Neurological disorders – including autism spectrum disorder (ASD), Alzheimer’s disease, and Parkinson’s disease – cause sleep disturbances that make life extra challenging for people with those conditions. Improving sleep not only helps improve their quality of life; evidence is mounting that good sleep is vital for a healthy brain and may reduce the risk of some neurological disorders, according to neurologists speaking at the Presidential Symposium – Exploring Sleep Disturbances in CNS Disorders plenary session at the 148th Annual Meeting of the American Neurological Association (ANA).
“Normal, healthy sleep is under assault by our 21st century environment – from artificial light to massive anxiety to social media – and sleep deprivation can exacerbate an existing neurological condition,” says Frances E. Jensen, MD, FANA, FACP, president of the ANA and Arthur Knight Asbury, MD Professor in Neurology and chair of the Department of Neurology at the Perelman School of Medicine, University of Pennsylvania, Philadelphia. “Anything that affects the brain can affect sleep and vice versa. It’s important to focus on how we can improve sleep at any age because it doesn’t just keep you healthy, it can be a great armor to prevent disease.”
Neurological disorders including ASD, Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, REM sleep disorder, epilepsy and traumatic brain injury interfere with sleep, but the mechanism of sleep interruption varies between disorders.
Disrupted sleep can, in turn, exacerbate problems associated with the specific condition. Focusing on getting good sleep not only helps people with neurological conditions but may reduce the risk of developing them.
Neurologists suggest getting good sleep by:
- keeping a regular schedule for going to sleep and waking up;
- making sure the bedroom is dark and all the lights are off;
- using ear plugs and eye masks, and ensuring the bedding is comfortable;
- shunning caffeine after 3 p.m.;
- avoiding screens (TV, phone) for at least an hour before bed;
- napping no more than 30 minutes a day (if at all);
- exercising regularly, but not in the evening;
- avoiding eating before bedtime; and
- having no more than one alcoholic drink a day.
Sleep is Critical for Brain Development and Health in Children with ASD
Consistent routines and methods can help children with ASD get better sleep, which improves their executive function (planning, focus, etc.), performance on working memory tasks and daytime behavior so they are less irritable, less aggressive and have fewer meltdowns during therapy, according to information being presented during the sleep symposium.
More than half (50% to 80%) of children and adolescents with ASD have significant sleep problems compared to 20% to 30% of neurotypical children.1 Difficulty falling asleep, staying asleep or obstructive sleep apnea disrupt the sleep that is vital for the healthy development of young brains, including memory, learning and social-emotional development. ASD may interrupt sleep by overly arousing the brain and disrupting the normal processing of melatonin (which promotes sleep). Genetics can also play a role, as well as other medical and psychiatric conditions and medications they are taking.
“Parents can help their children with ASD get better sleep by ensuring they don’t ingest too much caffeine such as in soda, coffee or tea, get lots of exercise, avoid screens close to bedtime and have a bedtime routine that’s not too early,” says Beth Malow, MD, MS, FANA, who presented on “Sleep and Neurodevelopmental Conditions” and is director of the Sleep Division at Vanderbilt University Medical Center, Nashville. “Clinicians should also be sure there isn’t a medical condition that is waking the child. While behavioral methods should be tried first, if they don’t help enough, medications may be tried using those that target a co-occurring condition if possible, starting at a low dose that is relatively safe and effective.”
She notes that children with ASD often are prescribed medications for sleep, including gabapentin, alpha-adrenergic agonists, trazadone, hydroxyzine, mirtazapine, tricyclic antidepressants, and others, but there is not enough research to show that they have a positive effect without causing other problems. Melatonin has the strongest track record in terms of research, but it is not regulated by the Food and Drug Administration.
“We need more studies with parent input to know which medications and behavioral treatments are most successful,” she says.
Sleep as a Factor in Alzheimer’s Disease
Poor sleep over long periods of time increases the risk of developing Alzheimer’s disease-type changes in the brain, suggests early research being presented during the symposium. These studies show that poor sleep accelerates changes in the brain, such as the buildup of amyloid beta plaques and tau tangles.
“Part of the reason that poor sleep might increase the risk of Alzheimer’s disease is related to changes to immune cells in the brain called microglia,” says David Holtzman, MD, FANA, who presented on the “Bidirectional Relationship Between Sleep and Alzheimer’s Disease-Related Pathology” and is scientific director of the Hope Center for Neurological Disorders and director of the Knight Alzheimer’s Disease Research Center at Washington University School of Medicine, St. Louis. “These cells are being explored as a potential target for new therapies for the disease.”
While researchers don’t know why Alzheimer’s disease disrupts sleep, it appears the underlying pathology affects some brain regions that control sleep.
“It has been shown that people who are in late middle age and cognitively normal who get low and high amounts of sleep decline faster than who get the middle ranges of sleep,” he says. “This suggests that there is an optimal range of sleep for each person that is associated with better performance over time.”
Sleep is Necessary to Clean the Brain, Reduce Risk of Neurological Disorders
The glymphatic system – which cleans the brain of waste products that increase the risk of neurological disorders – only works during sleep, which is why sleep is so important, according to a presentation at the symposium.
“Sleep is serious business, likely as important as exercising and avoiding smoking and excess weight gain,” says Maiken Nedergaard, MD, DMSc, who presented on “The Glymphatic System – and Relationship to Disorder,” and is co-director of the Center for Translational Neuromedicine, University of Rochester Medical Center, N.Y. “It’s important to develop good sleep habits because poor sleep accelerates neurological diseases and neurological diseases worsen sleep quality.”
The glymphatic system provides a basic housekeeping function for the brain by flushing cerebrospinal fluid into the brain during sleep to remove protein waste products, such as tau proteins and amyloid beta.
Gene mutations may protect short sleepers against diseases like Alzheimer’s
The genetic variants that enable short sleepers (those who get good sleep in four to six hours) may delay the onset and progression of Alzheimer’s-like diseases, and potentially other neurological disorders, suggests early research being presented at the symposium.
“The biological need for sleep varies dramatically among people,” says Ying-Hui Fu, PhD, who presented “Genetic Sleep Variants Protect Against Alzheimer-Like Diseases,” and is a neurology professor at the University of California at San Francisco Weill institute for Neuroscience. “Our research of familial sleep traits is beginning to shed light on how sleep is regulated and how it contributes to health.”
Dr. Fu’s group has identified four genes (DEC2, ADRB1, NPSR1 and GRM1) that are responsible for the ability to sleep for shorter periods of time. “We believe and predict these natural short sleep mutations can potentially protect the mutation carriers from various diseases, although we only have data for Alzheimer’s disease so far,” she says.