Connections between sleep and cognition in older adults

Sleep and Cognition in Community-Dwelling Older Adults: A Review of Literature

Changes in sleep and cognition occur with advancing age. While both may occur independently of each other, it is possible that alterations in sleep parameters may increase the risk of age-related cognitive changes. This review aimed to understand the relationship between sleep parameters (sleep latency, wake after sleep onset, sleep efficiency, sleep duration, general sleep complaints) and cognition in community-dwelling adults aged 60 years and older without sleep disorders. Systematic, computer-aided searches were conducted using multiple sleep and cognition-related search terms in PubMed, PsycINFO, and CINAHL. Twenty-nine manuscripts met the inclusion criteria. Results suggest an inconsistent relationship between sleep parameters and cognition in older adults and modifiers such as depressive symptoms, undiagnosed sleep apnea and other medical conditions may influence their association. Measures of sleep and cognition were heterogeneous. Future studies should aim to further clarify the association between sleep parameters and cognitive domains by simultaneously using both objective and subjective measures of sleep parameters. Identifying which sleep parameters to target may lead to the development of novel targets for interventions and reduce the risk of cognitive changes with aging.

Sleep Disturbances in the Elderly

Sleep disturbances are a common presenting symptom of older-age adults to their physicians. This article explores normal changes in sleep pattern with aging and primary sleep disorders in the elderly. Behavioral factors and primary psychiatric disorders affecting sleep in this population are reviewed. Further discussion examines sleep changes associated with 2 common forms of neurocognitive disorder: Alzheimer disease and Lewy Body Dementia. Common medical illnesses in the elderly are discussed in relation to sleep symptoms. Nonpharmacological and pharmacologic treatment strategies are summarized, with emphasis placed on risk of side effects in older adults. Future targets are considered.

Sleep in caregivers: what we know and what we need to learn

PURPOSE OF REVIEW

The number of informal caregivers providing assistance to adults is increasing commensurate with our aging society. Sleep disturbances are prevalent in caregivers and associated with negative physical, medical, and functional outcomes. Here, we describe the predisposing, precipitating, and perpetuating factors contributing to the development of sleep problems in caregivers, and discuss three understudied caregiving populations that have clinical importance and unique circumstances influencing sleep quality and health.

RECENT FINDINGS

There is clear evidence supporting the interaction between sleep loss, caregiving stress, and vulnerability to chronic disease. Telehealth and telemedicine sleep interventions for caregivers combined with assistive technologies targeting care-receivers have potential to be more individualized, affordable, and widely accessible than traditional in-person insomnia treatment approaches. Limited data exist describing the etiology and treatment of sleep problems in caregivers of veterans, medical patients newly discharged from the hospital, and developmentally disabled adults.

SUMMARY

There is a growing literature describing the general determinants of sleep disturbances in caregivers, the health consequences of these disturbances, and intervention strategies for treating them. Identifying effective sleep treatments suited to more specialized caregiving situations and increasing intervention access will help caregivers continue to provide quality care while protecting their own health and well-being.

Cognitive Impairment After Sleep Deprivation Rescued by Transcranial Magnetic Stimulation Application in Octodon degus

Sleep is indispensable for maintaining regular daily life activities and is of fundamental physiological importance for cognitive performance. Sleep deprivation (SD) may affect learning capacity and the ability to form new memories, particularly with regard to hippocampus-dependent tasks. Transcranial magnetic stimulation (TMS) is a non-invasive procedure of electromagnetic induction that generates electric currents, activating nearby nerve cells in the stimulated cortical area. Several studies have looked into the potential therapeutic use of TMS. The present study was designed to evaluate how TMS could improve learning and memory functions following SD in Octodon degus. Thirty juvenile (18 months old) females were divided into three groups (control, acute, and chronic TMS treatment-with and without SD). TMS-treated groups were placed in plastic cylindrical cages designed to keep them immobile, while receiving head magnetic stimulation. SD was achieved by gently handling the animals to keep them awake during the night. Behavioral tests included radial arm maze (RAM), Barnes maze (BM), and novel object recognition. When TMS treatment was applied over several days, there was significant improvement of cognitive performance after SD, with no side effects. A single TMS session reduced the number of errors for the RAM test and improved latency and reduced errors for the BM test, which both evaluate spatial memory. Moreover, chronic TMS treatment brings about a significant improvement in both spatial and working memories.

Daytime Sleepiness and Sleep Inadequacy as Risk Factors for Dementia

Background/Aims

To examine the association between self-reported sleep problems and incidence of dementia in community-dwelling elderly people.

Methods

1,041 nondemented participants over 65 years old were examined longitudinally. Sleep problems were estimated using the RAND Medical Outcomes Study Sleep Scale examining sleep disturbance, snoring, sleep short of breath or with a headache, sleep adequacy, and sleep somnolence. Cox regression analysis was used to examine the association between sleep problems and risk for incident dementia. Age, gender, education, ethnicity, APOE-ε4, stroke, heart disease, hypertension, diabetes, and depression were included as covariates.

Results

Over 3 years of follow-up, 966 (92.8%) participants remained nondemented, while 78 (7.2%) developed dementia. In unadjusted models, sleep inadequacy (‘Get the amount of sleep you need’) at the initial visit was associated with increased risk of incident dementia (HR = 1.20; 95% CI 1.02-1.42; p = 0.027). Adjusting for all the covariates, increased risk of incident dementia was still associated with sleep inadequacy (HR = 1.20; 95% CI 1.01-1.42; p = 0.040), as well as with increased daytime sleepiness (‘Have trouble staying awake during the day’) (HR = 1.24; 95% CI 1.00-1.54; p = 0.047).

Conclusion

Our results suggest that sleep inadequacy and increased daytime sleepiness are risk factors for dementia in older adults, independent of demographic and clinical factors.

Repeated cognitive stimulation alleviates memory impairments in an Alzheimer's disease mouse model

Alzheimer's disease is a neurodegenerative disease associated with progressive memory and cognitive decline. Previous studies have identified the benefits of cognitive enrichment on reducing disease pathology. Additionally, epidemiological and clinical data suggest that repeated exercise, and cognitive and social enrichment, can improve and/or delay the cognitive deficiencies associated with aging and neurodegenerative diseases. In the present study, 3xTg-AD mice were exposed to a rigorous training routine beginning at 3 months of age, which consisted of repeated training in the Morris water maze spatial recognition task every 3 months, ending at 18 months of age. At the conclusion of the final Morris water maze training session, animals subsequently underwent testing in another hippocampus-dependent spatial task, the Barnes maze task, and on the more cortical-dependent novel object recognition memory task. Our data show that periodic cognitive enrichment throughout aging, via multiple learning episodes in the Morris water maze task, can improve the memory performance of aged 3xTg-AD mice in a separate spatial recognition task, and in a preference memory task, when compared to naïve aged matched 3xTg-AD mice. Furthermore, we observed that the cognitive enrichment properties of Morris water maze exposer, was detectable in repeatedly trained animals as early as 6 months of age. These findings suggest early repeated cognitive enrichment can mitigate the diverse cognitive deficits observed in Alzheimer's disease.

Perimenopause as a neurological transition state

Perimenopause is a midlife transition state experienced by women that occurs in the context of a fully functioning neurological system and results in reproductive senescence. Although primarily viewed as a reproductive transition, the symptoms of perimenopause are largely neurological in nature. Neurological symptoms that emerge during perimenopause are indicative of disruption in multiple estrogen-regulated systems (including thermoregulation, sleep, circadian rhythms and sensory processing) and affect multiple domains of cognitive function. Estrogen is a master regulator that functions through a network of estrogen receptors to ensure that the brain effectively responds at rapid, intermediate and long timescales to regulate energy metabolism in the brain via coordinated signalling and transcriptional pathways. The estrogen receptor network becomes uncoupled from the bioenergetic system during the perimenopausal transition and, as a corollary, a hypometabolic state associated with neurological dysfunction can develop. For some women, this hypometabolic state might increase the risk of developing neurodegenerative diseases later in life. The perimenopausal transition might also represent a window of opportunity to prevent age-related neurological diseases. This Review considers the importance of neurological symptoms in perimenopause in the context of their relationship to the network of estrogen receptors that control metabolism in the brain.

DSM-5 and Mental Disorders in Older Individuals: An Overview

LEARNING OBJECTIVES

After participating in this activity, learners should be better able to:• Assess the changes in DSM-5 relative to earlier versions.• Evaluate the implications of the DSM-5 for practicing geriatric psychiatrists.

ABSTRACT

About every 20 years, the American Psychiatric Association revises its official classification of mental disorders. The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was published in 2013, prompting considerable commentary, debate, and criticism. This article briefly describes the process leading up to DSM-5 and the main changes from the previous version (DSM-IV) that would be of interest to a geriatric psychiatrist. The changes in the areas of schizophrenia, bipolar disorder, depressive disorders, and anxiety disorders have been many, but the majority of them are minor and unlikely to have major treatment implications. The classification of neurocognitive disorders, however, has seen a major revision and elaboration in comparison to DSM-IV; of special note is the introduction of "mild and major neurocognitive disorders," the latter equated with dementia. A common language has also been introduced for the criteria for the various etiological subtypes of neurocognitive disorders. All physicians treating patients with neurocognitive disorders should familiarize themselves with these criteria. Their use in research has the potential to harmonize the field.