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Subdural Hematoma

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Subdural Hematoma, Subdural Hemorrhage

  • See Also
  1. Head Injury
  2. Management of Severe Head Injury
  3. Increased Intracranial Pressure in Closed Head Injury
  4. Brainstem Herniation
  5. Neurovascular Anatomy
  6. Epidural Hematoma
  7. Subarachnoid Hemorrhage
  8. Intracerebral Hemorrhage
  • Epidemiology
  1. Represents 30% of Traumatic Intracranial Hemorrhage causes
    1. Six times more common than Epidural Hematoma
  • Risk Factors
  1. Anticoagulation (e.g. Warfarin)
  2. Brain atrophy predisposes to sudural Hematoma (even with minor Head Trauma)
    1. Elderly
    2. Alcoholism
  • Pathophysiology
  1. Cranial Trauma results in Subdural Hemorrhage
  2. Tear of bridging veins between Dura Mater and the arachnoid membrane on the surface of the brain
    1. Sudden acceleration-deceleration is typical cause
  3. Subdural Hematoma accumulation exerts pressure on the brain
    1. Results in neurologic tissue ischemia
    2. May progress to Cerebral Herniation (esp. acute Subdural Hematoma)
  • Precautions
  • Acute Subdural Hematoma
  1. Acute Subdural Hematomas are vastly different than chronic Subdural Hematoma
  2. Acute Subdural Hematoma has a 60-80% mortality rate
  3. Requires rapid assessment and management (surgical decompression)
  • Causes
  • Acute Subdural Hematoma
  1. Severe Closed Head Injury
  2. Rapid Deceleration Injury
  • Associated Conditions
  • Acute Subdural Hematoma
  1. Comorbid Brain Contusion
  • Symptoms
  1. Acute Subdural Hematoma (Rapid progression of symptoms)
    1. Headache
    2. Irritability
  2. Chronic Subdural Hematoma (Insidious symptom progression)
    1. Intermittent Headache
    2. Variable levels of Decreased Level of Consciousness
  • Signs
  1. Acute Subdural Hematoma (<24 hours)
    1. Fluctuating levels of consciousness
    2. Dilated pupils
    3. Hemiplegia
    4. Hyperreflexia
    5. Babinski's Sign
    6. Convulsions
  2. Subacute (24 hours to 2 weeks)
  3. Chronic Subdural Hematoma (>2 weeks)
    1. Progressively impaired intellect
    2. Agitation
    3. Impulsive behavior
    4. Hemiparesis
    5. Stupor
    6. Variable Level of Consciousness
  1. Subdural Hematoma appears as crescent-shaped Hematoma
    1. As this is below the dura, the Subdural Hematoma follows the surface of the brain
    2. Gyri are absent in region of Subdural Hematoma
      1. Helps identify subacute Subdural Hematoma which is isodense and more difficult to distinguish
  2. Appearance varies based on timing
    1. Acute: White blood collection
    2. Subacute: Isodense blood collection (may be subtle)
    3. Chronic: Dark blood collection
  • Labs
  • Cerebrospinal fluid
  1. Increased CSF Opening Pressure
  2. CSF Protein increased
  3. CSF Bloody or xanthochromic fluid
  • Diagnostic Testing
  • EEG
  1. Localized disturbance
  • Management
  1. Admit all patients with chronic or acute Subdural Hematoma (SDH)
  2. Anticoagulation and antiplatelet agent use predisposes to subdural expansion
  3. Manage systolic Blood Pressure, targets per neurosurgery, but typically <180 mmHg
  4. Surgical decompression
    1. Indications
      1. Subdural thickness >10 mm
      2. Midline shift >5 mm
      3. Glasgow Coma Scale decreases >2 points from initial injury
      4. Cerebral Herniation findings (e.g. acute Anisocoria)
    2. Over age 65 years old, are unlikely to need surgical intervention if
      1. Midline shift <=1 mm
      2. Width <= 10 mm
      3. Evans (2015) Injury 46(91): 76-9 [PubMed]
    3. Emergency surgical decompression if acute Subdural Hematoma with signs of Herniation
      1. See Skull Trephination
  • Prognosis
  1. Worse prognosis than Epidural Hematoma (given decompression)
    1. Subdural Hematomas are associated with greater brain parenchymal injury than Epidural Hematomas
  2. Predictors of worse prognosis
    1. Loss of consciousness at time of Closed Head Injury (associated with Diffuse Axonal Injury)
    2. Low initial glasgow coma score (GCS score)
    3. Increased Intracranial Pressure
    4. High injury mechanism
  • References
  1. Abuguyan (2024) Crit Dec Emerg Med 38(7): 4-11
  2. Dreis (2020) Crit Dec Emerg Med 34(7):3-21
  3. Marcolini and Swaminathan in Swadron (2023) EM:Rap 23(5): 13-14