Lack of Sleep May Lead to Concussion Symptoms, Study Suggests

Dark circles under your eyes aren’t the only thing that can come from a bad night’s rest. New research shows that a lack of sleep might actually lead to symptoms that resemble a concussion.

Not getting enough rest wasn’t the only thing that was linked with symptoms common after a head injury, though. The study, which looked at more than 30,000 student athletes and cadets who hadn’t had a recent concussion, found that stress and pre-existing mental health conditions also were associated with similar symptoms.

Experts say the findings may play a dual role in influencing the ways concussions are treated, as well as our understanding of sleep.

Findings on Lack of Sleep and Concussion Symptoms

For this study, published by the journal Sports Medicine on January 11, researchers from the Concussion Assessment, Research, and Education (CARE) Consortium set out to determine the base rates of post-concussion syndrome (PCS) symptoms in healthy student athletes and cadets who had not recently suffered a concussion.

A total of 18,548 students who participated in NCAA sports at 26 colleges and universities and 12,039 cadets from four U.S. military service academies, which require participation in athletics, met the criteria for the study. They underwent baseline preseason testing, including reporting their demographics and personal and family medical history. 

The participants also completed the symptom evaluation section of a test used to assess concussions in athletes. They were required to score the severity of 22 post-concussion symptoms, such as dizziness, headache, difficulty concentrating, irritability, and drowsiness, on a scale from zero (none) to six (severe) and report how many hours they slept the previous night. 

The results showed that between 11% and nearly 28% of participants had a cluster of symptoms that would meet the definition for PCS, despite no recent head injuries.

More specifically, around 18% of men and 28% of women in the cadet group showed concussion-like symptoms, as did roughly 11% of men and 20% of women in the student-athlete group. The most common PCS symptoms they reported were fatigue or low energy and drowsiness. 

Researchers also found that participants who had fewer hours of sleep, those with pre-existing mental health conditions, and cadets in their stressful freshmen year were more likely to report symptoms akin to having a recent concussion.

Considerations for Treating Athletes With Concussions

When an athlete has a head injury like a concussion, they are typically taken out of their sport until a doctor determines that it’s safe for them to return to play. Concussion experts say players shouldn’t resume sports after a concussion until their symptoms have gone away. 

Since these findings show that people can have PCS symptoms without having a recent head injury, doctors may want to consider a more individualized approach to managing an athlete’s concussion and getting them back to play, the study suggests. 

“This study underscores what those of us who treat patients with concussions on a regular bases have noted and believed for a while—that concussion symptoms are not specific to concussions,” says Vernon Williams, MD, sports neurologist, pain management specialist, and founding director of the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles.

Williams continues, “We need to be very careful in how we assess individuals after a concussion, and not assume the symptoms that they’re describing are a result of their concussion.”

Dr. Williams adds that taking a more detailed analysis about any symptoms a person experiences after a concussion, and asking whether or not they may have had those symptoms prior to a head injury, could help improve treatment recommendations.

The doctor may also want to take into account whether the person has a mental health condition, sleeps enough, or is going through a stressful time in their life (such as their first year away from home as a young adult) to assess whether those circumstances may be related to certain symptoms.

“People will need to be aware of this information so they’re not keeping someone away from playing when, for instance, they had similar symptoms prior to their head injury,” he says. “The take home message is that these PCS symptoms are not unique to concussion—they can occur for a variety of reasons and in a variety of scenarios.”

Connecting Lack of Sleep and Concussion Symptoms

While the study demonstrated a connection between insufficient rest and post-concussion symptoms, it’s important to note that poor sleep doesn’t mean you’re experiencing a concussion. Rather, the findings deepen our understanding of the many ways that a lack of sleep can impact a person’s day-to-day functioning and overall wellbeing.

“There’s a lot of crossover between poor sleep and the symptoms of a concussion,” says Katherine Green, MD, a sleep medicine specialist at UCHealth in Aurora, Colorado. “The conclusion from this article isn’t that poor sleep causes you to be post-concussive or have a traumatic brain injury, but it does speak to the fact that those two different processes have the same downstream effect.”

She says that the research is consistent with previous studies on the diversity of symptoms people, especially pre-teens and teenagers, often exhibit when they don’t get enough rest.

“Lots of data shows that the primary effects of poor sleep in teens isn’t necessarily daytime sleepiness or things we often see in adults, but more often are irritability, changes in mood or personality, hyperactivity, trouble with focus and memory, and having difficulty in school,” says Dr. Green.

She hopes that these findings and future research will continue to prop up the importance of sleep for a person to feel their best and perform well, whether that’s on the field, at school, at work, or in family life.

“Twenty years ago, it was a badge of honor to say you stayed up all night to work on a project and can still function today,” says Dr. Green. “What we know now is that the opposite is true to be your most optimized self, particularly in terms of concentration, memory, focus, and reaction time, but also in more vague things, like mood, depression, and anxiety. All of these things get better when you have sufficient sleep quantity and sleep quality."