Dr B Mandel and Dr B Bhowmick explain the little-known phenomenon that affects older people during the evening hours

Sunset is commonly associated with tranquillity and calmness, but for many elderly patients and their carers it can be a time of turbulence. The two terms, sundowning and sundown syndrome, are used synonymously to describe a phenomenon of increasing agitation that occurs near sunset or the evening among some older patients or those with organic brain disease. It is a form of delirium in which 'escaping' and calling out and wandering, with the apparent intent of seeking something or someone, tend to be marked features. In the USA it is a widely recognised condition and health care professionals involved in the care of the elderly are well aware of its pathophysiology and management. In the UK, knowledge of sundown syndrome is variable. Many professionals involved in the care of older people are unaware of the syndrome and its complex symptoms. This may be due to lack of research into the condition and the paucity of information in gerontology texts^1,2,3.

The syndrome appears to be confined largely to individuals with organic brain impairment, such as Alzheimer's disease or cerebrovascular disorders. Classical presentation of symptoms are seen predominantly during twilight hours. It is more marked when changes have taken place in patients' lives, such as being moved to a new or unfamiliar place ( a hospital or nursing home, for example). They present with a variety of restless activities, including escaping and searching behaviours and emotional states. They may also be seen trying to get out of the bed, wandering around, or sometimes dressed up to go out. Evans et al stated that the syndrome is predominantly associated with sensory deprivation, loneliness, fewer daytime activities and diminished physical health⁴.

Sleep apnea has also been associated with sundown syndrome⁵ and it was found that patients with sundown are more confused in the night than in the day. Before managing sundown syndrome effectively, any underlying, treatable conditions for nocturnal confusions should be identified (toxic, infections, metabolic and pharmacological) and dealt with accordingly. In the absence of such reversible conditions, treatment for the nocturnal agitation accompanying organic brain syndrome should be considered.

Both pharmacological and non-pharmacological agents have an important role to play together in the management of sundowning syndrome. Non-pharmacological agents: These are mainly based on environmental and activity factors, which greatly influence the etiology of sundowning syndrome. It has been shown that restriction of daytime sleep in people with sundowning syndrome ensures better sleep in the night⁷ and that these patients do well with minimal exposure to bright light, which also decreases nocturnal confusion. It has been suggested that increased contact with familiar people can be successful in decreasing symptoms⁸, while a study also demonstrated that managing patients with dementia in familiar surroundings significantly reduces incidence of sundowning. It is proposed that encouraging daytime activities reduces nocturnal confusion in patients with organic brain disease.

Pharmacological agents: Pharmacological treatment for nocturnal confusion associated with organic brain disease is a delicate balance between the potential benefits and the side effects of the drugs. Physicians involved in managing such patients should be well aware of the pharmacokinetics and side effects of the medications, since inappropriate use can worsen the symptoms and increase morbidity.

Treatment that has been found to be beneficial in these patients is low dose neuroleptics (haloperidol or thioradazine). The newer groups of neuroleptics might have fewer side effects. However, long term pharmacotherapy with neuroleptics can be problematic due to their side effects and periodic withdrawal is recommended. The role of benzodiazepine in management of sundowning is controversial, while it has been suggested that B blockers like pindolol and propanolol may be useful in its treatment. However, the FDA has not approved the use of B blockers for this condition.

Sundowning syndrome is associated with nocturnal behaviour disturbance in patients with organic brain disease. Both environmental and patient characteristics contribute towards the phenomenon. Suprachiasmetic nucleus that controls the sleep awake cycle may be responsible for disturbed circadian rhythm. Both pharmacological and non-pharmacological agents have a major role to play in the management of this condition. It appears sundowning may be the final, common expression of different underlying mechanisms impinging on the 'internal clock', but further research is needed for better understanding of this condition.

B. Mandal is Specialist Registrar, Geriatric Medicine and B. K. Bhowmick is Senior Lecturer and Consultant Physician, Department of Geriatric Medicine, Glan Clwyd hospital, RHYL, North Wales.

References

1 Norton D: Investigating the Sundown syndrome; Nursing standard 1991.vol 5, no 47; 26-29

2 Burney-Puckett M: Sundown syndrome etiology and management; journal of psychosocial nursing .1996; Vol 34, No 5; 40-43

3 Drake Lee: A new account of sundown syndrome; Nursing standard; 1997,Vol 12,number 7; 37-40

4 Evans. L: Sundown syndrome in institutionalized elderly. Journal of the American Geriatric society. 1987 35,2,101-108

5 Hoch CC et al: Clinical significance of sleep disorder, breathing in Alzheimer's disease: ournal of the American Geriatric society.1989.37; 138-144

6 Bliwise DL et al ; systematic 24 hours behavioral observation of sleep and wakefulness in a skilled care nursing facility.;1990:Psychology and aging ;5 (1),16- 24

7 Campbell, S , Stalin, A, Volicer, L.; Management of Behavioral and sleep disturbances in Alzheimer's patients using timed exposure to bright light (1991); Sleep research, 20,446

8 Owakawa, M, Mishima , K,and Hisikawa ,Y.;Circadian rhythm disorder in sleep awaking and body temperature in elderly patients with dementia and their treatment.: (1991). Sleep, 14, 478-485

9 Jenike, M.A. Geriatric psychiatry and Psychopharmacology. St Louis, MO: Mosby yearbook

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