Effects of donepezil on memory and cognition in multiple sclerosis

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).

Diagnostik und Therapie von Gedächtnisstörungen

Die wichtigsten Empfehlungen auf einen Blick

Diagnostik: Die Untersuchung von Gedächtnisstörungen erfordert mindestens ein Verfahren zur Erfassung der Gedächtnisspanne und des Arbeitsgedächtnisses sowie je ein Verfahren zur Untersuchung der unmittelbaren und verzögerten Reproduktion verbaler und figuraler Informationen. Darüber hinaus wird eine Untersuchung des Lernprozesses im Rahmen eines Lernparadigmas (z. B. Wortlisten-Lernen) empfohlen (A). Für die Untersuchung des für den Alltag so relevanten prospektiven Gedächtnisses sind vor allem die Verhaltensbeobachtung und die systematische Befragung z. B. mit Hilfe von Fragebögen von Bedeutung (B). Therapie: (1) Am Anfang der Therapie in der Frühphase steht häufig das Orientierungstraining. (2) Bei Patienten, bei denen die Diagnostik Hinweise auf eine erhaltene Konsolidierung gibt und bei denen der Rehabilitationsverlauf noch offen ist, wird empfohlen, internale Gedächtnisstrategien intensiv zu üben, um die Enkodierungsleistung zu verbessern (A). Für die Wirkung eines übenden Funktionstrainings, bei dem möglichst viele Informationen «auswendig gelernt» werden müssen, gibt es hingegen keine Evidenz. (3) Darüber hinaus ist die Behandlung der Gedächtnisstörung an den Alltagsanforderungen des Patienten zu orientieren und für spezifische gedächtnisrelevante Situationen sind Kompensationsstrategien zu erarbeiten (A). Ob die Patienten lediglich lernen können, auf externe Hilfen, die sie von Angehörigen oder Pflegepersonen erhalten, adäquat zu reagieren, oder ob sie diese selbstständig nutzen können, muss im Einzelfall im Therapieverlauf entschieden werden.

Effects of immunomodulatory treatment with subcutaneous interferon beta-1a oncognitive decline in mildly disabled patients with relapsing—remitting multiple sclerosis

The objective of this study was to assess the effects of subcutaneous (sc) interferon beta-1a (IFNβ-1a) on cognition in mildly disabled patients with relapsing—remitting multiple sclerosis (RRMS). Patients aged 18—50 years with RRMS (McDonald criteria; Expanded Disability Status Scale score ≤4.0) were assigned IFNβ therapy at the physician’s discretion and underwent standardized magnetic resonance imaging, neurological examination and neuropsychological testing at the baseline and regular intervals for up to three years.

This analysis included 459 patients who received sc IFNβ-1a (44 mcg: n = 236; 22 mcg: n = 223; three-year follow up was available for 318 patients). The hazard ratio for cognitive impairment over three years (44 mcg versus 22 mcg) was 0.68 (95% confidence interval [CI]: 0.480—0.972), suggesting a 32% lower risk with the higher dose treatment. At year 3, the proportion of patients who were cognitively impaired increased slightly from 23.5% at the baseline to 24.8% in the IFNβ-1a 22 mcg treatment group, but remained stable at 15.2% in the IFNβ-1a 44 mcg treatment group. The proportion of patients with cognitive impairment at year 3 was significantly higher in the 22 mcg group than in the 44 mcg group (P = 0.03), although a trend was also seen at the baseline (P = 0.058). Multivariate logistic regression (corrected for baseline cognitive deficits) indicated that treatment with the higher dose of IFNβ-1a was predictive of lower cognitive impairment at three years (odds ratio: 0.51, 95% CI: 0.26—0.99) compared with the lower dose of IFNβ-1a.

These findings suggest that sc IFNβ-1a may have dose-dependent cognitive benefits in mildly disabled patients with RRMS, and may support early initiation of high-dose IFNβ-1a treatment.

Cognitive impairment in multiple sclerosis

Multiple sclerosis (MS) is a progressive disease of the CNS that is characterised by widespread lesions in the brain and spinal cord. MS results in motor, cognitive, and neuropsychiatric symptoms, all of which can occur independently of one another. The common cognitive symptoms include deficits in complex attention, efficiency of information processing, executive functioning, processing speed, and long-term memory. These deficits detrimentally affect many aspects of daily life, such as the ability to run a household, participate fully in society, and maintain employment--factors that can all affect the overall quality of life of the patient. The increased use of neuroimaging techniques in patients with MS has advanced our understanding of structural and functional changes in the brain that are characteristic of this disease, although much remains to be learned. Moreover, examination of efforts to treat the cognitive deficits in MS is still in the early stages.

Cognitive impairment in multiple sclerosis

BACKGROUND

Cognitive impairment is increasingly being recognized as a common and disabling symptom of multiple sclerosis (MS) that contributes to poor quality of life in affected patients. Despite the high prevalence of cognitive impairment in MS, cognitive function is not assessed routinely in clinical practice or in clinical trials. The perception that cognitive assessments are costly, time-consuming, complicated, and difficult to administer and interpret has contributed, at least in part, to the failure to incorporate cognitive testing into standard clinical evaluation of patients with MS. Detailed studies of cognitive impairment in MS are rare and guidelines for the assessment of cognitive function in MS are lacking.

TREATMENT

How to manage cognitive decline in MS also requires further study. Licensed disease-modifying drug (DMD) treatments for MS reduce brain lesion development, and associations between brain lesions and cognitive performance have been reported, providing a rationale for DMD treatment of MS-associated cognitive impairment. There is some evidence for cognitive benefits of DMDs, but as few pivotal DMD trials included cognitive assessments, the effects of these agents on cognition are not fully understood and more studies are needed.

CONCLUSIONS

It is only through further studies that it will be possible to identify patients with, or at risk of, cognitive impairment and to provide appropriate therapy to limit the effects of this potentially devastating symptom.

Randomized double-blind placebo-controlled donepezil augmentation in antidepressant-treated elderly patients with depression and cognitive impairment: a pilot study

OBJECTIVE

To assess combined antidepressant and cognitive enhancer treatment in elderly patients presenting with depression plus cognitive impairment.

METHODS

Twenty-three elderly (>50 years old) depressed, cognitively impaired (DEP-CI) patients participated in a pilot study. We evaluated whether, after 8 weeks of open antidepressant treatment, donepezil HCl (Aricept) would afford added cognitive benefit compared to placebo in a randomized 12-week trial. A subsample continued in an 8-month extension phase of open treatment with donepezil. Neuropsychological testing (NPT) was performed and antidepressant response monitored at baseline and the 8, 20, and 52-week time points.

RESULTS

At 8-weeks, the antidepressant response rate was 61% (14/23). Improvement in SRT immediate recall (SRT-IR; e.g. episodic verbal memory) was observed in responders compared to non-responders. During the 12-week, placebo-controlled, donepezil add-on trial, patients on donepezil showed further improvement in SRT-IR versus patients on placebo. In the open extension phase, patients who continued open donepezil treatment (n = 6) maintained improvement in memory and tended to show an advantage over patients who never received donepezil and were evaluated at the 52-week time point (n = 6). There were no observed significant donepezil effects on non-memory cognitive domains.

CONCLUSION

These preliminary findings suggest that addition of a cholinesterase inhibitor (AChEI) following antidepressant medication treatment in elderly Dep-CI patients may improve cognition, and support the need for a confirmatory, larger randomized placebo-controlled trial.

Cognitive dysfunction in MS: bridging the gap between neurocognitive deficits, neuropsychological batteries and MRI

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the CNS. Its sequelae include both physical and cognitive disability. Advances in neuropsychological testing and screening have led to increased recognition of cognitive impairment in MS; more than half of MS patients have been found to have some degree of cognitive impairment. Strong correlations have been found between neuropsychological testing, brain atrophy and other brain imaging techniques. These tools can aid in the comprehensive evaluation of MS patients. Genetic markers, such as ApoE and brain-derived neurotrophic factor polymorphisms, may also correlate with cognitive impairment in MS. This review details advances in recognizing and predicting cognitive dysfunction in MS. Increased understanding and better evaluation and monitoring of cognitive status in MS may improve the sensitivity of studies designed to test new disease-modifying therapies and interventions for cognitive impairment.

Cognitive function after chemotherapy in adults with solid tumours

BACKGROUND

Evidence is emerging that some cancer survivors suffer cognitive impairment after chemotherapy; the cause is unknown.

METHODS

Here we review studies evaluating cognitive impairment in adult cancer survivors and discuss methodological challenges associated with this research. We evaluate evidence for cognitive impairment in cancer patients, the incidence of self-reported impairment, and identify potential mechanisms and confounders.

RESULTS

Most studies of cognitive function are cross-sectional and report impairment in 15-45% of subjects. Longitudinal studies suggest that some impairment is present prior to receiving chemotherapy, and that this worsens in some patients. The aetiology is unknown. A larger number of subjects self-report changes in cognitive function after chemotherapy; this does not correlate with objective testing.

CONCLUSIONS

Cognitive impairment occurs in a subset of cancer survivors and is generally subtle. Most evidence suggests an association with chemotherapy although other factors associated with the diagnosis and treatment of cancer may contribute.

Cognitive impairment in multiple sclerosis

Cognitive dysfunctions are frequent symptoms of multiple sclerosis (MS) and occur in up to 65% of patients. Especially memory, attention, executive and visual constructive functions are impaired. These problems strongly affect patients' ability to work, social relationships, and quality of life. Symptoms of physical disabilities can arise independently. Cognitive dysfunctions are clear indicators of MS progression, because they represent highly complex functions that depend on the integrity of the neuronal networks. Once manifested after a relapse, they remain stable . Given a differentiating diagnosis, it is possible to treat these dysfunctions by cognitive training and with pharmaceutical drugs, for example by immunomodulating drugs. However, treatment options are limited at present. This report provides a detailed description of cognitive functions and performance in MS patients, their comorbidities such as fatigue and depression and therapeutic options.

Cognitive impairment in multiple sclerosis: evidence-based analysis and recommendations

Cognitive impairment is common in multiple sclerosis (MS), occurring at all stages of the disease, and can be a major source of vocational disability, social impairment, and impoverished quality of life. Dysfunction in free recall from long-term memory, speed of information processing, working memory, and abstract reasoning are frequently observed in MS. Despite weak correlation with disease duration and physical disability status, the degree of cognitive impairment in MS has been related to the extent of topographically specific neuronal tissue damage and loss. Additional clinical factors including disease course, fatigue, affective disturbance, and medication can impact on the degree of MS-related cognitive impairment. We suggest that the symbol digits modalities test, paced auditory serial addition task, the clock drawing test and the MS neuropsychological screening questionnaire be considered as valid and relevant screening tests for cognitive impairment in MS.

Donepezil: an update

Donepezil hydrochloride is the most widely prescribed drug for Alzheimer's disease (AD). The main mechanism of action through which it influences cognition and function is presumed to be the inhibition of acetylcholinesterase enzyme in the brain; however, donepezil may also impact the pathophysiology of AD at several other points. Officially approved for mild-to-moderate and severe AD, donepezil has also been shown to be effective in early-stage AD, vascular dementia, Parkinson's disease dementia/Lewy body disease and cognitive symptoms associated with multiple sclerosis. In addition, one study suggested that donepezil may delay the onset of AD in subjects with mild cognitive impairment, a prodrome to AD. The pharmacokinetics, pharmacodynamics, safety/tolerability profile and drug interaction properties of donepezil make it an easy and safe agent to use. However, in general, the efficacy of donepezil is limited, and ongoing studies are investigating other agents that may ultimately overtake its present position as the mainstay of anti-AD therapy.

Cyclosporine A inhibits acetylcholinesterase activity in rats experimentally demyelinated with ethidium bromide

Cyclosporine A is the major immunosuppressive agent used for organ transplantation and for the treatment of a variety of autoimmune disorders such as multiple sclerosis. In this work, we investigated the effect of the cyclosporine A on the acetylcholinesterase activity in the cerebral cortex, striatum, hippocampus, hypothalamus, cerebellum and pons of the rats experimentally demyelinated by ethidium bromide. Rats were divided into four groups: I control (injected with saline), II (treated with cyclosporine A), III (injected with 0.1% ethidium bromide) and IV (injected with 0.1% the ethidium bromide and treated with cyclosporine A). The results showed a significant inhibition (p<0.05) of acetylcholinesterase activity in the groups II, III and IV in all brain structures analyzed. In the striatum, hippocampus, hypothalamus and pons the inhibition was greater (p<0.005) when ethidium bromide was associated with cyclosporine A. In conclusion, the present investigation demonstrated that cyclosporine A is an inhibitor of acetylcholinesterase activity and this effect is increased after an event of toxic demyelination of the central nervous system.

New Therapeutic Approaches for Multiple Sclerosis

Although several therapies exist for multiple sclerosis (MS), the most common inflammatory demyelinating disease of the central nervous system (CNS), there remains a large unmet clinical need for more effective immunomodulatory treatments in this category of diseases and for interventions that address their neurodegenerative component, which is currently untreated. Progress in our understanding of the immunology of MS over the past 30 years has recently synergized with novel computational methods and emerging high-throughput technologies that characterize variations in DNA, RNA, proteins, and metabolites to usher in a period of intense pathophysiologic investigation. These efforts are beginning to define subsets of patients with different forms of demyelinating disease. This partitioning of patients will prove valuable as we begin to tailor immunotherapy to the underlying pathophysiologic processes of individual patients using current therapies, emerging treatments, and rational combinations of all of these treatments. Preventing the entry of lymphocytes into the CNS and modifying the nature of the immune response are treatment approaches that work in the inflammatory component of MS but have little or no effect on neurodegeneration. Two challenges confront us: to develop cocktails of therapies that shift the immune homeostasis of patients with MS toward a healthy profile, and to identify and modulate the activity of targets within the neurodegenerative component of MS.