People with dementia often suffer from sleep disorders during the course of their illness. Waking up at night, excessive sleeping during the day, or long periods of falling asleep place a great burden on those affected and their relatives. Experts from the Munich Clinic rechts der Isar explain the causes and which therapies are useful.
Approximately half of all patients with dementia develop disorders of the sleep-wake rhythm during the course of their illness, with complaints of insomnia, nighttime restlessness, long daytime sleep episodes, and recurrent states of confusion, write Dr. Dirk Schwerthöffer and Prof. Hans Förstl in the journal „Der Neurologe & Psychiater.“ Due to the associated burden on family caregivers, this is one of the main reasons for early admission to a care facility.
Interaction between sleep and cognitive performance
The authors first address how sleep behavior generally changes with age: deep sleep phases at night decrease, night sleep is interrupted more frequently, and napping during the day becomes more common. Regarding the connection between sleep and dementia, they describe an interaction. For example, individuals with Alzheimer's disease often suffer from significant sleep disturbances, which further impair cognitive performance. Schwerthöffer and Förstl also present the different patterns of sleep disorders depending on the form of dementia, such as a prolonged sleep onset phase in Alzheimer's dementia, frequent nocturnal awakenings in Lewy body dementia, and excessive daytime sleepiness in dementias associated with Parkinson's disease.
The sundowning syndrome is also described, which refers to the deterioration of the cognitive state of people with dementia in the late afternoon or early evening due to depleted reserves. It includes symptoms such as anxiety, aggressive behavior, wandering, shouting, or even hallucinations. According to the authors, the more advanced the dementia, the more severe the sleep disturbances become.
A combination of different measures is most effective
To recognize the described sleep disorders, the authors recommend actigraphy as a diagnostic measure. Investigations of sleep patterns using movement measurements and keeping a sleep diary, with the help of caregivers depending on the degree of dementia. The most sensible treatment, in their assessment, is a combination of sleep hygiene (sleep-promoting behaviors such as fixed morning wake times and relaxing bedtime rituals), physical and social activity, light therapy, and medication. However, regarding the use of medication, experts point out that numerous undesirable side effects would need to be carefully weighed against the therapeutic benefit.
The full article can be found here:
Sleep-wake rhythm disorders in dementia (January 2020)
