What causes prolonged symptoms following concussion? Concussion 102

What causes prolonged symptoms following concussion? Concussion 102


Most patients with concussion recover rapidly. The average time to recovery is 7-10 days among adult patients.1 Recovery among children with concussion might take longer than recovery among adults. But some patients, both children and adults, continue to report symptoms months – even years – after the injury that caused a concussion. Why is that?

This post will explore some of the things that seemed to predict longer recovery among a large group of young patients with concussions related to sports.2


Postconcussion syndrome refers to prolonged symptoms following concussion. Unfortunately, the term is not well-defined. There is no clear agreement about how long symptoms must last or how many symptoms must be present to qualify as postconcussion syndrome.3 Many experts consider symptoms beyond 30 days to be prolonged.


In a study that evaluated information from 1,755 young people (aged 10-19 years) with sport concussions who saw their doctors until all symptoms improved.2 There were several things that seemed to predict longer symptoms:

  • Female sex
  • Individuals who continued participating in their sport or activity immediately after the injury
  • Patients with loss of consciousness (although this was not found in other studies)
  • Patients with amnesia (lack of memory) following the injury
  • Patients who reported having headaches before they had their concussion injury
  • Emotional symptoms (sadness, feeling emotional, nervousness, or irritability) on the day of injury or the day of the first clinic visit
  • Patients who reported confusion, dizziness, drowsiness, or fatigue on the day of the first clinic visit
  • Patients who reported worsening symptoms from the day of the injury to the day of first clinic evaluation
  • Lastly, patients who reported more symptoms tended to have longer recovery.

Each of the categories above was a risk factor for prolonged symptoms following concussion. This means that patients who fit in one or more of these categories were more likely to have prolonged symptoms than those who did not fit in any of the categories. For example, not all females had longer symptoms than all males, but being female increased the risk that symptoms were prolonged. Many of the patients with longer symptoms fit several categories.

Where does this leave us? The study described above gives us some information about the risk factors for prolonged concussion symptoms in young patients. Eventually, we might be able to predict which patients will develop prolonged concussion symptoms based solely on their risk factors at the time of their injury. But that is not possible yet. More research is needed.

A concussion requires evaluation by a trained healthcare provider. If you have experienced a concussion, it is important that you see a healthcare provider. If you continue to have symptoms 30 days after the injury, you might need to see a specialist.


  1. 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;47:250-258.
  2. Heyer GL, Schaffer CE, Rose SC, Young JA, McNally KA, Fischer AN. Specific Factors Influence Postconcussion Symptom Duration among Youth Referred to a Sports Concussion Clinic. J Pediatr. 2016;174:33-38.
  3. Rose SC, Fischer AN, Heyer GL. How long is too long? The lack of consensus regarding the post-concussion syndrome diagnosis. Brain Inj. 2015;29:798-803.