Concussions

Concussion is a clinical syndrome of head injury plus altered memory or mental status, and normal imaging does not rule it in or out. Most athletes recover quickly, but emergency care hinges on accurate diagnosis, smart CT use, and discharge guidance that sets expectations for return to learn and return to play.

Concussion Diagnosis and Early Decisions

• Clinical diagnosis framework: Concussion requires a head injury plus an alteration in memory or mental status; amnesia, delayed verbal response, discoordination, and emotional lability are classic bedside clues.
• Sideline removal rule: If concussion is suspected during play, immediate removal is the standard because same-day diagnosis can be uncertain and symptoms may evolve after the hit, a distinction we get into in the episode.
• Imaging limitation principle: CT cannot diagnose concussion because the process is neurochemical rather than structural; imaging is reserved to exclude hemorrhage or other pathology using decision tools or gestalt.
• Repeat visit reassessment: Persistent post-concussive symptoms after ED discharge do not by themselves mandate imaging; reassess for alternative diagnoses and apply head CT decision support again.

Recovery, Follow-Up, and Return to Play

• Expected recovery timeline: Reassurance matters: about 80% of athletes recover within 7 to 10 days, and roughly 90% have fully recovered by 1 month.
• Cognitive rest nuance: Strict brain rest is not evidence-based; if reading, schoolwork, texting, or screen time does not worsen symptoms, continued cognitive activity is reasonable.
• Stepwise return progression: Return to play follows a staged progression from rest to light aerobic activity to sport-specific contact, with symptom freedom required before advancing. We lay out the practical sequence in the chapter.
• Neuropsych testing limits: Neuropsych testing can support management, but performance is influenced by sleep, hydration, and effort, and it does not predict recovery length or determine who needs neuroimaging.
• Long-term risk framing: Repeated head trauma is linked to higher risk of chronic neurocognitive disease, but the relationship is nonlinear and likely shaped by multiple factors, including biology.

References:

1. Cunningham J, et al. Concussive symptoms in emergency department patients diagnosed with minor head injury. J Emerg Med. 2011 Mar;40(3):262-6. PMID: 19157755
2. McCrory P, et al. Summary and agreement statement of the 2nd International Conference on Concussion in Sport, Prague 2004. Br J Sports Med. 2005 Apr;39(4):196-204. PMID: 15793085.
3. Brown NJ, et al. Effect of cognitive activity level on duration of post-concussion symptoms. Pediatrics.  2014 Feb;133(2):e299-304. Epub 2014 Jan 6. PMID: 24394679
4. Thomas DG, et al. Benefits of strict rest after acute concussion: a randomized controlled trial. Pediatrics. 2015 Feb;135(2):213-23. Epub 2015 Jan 5. PMID: 25560444.
5. Grool AM, et al; Pediatric Emergency Research Canada (PERC) Concussion Team. Association Between Early Participation in Physical Activity Following Acute Concussion and Persistent Postconcussive Symptoms in Children and Adolescents. JAMA. 2016 Dec 20;316(23):2504-2514. PMID: 27997652.
6. Lehman EJ, et al. Neurodegenerative causes of death among retired National Football League players. Neurology. 2012 Nov 6;79(19):1970-4. Epub 2012 Sep 5. PMID: 22955124.