Neuro

Head Injury

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Head Injury, Head Trauma, Closed Head Injury, Craniocerebral Trauma, Traumatic Brain Injury

  • Epidemiology
  1. Incidence: 1.7 Million Traumatic brain injuries in U.S. per year
    1. Minor Head Injury in 75% of cases
    2. Hospitalizations: 275,000
    3. Deaths: 52,000
  • Pathophysiology
  1. Intracranial Pressure (ICP) association with injury
    1. Note measurements are in mmHg, not cmH2O
    2. Normal: 10 mmHg ICP
    3. Abnormal: 20 mmHg ICP
    4. Severe: 40 mmHg ICP
    5. Herniation: 50 mmHg ICP
  2. Cushing's Response
    1. Hypertensive response in face of increased ICP
    2. Helps maintain cerebral perfusion
    3. Do not use Antihypertensives to lower Blood Pressure
      1. Results in decreased brain perfusion
      2. Exception: Intracranial Bleeding (e.g. aneurysmal bleeding)
  • Precautions
  • Cardiopulmonary status in Head Injury
  1. Target PaO2: 200-300 mmHg
    1. PaO2 <200 mmHg and PaO2 >300 mmHg are both associated with higher mortality
    2. Option 1: Wean FIO2 to 50%, but still maintain O2Sat at 99-100% or
    3. Option 2:
      1. Wean oxygen to point that O2Sat starts to drop below 99-100% and
      2. Then increase the delivered oxygen by 2-4 L/min above that level
  2. Avoid Hyperventilation following intubation
    1. Hyperventilation is associated with worse outcomes in Traumatic Brain Injury
    2. Monitor End-Tidal CO2 or capnometer following intubation
    3. Maintain pCO2 at 35-40 mmHg (avoid pCO2 <25 mmHg)
    4. Maintain Respiratory Rate at 10-12 breaths per minute
  3. Avoid Hypotension
    1. Maintain systolic Blood Pressure >=100-110 mmHg (ATLS-10)
  4. References
    1. Majoewsky (2012) EM:RAP 12(5): 1-2
    2. Davis (2009) J Neurotrauma 26(12): 2217-23 [PubMed]
  • History
  1. See Concussion
  2. Medical History
    1. See AMPLE History
    2. Medications (e.g. Anticoagulants, antiplatelet agents, antiepileptics)
    3. Intoxicants (Alcohol, drugs)
    4. Pregnancy
  3. Time and mechanism of injury
    1. High severity accident (e.g. death at scene, high speed accident, unrestrained, ejection)
  4. Loss of Consciousness
    1. How long?
    2. Contiguous with initial injury?
    3. Events preceding impaired consciousness and Trauma (e.g. Syncope, Thunderclap Headache)
  5. Level of Consciousness (AVPU)
    1. Immediately post injury
    2. Subsequent evaluations
  6. Amnesia (Retrograde or antegrade)
  7. Headache
  8. Seizures
  9. Symptoms of Increased Intracranial Pressure
    1. Blurred Vision
    2. Severe Headache with Nausea, Vomiting
  • Evaluation
  • General
  1. Systematic evaluation (unless isolated Minor Head Injury)
    1. See Trauma Evaluation (includes Primary Survey)
    2. See Secondary Trauma Evaluation
  2. Glasgow Coma Scale (GCS)
    1. First GCS at the initial emergency Trauma Evaluation is the best indicator of outcome at one year
    2. Goal in Trauma is to optimize care and allow the best chance for recovery to the initial GCS
  3. Pupil exam
  4. Neurologic Exam (baseline and with neurologic change during evaluation)
    1. See Coma Exam
    2. Eye Neurologic Exam
    3. Motor Exam
    4. Sensory Exam
    5. Reflex Exam
    6. Coordination Exam
  5. Vital Signs
    1. Hypertension is typical response (see Cushing's Response above)
    2. Hypotension seen in pediatric Closed Head Injury
      1. Patrick (2002) Am J Surg 184:555-60 [PubMed]
    3. Cushing Triad (Increased Intracranial Pressure)
      1. Wide Pulse Pressure
      2. Bradycardia
      3. Irregular breathing pattern
  6. Signs Skull Fracture
    1. See Skull Fracture
    2. Vault Skull Fracture
    3. Basilar Skull Fracture
      1. CSF Rhinorrhea or Otorrhea
      2. Hemotympanum
      3. Post-auricular Bruising (Battle's Sign)
      4. Orbital Bruising (Raccoon's Eyes)
      5. CN VII palsy (Bell's Palsy)
  7. Signs impending Cerebral Herniation
    1. Declining Level of Consciousness or progressive neurologic deficits
    2. Pupil Dilation and loss of Pupillary Light Reflex (unilateral or bilateral)
    3. Decorticate Posturing (arms flexed, legs extended)
    4. Decerebrate Posturing (arms and legs extended)
    5. Cushing Triad (wide Pulse Pressure, Bradycardia, irregular breathing)
  8. Signs Intracranial Injury
    1. Focal
      1. Epidural Hemorrhage
      2. Subdural Hemorrhage
      3. Intracerebral Hemorrhage
    2. Diffuse
      1. Mild Concussion
      2. Classic Concussion
      3. Diffuse Axonal Injury
  9. Scalp Lacerations with Hemorrhage
    1. Risk of significant blood loss to the point of Hemorrhagic Shock (especially children)
    2. Apply direct pressure to prevent further bleeding
    3. Close bleeding scalp lesions quickly (even temporarily) with Sutures, staples or Raney Clips
    4. Carefully investigate Laceration for associated complications prior to final closure
      1. Skull Fracture (deformity, bony fragments, CSF Leakage)
      2. Subgaleal Hemorrhage may appear similar to Skull Fracture with deformity at the floor of the Laceration
  • Evaluation
  • Age under 2 years
  1. See Head Injury CT Indications in Children
  2. Red Flags suggestive of serious injury
    1. Skull Fracture
    2. Scalp swelling (80-100% of Skull Fracture)
    3. Younger the age, the greater the risk
    4. Non-accidental Trauma (Child Abuse)
    5. No clear history of Trauma
  3. Symptoms that do not predict serious Head Injury
    1. Loss of consciousness
    2. Vomiting
  4. References
    1. Dachs (2012) AAFP Board Review Express, San Jose
  • Imaging
  • Head and Neck
  1. CT Head
    1. Obtain in all cases of moderate or Severe Head Injury
  2. C-Spine imaging indications
    1. Brain injury is associated with Spinal Injury in 5% of cases
    2. See Cervical Spine Imaging in Acute Traumatic Injury
    3. See NEXUS Criteria
  3. Mild Head Injury Imaging Indications
    1. See Head Injury CT Indications in Adults
    2. See Head Injury CT Indications in Children
      1. Consider Head MRI in children in place of Head CT (due to radiation risk)
  1. See Anticoagulant Reversal
  2. Approach based on evidence below
    1. Consider imaging all patients on Anticoagulants regardless of Head Injury severity
    2. Consider repeat CT Head imaging at 24 hours for patients on Warfarin regardless of signs or symptoms
    3. Consider 24 hour observation and repeat CT Head for elderly patients or those with INR >3
    4. Newman in Herbert (2014) EM:Rap 14(1): 6
  3. Even Minor Head Injury on oral Anticoagulants is associated with significant bleeding risk (often without red flags)
    1. Clopidogrel was associated with an initial 12% CNS HemorrhageIncidence, but no delayed bleeding
    2. Warfarin was associated with an initial 6% CNS HemorrhageIncidence with 0.6% having delayed bleeding
    3. Nishijima (2012) Ann Emerg Med 59(6): 460-8 [PubMed]
  4. Antiicoagulants (esp. Warfarin) are associated with delayed Intracranial Bleeding
    1. One study demonstrated 6% of patients at 24 hours
      1. Bleeding may be delayed as long as 1 week after Head Injury
      2. Most patients with CNS Hemorrhage on Warfarin had GCS 14-15 and no focal neurologic changes
      3. Menditto (2012) Ann Emerg Med 59(6): 451-5 [PubMed]
    2. Other studies demonstrated a 0.4 to 1.4% risk of delayed Intracranial Hemorrhage
      1. In these studies, delayed head bleeding required neurosurgical intervention is rare
      2. Borst (2021) Surgery 170(2):623-7 +PMID: 33781587 [PubMed]
      3. Campiglio (2017) Neurol Clin Pract 7(4): 296-305 +PMID: 29185534 [PubMed]
      4. Cohan (2020) J Trauma Acute Care Surg 89(2):301-10 +PMID: 32332255 [PubMed]
      5. Hill (2018) Brain Inj 32(6):735-8 +PMID: 29485294 [PubMed]
      6. Kaen (2010) J Trauma 68(4):895-8 +PMID: 20016390 [PubMed]
      7. Lim (2016) Am J Emerg Med 34(1): 75-8 +PMID: 26458530 [PubMed]
      8. Turcato (2022) Am J Emerg Med 53:185-9 +PMID: 35063890 [PubMed]
    3. Conservative repeat Head CT protocol
      1. Repeat Head CT in 6-12 hours unless criteria below are met
        1. Most patients are observed in hospital while awaiting repeat Head CT
      2. Repeat Head CT not needed in minor Head Trauma if all of following criteria met (expert opinion)
        1. Initial Head CT negative (including no Skull Fracture and no Soft Tissue Injury) AND
        2. INR <2.5 AND
        3. Age < 65 years old AND
        4. Glasgow Coma Scale 15 AND
        5. Non-focal exam AND
        6. No persistent Emesis
    4. As of 2023, repeat Head CT after minor Trauma on Anticoagulants has become less common
      1. Delayed head bleed requiring intervention is rare following minor Head Trauma on Anticoagulants (see above)
      2. Early discharge after first CT relies on patient with normal baseline Neurologic Exam
      3. Use Shared Decision Making with patient regarding repeat Head CT
      4. Give the patient clear return precautions for changes in neurologic status
  • References
  1. (2012) ATLS, ACOS, Chicago, p. 149-73
  2. Abuguyan (2024) Crit Dec Emerg Med 38(7): 4-11