June 21, 2018

By Kris Schanilec

For many people who have Alzheimer’s disease, evenings are difficult. Right around sundown, uneasy feelings and confusion start to flow. The person may become forgetful, agitated – even aggressive, and start pacing or wandering. These symptoms can last through the night and make it tough for anyone in the household to get a good night’s sleep.

Could it be that these behaviors – known as nighttime agitation, or “sundowning” – are caused by RLS? And could treating the RLS lessen the nighttime agitation symptoms?

Researchers led by Kathy Richards, PhD, at the University of Texas at Austin are working to answer these questions. Dr. Richards and co-investigator Christine Kovach, PhD, from the University of Wisconsin-Milwaukee have been awarded a $3.9 million, five-year grant from the National Institute on Aging to evaluate whether there is an association between nighttime agitation and RLS in people who have Alzheimer’s disease.

“Nighttime agitation is the No. 1 reason why people with Alzheimer’s cannot be cared for at home,” says Dr. Richards. “If we can find a better and more precise way to treat nighttime agitation, we can improve the quality of life for many persons who are living with Alzheimer’s disease.”

Nighttime agitation is often treated with powerful antipsychotic drugs, which are only moderately effective and carry with them serious risks, such as falls, stroke and death.

Because nighttime agitation has a strong circadian component and shares symptoms with RLS, Dr. Richards and others have long postulated that for some people, undiagnosed RLS could be the underlying cause. In a previous study led by Dr. Richards, researchers examined symptoms in 59 people who had Alzheimer’s disease and nighttime agitation. They found that 24 percent of participants also had RLS.

In the current research, the team will validate this result in a pilot study – an eight-week, double-blind, randomized controlled trial with 136 long-term care residents who have nighttime agitation and RLS. Participants will receive either gabapentin enacarbil (Horizant, an FDA-approved medication for treating RLS) or a placebo. Data from the study will also help discern the effectiveness, safety and optimal dosage of gabapentin enacarbil for treating nighttime agitation, as well as whether the frequency of RLS symptoms may be linked to nighttime agitation.

The researchers will use a tool newly developed by Dr. Richards called the Behavioral Indicators Test-Restless Legs. This test includes a brief 20-minute observation and simple set of questions for caregivers. Previous studies have shown the tool to be an effective way to diagnose RLS in people who have Alzheimer’s, and one that has potential for future use with children and others who don’t have the ability to report their symptoms.

RLS Foundation Executive Director Karla Dzienkowski visited the University of Texas in May, where she gave a presentation about RLS and met with Dr. Richards’ team to extend the RLS Foundation’s support for the research endeavor. “Cognitively impaired seniors with RLS may have difficulty expressing RLS symptoms causing an inability to sit or lie still during the evening or nighttime hours,” says Dzienkowski. “This study will ensure seniors with cognitive impairments are accurately diagnosed and receive proper treatment to manage their RLS symptoms.”

Dr. Richards emphasizes that while there is no evidence suggesting that RLS causes Alzheimer’s, the study may show that it’s important for caregivers of people with any type of dementia to watch for possible signs of RLS that can then be treated to potentially reduce nighttime agitation.

It all comes down to quality of life for people who have dementia, says Richards. “I hope they will be more comfortable, and that they – and their caregivers – can get a good night’s sleep.”

Kathy Richards, PhD, is a member of the RLS Foundation Scientific and Medical Advisory Board. Read more about her research on the University of Texas at Austin School of Nursing newsletter.