Getting a concussion — whether due to a fall, a blow to the head, a car accident, or a sports-related injury, among other causes – can significantly impact daily life. This is particularly true when it comes to sleep issues, given the effects of poor sleep on other health issues, including depression, anxiety, and pain. But the relationship between concussions and sleep goes both ways, with sleep playing a key role in recovery and even helping reduce the risk of sustaining a concussion in the first place.
Read on for an overview of the interrelationship between concussions and sleep.
How common are concussions?
Concussions, also known as mild traumatic brain injuries (TBIs), account for about 80% of all TBIs and can include a brief loss of consciousness. They’re considered mild in comparison to moderate and severe TBIs, which can include losing consciousness for 30 minutes or more or even lapsing into a coma.
A mild TBI is still a form of brain trauma, however, and repeat concussions are linked to complications, including second impact syndrome as well as chronic traumatic encephalopathy (CTE).
Tracking exact numbers remains a challenge due to under-reporting: According to the Centers for Disease Control and Prevention, eight out of every nine concussions may go unreported. Nevertheless, one study found that close to 30% of respondents said they’d had at least one concussion at some point in their lives. Additionally, data from the CDC showed that in 2020, there were 214,000 concussions that resulted in hospitalization.
Should you stay awake initially?
You may have heard that it’s important to stay awake after sustaining a concussion. However, that’s only initially if you haven’t yet been assessed by a medical professional, says Dr. Hrayr Attarian, professor of neurology at Northwestern University’s Feinberg School of Medicine. In that scenario, he explains, staying awake for a few hours allows an observer to assess whether neurologic function is deteriorating. “There are no hard and fast guidelines,” he says. “But if they lose consciousness or appear dazed, they should seek medical attention.”
Sleep and concussion recovery
Sleep is known to be essential for healing, but the precise role it plays in post-concussion recovery isn’t yet known, says Attarian. “Sleep is a very complex process, and the brain is the most complex organ,” he points out, “so there are a lot of unknowns.”
That said, both sleep and rest are important aspects of recovery.
After being diagnosed with a concussion, you’ll likely be advised to take a few days to rest. “I generally recommend a couple of weeks of taking it easy,” says Attarian. “Treat yourself as if you had a viral infection.”
This includes avoiding strenuous activities and workouts, he says, but it isn’t a recommendation to stay in bed all day.
“Resting is important, but so is having a very strict daytime routine, getting plenty of light exposure in the morning, and avoiding long naps.” In fact, overall sleep hygiene is even more important during recovery. “If they were practicing sleep hygiene before, then they should double down on that,” he says. “And if they were not practicing sleep hygiene or were letting it go by the wayside, they should focus on it now.” Getting daytime light, the best-known zeitgeber, helps cue alertness during the day to keep the sleep-wake cycle synchronized.
When it comes to nighttime sleep, it’s important to log enough hours (7 to 9 hours for adults), but it’s not necessary to go overboard. “If they’re sleeping more than 9 hours and they weren’t long sleepers before the TBI, then there’s something wrong,” says Attarian, citing potential causes including underlying sleep apnea, medication interactions, or even a late onset subdural hematoma due to the head injury.
Although research into the role of sleep in concussion recovery is ongoing, one likely pathway for healing is via the glymphatic system, which clears waste from the brain while we’re asleep, Attarian explains.
Sleep issues following a concussion
When you’re healing from a concussion, you may find that sleep is actually harder to come by. “Insufficient and disturbed sleep are very common following a mild traumatic brain injury,” says Emerson Wickwire, Ph.D., professor of psychiatry and sleep medicine section chief at the University of Maryland School of Medicine. However, “for the vast majority of patients who experience a mild TBI, symptoms resolve within a few weeks or months.”
Insomnia
The most common sleep issue is insomnia, reported by up to two-thirds of those who sustain a concussion. This can be due to the concussion itself but can also be exacerbated by various behaviors to try to compensate.
“One of the most common patterns is that patients experience short-term sleep difficulty and, in an effort to experience relief, engage in compensatory behaviors such as sleeping in later, using caffeine, or trying harder to sleep,” explains Wickwire. “But in the long run, these behaviors often backfire and can lead to development of a chronic insomnia condition.”
There are also a number of other likely contributing causes, he says, including a change in the timing of melatonin secretion (which can lead to delayed bedtimes), an increase in stress hormones, and other concurrent issues such as pain.
In a 2022 study, Wickwire and his co-authors examined sleep issues in 2,000 U.S. adults with a diagnosed TBI (of which the vast majority were mild TBIs or concussions). Among their findings: Two weeks after their initial injury, 93% of the TBI patients had mild insomnia (as classified using the Insomnia Severity Index). By the one-year mark, however, close to a third of these patients no longer had insomnia.
How to address insomnia after a concussion
If you’re experiencing mild sleep issues, including insomnia, Attarian recommends waiting a couple of weeks to see if they start to improve. For insomnia that persists, both cognitive behavioral therapy for insomnia (CBT-I) and medications may be warranted, he says, although both come with caveats.
When taking medications, the potential side effects can be even harder to tolerate for people who are already struggling with other concussion symptoms. He cites an example: “If they already have some cognitive impairment, you don’t want to put them on something that’s going to make them feel hungover the next day.”
Similarly, cognitive behavioral therapy for insomnia (CBT-I) may be more difficult for someone who’s still healing from a concussion. “The thing you have to take into consideration is that you need someone who can pay attention, can focus on the instructions, and can follow through. And again, if they have a degree of cognitive problems due to the TBI, they may not be able to be as compliant.”
These aren’t reasons to avoid treating insomnia, though, he says, as it will likely worsen over time without treatment.
Ongoing insomnia after a concussion is also associated with other poor health outcomes, according to a new follow-up study by Wickwire and his co-authors. Of the 2,000 adults with a diagnosed traumatic brain injury (of which the majority were concussions), participants who had severe insomnia both initially (evaluated two weeks post-injury) and at the one-year mark had worse mental health, quality of life, and neurocognitive scores (including processing speed and executive function) compared to their counterparts, including those with persistent mild insomnia.
The researchers also found that having severe insomnia at the three-month or six-month mark was a risk factor for poor recovery at the one-year mark. Insomnia “can precede, exacerbate, or perpetuate numerous outcomes, including depression, anxiety, chronic pain, poor neurocognitive performance, and diminished quality of life,” Wickwire explains. Because of this, he says, focusing on treating insomnia in concussion patients offers a promising path to help improve their overall recovery.
Other potential sleep issues and how to address them
Sleep apnea
Obstructive sleep apnea, a condition that causes a person to stop breathing for brief but frequent periods of time during sleep, affects about 25% of those who sustain a concussion. This is about double the rate of the general population. The reasons for this aren’t entirely clear, though. “I don’t see a pathophysiologic reason why TBI should cause sleep apnea,” notes Attarian.
The recommended treatment, however, is the same as it is for others with obstructive sleep apnea: Seek a medical evaluation to confirm a diagnosis and determine next steps, which may include a continuous positive airway pressure (CPAP) device to wear during sleep.
Increased need for sleep
About 20% of people who sustain a concussion develop “posttraumatic hypersomnia,” which includes sleeping longer at night, feeling excessively sleepy during the day, or experiencing fatigue. Concussion-related pain is thought to be one potential cause, as is cellular damage that affects levels of hypocretin, a neurotransmitter that helps regulate sleep.
Circadian rhythm disorders
As with hypersomnia, disruption of the circadian rhythm, which throws off the body’s internal sleep-wake clock, is more common in more severe cases of brain injury than in cases of concussion. While this disruption can occur as a result of a concussion, it can also be triggered by external factors, Attarian says, citing the bright lights and noise in hospital environments as examples.
In addition, some of the issues caused by circadian rhythm disruption, such as sleepiness or trouble falling back asleep, can easily be mistaken for other sleep disorders, such as insomnia or primary hypersomnia, he notes.
In all cases, if you’re experiencing sleep issues that are getting worse, “seek help immediately,” says Attarian.
