Concussion Part I

By Sports Medicine & Performance Center staff
Posted: August 16, 2016 - 7:24 PM



Just the Facts
A concussion is a mild traumatic brain injury that can cause a wide variety of symptoms such as headache, dizziness, light/sound sensitivity, feeling “in a fog,” memory difficulty or nausea and vomiting. Less than 10 percent of concussions actually involve loss of consciousness. Concussion is caused by an impact to the head from the front, back, or the side, with or without rotation, or even by whiplash without an impact at all. Some concussions resolve quickly while others, which on first impression may seem mild, can take weeks to resolve. If symptoms remain, an athlete is up to four times more likely to have a second concussion. This can result in a catastrophic event called second impact syndrome that can result in brain swelling and death. This is a rare, avoidable situation. Because of second impact syndrome and other chronic problems associated with recurrent head injury, more caution is being used before sending athletes back to sport.

Chronic problems that can occur with recurrent head injury and concussions

  • Chronic memory problems and attention difficulty
  • Chronic headaches
  • Depression and behavioral changes
  • Dementia pugilistica (boxer’s dementia)
  • Parkinson’s-like changes
  • Balance and agility problems
  • Is it OK to play through the pain?

For certain sports injuries, playing with some pain might be acceptable. A concussion is not one of them! For instance, your trainer may allow you to play with some pain while recovering from an ankle sprain. Playing on an ankle sprain can result in a delay of improvement or not playing at 100 percent on the field. Playing with an unresolved concussion can cause a second concussion that can result in long-term consequences impacting not only an athlete’s sports potential but his or her life.

How a doctor evaluates a concussion and determines return to play After injury, athletes should be evaluated by a doctor specializing in concussion management. The doctor will determine the extent of injury with a detailed history, thorough physical and several tests with the goal to get an athlete back on the field as quickly and safely as possible.

Tests used to help diagnose and monitor concussion improvement

  • Neurologic testing
  • Balance/vestibular testing
  • Vision testing
  • Memory testing
  • Symptom scoring
  • Sleep questionnaire
  • ImPACT computer testing
  • SCAT II testing
  • Neuropsychology testing

Notice that special imaging is not part of routine concussion evaluation. X-rays, CTs (consider in the first 24 hours after impact in an athlete that has deteriorating or worsening symptoms) and MRIs (consider in the athlete with chronic problems or unresolving problems lasting more than a month) can help in certain circumstances, but typically do not assist the doctor in making recommendations for typical concussions.

The science of why rest is important
Research continues to expand our knowledge of concussion management and what happens to the brain afterwards. After an impact, the neurons go through a cascade of changes. Potassium rushes out of the cell as calcium rushes in. The surrounding neurons become hypersensitive over the next several days and symptoms may increase. While the brain attempts to correct these imbalances, there is a period of hypermetabolism (overworking). This is likely what causes the brain to enter a state of vulnerability, risking more devastating injury if a second impact occurs.

These changes are now being studied with functional MRI that can help researchers and doctors learn more by “seeing” changes. In the future, functional MRI may be used more during patient care, rather than just research. Because the adolescent brain is not yet mature, it is believed a longer time is necessary for adolsescents’ neurons to recover than those in most adults who suffer a concussion. Mental rest is recommended along with physical rest to enable the most complete recovery possible. Long-term changes in memory, concentration and personality could result from the neurons not having enough time to recover. Ongoing research may lead to future diagnostic tests that can improve current concussion management and make recommendations even better.

Once the symptoms are gone
In the “old days,” athletes might have returned to play the same day as their initial concussion. Today’s recommendations (including Kansas state law) require a doctor specialized in concussion management to evaluate the athlete within 24 hours of the incident. Athletes must be evaluated before returning to sport.  Once all symptoms have resolved, and testing suggests improvement, the athlete can begin a graduated return to sport. This could be as soon as 24 hours or as long as a month or more depending on each individual athlete’s story, exam, and testing results. This return to sport is typically a five-step process starting with minimal aerobic activity and increasing to full contact practice with the goal of competition so long as symptoms do not return. It is helpful to have an athletic trainer involved to help monitor progress. Concussion is a big deal in all levels of sports. Sports organizations such as the NFL, along with dozens of government and medical agencies, are teaching schools, teams and athletes that concussion must be taken seriously. While the first concussion cannot always be prevented, a second injury should never be allowed to occur while still recovering from the first.

For more sports medicine articles and information on the Sports Medicine & Performance Center at the University of Kansas Hospital, go to sportsmedicine.kumed.com or follow @KUSportsMed1 on twitter.

 

 


 

The University of Kansas Hospital Sports Medicine Archive