What is Sundowning Syndrome, also known as Late-Day Confusion?

From the Guidelines

Sundowning syndrome, also known as late-day confusion, is a neurological phenomenon where individuals with dementia or cognitive impairment experience increased confusion, agitation, and behavioral problems in the late afternoon, evening, or night. This condition typically affects people with Alzheimer's disease and other forms of dementia, causing symptoms like anxiety, aggression, pacing, wandering, and resistance to care that worsen as daylight fades. The exact cause isn't fully understood, but factors include:

• Fatigue
• Disrupted circadian rhythms
• Reduced lighting causing shadows that may trigger confusion
• Hormonal imbalances that occur later in the day Management strategies include:
• Maintaining consistent daily routines
• Ensuring adequate lighting in the evening
• Scheduling activities and appointments earlier in the day when the person is more alert
• Limiting caffeine and sugar intake later in the day
• Creating a calm environment In some cases, medications like low-dose antipsychotics or melatonin might be prescribed, though non-pharmacological approaches are preferred initially, as suggested by the American Academy of Sleep Medicine clinical practice guideline 1. Caregivers should track patterns to identify specific triggers and adjust the environment accordingly to minimize symptoms. It is essential to note that the use of melatonin or agonists as a treatment for patients with ASWPD is not supported by evidence, as stated in the 2015 clinical practice guideline 1. Additionally, the guideline suggests that clinicians avoid the use of combined treatments consisting of light therapy in combination with melatonin in demented, elderly patients with ISWRD 1. Overall, a comprehensive approach that incorporates non-pharmacological strategies and, when necessary, carefully selected medications, can help manage sundowning syndrome and improve the quality of life for individuals with dementia or cognitive impairment.

From the Research

Definition and Characteristics of Sundowning Syndrome

• Sundowning syndrome, also known as Late-Day Confusion, refers to the emergence or worsening of neuropsychiatric symptoms (NPS) in the late afternoon or early evening 2, 3.
• The syndrome is characterized by the emergence or increment of neuropsychiatric symptoms such as agitation, confusion, anxiety, and aggressiveness in late afternoon, in the evening, or at night 3.
• Sundowning is highly prevalent among individuals with dementia, with a prevalence ranging from 1.6% to 66% of patients with dementia 4.

Pathophysiological Determinants and Clinical Relevance

• The occurrence and phenotypic characteristics of sundowning may be influenced by diverse neurobiological, psychosocial, and environmental determinants 2.
• Sundowning is thought to be associated with impaired circadian rhythmicity, environmental and social factors, and impaired cognition 3.
• Neurophysiologically, it appears to be mediated by degeneration of the suprachiasmatic nucleus of the hypothalamus and decreased production of melatonin 3.
• Sundowning is associated with several adverse outcomes, such as institutionalization, faster cognitive worsening, and greater caregiver burden 2.

Diagnostic Challenges and Treatment Options

• Sundowning may pose diagnostic challenges in relation to other common causes of behavioral disruptions 2.
• A variety of treatment options have been found to be helpful to ameliorate the neuropsychiatric symptoms associated with this phenomenon, including bright light therapy, melatonin, acetylcholinesterase inhibitors, N-methyl-d-aspartate receptor antagonists, antipsychotics, and behavioral modifications 3, 4.
• Pharmacotherapy with sedatives can be effective but is related to severe side effects, while behavioral interventions are more efficacious but require intense involvement of caregivers 4.