Nighttime Agitation in Persons with Dementia as a Manifestation of Restless Legs Syndrome

Abstract

Objectives: Nighttime agitation or "sundowning" is challenging for clinicians and caregivers to manage in older adults in the dementia stage of Alzheimer's disease (AD-D). Our research previously revealed that nighttime agitation might be a manifestation of restless legs syndrome (RLS). The current study aims to describe the characteristics of older adults with AD-D, nighttime agitation, and RLS, and to evaluate sleep disturbance and iron status in relation to nighttime agitation severity.

Design: An observational study with baseline descriptive and correlational data from a clinical trial.

Setting and participants: Long-term care (n = 69) and independent living (n = 7); age 82.91 ± 9.46 years, with AD-D, nighttime agitation, and RLS.

Measurements: Trained observers counted nighttime agitation behaviors. Independent variables were age; cognition measured by the Mini-Mental State Examination; minutes slept from actigraphy; transferrin saturation percentage (TS%) and transferrin from fasting blood samples; and illness severity using the Cumulative Illness Rating Scale for Geriatrics. Bivariate and multivariable linear regression models were generated.

Results: In the multivariable model, sleep minutes (P = .002) and TS% (P = .003) were negatively associated with frequency of nighttime agitation behaviors, and they explained 20% of the variance. Seventy-nine percent received 1 or more medications that worsen RLS symptoms, such as antihistamines and serotonin reuptake inhibitors.

Conclusions and implications: We encourage clinicians to consider nighttime agitation as a manifestation of RLS. Treatment of iron deficiency indicated by low TS% and deprescribing medications that exacerbate RLS may decrease nighttime agitation, improve sleep, and enhance quality of life in older adults with AD-D.

Keywords: Alzheimer's disease; Behavioral Indicators Test–Restless Legs; RLS; agitation; sleep disorders.