A Primer on Concussions

As physical therapists and physical therapy students, we are well equipped to evaluate and address many of the deficits that occur as a result of a concussion. Plus, our profession is also in a good position to educate the public about safety in athletics. Whether or not you feel like you know enough about concussions, the signs and symptoms and treatment strategies are concepts that are a part of our physical therapy education. Here are some basics about concussions, including links to some very comprehensive resources. While we want this post to serve as good refresher or a quick reference, I highly recommend reading some or all of these resources.

A concussion, as defined at the 4th International Conference on Concussion in Sport in 2012, “is a brain injury and is defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces.”

The effects that occur as the result of a concussion are due to functional disturbance of the brain without actual structural injury. After a concussive trauma, metabolic changes occur in the intra- and extra-cellular environment, which causes an inability to meet the metabolic demands in the brain. Since structural damage does not usually occur, neuroimaging of the brain should appear normal after a concussion and is not typically indicated.

The effects of a concussion can resolve in as little as 7-10 days, with 80% of those who suffer seeing resolution of symptoms in 3 weeks or less. Children and adolescents can take longer to recover and require a more conservative approach than adults. Additionally, athletes who have previously experienced a concussion, especially in the same season, require a more conservative return to play approach and may require a longer time to recover.

Symptoms

Symptoms vary, with no single symptom occurring in all individuals following a concussion. There are many questionnaires that can be utilized for assessment of symptoms in individuals who have experienced a concussion, including the Rivermead Post-Concussion Symptoms Questionnaire, the Post-Concussion Symptom Scale, and the Neurobehavioral Symptom Inventory (military specific). Common symptoms are typically divided into four categories:

·    Somatic: headache, dizziness, light and sound sensitivity

·    Cognitive: difficulty concentrating or paying attention, fogginess

·   Emotional: anxiety, sadness, irritability

·   Sleep: hypersomnia, insomnia

Neurocognitive Testing

If an individual is suspected of, or has been diagnosed with a concussion, neurocognitive (or neuropsychological) testing is useful in helping to confirm the diagnosis and track progress throughout the rehabilitation process. Whenever possible, athletes should undergo baseline neurocognitive testing prior to the beginning of the season so that results can be compared the individual’s baseline. The 4th International Conference on Concussion in Sport recommended the use of the Sports Concussion Recognition Tool Version 3 (SCAT3) and the Standardized Assessment of Concussion (SAC).  For children and adolescents under the age of 13 years old, the Child Scat3 should be used instead. The computerized test, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), is commonly utilized in team settings for preseason baseline testing and post-concussion evaluation. With any baseline testing, clinicians should be aware of athletes purposely underperforming to establish a lower baseline.

Evaluation, Treatment, and Return to Play

Physical therapists evaluating and treating patients who have sustained a concussion should always screen for cervical, vestibular, and oculomotor involvement. The clinical summary on concussions on PTNow provides extensive tests and measures utilized to screen for and identify these problems.

When working towards returning a patient to normal activities, a graded progression should be applied for both physical and cognitive exertion.

  Photo  by  John Martinez Pavliga  is licensed under  CC BY 2.0

·  Stage 1: No activity and complete rest

·  Stage 2: Light aerobic activity

·   Stage 3: Sport-specific exercise

· Stage 4: Noncontact training drills

· Stage 5: Full contact practice

· Stage 6: Return to play

Progression to the next stage can occur after the individual has been asymptomatic for 24 hours. He or she should go back to the previous asymptomatic stage for another 24 hours if symptoms are experienced during any stage.  A similar step-wise progression should be used for return to school activities for student athletes.

As concussions and their effects are now being heavily researched, protocols could easily change with new information. So, I also encourage everyone to stay up to date on any new research that comes out related to concussions. One such study by Zemek et al. was published in the March 2016 issue of JAMA, which developed a risk prediction score for Persistent Postconcussion Symptoms (PPCS) in children who presented to the emergency department with concussion. The risk score was found to be able to stratify risk of PPCS at 28 days post injury, but it is not yet clinically applicable.

This primer on concussions is far from comprehensive, but I hope it can serve as a quick reference tool. Again, I encourage everyone to check out the valuable resources referenced if you would like to learn more about concussions and stay up to date on new evidence that continues to come out.

References

  1. Khurana VG, Kaye AH. An overview of concussion in sport. J Clin Neurosci. 2012;19(1):1-11.
  2. King NS, Crawford S, Wenden FJ, Moss NE, Wade DT. The Rivermead Post Concussion Symptoms Questionnaire: a measure of symptoms commonly experienced after head injury and its reliability. J Neurol. 1995;242(9):587-92.
  3. Mccrory P, Meeuwisse WH, Aubry M, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. Br J Sports Med. 2013;47(5):250-8.
  4. Mucha A, Troutman-Enseki C. Concussion Clinical Summary. January 30, 2015. PTNow.org.
  5. Reddy CC, Collins MW. Sports concussion: management and predictors of outcome. Curr Sports Med Rep. 2009;8(1):10-5.
  6. Zemek R, Barrowman N, Freedman SB, et al. Clinical Risk Score for Persistent Postconcussion Symptoms Among Children With Acute Concussion in the ED. JAMA. 2016;315(10):1014-25.