What is the sundowning phenomenon? Causes, symptoms, and coping strategies

According to some estimates, up to 20% of Alzheimer's patients experience the confusing and distressing symptoms of sundowning. The sundowning phenomenon is a pattern of increased confusion, anxiety, and agitation that occurs in the late afternoon and evening, primarily affecting individuals with dementia.

Quick Summary

Sundowning is a complex neurobiological and behavioral syndrome in which dementia symptoms, such as confusion and agitation, intensify in the late afternoon and evening hours, impacting both the patient's well-being and caregiver stress levels.

Key Points

• Circadian Rhythm Disruption: Sundowning is primarily linked to the dysfunction of the body's internal clock, regulated by the suprachiasmatic nucleus, which is damaged by neurodegeneration in dementia.

• Symptoms of Sundowning: Key symptoms include heightened confusion, agitation, anxiety, restlessness, and mood swings that occur late in the day.

• Environmental and Physiological Triggers: Low lighting, fatigue, overstimulation, unmet basic needs, and changes in routine can all worsen sundowning symptoms.

• Multifactorial Causes: The exact cause is unknown, but it is believed to be a combination of neurobiological factors (melatonin deficiency, cholinergic system damage) and external triggers.

• Management Strategies: Coping mechanisms include maintaining a consistent daily schedule, ensuring proper lighting, using calming activities, and avoiding overstimulation in the evening.

• Genetic Links: Research suggests a potential genetic component, with some studies linking the APOE ε4 allele to a higher incidence of sundowning.

• Impact on Caregivers: Sundowning can be highly stressful for caregivers, potentially leading to burnout and contributing to the decision to place patients in residential care.

Understanding the Neurobiological Basis of Sundowning

Sundowning is not a disease in itself but rather a syndrome associated with the progression of neurodegenerative conditions, particularly dementia. The underlying mechanisms are still under investigation, but research points to disruptions in the brain's internal clock and other neurochemical imbalances.

Circadian Rhythm Disruption

• The Body's Internal Clock: The human body operates on an internal 24-hour cycle known as the circadian rhythm, which regulates the sleep-wake cycle, body temperature, and hormone release. The suprachiasmatic nucleus (SCN) in the hypothalamus serves as the master pacemaker for this rhythm.
• Degeneration in Dementia: In dementia, neurodegeneration can damage the SCN and its associated pathways. Studies have shown neuronal loss and neurofibrillary tangles in the SCN of Alzheimer's patients, which can flatten the normal daily fluctuation of activity levels.
• Melatonin Production: The SCN regulates the pineal gland's production of melatonin, the hormone that promotes sleep. In people with dementia, this regulation is often impaired, leading to lower melatonin levels and disrupted sleep patterns, which can contribute to nocturnal hyperactivity and agitation.

Neurochemical Imbalances

• Cholinergic System: The neurotransmitter acetylcholine is crucial for cognitive functions and circadian rhythm regulation. It has been shown that cholinergic transmission is impaired in dementia, further disrupting the body's internal clock and potentially contributing to sundowning.
• Genetic Factors: Genetic predispositions may also play a role. Some studies have suggested a link between the apolipoprotein E (APOE) gene's ε4 allele, a known risk factor for Alzheimer's, and the occurrence of sundowning symptoms. This indicates a complex interplay between genetics and neurodegeneration.

Common Symptoms of Sundowning

Identifying the symptoms of sundowning is the first step toward managing it effectively. Symptoms can vary in severity and presentation but often follow a predictable daily pattern, worsening as daylight fades. Some of the most common signs include:

• Increased agitation and restlessness: Pacing, wandering, or fidgeting, often coupled with an inability to settle down.
• Confusion and disorientation: The individual may become confused about their location, who people are, or the time of day.
• Mood swings and emotional outbursts: Sudden crying, aggression, or irritability, sometimes in response to minor triggers.
• Anxiety and paranoia: Feeling insecure, fearful, or suspicious of others, which can be particularly distressing.
• Hallucinations and delusions: Seeing or hearing things that are not there or believing things that are not true.
• Difficulty sleeping: Problems with falling or staying asleep, which exacerbates daytime fatigue and can worsen the cycle.

Environmental and Physiological Triggers

While neurobiological factors are foundational, external triggers can intensify sundowning symptoms. Caregivers can often minimize the impact of sundowning by addressing these factors.

• Lighting: As natural light diminishes, increasing shadows can be disorienting and frightening, potentially triggering fear or hallucinations. Insufficient light exposure during the day can also disrupt the circadian rhythm.
• Fatigue: Physical and mental exhaustion, especially from a long, stimulating day or poor nighttime sleep, can lower a person's stress threshold and exacerbate symptoms.
• Overstimulation: A noisy or overly busy environment can overwhelm someone with dementia, leading to agitation and confusion in the evening.
• Physiological needs: Unmet basic needs, such as hunger, thirst, or pain, can heighten irritability. A drop in blood pressure or blood glucose levels after a meal can also contribute.
• Change in routine: Disruptions to a person's established daily schedule can increase anxiety and trigger sundowning behavior.

How to Manage the Sundowning Phenomenon: Strategies for Caregivers

Effective management of sundowning requires a multi-pronged approach that combines behavioral strategies with environmental adjustments. The following table provides a comparison of these approaches:

Strategy Type	Behavioral Management	Environmental Adjustments
Routine	Create and stick to a consistent daily schedule for meals, waking, and sleeping to provide stability and reduce confusion.	Ensure a well-lit environment in the evening to minimize shadows and disorientation. Use nightlights in bedrooms and bathrooms.
Activity	Schedule regular, light physical activity during the day, such as a walk, to reduce restlessness and promote better sleep at night.	Reduce evening noise and chaos. Turn off loud televisions and keep the home quiet and calm during late afternoon and evening hours.
Caregiver-Patient Interaction	Use redirection and distraction during an episode. Instead of arguing, engage the person in a calming activity or conversation.	Check for and address unmet physiological needs, such as hunger, thirst, or bathroom use, which can be triggers.
Napping	Discourage long naps late in the day to prevent disruption of the nighttime sleep cycle, as excessive daytime sleepiness can worsen symptoms.	Use music therapy, nature sounds, or calming scents to create a more relaxing and predictable atmosphere in the evening.

Conclusion

The sundowning phenomenon is a challenging but common aspect of dementia that stems from a combination of neurobiological changes and external triggers. While the precise causes are still being researched, understanding the role of circadian rhythm disruption and related factors is key. By implementing a stable routine, managing environmental factors like lighting and noise, and employing patient, compassionate behavioral strategies, caregivers can significantly reduce the severity and frequency of sundowning episodes, improving the quality of life for those with dementia and their families.

For more information on managing behavior changes in dementia, visit the National Institute on Aging's website. https://www.nia.nih.gov/health/alzheimers-changes-behavior-and-communication/coping-agitation-aggression-and-sundowning

Frequently Asked Questions

What is the primary neurobiological cause of sundowning?

While the exact cause is not fully understood, a primary factor is believed to be a disruption of the circadian rhythm, or the body's internal clock. Neurodegeneration in the brain region that regulates this clock, coupled with decreased melatonin production, can lead to confusion and agitation in the evening.

Who is most likely to experience the sundowning phenomenon?

Sundowning is most common in individuals with dementia, particularly those in the middle to later stages of Alzheimer's disease. However, it can also affect people with other types of dementia and, in some cases, elderly individuals without a dementia diagnosis.

How can a caregiver help manage sundowning symptoms?

Caregivers can help by maintaining a consistent daily schedule, ensuring adequate light exposure during the day and minimizing shadows in the evening. Calming activities, reducing noise, and avoiding overstimulation in the late afternoon can also be effective strategies.

Can diet and medication influence sundowning?

Yes, both diet and medication can play a role. Certain medications may have side effects that worsen confusion, while unmet needs like hunger or thirst can trigger agitation. It's important to discuss the patient's diet and medication regimen with a doctor.

Is sundowning the same as delirium?

No, sundowning is different from delirium. Sundowning is typically a recurring, predictable pattern of behavioral change in the late afternoon and evening in a person with a known cognitive decline. Delirium is an acute, sudden change in mental state that can be caused by an underlying medical condition, like an infection, and does not follow a predictable time pattern.

Do symptoms of sundowning always occur around sunset?

While the term "sundowning" refers to symptoms appearing around sunset, the behavioral changes can occur at any time of day or night. The pattern, however, is often linked to the fading daylight.

Can sundowning be prevented or cured?

There is currently no cure for sundowning, as it is a consequence of a progressive disease. However, the severity and frequency of episodes can often be significantly reduced through careful management of routines, environment, and behavioral triggers.