Acetylcholinesterase inhibitor in combination with cognitive training in older adults

Multimodal Exercise and Cognitive Training Program Improves Cognitive Function in Amnestic Mild Cognitive Impairment

OBJECTIVE

To investigate the preliminary efficacy of a combined physical exercise + cognitive training intervention for older adults with amnestic mild cognitive impairment (aMCI).

DESIGN

Randomized clinical trial.

SETTING

Veteran Affairs Hospital, Palo Alto, CA.

PARTICIPANTS

Sample included 72 community-dwelling volunteers (mean age 72.4 ± 9.5) diagnosed with aMCI.

INTERVENTION

Participants were randomized to either a combined aerobic and resistance exercise + cognitive training (CARE+CT) or stretching exercise + CT (SE+CT).

MEASUREMENTS

Primary outcomes included intervention specific assessments of word list and name-face recall. Secondary cognitive outcomes included standardized composite scores that reflect cognitive domains (e.g., learning and memory, executive function, processing speed, visuospatial ability, language). Secondary physiological outcomes included VO2 max and functional capacity (e.g., distance walked 6-minute walk test). APOE and BDNF were determined from whole blood samples.

RESULTS

Controlling for age and employment status, linear mixed effects models revealed that all participants experienced significant improvement in the delayed recall of word list, learning and memory and executive function. Only the CARE+CT condition had significant improvement in processing speed and functional capacity. APOE4 status impacted cognitive benefits of those in the SE+CT condition.

CONCLUSIONS

Results provide preliminary support for combined exercise and cognitive training interventions for older adults with aMCI. Further research is needed to understand the mechanisms involved as well as the impact of these interventions in diverse samples.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01962038.

Turning the Spotlight to Cholinergic Pharmacotherapy of the Human Language System

Even though language is essential in human communication, research on pharmacological therapies for language deficits in highly prevalent neurodegenerative and vascular brain diseases has received little attention. Emerging scientific evidence suggests that disruption of the cholinergic system may play an essential role in language deficits associated with Alzheimer's disease and vascular cognitive impairment, including post-stroke aphasia. Therefore, current models of cognitive processing are beginning to appraise the implications of the brain modulator acetylcholine in human language functions. Future work should be directed further to analyze the interplay between the cholinergic system and language, focusing on identifying brain regions receiving cholinergic innervation susceptible to modulation with pharmacotherapy to improve affected language domains. The evaluation of language deficits in pharmacological cholinergic trials for Alzheimer's disease and vascular cognitive impairment has thus far been limited to coarse-grained methods. More precise, fine-grained language testing is needed to refine patient selection for pharmacotherapy to detect subtle deficits in the initial phases of cognitive decline. Additionally, noninvasive biomarkers can help identify cholinergic depletion. However, despite the investigation of cholinergic treatment for language deficits in Alzheimer's disease and vascular cognitive impairment, data on its effectiveness are insufficient and controversial. In the case of post-stroke aphasia, cholinergic agents are showing promise, particularly when combined with speech-language therapy to promote trained-dependent neural plasticity. Future research should explore the potential benefits of cholinergic pharmacotherapy in language deficits and investigate optimal strategies for combining these agents with other therapeutic approaches.

Acting Before; A Combined Strategy to Counteract the Onset and Progression of Dementia

Brain aging and aging-related neurodegenerative disorders are posing a significant challenge for health systems worldwide. To date, most of the therapeutic efforts aimed at counteracting dementiarelated behavioral and cognitive impairment have been focused on addressing putative determinants of the disease, such as β-amyloid or tau. In contrast, relatively little attention has been paid to pharmacological interventions aimed at restoring or promoting the synaptic plasticity of the aging brain. The review will explore and discuss the most recent molecular, structural/functional, and behavioral evidence that supports the use of non-pharmacological approaches as well as cognitive-enhancing drugs to counteract brain aging and early-stage dementia.

The neurobiology of HIV and its impact on cognitive reserve: A review of cognitive interventions for an aging population

The medications used to treat HIV have reduced the severity of cognitive deficits; yet, nearly half of adults with HIV still exhibit some degree of cognitive deficits, referred to as HIV-associated neurocognitive disorder or HAND. These cognitive deficits interfere with everyday functioning such as emotional regulation, medication adherence, instrumental activities of daily living, and even driving a vehicle. As adults are expected to live a normal lifespan, the process of aging in this clinical population may exacerbate such cognitive deficits. Therefore, it is important to understand the neurobiological mechanisms of HIV on cognitive reserve and develop interventions that are either neuroprotective or compensate for such cognitive deficits. Within the context of cognitive reserve, this article delivers a state of the science perspective on the causes of HAND and provides possible interventions for addressing such cognitive deficits. Suggestions for future research are also provided.

Memory intervention: the value of a clinical holistic program for older adults with memory impairments

OBJECTIVES

Increasingly, cognitive training appears an asset in improving attention and working memory for older adults. We conducted a study involving a 'holistic' training program for several cohorts of older adults (N = 112), targeting community residents with a spectrum of memory complaints ranging from Age Associated Memory Impairment to mild dementia.

METHOD

We developed a 7-session, manualized program targeting concentration, as well as mindfulness, exercise, stress reduction, socialization, diet, and values/identity techniques. We applied this model to 11 cohorts and conducted pre- and post-testing on memory (List Learning, Story Memory, Coding, Digit Span, Recall, and Recognition) and function (Functional Assessment Questionnaire). We also divided the Memory Group by Risk Status - Low, Medium, and High.

RESULTS

Results showed that the Memory Clinic Group as a whole improved on this training on most scales. When broken down by risk status, the Low and Medium Risk Groups were statistically superior to the High Risk Group on cognitive measures.

CONCLUSION

There were differences also on adjustment, this time favoring only the Low Risk Groups. Holistic memory training seems to be impactful for older adults.

Which older adults maintain benefit from cognitive training? Use of signal detection methods to identify long-term treatment gains

BACKGROUND

Cognitive training has been shown to improve memory in older adults; however, little is known about which individuals benefit from or respond best to training in the long term. Identification of responders' characteristics would help providers match cognitive interventions to individuals to improve their effectiveness. Signal detection methods may prove more informative than more commonly used analytic methods. The goal of the current study is to identify baseline characteristics of long-term treatment responders and of those able to maintain their initial benefit from cognitive training.

METHODS

Participants were 120 non-demented, community-dwelling older adults who had participated in a cognitive training intervention. Tested predictors included both demographic and neurocognitive variables. Primary outcome variables were performance on measures of memory at one-year follow-up.

RESULTS

Results of the signal detection analysis indicated that different neurocognitive performances predicted long-term effects of memory training and maintenance of initial treatment response according to different types of to-be-remembered material. Higher baseline scores on tests of associative memory, delayed verbal memory, attention, episodic memory, and younger age were found predictive of long-term response one year later. Higher associative memory scores and lower initial gains at the end of treatment (week 14) predicted successful maintenance of training gains at week 52.

CONCLUSIONS

To derive long-term benefit from particular cognitive training programs, it appears necessary for older adults to have specific neurocognitive profiles. Further, inclusion of booster sessions to cognitive training programs may assist in maintenance of initial treatment gains.

Prevention, Rehabilitation, and Mitigation Strategies of Cognitive Deficits in Aging with HIV: Implications for Practice and Research

Highly active antiretroviral therapy has given the chance to those living with HIV to keep on living, allowing them the opportunity to age and perhaps age successfully. Yet, there are severe challenges to successful aging with HIV, one of which is cognitive deficits. Nearly half of those with HIV experience cognitive deficits that can interfere with everyday functioning, medical decision making, and quality of life. Given that cognitive deficits develop with more frequency and intensity with increasing age, concerns mount that as people age with HIV, they may experience more severe cognitive deficits. These concerns become especially germane given that by 2015, 50% of those with HIV will be 50 and older, and this older cohort of adults is expected to grow. As such, this paper focuses on the etiologies of such cognitive deficits within the context of cognitive reserve and neuroplasticity. From this, evidence-based and hypothetical prevention (i.e., cognitive prescriptions), rehabilitation (i.e., speed of processing training), and mitigation (i.e., spaced retrieval method) strategies are reviewed. Implications for nursing practice and research are posited.

Assessing and treating forgetfulness and cognitive problems in adults with HIV

In addition to the immune system, HIV affects the nervous system and the brain, producing neurological sequelae, often resulting in forgetfulness and cognitive problems. These problems can compromise medication adherence, interfere with instrumental activities of daily living such as driving and managing finances, increase dependency, and decrease quality of life. Cognitive problems emerge due to a variety of reasons; likewise, several evidence-based methods to mitigate causes and compensate for cognitive problems can be used alone or in combination. This article focuses on nonpathological, nondementia forgetfulness and cognitive problems. However, dementia must be considered and assessed as measured by marked cognitive decline over time. Methods for assessing and measuring forgetfulness and cognitive problems are provided. In addition, methods of treating nonpathological cognitive problems are provided, ranging from Recommended for Practice to Not Recommended for Practice. A case study is presented to demonstrate how to implement recommended treatment options.

Cholinesterase inhibitors for mild cognitive impairment

BACKGROUND

Mild cognitive impairment is hypothesised to represent a pre-clinical stage of dementia but forms a heterogeneous group with variable prognosis.

OBJECTIVES

To assess the safety and efficacy of cholinesterase inhibitors in people with mild cognitive impairment.

SEARCH METHODS

Trials were identified from the Cochrane Dementia and Cognitive Improvement Group's Specialised Register, which is frequently updated from the major healthcare databases (MEDLINE, EMBASE, CINAHL, PsycINFO and Lilacs) as well as trial registers and grey literature.

SELECTION CRITERIA

Double-blind, placebo-controlled randomised trials of any cholinesterase inhibitor in people with mild cognitive impairment.

DATA COLLECTION AND ANALYSIS

Data were extracted from the published reports of the included studies, combined by meta-analysis where appropriate, and treatment efficacy and risk of adverse events were estimated.

MAIN RESULTS

Nine studies (from eight published reports) of 5149 individuals with mild cognitive impairment (however defined) were included in the review. Limited pooling of results was possible owing to different lengths of trials. Meta-analysis of the three studies reporting conversion to dementia gives no strong evidence of a beneficial effect of cholinesterase inhibitors on the progression to dementia at one, two or three years. The risk ratio (RR) for conversion at two years was significantly different from unity (0.67; 95% confidence interval (CI) 0.55 to 0.83), but this is based on only two studies reported in the same article. There was essentially no effect of cholinesterase inhibitors on cognitive test scores.Based on the results from 4207 individuals, there were significantly more adverse events in the cholinesterase inhibitor groups (RR 1.09; 95% CI 1.02 to 1.16), but no more serious adverse events or deaths. Gastrointestinal side effects were much more common (diarrhoea: RR 2.10; 95% CI 1.30 to 3.39; nausea: RR 2.97; 95% CI 2.57 to 3.42; vomiting: RR 4.42; 95% CI 3.23 to 6.05). Cardiac problems were no more likely in either group (RR 0.71; 95% CI 0.25 to 2.02). Other side effects reported significantly more often in the cholinesterase inhibitor group were muscle spasms/leg cramps (RR 7.52; 95% CI 4.34 to 13.02), headache (RR 1.34; 95% CI 1.05 to 1.71), syncope or dizziness (RR 1.62; 95% CI 1.36 to 1.93), insomnia (RR 1.66; 95% CI 1.36 to 2.02) and abnormal dreams (RR 4.25; 95% CI 2.57 to 7.04).

AUTHORS' CONCLUSIONS

There is very little evidence that cholinesterase inhibitors affect progression to dementia or cognitive test scores in mild cognitive impairment. This weak evidence is overwhelmed by the increased risk of adverse events, particularly gastrointestinal. Cholinesterase inhibitors should not be recommended for mild cognitive impairment.

Comorbidities and cognitive functioning: implications for nursing research and practice

Optimal cognitive functioning is necessary to successfully negotiate one's environment, yet medical conditions can interfere with brain health, thus negatively impacting cognitive functioning. Such comorbidities include hypertension, heart disease, diabetes, depression, and HIV, as well as others. The physiological properties of these comorbidities can reduce one's cognitive reserve and limit one's cognitive efficiency. This article provides an overview of a few common comorbidities known to affect cognitive functioning and addresses ways in which cognitive functioning may be ameliorated and protected or mitigated in lieu of cognitive declines in such clinical populations. Implications for nursing practice and research are posited.

Cognitive exercise and its role in cognitive function in older adults

Converging lines of research indicate that complex mental activity is associated with reduced dementia risk. Thus, intense interest exists in whether different forms of cognitive exercise can help protect against cognitive decline and dementia. However, there is considerable confusion in terminology that is hindering progress in the field. We therefore introduce a concrete definition of cognitive training (CT) and make this the focus of our article. Clinical research that has evaluated CT in normal aging, mild cognitive impairment, and dementia is then critically reviewed. Despite many methodological shortcomings, the overall findings indicate that multidomain CT has the potential to improve cognitive function in healthy older adults and slow decline in affected individuals. Finally, practical issues, including the strengths and weaknesses of commercial products, are explored, and recommendations for further research and clinical implementation are made.

Phasic acetylcholine release and the volume transmission hypothesis: time to move on

Traditional descriptions of the cortical cholinergic input system focused on the diffuse organization of cholinergic projections and the hypothesis that slowly changing levels of extracellular acetylcholine (ACh) mediate different arousal states. The ability of ACh to reach the extrasynaptic space (volume neurotransmission), as opposed to remaining confined to the synaptic cleft (wired neurotransmission), has been considered an integral component of this conceptualization. Recent studies demonstrated that phasic release of ACh, at the scale of seconds, mediates precisely defined cognitive operations. This characteristic of cholinergic neurotransmission is proposed to be of primary importance for understanding cholinergic function and developing treatments for cognitive disorders that result from abnormal cholinergic neurotransmission.