Concussions and the health problems that can follow them have been a topic of concern for athletes of all ages, especially for college student athletes who have to balance their class load on top of their performance on the field. But a new study has found that many college athletes are experiencing persistent concussion-like symptoms without any history of having a concussion.

While most people who suffer a concussion have symptoms that resolve within two weeks to a month, those who have post-concussion syndrome, or PCS, defined as concussion symptoms persisting beyond the normal course of a recovery period, can experience symptoms that last two months or longer. 

The development of PCS can be disruptive to a person’s life and can lead to persistent headaches and troubles with attention or memory, as well as to higher levels of anxiety, depression or irritability. PCS is estimated to impact between 5% and 30% of patients diagnosed with a concussion, depending on age group.

The research, published Jan. 11 in Sports Medicine, sought to highlight the issues that can arise in properly diagnosing a concussion in a clinical setting, according to study lead author Jaclyn Caccese, an assistant professor at The Ohio State University School of Health and Rehabilitation Services.

“Unfortunately, concussion symptoms are nonspecific, and many things can mimic concussion-like symptoms,” Caccese said. “This paper was supposed to highlight one of the challenges in symptom reporting to encourage clinicians to consider both injury-related factors, as well as non-injury-related factors … in evaluating an athlete following concussion.”

The study featured a national sample from the CARE Consortium, a large multi-site study that includes more than 21,000 student athletes from 26 different colleges, as well as more than 13,000 cadets from four U.S. military service academies. A significant amount of both groups reported clusters of symptoms that would meet the symptom criteria for PCS, with 17.8% of male cadets, 27.6% of female cadets, 11.4% of male athletes and 20% of female athletes surveyed meeting that criteria.

Participants were asked to self-evaluate a variety of different symptoms, including difficulty remembering, dizziness, balance problems, irritability, nausea and trouble falling asleep. They ranked themselves on a 0-6 scale, with 0 meaning no symptoms and 5-6 being severe symptoms.

The study found that the most common factors likely to predict PCS-like symptoms without having experienced a concussion itself were a lack of sleep, preexisting mental health problems and a high level of stress.

The findings suggest that concussion diagnoses should be interpreted on a more individual basis, the researchers said, as the symptom criteria for PCS is a nonspecific cluster of symptoms that can essentially be mimicked by preexisting conditions. When interpreting symptoms that present following a concussion, it’s important that clinicians “consider both injury-related factors, as well as other factors not necessarily associated with the injury” such as the patient’s mental health history, Caccese said.

“These are elite athletes, who are extremely physically active, and they are still experiencing many symptoms throughout life that are consistent with symptoms experienced by individuals following concussion,” Caccese added. “These findings highlight that concussion symptoms are not specific, and thus, we must consider both injury-related factors and non-injury-related factors when evaluating patients following a concussion.”

The fact that many people experience concussion-like symptoms throughout their lives in a manner such as this highlights how diagnosing and managing a concussion “needs to be on a person-specific basis,” especially if that person reported symptoms before a head injury, Cacesse said.

Cacesse said that research into this topic is ongoing, and that the team will be using more data collected through the CARE Consortium to develop a model of symptoms that is better able to differentiate a concussed person from a non-concussed person.

The article, “Factors Associated with Symptom Reporting in U.S. Service Academy Cadets and NCAA Student Athletes without Concussion: Findings from the CARE Consortium,” was published Jan. 11 in Sports Medicine. It was authored by Jaclyn Caccese of The Ohio State University; Grant Iverson of Harvard Medical School; Katherine Hunzinger, Kelsey Bryk, Thomas Buckley and Alexander Enrique, all of the University of Delaware; Breton Asken of the University of California; James Clugston of the University of Florida; Kenneth Cameron, Megan Houston, and Steven Svoboda, all of the United States Military Academy; Jonathan Jackson and Gerald McGinty of the United States Air Force Academy; Carlos Esteves of the United States Coast Guard Academy; Adam Susmarski of the United States Naval Academy; Steven Broglio of the University of Michigan; Thomas McAllister of Indiana University; Michael McCrea of the Medical College of Wisconsin; Paul Pasquina of the Walter Reed Medical Center; and CARE Consortium Investigators.