Pharmacotherapies for sleep disturbances in Alzheimer's disease

Sleep, Cognition and Dementia

The older patient population is growing rapidly around the world and in the USA. Almost half of seniors over age 65 who live at home are dissatisfied with their sleep, and nearly two-thirds of those residing in nursing home facilities suffer from sleep disorders. Chronic and pervasive sleep complaints and disturbances are frequently associated with excessive daytime sleepiness and may result in impaired cognition, diminished intellect, poor memory, confusion, and psychomotor retardation all of which may be misinterpreted as dementia. The key sleep disorders impacting patients with dementia include insomnia, hypersomnolence, circadian rhythm misalignment, sleep disordered breathing, motor disturbances of sleep such as periodic leg movement disorder of sleep and restless leg syndrome, and parasomnias, mostly in the form of rapid eye movement (REM) sleep behavior disorder (RBD). RBD is a pre-clinical marker for a class of neurodegenerative diseases, the "synucleinopathies", and requires formal polysomnographic evaluation. Untreated sleep disorders may exacerbate cognitive and behavioral symptoms in patients with dementia and are a source of considerable stress for bed partners and family members. When left untreated, sleep disturbances may also increase the risk of injury at night, compromise health-related quality of life, and precipitate and accelerate social and economic burdens for caregivers.

The sleep-wake cycle and Alzheimer's disease: what do we know?

Sleep-wake disturbances are a highly prevalent and often disabling feature of Alzheimer's disease (AD). A cardinal feature of AD includes the formation of amyloid plaques, associated with the extracellular accumulation of the amyloid-β (Aβ) peptide. Evidence from animal and human studies suggests that Aβ pathology may disrupt the sleep-wake cycle, in that as Aβ accumulates, more sleep-wake fragmentation develops. Furthermore, recent research in animal and human studies suggests that the sleep-wake cycle itself may influence Alzheimer's disease onset and progression. Chronic sleep deprivation increases amyloid plaque deposition, and sleep extension results in fewer plaques in experimental models. In this review geared towards the practicing clinician, we discuss possible mechanisms underlying the reciprocal relationship between the sleep-wake cycle and AD pathology and behavior, and present current approaches to therapy for sleep disorders in AD.

Use of Benzodiazepines in Alzheimer's Disease: A Systematic Review of Literature

BACKGROUND

Benzodiazepines are frequently prescribed in patients with Alzheimer's disease. Unfortunately, studies evaluating their benefits and risks in these patients are limited.

METHODS

Clinical trials focusing on the effect of benzodiazepines on cognitive functions, disease progression, behavioral symptoms, sleep disturbances, and the general frequency of benzodiazepine use were included in this review. Published articles from January 1983 to January 2015 were identified using specific search terms in MEDLINE and PubMed Library according to the recommendations of The Strengthening the Reporting of Observational Studies in Epidemiology initiative.

RESULTS

Of the 657 articles found, 18 articles met predefined selection criteria and were included in this review (8 on frequency, 5 on cognitive functions, 5 on behavioral and sleep disturbances). The frequency of benzodiazepine use ranged from 8.5% to 20%. Five studies reported accelerated cognitive deterioration in association with benzodiazepine use. Two studies reported clinical efficacy for lorazepam and alprazolam to reduce agitation in Alzheimer's disease patients. No evidence was found for an improvement of sleep quality using benzodiazepines.

CONCLUSION

This systematic review shows a relatively high prevalence of benzodiazepine use but limited evidence for clinical efficacy in Alzheimer's disease patients. However, there is a paucity of methodologically high quality controlled clinical trials. Our results underscore a need for randomized controlled trials in this area.

[Sleep disorders in dementia patients]

Dementia is characterized by cognitive and also behavioral and psychological symptoms of dementia (BPSD). The most prominent BPSD are depression and apathy but sleep disorders also complicate the clinical course of dementia. These symptoms are a severe burden for patients and caregivers and are difficult to treat partly due to comorbidities. Common sleep disorders in dementia are insomnia, hypersomnia, circadian rhythm alterations and aberrant nocturnal motor behavior. Sleep duration and rapid eye movement (REM) sleep are reduced. The diagnostic assessment of sleep disorders should include an evaluation of the underlying risk factors and a detailed sleep history for which several assessment instruments are available. The therapy of sleep disorders of dementia is primarily nonpharmacological: sleep counseling, sleep hygiene regulation, relaxation and psychotherapy techniques are given priority. Pharmacological treatment often has severe side effects in this elderly, vulnerable population and can only be considered if other nonpharmacological options have been unsuccessful. The application of medication should be limited in time and dosage. The pharmacological therapeutic options are critically discussed in detail.

Managing anxiety associated with neurodegenerative disorders

Anxiety is a common symptom among patients with cognitive impairment. The presence of anxiety is correlated with poorer outcomes; despite this, there is limited research on anxiety related to neurodegenerative disorder. In this article, we discuss the prevalence of anxiety and factors involved in the etiology of anxiety in patients with diagnosed neurodegenerative disorders and related states of cognitive impairment as well as the evidence for currently available methods of evaluating and treating these symptoms. Specific treatments are highlighted in light of current evidence, followed by a discussion of the difficulties inherent in the study and treatment of anxiety in this population.