“Sleep complaints are common in TBI patients, so the association itself is not surprising,” says the lead study author, Yue Leng, MD, PhD, a psychiatry researcher and an assistant professor at the University of California in San Francisco. “It is fascinating that there is an increased risk of sleep disorders even years after TBI, not only short-term,” Dr. Leng says. For the study, researchers examined data on almost 200,000 Iraq and Afghanistan-era veterans, roughly half of whom had been diagnosed with a brain injury. Over an average follow-up period of almost five years, 23.4 percent of the veterans with TBIs developed sleep disorders, compared with 15.8 percent of the veterans without TBIs. TBIs were associated with a 50 percent higher risk of insomnia and what’s known as hypersomnia, or excessive daytime sleepiness, as well as a 33 percent greater risk for sleep-related movement disorders like restless leg or leg cramps and a 28 percent higher risk for sleep-related breathing disorders such as obstructive sleep apnea. RELATED: Talking TBI: A Glossary of Formal and Informal Terms Used to Describe TBI Treatment, Professionals, and More

Bigger Risk With Milder Injuries

Post-traumatic stress disorder, common among veterans with and without head injuries, didn’t appear to influence the risk of sleep problems in those who did have TBIs. Veterans did have a higher risk of sleep disorders with concussions than with moderate to severe TBIs, which may reflect differences in how these injuries impact the brain, Leng says. Mild TBIs, or concussions, often involve blows to the head that can cause the brain to shift rapidly back and forth inside the skull, leading to inflammation as well as tissue damage in several regions of the brain, Leng says. By contrast, moderate to severe TBIs are typically due to a direct blow with more extensive damage concentrated in a smaller area of the brain. “Therefore, the symptoms of mild TBIs and more severe TBIs may differ,” Leng says. One limitation of the study is that some veterans may have had undiagnosed sleep disorders, particularly if they had milder problems, leaving a disproportionate number of cases with more severe sleep symptoms in the study, the researchers noted. This study also didn’t examine the impact of multiple TBIs on sleep. RELATED: Your Everyday Guide to Living Well With Traumatic Brain Injury

Traumatic brain injuries have been linked to lasting sleep issues in previous studies of veterans. A study published in July 2017 in JAMA Neurology, for example, found that more than half of veterans with concussions experienced moderate to severe sleep impairment up to five years after their injuries, compared with one in five combat veterans with no history of TBI. Another study, published in 2018 in the Journal of Clinical Sleep Medicine also linked TBI to sleep disorders in veterans, although this study found the risk was increased when they also had PTSD. And an earlier study, published in Sleep, examined sleep disturbances among military personnel and found that only about 1 in 20 people without any history of TBI had insomnia. But one in five people who had a prior TBI had insomnia, as did one in two people with a history of multiple TBIs. Sports concussions have been linked to sleep problems before. A study published in Sleep Medicine found sports concussions associated with increased wakefulness. More recently, a study published in February 2019 in Behavioral Sleep Medicine found that repeat concussions were associated with longer recovery and more severe sleep disturbances, and that those with sleep problems also had more severe cognitive impairment, headaches, and mood disorders. While concussion has long been associated with sleep disorders, these symptoms are often seen soon after the TBI, says Jack Tsao, MD, DPhil, a neurology professor at the University of Tennessee Health Science Center in Memphis who wasn’t involved in the latest study. The new study suggests that this connection may persist much longer than previously thought, Dr. Tsao says. RELATED: 8 Health Problems Linked to Not Getting Enough Sleep

What Helps With Sleep After a TBI

Some things that help with sleep after a concussion are the same things that can help people without brain injuries get a better night’s rest, Tsao says. Like everybody else, people recovering from TBIs need to practice what’s known as good sleep hygiene. “Good sleep hygiene is critical,” Tsao says. “This means getting eight hours of sleep per night, going to bed at a consistent time, not drinking coffee in the afternoon or evening, and no computer or smartphone use right before bedtime.” The U.S. Centers for Disease Control and Prevention (CDC) also endorses this approach to good sleep hygiene, and offers the following tips:

Get up and go to bed at the same times each day, even on weekends.Keep your bedroom dark, quiet, and at a comfortable temperature.Keep electronics — including your phone — out of your bedroom.Don’t eat large meals or drink caffeine or alcohol close to bedtime.Get plenty of exercise.

If sleep problems persist, it’s worth following up with a specialist who treats concussion patients, Leng says. That’s because if no sleep issues surface in the weeks or months immediately after a TBI, the study results suggest that these injuries could be involved if sleep problems develop down the line. “Long-term follow-up for the possibility of developing sleep disorders is also needed, given that the risk of sleep disorders was increased even years after TBI,” Leng says. RELATED: Is COVID-19 Anxiety Messing With Your Sleep? 8 Tips for Getting It Back on Track