METHODS

In this article, a literature search of these dysfunctions was conducted with the assistance of a research librarian in the MEDLINE/PubMed Database.

RESULTS

Xerostomia, or dry mouth syndrome, can be caused by medication, systemic diseases such as Sjögren's Syndrome, glandular pathologies, and radiotherapy of the head and neck. Treatment of dry mouth is aimed at both minimizing its symptoms and preventing oral complications with the employment of sialogogues and topical acting substances. Sialorrhea and drooling, are mainly due to medication or neurological systemic disease. There are various therapeutic, pharmacologic, and surgical alternatives for its management. The pharmacology of most of the substances employed for the treatment of salivary disorders is well-known. Nevertheless, in some cases a significant improvement in salivary function has not been observed after their administration.

CONCLUSION

At present, there are numerous frequently prescribed drugs whose unwanted effects include some kind of salivary disorder. In addition, the differing pathologic mechanisms, and the great variety of existing treatments hinder the clinical management of these patients. The authors have designed an algorithm to facilitate the decision making process when physicians, oral surgeons, or dentists face these salivary dysfunctions.

Role of antipsychotics for treating behavioral and psychological symptoms of dementia

Over the past three decades, concerns about the high prevalence of antipsychotic use in the nursing homes (NHs) for the management of behavioral and psychological symptoms of dementia continue to be emphasized and intervened by many. However, despite the numerous side effects and the recent blackbox warning by the United States Food and Drug Administration about the increased risks for stroke and sudden death associated with the use of antipsychotics in dementia, the prevalence of antipsychotic use in NHs remains high. While the use of antipsychotics appeared to have modest efficacy in reducing symptoms of aggression and psychosis in dementia, there is insufficient evidence to routinely recommend the use of alternative psychopharmacological treatments for these symptoms. Hence, clinicians have to balance the safety warnings against the need to treat these symptoms in order to prevent harm to the resident that may result from his/her dangerous behaviors. Although the use of antipsychotics may be warranted in some cases, organizational, resource and training support should be provided to encourage and equip NH staff to participate in interventions so as to minimize inappropriate use of these medicines in NHs. This review will discuss the place in therapy, the trend and appropriateness of antipsychotic use in NHs, as well as the effectiveness of current and future strategies for reducing antipsychotic use in the NHs.

Rivastigmine for subcortical vascular dementia

Rivastigmine is a second-generation cholinesterase inhibitor with selectivity for the CNS, with capacity to inhibit both acetylcholinesterase and butyrylcholinesterase. Rivastigmine is currently approved for the treatment of mild-to-moderate Alzheimer's disease. In addition to its effects on cognition and activities of daily living, rivastigmine appears to be useful in preventing and controlling behavioral and neuropsychiatric manifestations in Alzheimer's disease and dementia with Lewy bodies. This drug profile could be potentially useful in patients with subcortical vascular dementia who often present these symptoms. Small open-label studies of patients with subcortical vascular dementia showed that rivastigmine improved attention, executive function, apathy and other behavioral deficits. Rivastigmine appears to be a promising agent in vascular dementia but its effects remain to be established in double-blind, placebo-controlled clinical trials.

Rivastigmine in moderately severe-to-severe Alzheimer's disease: Severe Impairment Battery factor analysis

Introduction

The Severe Impairment Battery (SIB) is validated for assessing cognition in patients with severe dementia. The current analysis aimed to further investigate the cognitive efficacy of rivastigmine capsules, as assessed by SIB factor scores, in patients with moderately severe-to-severe Alzheimer’s disease (AD).

Methods

This was a retrospective analysis of a 26-week, multicenter, randomized, double-blind, placebo-controlled study of oral rivastigmine conducted in Spain. Previously reported outcome measures included the full SIB. Current analyses examined calculated scores and effect sizes for the change from baseline at Week 26 on: newly defined SIB subscales (derived by a factor analysis of the 40 SIB items, using the PROC FACTOR function (SAS)); previously defined memory, language and praxis subscales (derived by previous analysis of the nine SIB domains); and the individual SIB items. Treatment differences were assessed.

Results

SIB data were provided by 104 rivastigmine-treated patients and 106 patients receiving placebo (Intent-To-Treat Last Observation Carried Forward population). Significantly less decline was observed on the previously defined memory and language subscales, and the newly defined working memory/memory subscale in rivastigmine-treated patients (all P < 0.05 versus placebo). Calculation of effect sizes demonstrated numerically greater efficacy of rivastigmine versus placebo on each of the subscales, and a broad range of SIB items; greatest effect sizes were observed on SIB items assessing the current month (effect size = 0.30) and digit span series (effect size = 0.33).

Conclusions

These data suggest the observed efficacy of rivastigmine in moderately severe-to-severe AD is likely a cumulative effect across a range of tasks. Rivastigmine demonstrates broad cognitive efficacy in this patient population.

Nicotinic receptors in neurodegeneration

Many studies have focused on expanding our knowledge of the structure and diversity of peripheral and central nicotinic receptors. Nicotinic acetylcholine receptors (nAChRs) are members of the Cys-loop superfamily of pentameric ligand-gated ion channels, which include GABA (A and C), serotonin, and glycine receptors. Currently, 9 alpha (α2-α10) and 3 beta (β2-β4) subunits have been identified in the central nervous system (CNS), and these subunits assemble to form a variety of functional nAChRs. The pentameric combination of several alpha and beta subunits leads to a great number of nicotinic receptors that vary in their properties, including their sensitivity to nicotine, permeability to calcium and propensity to desensitize.

In the CNS, nAChRs play crucial roles in modulating presynaptic, postsynaptic, and extrasynaptic signaling, and have been found to be involved in a complex range of CNS disorders including Alzheimer’s disease (AD), Parkinson’s disease (PD), schizophrenia, Tourette´s syndrome, anxiety, depression and epilepsy. Therefore, there is growing interest in the development of drugs that modulate nAChR functions with optimal benefits and minimal adverse effects. The present review describes the main characteristics of nAChRs in the CNS and focuses on the various compounds that have been tested and are currently in phase I and phase II trials for the treatment of neurodegenerative diseases including PD, AD and age-associated memory and mild cognitive impairment.

NMDA Neurotransmission Dysfunction in Behavioral and Psychological Symptoms of Alzheimer's Disease

Dementia has become an all-important disease because the population is aging rapidly and the cost of health care associated with dementia is ever increasing. In addition to cognitive function impairment, associated behavioral and psychological symptoms of dementia (BPSD) worsen patient’s quality of life and increase caregiver’s burden. Alzheimer’s disease is the most common type of dementia and both behavioral disturbance and cognitive impairment of Alzheimer’s disease are thought to be associated with the N-methyl-D-aspartate (NMDA) dysfunction as increasing evidence of dysfunctional glutamatergic neurotransmission had been reported in behavioral changes and cognitive decline in Alzheimer’s disease. We review the literature regarding dementia (especially Alzheimer’s disease), BPSD and relevant findings on glutamatergic and NMDA neurotransmission, including the effects of memantine, a NMDA receptor antagonist, and NMDA-enhancing agents, such as D-serine and D-cycloserine. Literatures suggest that behavioral disturbance and cognitive impairment of Alzheimer’s disease may be associated with excitatory neurotoxic effects which result in impairment of neuronal plasticity and degenerative processes. Memantine shows benefits in improving cognition, function, agitation/aggression and delusion in Alzheimer’s disease. On the other hand, some NMDA modulators which enhance NMDA function through the co-agonist binding site can also improve cognitive function and psychotic symptoms. We propose that modulating NMDA neurotransmission is effective in treating behavioral and psychological symptoms of Alzheimer’s disease. Prospective study using NMDA enhancers in patients with Alzheimer’s disease and associated behavioral disturbance is needed to verify this hypothesis.

A population-based study of dosing and persistence with anti-dementia medications

PURPOSE

Cholinesterase inhibitors and memantine are the mainstay of pharmacological intervention for the cognitive symptoms of Alzheimer's disease (AD). This study assessed the adequacy of dosing and persistence with AD medications and the predictors of these variables in the 'real world' (outside the clinical trial setting).

METHODS

The Health Service Executive-Primary Care Reimbursement Services prescription claims database in the Republic of Ireland contains prescription information for 1.6 million people. Patients aged >70 years who received at least two prescriptions for donepezil, rivastigmine, galantamine and memantine between January 2006 and December 2010 were included in the study. Rates of dose-maximisation were recorded by examining the initiation dose of each AD drug commenced during the study period and any subsequent dose titrations. Non-persistence was defined by a gap in prescribing of more than 63 consecutive days. Predictors of dose-maximisation and non-persistence were also analysed.

RESULTS

Between January 2006 and December 2010, 20,729 patients aged >70 years received a prescription for an AD medication. Despite most patients on donepezil and memantine receiving a prescription for the maximum drug dose, this dose was maintained for 2 consecutive months in only two-thirds of patients. Patients were significantly more likely to have their doses of donepezil and memantine maximised if prescribed in more recent years (2010 vs. 2007). Rates of non-persistence were 30.1 % at 6 months and 43.8 % at 12 months. Older age [75+ vs. <75 years; hazards ratio (HR) 1.16, 95 % confidence interval (CI) 1.06-1.27] and drug type (rivastigmine vs. donepezil; HR 1.15, 95 % CI 1.03-1.27) increased the risk of non-persistence. Non-persistence was lower for those commencing therapy in more recent years (2010 vs. 2007; HR 0.81, 95 % CI 0.73-0.89, p < 0.001) and for those on multiple anti-dementia medications (HR 0.59, 95 % CI 0.54-0.65, p < 0.001). Persistence was significantly higher when memantine was co-prescribed with donepezil (p < 0.0001).

CONCLUSION

Future studies should explore the reasons underlying non-persistence and failure to maintain dose-maximisation in patients on AD medications. There may be scope to improve the dosing and persistence with these medications in the community.

Inappropriate long-term use of antipsychotic drugs is common among people with dementia living in specialized care units

Background

Antipsychotic drugs are widely used for the treatment of Behavioral and Psychological Symptoms of Dementia (BPSD), despite their limited efficacy and concerns about safety. The aim of this study was to describe antipsychotic drug therapy among people with dementia living in specialized care units in northern Sweden.

Methods

This study was conducted in 40 specialized care units in northern Sweden, with a total study population of 344 people with dementia. The study population was described in regard to antipsychotic drug use, ADL function, cognitive function and BPSD, using the Multi-Dimensional Dementia Assessment Scale (MDDAS). These data were collected at baseline and six months later. Detailed data about antipsychotic prescribing were collected from prescription records.

Results

This study showed that 132 persons (38%) in the study population used antipsychotic drugs at the start of the study. Of these, 52/132 (39%) had prescriptions that followed national guidelines with regard to dose and substance.

After six months, there were 111 of 132 persons left because of deaths and dropouts. Of these 111 people, 80 (72%) were still being treated with antipsychotics, 63/111 (57%) with the same dose. People who exhibited aggressive behavior (OR: 1.980, CI: 1.515-2.588), or passiveness (OR: 1.548, CI: 1.150-2.083), or had mild cognitive impairment (OR: 2.284 CI: 1.046-4.988), were at increased risk of being prescribed antipsychotics.

Conclusion

The prevalence of antipsychotic drug use among people with dementia living in specialized care units was high and inappropriate long-term use of antipsychotic drugs was common.

Reduced tissue levels of noradrenaline are associated with behavioral phenotypes of the TgCRND8 mouse model of Alzheimer's disease

Noradrenergic cell loss is well documented in Alzheimer's disease (AD). We have measured the tissue levels of catecholamines in an amyloid precursor protein-transgenic 'TgCRND8' mouse model of AD and found reductions in noradrenaline (NA) within hippocampus, temporoparietal and frontal cortices, and cerebellum. An age-related increase in cortical NA levels was observed in non-Tg controls, but not in TgCRND8 mice. In contrast, NA levels declined with aging in the TgCRND8 hippocampus. Dopamine levels were unaffected. Reductions in the tissue content of NA were found to coincide with altered expression of brain-derived neurotrophic factor (BDNF) mRNA and to precede the onset of object memory impairment and behavioral despair. To test whether these phenotypes might be associated with diminished NA, we treated mice with dexefaroxan, an antagonist of presynaptic inhibitory α(2)-adrenoceptors on noradrenergic and cholinergic terminals. Mice 12 weeks of age were infused systemically for 28 days with dexefaroxan or rivastigmine, a cholinesterase inhibitor. Both dexefaroxan and rivastigmine improved TgCRND8 behavioral phenotypes and increased BDNF mRNA expression without affecting amyloid-β peptide levels. Our results highlight the importance of noradrenergic depletion in AD-like phenotypes of TgCRND8 mice.

Treatment guidelines for Alzheimer's disease: redefining perceptions in primary care

BACKGROUND

Current treatment guidelines for Alzheimer's disease (AD) do not reflect more recently collected data on therapeutic outcomes other than cognitive function and memory, and this has led to a limited understanding of the value of drug therapy in AD.

OBJECTIVES

To evaluate the need to revise treatment guidelines for AD, to review data that have become available since the publication of current guidelines, and to communicate how existing guidelines and relevant new data can be valuable to the primary care provider who assesses and treats patients with AD.

DATA SOURCES

A MEDLINE search was conducted to identify existing treatment guidelines using the MeSH headings Alzheimer disease-drug therapy AND practice guidelines. The alternative terms treatment guidelines, practice parameter, and practice recommendation were also searched in conjunction with the MeSH term Alzheimer disease-drug therapy. Additionally, MEDLINE was searched using the term dementia and publication type "practice guideline." All searches were limited to articles published within the last 10 years, in English. A total of 116 articles were identified by these searches. Additional publications were identified by manually searching the reference lists of these articles and of published clinical trials of AD therapies.

STUDY SELECTION AND DATA EXTRACTION

Current AD treatment guidelines and clinical trial results for AD treatment options were extracted, reviewed, and summarized to meet the objectives of this article.

DATA SYNTHESIS

Current guidelines support the use of cholinesterase inhibitors in patients with mild to moderate AD. More recent clinical research indicates that cholinesterase inhibitor treatment provides effectiveness across a wide range of dementia severity and multiple symptom domains. These medications also significantly decrease caregiver burden and may lower the risk for nursing home placement.

CONCLUSIONS

The expanding literature on AD medications suggests that treatment guidelines need to be reexamined. Recent data emphasize preservation of abilities and delay of adverse outcomes in AD patients rather than short-term improvements in cognitive test scores. Treatment appears to provide the greatest benefit when it is initiated early in the course of the disease and maintained over the long term. Revised treatment guidelines should address newer medications and more recent outcomes considerations, as well as provide guidance on how long to continue and when to discontinue pharmacotherapy for AD.

Dose effects associated with rivastigmine transdermal patch in patients with mild-to-moderate Alzheimer's disease

AIM

The cholinesterase inhibitor rivastigmine is available in both oral and transdermal forms. The efficacy of oral rivastigmine appears to be dose-dependent. The current analysis investigates the effect of dose on the efficacy of the rivastigmine transdermal patch.

METHODS

This was a retrospective analysis of a large, international, 24-week, randomised, placebo- and active-controlled trial (IDEAL, CENA713D2320) of rivastigmine in patients with mild-to-moderate Alzheimer's disease (AD). Patients received the 9.5 mg/24 h rivastigmine patch, the 17.4 mg/24 h rivastigmine patch, 12 mg/day rivastigmine capsules or placebo. Changes from baseline at week 24 on the AD Assessment Scale-cognitive subscale (ADAS-cog), AD Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) and the AD Cooperative Study-Activities of Daily Living (ADCS-ADL) scale were calculated based on the patient's mode and last prescribed patch dose. The analysis included the 4.6 mg/24 h and 13.3 mg/24 h patch doses, for which efficacy data have not previously been reported.

RESULTS

Significant differences (p<0.05 vs. placebo) were seen on the ADAS-cog and ADCS-ADL for all mode rivastigmine patch doses (except 4.6 mg/24 h) and all last prescribed rivastigmine patch doses (except 4.6 mg/24 h and 13.3 mg/24 h). Patients with a last prescribed/mode patch dose of 9.5 mg/24 h and 13.3 mg/24 h showed significant improvements (p<0.05 vs. placebo) on the ADCS-CGIC.

CONCLUSION

Rivastigmine patch doses higher than 9.5 mg/24 h may offer additional benefits. The 13.3 mg/24 h patch is worthy of further investigation.

Expert opinion on the management of behavioural and psychological symptoms of dementia (BPSD) and investigation into prescribing practices in the UK

BACKGROUND

The management of Behavioural and Psychological Symptoms of Dementia (BPSD) has been the subject of considerable debate over the last few years in view of the poor evidence base for pharmacological agents and concerns about their safety.

OBJECTIVES

This study sought to obtain expert opinion on the management of BPSD and to investigate current prescribing practices in the UK.

METHOD

A total of 166 expert opinion surveys were emailed to UK consultants in Old Age Psychiatry asking them to rate the appropriateness of psychotropics in different aspects of BPSD. A service evaluation was also carried out in 8 UK centres to investigate prescribing patterns.

RESULTS

Overall, 59 consultants returned completed questionnaires, a response rate of 35%. Results revealed that experts rated quetiapine as the most appropriate agent for all BPSD followed by acetylcholinesterase inhibitors for psychotic symptoms, benzodiazepines for agitation or aggression and trazodone for behavioural symptoms such as disinhibition. The service evaluations showed that benzodiazepines were most frequently prescribed for BPSD.

CONCLUSIONS

Although quetiapine was judged by experts to be the most appropriate agent for BPSD, it appears that in clinical practice benzodiazepines are most often used to manage these symptoms. Evidence from both studies show wide inconsistencies in prescribing trends.

Present and prospective clinical therapeutic regimens for Alzheimer's disease

Alzheimer's disease (AD) is an incurable neurodegenerative disorder that produces cognitive impairments that increase in severity as the disease progresses. The clinical symptoms are related to the presence of neuritic plaques and neurofibrillary tangles in the cerebral cortex which represent the pathophysiological hallmarks of AD. The debilitating nature of the disease can result in clinical burden for the patient, emotional strain for those that care for patients with Alzheimer's, and significant financial burden to society. The goals of current treatments, such as cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonist, are to reduce the severity or slow the progression of cognitive symptoms. Although these treatments have demonstrated modest clinical benefit, they are unable to prevent, prohibit, or reverse the underlying pathophysiology of AD. Considerable progress has been made toward the development of disease-modifying treatments. Treatments currently under development mainly target the production, aggregation, and removal of existing amyloid beta-peptide aggregates which are believed to instigate the overall development of the neuropathology. Additional strategies that target tau pathology are being studied to promote neural protection against AD pathology. The current research has continued to expand our knowledge toward the development of disease modifying Alzheimer's therapies; however, no specific treatment strategy capable of demonstrating empirical efficacy and safety has yet to emerge.

Different responses to rivastigmine in subcortical vascular dementia and multi-infarct dementia

Vascular dementia (VaD) is associated with a large amount of heterogeneity, as it groups together a broad category of patients in whom various manifestations of cognitive decline are attributed to cerebrovascular or cardiovascular disease. Thus, a study was designed to determine the effects of rivastigmine on cognitive function, global daily living performance, and behavioral disorders in VaD patients versus an active control (nimodipine), stratifying patients according to the type of VaD, subcortical vascular dementia (sVAD), and multi-infarct dementia (MID). The trial was a prospective study. This study shows that long-term treatment with rivastigmine, at dosages approved for therapeutic use in Alzheimer's disease, produces significant improvement in all behavioral symptoms in 2 forms of VaD, MID and sVaD, except delusions. It also suggests that rivastigmine may enable a reduction in concomitant neuroleptics and benzodiazepines in VaD, especially in MID. The results are discussed with an overview of the literature.

The use of cognitive enhancers in behavioral disturbances of Alzheimer's disease

OBJECTIVE

To review the literature for double-blind, placebo-controlled trials that examined the efficacy of cognitive enhancers in the psychopathology of Alzheimer's disease.

DATA SOURCES

Literature searches were conducted using MEDLINE and EMBASE databases and clinicaltrials.gov.

STUDY SELECTION

Overall, 55 articles were reviewed for inclusion. Several open-label studies and case reports were found on this topic, but only those involving both tacrine and use of the Neuropsychiatric Inventory were included. Regarding other drugs, only double-blind, placebo-controlled trials were selected for inclusion.

DATA SYNTHESIS

Limited data suggest that the anticholinesterase inhibitors and memantine offer an alternative or adjunct to the antipsychotics for the treatment of moderate-to-severe behaviors. The author reviewed the literature for pharmacological management of behavioral and psychological symptoms of dementia (BPSD) using these cognitive enhancers.

CONCLUSION

The majority of patients with Alzheimer's disease will experience behavioral disturbances during the course of their disease. Atypical antipsychotics are used routinely in these situations to treat the psychotic features and agitation. However, atypicals now carry a "black box" warning issued by the Food and Drug Administration on the basis of evidence that their use in geriatric patients with dementia-related psychosis may put patients at increased risk of mortality as a result of cardiovascular or infectious events. An alternative to the atypicals may be the acetylcholinesterase inhibitors and memantine, which have been shown to stabilize cognitive as well as behavioral issues in patients, utilizing the "gold standard" for behavior, the Neuropsychiatric Inventory. Efficacy varies among agents, with the greatest positive effects seen with donepezil, which also has the greatest number of studies. Drug benefits were harder to demonstrate for mild-to-moderate BPSD compared with moderate-to-severe symptoms.

Rivastigmine in the treatment of Alzheimer's disease: an update

Alzheimer's disease is the most common form of dementia in industrialized countries. In the European Union, about 54% of dementia cases are believed to be due to Alzheimer's disease. The condition is an age-related neurodegenerative disorder characterized by multiple cognitive deficiencies, including loss of memory, judgment, and comprehension. These manifestations are accompanied by behavioral and mood disturbances. Although no cure has yet been discovered for Alzheimer's disease, symptomatic therapies are now widely available and offer significant relief to patients and benefits to caregivers in terms of reduced care burden. At the start of the 21st century, health technology assessments recommended three agents for the symptomatic treatment of mild to moderate Alzheimer disease: rivastigmine, donepezil, and galantamine. Rivastigmine (Exelon, Novartis Basel-Switzerland) is a slowly reversible inhibitor of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), while donepezil (Aricept, Pfizer, New York, USA) and galantamine (Reminyl, Janssen, New Jersey, USA) show no functional inhibition of BuChE, and are considered AChE-selective, rapidly-reversible inhibitors. The efficacy of all three agents has been evaluated in large, double-blind, placebo-controlled clinical trials of up to 6 months' duration. Rivastigmine treatment in mild to moderate Alzheimer's disease improves cognition, activities of daily living, and global function.

[Stereology as a tool to estimate brain volume and cortical atrophy in elders with dementia]

INTRODUCTION

stereology is a body of methods that allow unbiased and efficient estimation of geometric quantities defined in arbitrary physical structures. In particular, stereology is a valuable tool to assist neuroimaging in the estimation of morphometric parameters in the brain. Therefore, stereology may confer objectivity in the complementary and diagnostic evaluation of dementia by adding disease by adding quantitative data to clinical evaluation.

OBJECTIVES AND METHODS

our purpose was to illustrate estimation of brain volume and pial surface area by means of quantitative, computer-assisted stereological methods. Both parameters were estimated by means of a vertical design with a single series of parallel Cavalieri sections at a random orientation and perpendicular to a fixed horizontal plane. The sections were obtained by magnetic resonance imaging. Suitable test systems (of test points for volume, and of cycloids for surface area) were superimposed on these sections with the aid of special software.

RESULTS

to explore the statistical error of the volume estimator due to stereological sampling, 5 or 10 systematic sections were used in combination with two test point densities in a ratio of 1:4, so that the workload varied in the proportions 1:2:4:8. The four resulting estimators varied between 986 and 1120 cm(3). The surface area estimators varied between 1947 and 2096 cm(2), with workloads varying in the proportions of 1:2:2.3:4.6.

CONCLUSIONS

stereology is a simple and efficient tool to obtain objective brain volume and surface area estimators that are unbiased by design and accurate at a modest cost. Thus the corresponding methods can effectively assist in diagnostic and follow-up evaluation of elders with dementia.

Effects of dietary supplementation with N-acetyl cysteine, acetyl-L-carnitine and S-adenosyl methionine on cognitive performance and aggression in normal mice and mice expressing human ApoE4

In addition to cognitive impairment, behavioral changes such as aggressive behavior, depression, and psychosis accompany Alzheimer's Disease. Such symptoms may arise due to imbalances in neurotransmitters rather than overt neurodegeneration. Herein, we demonstrate that combined administration of N-acetyl cysteine (an antioxidant and glutathione precursor that protects against A beta neurotoxicity), acetyl-L-carnitine (which raises ATP levels, protects mitochondria, and buffers A beta neurotoxicity), and S-adenosylmethionine (which facilitates glutathione usage and maintains acetylcholine levels) enhanced or maintain cognitive function, and attenuated or prevented aggression, in mouse models of aging and neurodegeneration. Enhancement of cognitive function was rapidly reversed upon withdrawal of the formulation and restored following additional rounds supplementation. Behavioral abnormalities correlated with a decline in acetylcholine, which was also prevented by this nutriceutical combination, suggesting that neurotransmitter imbalance may contribute to their manifestation. Treatment with this nutriceutical combination was able to compensate for lack of dietary folate and vitamin E, coupled with administration of dietary iron as a pro-oxidant (which collectively increase homocysteine and oxidative damage to brain tissue), indicating that it provided antioxidant neuroprotection. Maintenance of neurotransmitter levels and prevention of oxidative damage underscore the efficacy of a therapeutic approach that utilizes a combination of neuroprotective agents.