Post-concussion Cognitive Rest: How Much Time Is Enough Time?

Naomi J. Brown, MD


February 03, 2014

Editorial Collaboration

Medscape &

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Hi. I am Dr. Naomi Brown, pediatric sports medicine specialist at the Children's Hospital of Philadelphia. Today I would like to talk about a recent publication in the journal Pediatrics.[1] I am the first author of this study looking at cognitive rest and concussion recovery.

We looked at 335 patients presenting to a concussion clinic, ages 8-23 years, who presented within the first 3 weeks following the initial injury. We asked each participant to rate their cognitive activity, ranging from minimal activity to full activity. Minimal activity would have implied that they were out of school and not doing much reading or watching TV. Full activity implies that they were back to school and acting as if they had never had a concussion, and participating in that full amount of activity.

We then looked at cognitive activity days and the time to recovery, and divided participants into quartiles. We found that those participating in the most amount of activity, meaning the highest quartile, took 100 days to recover vs those in the other 3 quartiles, who took 20-50 days to recover.

This study, I believe, has 2 important findings. The first is that those who participated in the most amount of cognitive activity took the longest to recover. This is important because up until now, there has been very little data to actually suggest that cognitive rest is important. While most physicians have been recommending cognitive rest as a mainstay of concussion treatment, we did not have any actual data to support this up until now.

The second most important part of this is that those in the other 3 quartiles took relatively the same amount of time to recover. This would suggest that mild to moderate activity after the initial amount of rest that is recommended is not detrimental to patient recovery and that perhaps cognitive activity at some level may be beneficial.

Cognitive activity is defined as anything that taxes the brain. This would include anything from reading, to doing homework, to watching TV or going to a movie, and it also includes texting, being on the phone, or being on the computer.

It is very important to limit the amount of cognitive activity as a study recommends, but after the initial 3-5 days, during which we recommend as much cognitive rest as possible, we suggest something called a subthreshold activity level. This suggests that if you can participate in 15 minutes of reading or watching 20 minutes of television, and you do not have an increase in your concussion symptoms, then it is okay to do that amount of cognitive activity. Once you try out the amount of cognitive activity that you can do and tolerate, you can then increase it as your subthreshold activity level will allow you to do.

This also implies a physical activity subthreshold level. This means that after the initial cognitive activity is able to be increased without increasing your symptoms, you can try to do some amount of physical activity as directed by your doctor. This implies that you can take a walk around the block or perhaps walk for half a mile or do some light biking or swimming, if it does not increase your concussion activity symptoms.

It is important to emphasize to scholar athletes that minimizing the amount of activity and physical activity that they do early on is very important because not doing so will delay resolution of concussion symptoms and recovery, as the study demonstrates.

A lot of scholar athletes want to go back to school immediately. It is important to emphasize to them that they may be doing themselves more harm than good by trying to get back to a full day of school. We recommend, as the Return to Learn program describes, that they slowly go back to some schoolwork at home, and then increase the amount that they can go to school. For example: going for 1-2 hours, then going for half a day, and finally, if they're able to tolerate it without having increased concussion symptoms, going back to school for a full day.

It is hard for students to withdraw from school when they're trying to return from a concussion, and we do not want students to become depressed. We know that if we tell a student that they cannot text or talk to their friends at all, that they will be very angry and perhaps will rebel and try to do more than they should in terms of recovery from concussion. We want them to have some activity with their friends but not enough activity that it's causing more harm to them in terms of increased concussion symptoms.

We know that it is difficult for physicians to give guidelines to families and patients as to how long it will take them to recover. Future research is needed in the area of risk factors for those who may be at increased risk for prolonged concussion, as well as what level of cognitive activity is recommended.

We know, based on this research, that full cognitive rest is beneficial for the first few days. At some point, some activity level is helpful as long as it is not full cognitive activity. What that level is, future research needs to help us with. Thank you for your time.