Updated April 16, 2015.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Did you know that after a concussion, symptoms in kids can change over time? At first, a child who's suffered a concussion (also called mTBI, or mild traumatic brain injury) often has physical symptoms, such as headaches, fatigue, and dizziness. But emotional symptoms (for example, irritability and  frustration) may not occur until later. Throughout the recovery period, the child may experience cognitive symptoms, such as forgetfulness and poor concentration.

To find out more about concussion symptoms in kids and teens, a 2014 research study examined how long symptoms last, and how they change during the course of recovery. It looked at patients who came into a pediatric hospital emergency department following an mTBI, and followed them for three months. All of the patients were 11 to 22 years old, and none had broken bones, bleeding in the brain, or pre-existing cognitive or developmental delays. Some of the findings about symptoms:

• Most common at first: When patients first came to the hospital, their most common symptoms were headache, fatigue, dizziness, and taking longer to think.
• Developed later: Sleep disturbance, frustration, forgetfulness, and fatigue were most likely to appear during the follow-up period (without being present at the initial time of injury).
• Persisted longest: Kids continued to complain of irritability, sleep disturbance, frustration, and poor concentration well after their injury.
• Eased fastest: Nausea, depression, dizziness, and double vision were the symptoms that disappeared the most quickly.

• By the numbers: The study reported that "one month after injury, nearly one-quarter of children still complained of headache, 20% suffered from fatigue, and nearly 20% reported taking longer to
  think."

The Recovery Process

For many kids, one of the toughest parts of the recovery process is cognitive rest (no homework, reading, or screen time). This helps the brain heal, but not every patient follows through with the recommendation. In this study, a little more than half of patients reported "at least moderately limiting cognitive activity." The remainder rested only minimally or not at all. Patients were more likely to follow through with restrictions on physical activity.

Happily, concussion symptoms dissipated quickly, within two weeks, for most kids in this study (even though they may have been more severely injured than other concussion patients, since they were referred to the emergency department).

What Parents Should Know

You need to rely on your child to report his own concussion symptoms, since most cannot be measured with an objective test. So it's important to be very familiar with the symptoms your child might develop. It also can be reassuring for him to know what is common. The authors of this study specifically point to:

• Sleep disturbance: "Children who have a concussion should be warned about the possibility
  of developing fatigue and sleep issues, and these symptoms should be specifically assessed during follow-up evaluation." About 20% of kids in the study developed sleep disturbance after their initial visit to the emergency department.
• Emotional symptoms: "The emotional symptoms of concussion (frustration, depression, irritability, and restlessness) were not commonly reported on presentation, but did develop
  in large numbers of patients during follow-up and were among the symptoms that lasted the longest."

 
<sub>Source:

Eisenberg MA, Meehan WP, and Mannix R. Duration and course of post-concussive symptoms. Pediatrics Vol 133, No 6, June 2014.</sub>