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Concussion

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Concussion, Concussion in Sports, Brain Concussion, Concussion Red Flags

  • Definitions
  1. Concussion
    1. Synonymous with Mild Traumatic Brain Injury (preferred overall term) and Minor Head Injury
    2. Mildest form of Traumatic Brain Injury (see Mild Traumatic Brain Injury) in which GCS is 13-15
    3. Acute Trauma-induced mental function alteration
    4. Transient loss of consciousness variably present (10% overall, 40% of Emergency Department evaluations)
  • Epidemiology
  1. See Mild Traumatic Brain Injury
  2. Incidence: 1 in 220 children annually (30-50% sports related, esp. football and soccer)
  • Pathophysiology
  1. Concussion results in acute Neuron injury (esp. axonal Stretching and shearing)
    1. Leads to extracellular release of ions (esp. Potassium) and excitatory neurotransmitters (esp. glutamate)
  2. Increased energy demands (esp. ATP) to correct ion disruption (e.g. Sodium-Potassium ATP Pump)
    1. Yet decreased blood flow to injured tissue results in energy delivery deficit
  3. Metabolic derangements resolve over the course of weeks (corresponding to symptom improvement)
    1. Symptoms improve or resolve by 72 hours
    2. Recovery may approach 7 weeks (or longer in younger children)
      1. Adults may fully recover by 2 weeks in some studies, but other studies suggest as long as 3 months
      2. Children recover fully by one to three months (70-80%)
      3. In some cases, especially in young children, effects may persist longterm
      4. Kerrigan (2017) Childs Nerv Syst 33(10): 1669-75 [PubMed]
  • Risk Factors
  1. Active duty military deployed to combat regions
    1. Traumatic Brain Injury affected 15% U.S. troups involved in Iraq and Afghanistan
  2. Non-Sports related injury
    1. Falls (38%)
    2. Vehicle-related injuries (31%)
    3. Non-accidental Trauma (11%)
  3. Contact Sports Participation
    1. Football
      1. Most common cause of sports-related Concussion in U.S.
      2. Concussion in 20% of high school and 10% of college athletes each year
    2. Ice Hockey
    3. Soccer
      1. Second most common cause of Concussion in U.S. (especially in female athletes)
    4. Boxing
    5. Lacrosse
    6. Wrestling
    7. Basketball
    8. Softball
  4. Non-Contact Sports Participation
    1. Bicycling
    2. Playground-related injuries
    3. Gymnastics
    4. Skiing
    5. Sledding
    6. Ice Skating
    7. Inline Skating
    8. Horseback riding
  5. Female Gender
    1. Women are at higher risk of Concussions, secondary symptoms, cognitive Impairment and prolonged recovery
    2. Women are more likely to be injured by contact with playing surface or equipment
      1. Contrast with men who are most often injured by player to player contact
    3. Covassin (2011) Clin Sports Med 30(1):125-31 [PubMed]
  • Symptoms
  1. See Concussion Symptom Checklist
  2. Headache (75%, most common)
  3. Blurred vision (75%)
  4. Dizziness (60%)
  5. Nausea or Vomiting (54%)
  6. Double Vision (11%)
  7. Noise sensitivity or light sensitivity (4%)
  8. Slurred speech
  9. Imbalance or Incoordination
    1. Typically lasts 3-5 days after Concussion
  10. Loss of consciousness
    1. Present in 10% of Concussions
  • Signs
  1. Amnesia
  2. Disorientation
  3. Confusion
    1. Vacant stare
    2. Disorientation
    3. Delayed answers to questions
    4. Poor concentration
    5. Inattention
    6. Decreased verbal learning and memory
  1. Mental status changes
    1. Loss if consciousness for more than 60 seconds
    2. Somnolence or confusion
    3. Disorientation
    4. Language or speech deficit
    5. Memory deficit
  2. Eye findings (Brainstem dysfunction)
    1. Visual disturbance
    2. Pupils unequal, fixed or dilated
    3. Extraocular Movements abnormal
  3. Deep Tendon Reflexes (Upper Motor Neuron dysfunction)
    1. Hyperreflexia
    2. Babinski Reflex present
  4. Muscle Strength
    1. See Motor Exam
    2. Decreased muscle tone or weakness (especially asymmetric)
    3. Involuntary movements (consider Basal Ganglia or cerebellar injury)
  5. Sensory deficit
    1. See Sensory Exam
    2. Numbness or abnormal sensation (consider dermatomal pattern for spinal root deficit)
  6. Incoordination or Balance problem (Cerebellar dysfunction)
    1. Rhomberg sign positive
    2. Ataxic gait
    3. Postural instability (e.g. abnormal Balance Error Scoring System)
    4. Finger-to-Nose Test
  • Labs
  1. Serum biomarkers are NOT recommended (beyond research) per pediatric mTBI working group
    1. S100B
    2. Tau Protein
    3. Ubiquitin C-Terminal Hydrolase
    4. Glial Fibrillary Acidic Protein
  • Grading
  • Evaluation
  • Acute clinical
  1. See Head Injury
  2. Systematic evaluation (unless isolated Minor Head Injury)
    1. See Trauma Evaluation (includes Primary Survey)
    2. See Secondary Trauma Evaluation
  3. Neurologic evaluation
    1. See Emergency Neurologic Exam
    2. Glasgow Coma Scale (GCS)
    3. Complete Neurologic Exam
    4. Oculomotor testing
      1. Sensitive for minor Concussion
      2. Observe for Nystagmus, saccades, CN IV palsy, Anisocoria
  4. Assess for significant head and neck injuries
    1. Intracranial Hemorrhage (Epidural Hemorrhage, Subdural Hemorrhage)
    2. Skull Fracture
    3. Scalp Laceration with active bleeding (control bleeding as part of Primary Survey)
    4. Cervical Spine Injury (or Pediatric Cervical Spine Injury)
  • Evaluation
  • Sideline or in sports medicine evaluation
  1. Sport Concussion Assessment Tool ( SCAT5)
    1. Comprehensive - includes all other tests listed below
    2. Age 13 years old and older (SCAT5)
      1. https://bjsm.bmj.com/content/bjsports/early/2017/04/26/bjsports-2017-097506SCAT5.full.pdf
    3. Age 5 to 12 years old (Child-SCAT5)
      1. https://bjsm.bmj.com/content/bjsports/early/2017/04/28/bjsports-2017-097492childscat5.full.pdf
  2. Tools included in Standardized Assessment of Concussion (SCAT5)
    1. Immediate On Field Assessment
      1. Red Flags (e.g. Altered Level of Consciousness, focal neurologic deficits, Seizures, Agitation, Neck Pain)
      2. Observable signs (e.g. Altered Level of Consciousness, neurologic deficits)
      3. Cervical Spine Assessment (pain at rest, active range of motion, extremity motor/sensory)
      4. Glasgow Coma Scale (15 points)
      5. Maddocks Score (5 points)
    2. Other testing in office, hospital or on field
      1. Concussion Symptom Checklist (22 points)
      2. Modified Balance Error Scoring System or MBess (30 points)
      3. Cognitive Screening of orientation, memory, recall, concentration
        1. Similar to Standard Assessment of Concussion
      4. Neuro screen exam (read aloud, cervical Neck Pain, coordination, Diplopia)
  3. Other tools
    1. Computer based Neuropsychological Testing (e.g. ImPACT)
      1. In some sports, baseline testing is performed
      2. Baseline testing is not recommended in young children (high variability)
    2. Postconcussive Symptom Scale
      1. http://www.hawaiiconcussion.com/pdf/post-concussion-symptom-scale.aspx
  • Imaging
  1. Head imaging indications
    1. See Head Injury CT Indications in Adults
    2. See Head Injury CT Indications in Children
    3. CT Head is indicated in all moderate and Severe Head Trauma (GCS <13)
      1. Imaging is NOT indicated in uncomplicated Concussion
      2. CT Head has a higher Test Sensitivity for Intracranial Hemorrhage than MRI Head
      3. Inform parents about CT-associated Radiation Exposure
    4. Other advanced imaging (MRI, SPECT) is not recommended routinely in children (cost, sedation)
    5. Skull XRays are not recommended (low Test Sensitivity: 63%)
  2. C-Spine imaging indications
    1. See Cervical Spine Imaging in Acute Traumatic Injury
    2. See NEXUS Criteria
  • Management
  1. See Head Injury
  2. See Management of Mild Head Injury
  3. See Cervical Spine Injury
  4. See Pediatric Cervical Spine Injury
  5. Precautions
    1. Acute evaluation and management should follow Head Injury protocol
    2. Follow core Trauma tenets
      1. ABC Management
      2. Cervical Spine evaluation and stabilization
      3. Assess for focal neurologic deficits
      4. Consider higher level of care
        1. Sideline to emergency department
        2. Emergency department to Trauma Center
    3. Patient should not return to play until medical clearance
      1. See protocols as below
  • Management
  • Disposition
  1. See Mild Head Injury Home Management
    1. Includes Head Injury Precautions (criteria for immediate follow-up)
  2. See Return to Play after Concussion
    1. Includes graduated (stepped) return to play protocol
  3. See Cognitive Deficit following Concussion
  4. See Postconcussion Syndrome
  5. Follow-up with medical provider
    1. Consider Concussion clinic (sports medicine) follow-up
  • Course
  1. Symptoms may evolve or worsen over the first few days after Concussion
  2. Symptoms may persist for weeks to months
  3. Common Symptoms typically resolve by 1 week in most cases
    1. Headache (most common)
    2. Dizziness
    3. Sleep disturbance (daytime Somnolence, difficulty initiating and maintaining sleep)
  4. Cognitive Symptoms typically resolve by 2-4 weeks in most cases
    1. Impaired attention and memory
    2. Difficult Executive Function (e.g. organization, planning, reasoning)
  5. Prolonged course in a sizeable majority
    1. Anticipate resolution by 3 months (even in prolonged cases)
      1. In rare cases, symptoms persist years
    2. Postconcussion Syndrome (lasting 3 months)
      1. Identified on neurocognitive testing in up to 30% of children at 3 months
      2. Overall, more sensitive testing suggests >38% develop Postconcussion Syndrome
    3. Prolonged recovery is not consistently predicted by any specific factors
      1. Loss of consciousness and amnesia do not consistently predict recovery period
      2. Some factors that are more predictive of prolonged recovery
        1. More severe symptoms at onset (amnesia, Disorientation, mental status changes)
        2. Persistent neurocognitive deficit
        3. Prior Concussion
        4. Fatigue or fogginess
        5. Early onset Headache
  • Complications
  1. Postconcussion Syndrome
  2. Recurrent Head Injury (especially if next Head Injury before recovery from the last)
    1. Second Impact Syndrome
    2. Cumulative neuropsychologic deficits
      1. See Cognitive Deficit following Concussion
    3. Chronic Traumatic encephalopathy
  3. Serious acute and subacute complications
    1. Cerebral edema
    2. Intracranial bleeding (Epidural Hematoma, Subdural Hematoma)
  • Prevention
  1. Mouth guards prevent dental injury but not Concussion
  2. CDC Heads Up Campaign
    1. https://www.cdc.gov/headsup/index.html