Sundown Syndrome

Sundown Syndrome is also known as sundowning. It is a neurological phenomenon associated with increased confusion and restlessness in people with delirium or some form of dementia. It is most commonly associated with Alzheimer's disease, but also found in those with other forms of dementia.

The term 'sundowning' was first used by Louis K. Evans in 1987 due to the timing of the person's increased confusion beginning in the late afternoon and early evening[1].

For people with Sundown Syndrome, a multitude of behavioural problems begin to occur and are associated with long term adverse outcomes. People are generally able to understand that this behavioural pattern is abnormal. Research shows that 20–45% of people with Alzheimer's will experience some variation of confusion related to Sundown Syndrome.

Some preliminary research tries to link the Sundown Syndrome to accidents[2].

Symptoms are not limited to but may include:
– Increased general confusion as natural light begins to fade and increased shadows appear;
– Agitation and mood swings. Individuals may become fairly frustrated with their own confusion as well as aggravated by noise. Individuals found that yelling and becoming increasingly upset with their caregiver is not uncommon;
– Mental and physical fatigue increase with the setting of the sun. This fatigue can play a role in the individual's irritability;
– An individual may experience an increase in their restlessness while trying to sleep. Restlessness can often lead to pacing and or wandering which can be potentially harmful for an individual in a confused state;
– Hallucinations (visual and/or auditory) and paranoia can cause increased anxiety and resistance to care.

Because the Sundown Syndrome is still a relatively novel syndrome, sufficient research has yet been carried out. Possibly the aberrant behaviour can be seen as 'normal' in patients with variant types of dementia. This uncertainty in all aspects of this syndrome also results in a a wide range of reported prevalence. The latest edition of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) does not regard the Sundown Syndrome as an accepted disorder.

[1] Evans: Sundown syndrome in institutionalized elderly in Journal of the American Geriatric society – 1987
[2] Renner et al: Diurnal variation and injury due to motor vehicle crashes in older trauma patients in Traffic Injury Prevention -2011