Date: May 21st, 2021

Guest Skeptic: Dr. Lauren Westafer an Assistant Professor in the Department of Emergency Medicine at the University of Massachusetts Medical School – Baystate. She is the cofounder of FOAMcast and a pulmonary embolism and implementation science researcher. Dr. Westafer serves as the Social Media Editor and a research methodology editor for Annals of Emergency Medicine and an Associate Editor for the NEJM Journal Watch Emergency Medicine.

Reference: Varner et al. A randomized trial comparing prescribed light exercise to standard management for emergency department patients with acute mild traumatic brain injury. AEM May 2021

Case: A 32-year-old female presents with headache after a low-speed motor vehicle collision as a restrained driver. She was ambulatory on scene. The patient is not anticoagulated, has no midline neck pain, and no evidence of other injuries. She is generally well appearing without any deficients on neurological examination, given her minor mechanism, and normal examination no imaging or further testing is required. You tell her you believe she has a concussion.

Background: Concussions or mild traumatic brain injury (mTBI) are commonly diagnosed in the Emergency Department (ED). Most patients recover within the first week; however, 15-30% of patients develop persistent post-concussive symptoms.

Historically, cognitive and physical rest have been recommended following the diagnosis of mTBI and patients have been advised to resume exercise only once symptoms have abated. Recent studies have challenged this dogma of “rest is best” with one multicenter study finding that early return to physical activity within a week of injury was associated with an improvement in time to symptom reduction.

One of the issues that comes up with minor head injuries is do we need to get advanced imaging. We looked at the Canadian CT Head Rule (CCHR) published by Dr. Ian Stiell in the Lancet 2001 on SGEM#106. You can find this clinical decision instrument on MDCalc.

The SGEM has also covered the issue of getting CT scans in pediatric patients with minor head injuries. That used the PECARN data which has a protocol for children less than two years of age and those older than two years of age.

That SGEM#112 episode on pediatric concussions was covering a study that asked if there is a benefit to recommending strict rest after a child has a concussion. The bottom line from that episode was that in children with concussion, two days of rest followed by a gradual return to activity is preferred over five days of rest followed by a gradual return to activity. The longer strict rest period appears to cause more post-concussive symptoms.

We have also looked at the diagnostic accuracy if the CCHR in patients 65 years of age or older in predicting clinically important brain injuries (SGEM#266). The published study opened the door for reducing the number of unnecessary head CTs in this cohort of patients, but further high-quality prospective studies are required prior to clinical application.

There is limited information on the best strategy for preventing post-concussion syndrome (PCS).


Clinical Question: Are patients presenting to the ED with mild concussion who are prescribed light exercise less likely to develop post-concussive syndrome at 30 days compared with those given standard discharge instructions?


Reference: Varner et al. A randomized trial comparing prescribed light exercise to standard management for emergency department patients with acute mild traumatic brain injury. AEM May 2021

  • Population: Adults 18-64 years old presenting to the ED with a mild TBI. This was defined as a direct blow to body with force transmitted to the head resulting in somatic, cognitive, emotional, or behavioral or sleep symptoms within the prior 48 hours.
    • Exclusions: Patients with acute intracranial injury, multisystem injuries preventing light exercise, GCS <15 at time of discharge, intoxication at time of discharge, or inability for telephone follow up
  • Intervention: Standardized discharge instructions that included 48 hours of rest and then gradual return to usual activity with a prescription for 30 minutes of light exercise daily (ex walking)
  • Comparison: 48 hours of rest and then gradual return to usual activity but instructed not to exercise until symptoms had resolved or advised to do so by a medical provider
  • Outcomes:
    • Primary Outcome: Proportion of patients with post-concussive syndrome at 30 days, defined as the presence of three or more symptoms on the Rivermead Post-concussion Symptoms Questionnaire (RPQ) at 30 days
    • Secondary Outcomes: Change in RPQ from baseline to 7, 14, and 30 days after the initial ED visit; number of missed days of school or work; and repeat visits to a health care provider.

Dr. Catherine Varner

This is an SGEMHOP episode which means we have the lead author on the show. Dr. Catherine Varner is an emergency physician and clinician scientist at the Schwartz / Reisman Emergency Medicine Institute at Mount Sinai Hospital in Toronto and Assistant Professor in the Faculty of Medicine at the University of Toronto. Her research areas are in both concussion and obstetrical emergencies.

This trial used the Rivermead Post-concussion Symptom Questionnaire (RPQ). It is a self-report scale to measure the severity of post-concussive symptoms following a mild traumatic brain injury. It asks participants to compare their symptoms at the time of assessment to before the injury on a scale of 0 to 4, where 0 means the symptom is not experienced at all, 1 is no more of a problem and 4 is a severe problem. The questionnaire asks about 16 defined symptoms and 2 undefined symptoms, and has been used in the emergency department setting and over the telephone.

Authors’ Conclusions: In this trial of prescribed early light exercise for acute mTBI, there were no differences in recovery or health care utilization outcomes. Results suggest that early light exercise may be encouraged as tolerated at ED discharge following mTBI, but this guidance is not sufficient to prevent PCS.

Quality Checklist for Randomized Clinical Trials:

  1. The study population included or focused on those in the emergency department. Yes
  2. The patients were adequately randomized. Yes
  3. The randomization process was concealed. Yes
  4. The patients were analyzed in the groups to which they were randomized. Yes
  5. The study patients were recruited consecutively (i.e. no selection bias). No
  6. The patients in both groups were similar with respect to prognostic factors. Yes
  7. All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No
  8. All groups were treated equally except for the intervention. Unsure
  9. Follow-up was complete (i.e. at least 80% for both groups). No
  10. All patient-important outcomes were considered. Yes
  11. The treatment effect was large enough and precise enough to be clinically significant. No

Results: They enrolled 367 patients with a median age of 32 years 57% were female. The most common mechanism of injury was a fall (32%) followed by bike/motor vehicle (28%). One-third of included patients had a history of anxiety and more than one-quarter had a history of depression. A third of patients had a history of a previous concussion.


Key Result: No statistical difference between the light exercise group and the comparison group.


  •  Primary Outcome: Proportion of patients with PCS at 30 days
    • 13.4% in the control group vs 14.6% in the intervention group
    • Absolute difference of 1.2% (95% CI; −6.2 to 8.5).
  • Secondary Outcomes: 
    • The median change of RPQ scores, number of return visits to a healthcare provider, number of missed days of work or school were not different between groups.
    • There were more unplanned return ED visits within 30 days in the control group (9.9%) compared with the intervention group (5.6%); however, this difference was not statistical significance.

We asked Dr. Varner five questions to better understand her research publication. Listen to the SGEM podcast to hear her responses.

1. Lack of Blinding – Both the physician and the patient knew the group allocation. Did they know the hypothesis of the study? It would have been good to get some baseline data on what the physicians and patients thought was best (rest or early light exercise) to try and control for any pre-conceived notions that could have influenced the results.

2. Adherence to the Assigned Groups – Participants in the control group reported 30 minutes of light exercise at 7 days and those in the light exercise group reported 35 minutes – a similar relationship was found at all measured time points. This suggests that adherence in the intervention group (where 30 minutes of exercise 5x/week was advised after the first 48 hours) was quite low. It’s doubtful that a difference of 5 minutes of exercise over the course of a week (or 30 days) would have a measurable impact. Thus, we wouldn’t expect a difference between groups if there was no difference in light exercise between groups.

3. Potential Biases – Participants self-reported how frequently and for how many minutes they exercised on surveys at 7, 14, and 30 days. This could have introduced some reporting bias. Without  diary entries or other near real-time entries, it’s difficult to tell whether participants were reporting accurately or over-or-under reported.

Speaking of bias, nearly 20% of potentially eligible patients were missed. This could have introduced some selection bias. Without having information on those who were ‘missed’ for inclusion in this trial, it’s impossible to know if these patients were somehow different than those who were ultimately enrolled in the trial.

4. Cohort – The patients included in this trial had a 2 to 3 times higher history of mood or anxiety disorder than reported in the adult Canadian population. Do you think this could have impacted your results and limited the external validity to other populations?

5. Loss to Follow Up – Nearly 30% of patients who were randomized in this trial did not have 30-day follow up. One concern with a significant amount of loss to follow up is that there may be a difference in the characteristics or outcomes of those who followed up and those who did not. For example, did a patient not follow-up because they were still symptomatic and didn’t feel well or, alternatively, perhaps those that had no symptoms were less likely to follow up.

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We think the loss to follow-up and the lack of difference between the two groups for minutes of daily exercise prevent us from making any strong conclusions.


SGEM Bottom Line: After a couple days rest it is reasonable to suggest patients with minor traumatic brain injury start light-physical exercise if they are feeling well enough.


Case Resolution: She is sent home with discharge instructions that allow for light physical exercise (30 minutes of daily walking) after a 48-hour period of rest.

Dr. Lauren Westafer

Clinical Application: When has strict bed rest been good for anything? Once people are feeling better it is reasonable for them to start some light activity. While this study does not provide robust evidence for light-physical activity we do not have good evidence that strict rest provides a patient-oriented benefit. Given the lack of compelling information to guide our care in either direction it reasonable to allow patients to start light activities a couple of days after their mTBI.

What Do I Tell My Patient?  It appears that you have a concussion. While you recover, it is very important to prevent another head injury, which means avoiding things like contact sports. Most people get better within a few days, but some people do have persistent symptoms. While we recommend you take it easy over the next couple of days, if you are feeling better after that point, you can begin re-introducing some very light exercise like walking. If you are getting worse or are worried, please return to the ED for reassessment.

Keener Kontest: Last weeks’ winner was Dr. Ryker Kiel from Douglas, Wyoming. He knew Godfrey Housfield is the person that invented the first CT scanner.

Listen to the podcast this week to hear the trivia question. Email your answer to TheSGEM@gmail.com with “keener” in the subject line. The first correct answer will receive a cool skeptical prize.

SGEMHOP: Now it is your turn SGEMers. What do you think of this episode on activity after mTBI? Tweet your comments using #SGEMHOP.  What questions do you have for Catherine and her team? Ask them on the SGEM blog. The best social media feedback will be published in AEM.

Also, don’t forget those of you who are subscribers to Academic Emergency Medicine can head over to the AEM home page to get CME credit for this podcast and article.

Even those who are not subscribers can earn CME credit for this SGEM episode. Click on the link on the SGEM blog to support this #FOAMed project. The content is always free but there is a small fee for the CME


Remember to be skeptical of anything you learn, even if you heard it on the Skeptics Guide to Emergency Medicine.