• Concussion is synonymous with mild traumatic brain injury (mTBI).
• Results from direct external forces to and/or acceleration/deceleration of the head.
• Classic symptoms are confusion and amnesia, with or without loss of consciousness.

mTBI Definition (World Health Organization)

1. One or more of:

• confusion or disorientation
• loss of consciousness ≤ 30 minutes
• post-traumatic amnesia ≤ 24 hours
• other abnormalities such as focal signs, seizure, and intracranial lesions not requiring surgery.

2. Glasgow Coma Scale score of 13-15 ≥ thirty minutes post-injury.

3. Not due to:

• drugs, alcohol, or medications
• other injuries or their treatments (e.g. systemic injuries, facial injuries or intubation)
• psychological trauma, communication barrier or coexisting medical conditions
• penetrating injury.

• MRI is generally not indicated

Head CT based on the Canadian CT Head Rule

• High-Risk Injury (may require neurosurgical intervention)
  • GCS score < 15 at 2 hr after injury
  • Suspected open or depressed skull fracture
  • Signs of basal skull fracture (hemotympanum, periorbital bruising (Raccoon eyes), CSF otorrhea or rhinorrhea, retroauricular bruising (Battle’s sign))
  • Vomiting ≥ two episodes
  • Age ≥ 65 years.

• Medium-Risk Injury (may have important brain injury on CT)
  • Amnesia before impact ≥ 30 min
  • Dangerous mechanism (pedestrian struck by vehicle, occupant ejected from vehicle, fall from elevation >3 feet [five stairs]).

• Rule not applicable if:
  • Non-trauma cases
  • GCS < 13
  • Age < 16
  • Coumadin or bleeding disorder.
  • Obvious open skull fracture

• Additionally, others recommend CT if:
  • Neurologic deficits
  • Seizure
  • Bleeding diathesis or oral anticoagulant use
  • Return visit for reassessment of a head injury.

Clinical diagnosis of concussion

Common symptoms of mTBI are diffuse and variable:

• Headache
• Dizziness or balance issues
• Fatigue
• Drowsiness
• Visual changes (ie. diplopia, or blurry vision, photophobia)
• Insomnia or hypersomnia
• Difficulty multitasking, attentional dysfunction, short-term memory and learning problems
• Phonophobia
• Emotional changes.

Common signs of mTBI:

• Loss of consciousness
• Anterograde or retrograde amnesia
• Confusion
• Emotional lability
• Behaviour or personality changes.

• GCS <15
• CT head abnormalities
• Seizures
• Underlying bleeding diathesis or oral anticoagulation
• Neurologic deficit
• Recurrent vomiting.

Acute evaluation of an adult with mild head trauma:

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Adapted from UpToDate: Acute mild traumatic brain injury (concussion) in adults

1. Rosen’s Emergency Medicine: Concepts and Clinical Practice, Chapter 34, 301-329

   
   

2. Youmans & Winn. Neurological Surgery: Mild Traumatic Brain Injury in Adults and Concussion in Sports

   
   

3. UpToDate: Acute mild traumatic brain injury (concussion) in adults

   
   

4. www.parachutecanada.org

   
   

5. Stiell, I. G., Wells, G. A., Vandemheen, K. V., Clement, C., Lesiuk, H., Laupacis, A., … Worthington, J. (2001). The Canadian CT Head Rule for patients with minor head injury. The Lancet, 357(9266), 1391-1396.