What Every HD Clinician Needs to Know
As many as 88% of people with HD report sleep problems, and sleep impairment is known to contribute to cognitive dysfunction. Considering that HD causes cognitive impairment, and sleep dysfunction can often be remediated with treatment, treatment for sleep impairment should be a priority for people with HD and sleep complaints so that any cognitive dysfunction they are experiencing is not worsened by poor sleep.
In 2020, one of us (EF) commenced a PhD project to determine how sleep is impacted in premanifest HD and whether sleep disruption may be contributing to any emerging cognitive decline. Our review of the literature, published in the Journal of Huntington’s Disease (2023, Vol 12, No. 3, pages 203-304) indicated that most sleep research in HD has focused on symptomatic HD, with fewer studies in people confirmed to have the CAG expansion, who have not yet been diagnosed.
Sleep Across the Premanifest to Early Diagnosed Phase of HD
Sleep, like many other physical and mental functions, begins to show subtle signs of change in premanifest HD, but only shows significant function changes after diagnosis in most people with the HD CAG expansion. Our recent study of premanifest HD, using actigraphy and self-report indicated that on average, people in the premanifest stage, show increased nighttime awakenings compared to healthy comparison participants, even as early as 15 years before the predicted time of symptomatic HD (i.e., motor diagnosis).
Despite greater nighttime awakening in premanifest HD, studies using polysomnography, which provides more detailed information including sleep stages, reveal minimal to no differences in pre-HD samples. For example people in the pre-HD phase appear to fall asleep and have similar duration of light and deep sleep as their neurologically healthy counterparts. Complementing the objective measures (actigraphy and polysomnography), self-report questionnaires, which indicate peoples’ subjective experiences, indicate that people with premanifest HD rate their sleep as being of similar quality to the healthy controls.
In contrast, after motor diagnosis (i.e., manifest HD), polysomnographic studies show that sleep worsens, that it takes longer to fall asleep, sleep is more interrupted by periods of wake, and time spent in bed gets longer. Further, in manifest HD, less time is spent in deeper sleep stages (e.g., slow-wave sleep), and more time in light sleep than neurologically healthy research participants.
People with manifest HD also experience their sleep as worse, as indicated on self-report questionnaires, compared to how healthy age-matched controls describe their sleep experience. Consistent with evidence of poor sleep on direct, objective measures of sleep, their self-report questionnaires indicate their sleep is short and restless, that they experience difficulty falling and staying asleep, and that they awaken too early.
Partners and caregivers also struggle with their own sleep, which is not surprising. As many as 55% of HD caregivers report sleep problems of their own, including 18% of caregivers who say they have problems falling and staying asleep at night, and 37% who say that they wake up early and are unable to get back to sleep.
Can a Bad Night’s Sleep Influence Mood and Thinking Skills in HD?
In the neurologically healthy population, poor sleep is linked to feeling down or anxious, a pattern also observed in HD. Cognitive testing links poor sleep in manifest HD worse performance on cognitive tests, suggesting that poor sleep quality may compound cognitive symptoms in HD. Our research in pre-HD also showed that more fragmented sleep was associated with worse performance on cognitive tasks, specifically those assessing memory and attentional functions.
Promoting Better Sleep
Sleep experts suggest that the first line of treatment for sleep complaints should be behavioral, rather than using medication right away.
What to Tell Patients: Sleep Hygiene Tips
Adopting good sleep habits facilitates good sleep (i.e., sleep hygiene). What works for one person might not work for another, so encourage patients to test various strategies to find what works best.
Strategies to combat nighttime wakening
- Slow deep breathing can promote relaxation and return to sleep. For example, using the the 4-7-8 breathing method: inhale slowly through the nose for 4 seconds, hold for 7 seconds, then gently exhale through the mouth for 8 seconds. Repeat 3-4 times.
- Try a progressive muscle relaxation. Start by tensing the muscles in the feet for 5 seconds while inhaling, then slowly release muscles while exhaling, paying attention to tension leaving the muscles. Move from the toes to the head, tensing and relaxing each muscle group.
- Use imagery. Imagine a peaceful or comforting place and relax the body.
- Avoid drinking too much water or other fluid before bed to avoid frequent trips to bathroom.
- Avoid alcohol later in the day as it disrupts sleep later in the night.
- Try listening to calming music or stories to help block out anxious thoughts.
What to do if falling asleep is a problem?
- Regular habits are key. This means going to bed and get up at the same time every day to train the body to sleep well. Bedtime routines and rituals also signal the brain to wind
down for the night. Meditation, listening to relaxing music,
or a warm bath or shower may also be useful strategies. - Screens (e.g., phone, TV) should be off for at least 30 minutes before bed to avoid disrupting melatonin, the hormone that promotes sleep.
- Avoid caffeine late in the day.
- Avoid lying in bed without sleeping for more than 20-30 minutes. If not sleeping, get up and do something boring or relaxing, such as breathing exercises in a dim room. Only go back to bed when sleepy.
Other Tips
- Reserve time bed only for sleeping and intimacy. Avoid reading, watching TV, or working in bed. This helps the body to associate bed with sleeping.
- Create a comfortable environment.
This may include investing in a comfortable mattress and pillows, sleeping in a darkened room with lights off, and keeping the room quiet and temperature cool. Wearing earplugs and an eye mask may be useful. A white noise machine or a fan to block out any noise may be helpful.
Clinical Interventions
No large-scale studies investigating sleep interventions in HD have been published, however several treatment options have proven useful in other populations.
- Melatonin supplements can help some people fall asleep. Slow-release melatonin, which dissolves slowly and gradually releases melatonin during the night, may also help people stay asleep.
- Cognitive Behavioral Therapy for Insomnia (CBT-I) is the gold-standard behavioral treatment for adults with insomnia. CBT-I involves reducing thoughts, feelings and behaviors that contribute to sleep problems. Key techniques include cognitive restructuring, sleep education, bed restriction, stimulus control and relaxation techniques.
- Brief Behavioral Intervention for Insomnia (BBT-I) is a brief manualised treatment that focusing on the behavioral components of CBT-I in four brief sessions, which can be delivered by any healthcare professional, including a nurse or general practitioner. •
WHEN TO REFER HD CLINIC PATIENTS TO A SLEEP SPECIALIST
- They snore or gasp for air while asleep
- They can no longer perform their daily activities because they are too tired and behavioral treatments are not working
- They or a bed partner complain of excessive leg movements or frequent acting out of dreams