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    Concussion – Diagnosis

    Neurological, Trauma

    Last Updated Aug 07, 2019
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    • 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.

    Diagnostic Process

    • 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.

    Criteria For Hospital Admission

    • 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:


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

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