Controversies in geriatric medicineSundown syndrome and dementia
Introduction
The behavioural and neuropsychiatric symptoms of dementia and Alzheimer's disease (AD) have become an increasingly important focus of clinical research. They include aggressiveness [1], repetitive behaviour [2], delusions [3], [4] (some bizarre and uncommon) [5], [6], misidentifications [7], wandering [8], apathy [9], suicidal [10] and sociopathic behaviour [11]. Both normal aging and dementia are associated with altered circadian regulation of physiology and behaviour. The clinical phenomenon of exacerbation of behavioural symptoms that occurs in the late afternoon or evening among dementia patients or elderly institutionalised patients has been reported in the clinical literature more than 70 years ago [12]. These behaviours include increased disorientation, confusion, agitation, restlessness, wandering and anxiety.
Section snippets
Nosology and clinical characteristics
The terms “sundown syndrome”, “sundowning” or “nocturnal delirium” are used to describe a wide range of neuropsychiatric symptoms occurring in individuals with dementia. It is a poorly defined entity. It is not a disease, but a set of symptoms that occur at a specific time of the day that may affect people with dementia. Sundowning shares similarities with delirium, e.g. attention deficits and activity disturbances [13]. However, contrary to delirium, sundowning seems to persist for a longer
Outcomes
Sundowning has been described as a problem of considerable magnitude in the management of demented patients [24]. The phenomenon is associated with significant caregiver distress [25] and it is a frequent or major cause for families to move the patient from home into a skilled nursing facility [26], [27]. Obviously, if a person with dementia is awake and roaming around the house at night, this behaviour impacts the caregiver's sleep as well: according to a large study in Germany, 51% of
Aetiology
The cause of sundown syndrome still remains unclear. Interpretations have ranged from behavioural theories to specifically biological ones. Studies that have attempted to explain aetiology of sundown syndrome can be divided into three major groups: physiological, psychological, and environmental. The inadequate influence of external “Zeitgebers” such as social conventions and daylight may also contribute to the syndrome [32], [33].
Other potential aetiological factors
Several drugs may induce side effects such as akathisia, tardive dyskinesia, muscle rigidity, anticholinergic toxicity (tachycardia, constipation, and confusion), orthostatic hypotension, and others and may further contribute to development of sundowning in demented patients [47]. Also, diurnal mood variation, a pattern of mood variability in which a person's worst mood and best mood vary in a predictable fashion, is a symptom of major depression and might explain some cases of sundowning [45].
Management
It is essential to adopt a multifactorial strategy to both understanding and intervening in sundown syndrome; the approaches must be based on the particular circumstances of each individual. At present, treatment options for sundowning are limited, primarily because of our limited knowledge of the aetiology and pathophysiology of this disorder. Obviously, treatment of this illness must take into account all the associated conditions that, according to the literature, may contribute to trigger
Conclusions
Despite the lack of a formal recognition, “sundowning” is broadly used to describe a set of neuropsychiatric symptoms occurring in elderly patients with or without dementia at the time of sunset, at evening, or at night. It is a complex behavioural disorder with tremendous costs for families, caretakers, and patients themselves. It represents a concrete problem, which is difficult to manage for physicians and caregivers, and it is probably linked to various biological, psychological and social
Disclosure of interest
The authors declare that they have no conflicts of interest concerning this article.
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