Randomised multicentre trial on safety and efficacy of rivastigmine in cognitively impaired multiple sclerosis patients

Rivastigmine Regulates the HIF-1α/VEGF Signaling Pathway to Induce Angiogenesis and Improves the Survival of Random Flaps in Rats

Random skin flaps are frequently used to repair skin damage. However, the ischemic and hypoxic necrosis limits their wider application. Rivastigmine, a carbamate cholinesterase inhibitor (ChEI), has also been shown to reduce ischemia–reperfusion injury (IRI) and inflammation. This study was performed to examine the effect of rivastigmine on flap survival. Sixty male Sprague–Dawley rats with a modified McFarland flap were randomly divided into three groups: control group, 1 ml of solvent (10% DMSO + 90% corn oil); low-dose rivastigmine group (Riv-L), 1.0 mg/kg; and high-dose rivastigmine group (Riv-H), 2.0 mg/kg. All rats were treated once a day. On day 7, the skin flap survival area was measured. After staining with hematoxylin and eosin (H&E), the pathological changes and microvessel density (MVD) were examined. The expression of inflammatory factors IL-1β and IL-18, CD34, hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) was examined by immunohistochemical staining. The malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were examined to determine the degree of oxidative stress. Lead oxide/gelatin angiography showed neovascularization and laser Doppler blood flowmetry showed the blood filling volume. Rivastigmine significantly increased the flap survival area and improved neovascularization. CD34, VEGF, and HIF-1α expression were increased, These changes were more pronounced in the Riv-H group. Treatment with rivastigmine reduced the level of MDA, improved SOD activity, and reduced expression of IL-1β and IL-18. Our results indicate that Rivastigmine can increase angiogenesis and significantly improve flap survival.

Acetylcholinesterase Inhibitors in the Treatment of Neurodegenerative Diseases and the Role of Acetylcholinesterase in their Pathogenesis

Acetylcholinesterase (AChE) plays an important role in the pathogenesis of neurodegenerative diseases by influencing the inflammatory response, apoptosis, oxidative stress and aggregation of pathological proteins. There is a search for new compounds that can prevent the occurrence of neurodegenerative diseases and slow down their course. The aim of this review is to present the role of AChE in the pathomechanism of neurodegenerative diseases. In addition, this review aims to reveal the benefits of using AChE inhibitors to treat these diseases. The selected new AChE inhibitors were also assessed in terms of their potential use in the described disease entities. Designing and searching for new drugs targeting AChE may in the future allow the discovery of therapies that will be effective in the treatment of neurodegenerative diseases.

Anti-inflammatory and Neuroprotective Agents in Clinical Trials for CNS Disease and Injury: Where Do We Go From Here?

Neurological disorders are major contributors to death and disability worldwide. The pathology of injuries and disease processes includes a cascade of events that often involve molecular and cellular components of the immune system and their interaction with cells and structures within the central nervous system. Because of this, there has been great interest in developing neuroprotective therapeutic approaches that target neuroinflammatory pathways. Several neuroprotective anti-inflammatory agents have been investigated in clinical trials for a variety of neurological diseases and injuries, but to date the results from the great majority of these trials has been disappointing. There nevertheless remains great interest in the development of neuroprotective strategies in this arena. With this in mind, the complement system is being increasingly discussed as an attractive therapeutic target for treating brain injury and neurodegenerative conditions, due to emerging data supporting a pivotal role for complement in promoting multiple downstream activities that promote neuroinflammation and degeneration. As we move forward in testing additional neuroprotective and immune-modulating agents, we believe it will be useful to review past trials and discuss potential factors that may have contributed to failure, which will assist with future agent selection and trial design, including for complement inhibitors. In this context, we also discuss inhibition of the complement system as a potential neuroprotective strategy for neuropathologies of the central nervous system.

Pharmacotherapy in multiple sclerosis-induced cognitive impairment: A systematic review and meta-analysis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) commonly complicated by cognitive impairment. Unfortunately, no medical therapy has been proved to improve cognitive problems in these patients. This meta-analysis investigated the effectiveness of different categories of drugs on the minimal assessment of cognitive function in MS (MACFIMS)-related tasks outcome in MS patients. To this end, a systematic evaluation was conducted using PubMed, Google Scholar, and Scopus databases. Among a total of 128 publications, 31 studies met our inclusion criteria, and 22 included in the meta-analysis. We found that symbol digit modalities test (SDMT), paced auditory serial addition test (PASAT), controlled oral word association test (COWAT), and California verbal learning test (CVLT) were the most frequently reported tasks in included studies. The frequently reported drugs were classified into five main groups of acetylcholine esterase inhibitors, CNS stimulants, fampridine, herbal remedies, and miscellaneous. Overall heterogeneity of the studies was modest. The treatments did not affect cognitive function in any of the tasks (p>0.05). However, in subgroup analysis, we found significant improvement in SDMT task outecomes after treatment by fampridine (0.283 SMD, 95%CI, 0.015 to 0.550, p = 0.039, I2=11.7%). Our meta-analysis highlighted that the currently proposed therapeutic agents had no beneficial effects on the alleviation of MS-induced cognitive impairment.

Cognitive Efficacy of Pharmacologic Treatments in Multiple Sclerosis: A Systematic Review

INTRODUCTION

Cognitive impairment is prevalent and debilitating among persons with multiple sclerosis (MS). While many pharmacologic treatments have shown good efficacy in reducing clinical relapses, brain lesions, and improving certain physical symptoms, their efficacy for improving cognitive function is not well understood.

OBJECTIVES

The current systematic review aimed to evaluate the efficacy of pharmacologic treatments for improving cognitive function among persons with MS.

METHODS

A literature search was conducted through the PubMed and PsycINFO databases. Two independent reviewers assessed each paper, and a third reviewer weighed in if the two reviewers could not reach a consensus. Classification of evidence was determined using the 2017 American Academy of Neurology (AAN) criteria for therapeutic trials. Standardized effect sizes (Cohen's d) were calculated to compare across studies.

RESULTS

Eighty-seven journal articles published between 1990 and January 2020 were included in the current review. Overall, there is insufficient evidence to support the use of pharmacologic treatments to improve cognitive function in persons with MS. There were many contradictory findings observed in this review, which may be due to possible unidentified moderating treatment response variables and/or lack of standardization in assessment procedures. There was also an overreliance on statistical significance (most papers did not provide sizes of treatment effects), which may not be clinically meaningful.

CONCLUSIONS

Higher-quality randomized controlled trials are needed to establish the cognitive efficacy of pharmacologic treatments for MS-related cognitive dysfunction, with cognition as the primary endpoint. Researchers are urged to use standardized criteria (such as the AAN criteria) to guide their research designs. Clinicians should consider effect sizes of studies before deciding whether to prescribe certain medications to ameliorate cognitive symptoms.

Glutamine antagonism attenuates physical and cognitive deficits in a model of MS

OBJECTIVE

To measure the impact of JHU-083, a novel prodrug of the glutamine antagonist 6-diazo-5-oxo-l-norleucine, on immune cell proliferation and activation, along with physical and cognitive impairments associated with the experimental autoimmune encephalomyelitis (EAE) mouse model of MS.

METHODS

Splenic-derived T cells and bone marrow-derived dendritic cells (DCs) were cultured, activated, and treated daily with vehicle or JHU-083. Proliferation and activation were measured via flow cytometry and IncuCyte live cell analysis. C57BL/6 mice were immunized for EAE. Vehicle or JHU-083 was administered orally every other day either from the time of immunization in the prevention paradigm or from the time of disease onset in the treatment paradigm. Disease scores and body weight were monitored. In the treatment paradigm, cognition was evaluated using the Barnes maze test.

RESULTS

JHU-083 selectively inhibits T-cell proliferation and decreases T-cell activation, with no effect on DCs. In vivo, orally administered JHU-083 significantly decreases EAE severity in both prevention and treatment paradigms and reverses EAE-induced cognitive impairment.

CONCLUSIONS

JHU-083, a well-tolerated, brain penetrable glutamine antagonist, is a promising novel treatment for both the physical and cognitive deficits of MS.

A structural MRI study of cholinergic pathways and cognition in multiple sclerosis

Background

White matter hyperintensities (WMH) in the cholinergic pathways are associated with cognitive performance in Alzheimer's disease. This study aimed to evaluate the relationship between the volume reduction of cholinergic pathways and cognitive function in patients with multiple sclerosis (MS).

Methods

Thirty-two MS patients underwent a brain MRI and cognitive measurements including the Mini-Mental State Examination (MMSE) and the Japanese version of the Montreal Cognitive Assessment (MoCA-J). The extent of WMH within the cholinergic pathways was assessed using the Cholinergic Pathways Hyperintensities Scale (CHIPS). Computerized WMH volumes were also obtained. FreeSurfer was used to measure regional volumes including the cortical and subcortical volumes. The correlations among the CHIPS, the WMH volume, and the clinical data were assessed, in addition to the correlations between the cognitive scores and regional volumes measured by FreeSurfer.

Results

The CHIPS score and the WMH volume were strongly positively correlated with each other (r = 0.87, P < 0.001). The CHIPS score had significantly negative correlations with the MMSE (r = - 0.49, P = 0.003) and the MoCA-J (r = - 0.47, P = 0.005) results. The WMH volume had significantly negative correlations with the MMSE (r = - 0.54, P = 0.001) and the MoCA-J (r = - 0.57, P < 0.001) results. In the analysis by FreeSurfer, both the MMSE and MoCA-J scores had significant positive correlations only with the volume of the corpus callosum.

Conclusions

The CHIPS score tended to be less sensitive to the WMH volume in cognitive function evaluation, although the difference did not reach the level of statistical significance. Thus the CHIPS method may not be as effective in MS patients.

Symptomatic treatment in multiple sclerosis-interim analysis of a nationwide registry

OBJECTIVE

To analyze symptomatic treatment in patients with multiple sclerosis (MS).

BACKGROUND

Multiple sclerosis is a chronic inflammatory disease of the central nervous system, with accumulating disability symptoms like spasticity, voiding disorders, depression, and pain might occur.

MATERIAL AND METHODS

The nationwide German MS registry was initiated 2001 under guidance of the German MS society (Deutsche MS Gesellschaft). This study was performed as an interim analysis to lay foundation for future work on this topic. A subcohort of 5113 patients was assessed for this interim analysis. The mean age of the patients was 45.3 years; mean EDSS was 4.2. More than two-third of the enrolled patients were females (70.9%).

RESULTS

Most frequent symptoms were fatigue (60%), followed by spasticity (52.5%) and voiding disorders (51.7%). The likelihood of treatment was highest for epileptic disorders (68.8%), spasticity (68.5%), pain (60.7%), and depression (58.9%). Multivariate regression analysis showed that retirement was the strongest factor predictive for antispastic treatment (β=.061, P=.005).

CONCLUSION

Almost all patients in this analysis suffer from symptoms due to advanced MS. Treatment for the various symptoms differed tremendously. The likelihood of treatment correlated with the availability of effective therapeutic agents. Clinicians should put more awareness on MS symptoms. Symptomatic treatment may improve quality of life.

Impact of Pharmacotherapy on Cognitive Dysfunction in Patients with Multiple Sclerosis

Cognitive impairment is a common symptom of multiple sclerosis (MS), adversely impacting many spheres of daily functioning. Yet the effectiveness of pharmacological interventions for cognitive impairment in MS is unclear. Clinicians and patients alike would benefit from formal guidelines regarding effective management of cognitive symptoms. We reviewed the background on the measurement, pathophysiology and risk factors for cognitive dysfunction in MS, and then examined the published clinical trials of pharmacotherapy, including both disease-modifying treatments (DMTs) and symptom-management therapies (SMTs). Our review of DMTs revealed only a single well-designed, randomized, controlled trial where intramuscular interferon (IFN)-β1a, administered once weekly, was compared with placebo. The results showed significant benefits in terms of cognitive processing speed and memory. Less convincing but promising data have shown the potential benefits of IFN-β1b and natalizumab. The literature on SMTs is replete with placebo-controlled, single-centre studies, with a failure to replicate initially promising results. The results for SMTs such as acetylcholinesterase inhibitors and psychostimulants are mixed. Some encouraging data show promise but not to a threshold of indication for standard clinical use. Numerous methodological factors hamper research in this area. Acknowledging the lack of firm conclusions, we argue that all DMTs are likely to benefit cognition and that, if otherwise safe, SMTs with some empirical support may be attempted at the discretion of the treating clinician. We offer some guidance on the assessment and monitoring of cognitive function to inform off-license treatment of cognitive impairment in MS patients.

Cholinesterase inhibitors for rarer dementias associated with neurological conditions

BACKGROUND

Rarer dementias include Huntington's disease (HD), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), frontotemporal dementia (FTD), dementia in multiple sclerosis (MS) and progressive supranuclear palsy (PSP). Cholinesterase inhibitors, including donepezil, galantamine and rivastigmine, are considered to be the first-line medicines for Alzheimer's disease and some other dementias, such as dementia in Parkinson's disease. Cholinesterase inhibitors are hypothesised to work by inhibiting the enzyme acetylcholinesterase (AChE) which breaks down the neurotransmitter acetylcholine. Cholinesterase inhibitors may also lead to clinical improvement for rarer dementias associated with neurological conditions.

OBJECTIVES

To assess the efficacy and safety of cholinesterase inhibitors for cognitive impairment or dementia associated with neurological conditions.

SEARCH METHODS

We searched the Cochrane Dementia and Cognitive Improvement Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS, several trial registries and grey literature sources in August 2013.

SELECTION CRITERIA

We included randomised, double-blind, controlled trials assessing the efficacy of treatment of rarer dementias associated with neurological conditions with currently marketed cholinesterase inhibitors.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and quality of trials, and extracted data. We used the standard methodological procedures of the Cochrane Collaboration.

MAIN RESULTS

We included eight RCTs involving 567 participants. Six studies used a simple parallel-group design; the other two consisted of an open-label treatment period followed by a randomised phase. All trials were well concealed for allocation and double-blind, however the sample sizes of most trials were small. All trials used placebo as control. We performed meta-analyses for some outcomes in patients with MS. For all other conditions, results are presented narratively.Two trials included patients with HD; one found that cholinesterase inhibitor use in the short-term had no statistically significant impact on the cognitive portion of the Alzheimer Disease Assessment Scale (ADAS-Cog; 1 study, WMD 1.00, 95% CI -1.66 to 3.66, P = 0.46; low quality evidence), Unified Huntington's Disease Rating Scale (UHDRS) Verbal Fluency Test (1 study, WMD -1.20, 95% CI -7.97 to 5.57, P = 0.73; low quality evidence), UHDRS Symbol Digit Modalities Test (SDMT; 1 study, WMD 2.70, 95% CI -0.95 to 6.35, P = 0.15; low quality evidence) and other psychometric tests. The other study found that cholinesterase inhibitor use in the medium-term improved the results of the verbal fluency test (1 study, WMD 6.43, 95% CI 0.66 to 12.20, P = 0.03; moderate quality evidence) and California Verbal Learning Test - Second Edition (CVLT-II) Recognition Task (1 study, WMD 2.42, 95% CI 0.17 to 4.67, P = 0.04; moderate quality evidence). There was no statistically significant difference between groups on the SDMT (1 study, WMD -0.31, 95% CI -7.77 to 7.15, P = 0.94; moderate quality evidence), CVLT-II trials 1-5 (1 study, WMD -2.09, 95% CI -11.65 to 7.47, P = 0.67; moderate quality evidence), short-delay recall (1 study, WMD 0.35, 95% CI -2.87 to 3.57, P = 0.83; moderate quality evidence), or long-delay recall (1 study, WMD -0.14, 95% CI -3.08 to 2.80, P = 0.93; moderate quality evidence), and other psychometric tests.Four trials included patients with MS; one found no differences between the cholinesterase inhibitors (short-term) and placebo groups on the Wechsler Memory Scales general memory score (1 study, WMD 0.90, 95% CI -0.52 to 2.32, P = 0.22; low quality evidence). The three other trials found that, in the medium-term - cholinesterase inhibitors improved the clinician's impression of cognitive change (2 studies, OR 1.96, 95% CI 1.06 to 3.62, P = 0.03; high quality evidence). However, the treatment effect on other aspects of cognitive change were unclear, measured by the Selective Reminding Test (3 studies, WMD 1.47, 95% CI -0.39 to 3.32, P = 0.12; high quality evidence), patient's self-reported impression of memory change (2 studies, OR 1.67, 95% CI 0.93 to 3.00, P = 0.08; high quality evidence) and cognitive change (1 study, OR 0.95, 95% CI 0.45 to 1.98, P = 0.89; high quality evidence), clinician's impression of memory change (1 study, OR 1.50, 95% CI 0.59 to 3.84, P = 0.39; moderate quality evidence), other psychometric tests, and activities of daily living - patient reported impact of multiple sclerosis activities (1 study, WMD -1.18, 95% CI -3.02 to 0.66, P = 0.21; low quality evidence).One study on patients with CADASIL found a beneficial effect of cholinesterase inhibitors on the Executive interview, and Trail Making Test parts A and B. The impact of cholinesterase inhibitors on the Vascular ADAS-Cog score (1 study, WMD 0.04, 95% CI -1.57 to 1.65, P = 0.96; high quality evidence), the Clinical Dementia Rating Scale Sum of Boxes (1 study, WMD -0.09, 95% CI -0.48 to 0.03, P = 0.65; high quality evidence) Disability Assessment for Dementia scale (1 study, WMD 0.58, 95% CI -2.72 to 3.88, P = 0.73; moderate quality evidence), and other measures was unclearOne study included patients with FTD. This trial consisted of an open-label treatment period followed by a randomised, double-blind, placebo-controlled phase. No data of primary outcomes were reported in this study.In the included studies, the most common side effect was gastrointestinal symptoms. For all conditions, compared to the treatment group, the placebo group experienced significantly less nausea (6 studies, 44/257 vs. 22/246, OR 2.10, 95% CI 1.22 to 3.62, P = 0.007; high quality evidence), diarrhoea (6 studies, 40/257 vs. 13/246, OR 3.26, 95% CI 1.72 to 6.19, P = 0.0003; moderate quality evidence) and vomiting (3 studies, 17/192 vs. 3/182, OR 5.76, 95% CI 1.67 to 19.87, P = 0.006; moderate quality evidence).

AUTHORS' CONCLUSIONS

The sample sizes of most included trials were small, and some of the results were extracted from only one study. There were no poolable data for HD, CADASIL and FTD patients and there were no results for patients with PSP. Current evidence shows that the efficacy on cognitive function and activities of daily living of cholinesterase inhibitors in people with HD, CADASIL, MS, PSP or FTD is unclear, although cholinesterase inhibitors are associated with more gastrointestinal side effects compared with placebo.

Epstein-Barr virus and multiple sclerosis: potential opportunities for immunotherapy

Multiple sclerosis (MS) is a common chronic inflammatory demyelinating disease of the central nervous system (CNS) causing progressive disability. Many observations implicate Epstein–Barr virus (EBV) in the pathogenesis of MS, namely universal EBV seropositivity, high anti-EBV antibody levels, alterations in EBV-specific CD8⁺ T-cell immunity, increased spontaneous EBV-induced transformation of peripheral blood B cells, increased shedding of EBV from saliva and accumulation of EBV-infected B cells and plasma cells in the brain. Several mechanisms have been postulated to explain the role of EBV in the development of MS including cross-reactivity between EBV and CNS antigens, bystander damage to the CNS by EBV-specific CD8⁺ T cells, activation of innate immunity by EBV-encoded small RNA molecules in the CNS, expression of αB-crystallin in EBV-infected B cells leading to a CD4⁺ T-cell response against oligodendrocyte-derived αB-crystallin and EBV infection of autoreactive B cells, which produce pathogenic autoantibodies and provide costimulatory survival signals to autoreactive T cells in the CNS. The rapidly accumulating evidence for a pathogenic role of EBV in MS provides ground for optimism that it might be possible to prevent and cure MS by effectively controlling EBV infection through vaccination, antiviral drugs or treatment with EBV-specific cytotoxic CD8⁺ T cells. Adoptive immunotherapy with in vitro-expanded autologous EBV-specific CD8⁺ T cells directed against viral latent proteins was recently used to treat a patient with secondary progressive MS. Following the therapy, there was clinical improvement, decreased disease activity on magnetic resonance imaging and reduced intrathecal immunoglobulin production.

Pharmacological treatment for memory disorder in multiple sclerosis

BACKGROUND

This is an update of the Cochrane review "Pharmacologic treatment for memory disorder in multiple sclerosis" (first published in The Cochrane Library 2011, Issue 10).Multiple sclerosis (MS) is a chronic immune-mediated, inflammatory, demyelinating, neurodegenerative disorder of the central nervous system (CNS) and can cause both neurological and neuropsychological disability. Both demyelination and axonal and neuronal loss are believed to contribute to MS-related cognitive impairment. Memory disorder is one of the most frequent cognitive dysfunctions and presents a considerable burden to people with MS and to society due to the negative impact on function. A number of pharmacological agents have been evaluated in many existing randomised controlled trials for their efficacy on memory disorder in people with MS but the results were not consistent.

OBJECTIVES

To assess the absolute and comparative efficacy, tolerability and safety of pharmacological treatments for memory disorder in adults with MS.

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Trials Register (24 July 2013), PsycINFO (January 1980 to 26 June 2013) and CBMdisc (1978 to 24 June 2013), and checked reference lists of identified articles, searched some relevant journals manually, registers of clinical trials and published abstracts of conference proceedings.

SELECTION CRITERIA

All double-blind, randomised controlled parallel trials on pharmacological treatment versus placebo or one or more pharmacological treatments in adults with MS who had at least mild memory impairment (at 0.5 standard deviations below age- and sex-based normative data on a validated memory scale). We placed no restrictions regarding dose, route of administration and frequency; however, we only included trials with an administration duration of 12 weeks or greater.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We discussed disagreements and resolved them by consensus among review authors. We contacted principal investigators of included studies for additional data or confirmation.

MAIN RESULTS

We included seven randomised controlled trials (RCTs) involving 625 people mostly with relapsing-remitting, secondary-progressive and primary-progressive MS, evaluating the absolute efficacy of donepezil, ginkgo biloba, memantine and rivastigmine versus placebo in improving memory performance with diverse assessment scales. Overall, clinical and methodological heterogeneities existed across these studies. Moreover, most of them had methodological limitations on non-specific selections of targeted sample, non-matched variables at baseline or incomplete outcome data (high attrition bias). Only the two studies on donepezil had clinical and methodological homogeneity and relatively low risks for bias. One RCT evaluating estriol versus placebo is currently ongoing.We could not carry out a meta-analysis due to the heterogeneities across studies and the high attrition bias. A subgroup analysis for donepezil versus placebo showed no treatment effects on total recall on the Selective Reminding Test (mean difference (MD) 1.68; 95% confidence interval (CI) -2.21 to 5.58), total correct scores on the 10/36 Spatial Recall Test (MD -0.93; 95% CI -3.18 to 1.32), the Symbol Digit Modalities Test (MD -1.27; 95% CI -3.15 to 0.61) and the Paced Auditory Serial Addition Test (2+3 sec) (MD 2.23; 95% CI -1.87 to 6.33). Concerning safety, the main adverse events were: diarrhoea (risk ratio (RR) 3.88; 95% CI 1.66 to 9.05), nausea (RR 1.71; 95% CI 0.93 to 3.18) and abnormal dreams (RR 2.91; 95% CI 1.38 to 6.14). However, the results in both studies were subjected to a serious imprecision resulting from the small sample sizes and the low power of test (lower than 80%), which contributed to a moderate quality of the evidence. No serious adverse events were attributed to the treatments in all experimental groups.

AUTHORS' CONCLUSIONS

We found no convincing evidence to support the efficacy of pharmacological symptomatic treatment for MS-associated memory disorder because most of available RCTs had a limited quality. Whether pharmacological treatment is effective for memory disorder in patients with MS remains inconclusive. However, there is moderate-quality evidence that donepezil 10 mg daily was not effective in improving memory in MS patients with mild memory impairment, but had a good tolerability. Adverse events such as nausea, diarrhoea and abnormal dreams were not frequent but were associated with treatment. Ginkgo biloba, memantine and rivastigmine were safe and well tolerated and no serious adverse effects were reported. Future large-scale RCTs with higher methodological quality are needed.