Subdural hemorrhage (summary)

Dr Craig Hacking and Dr Derek Smith et al.
This is a basic article for medical students and other non-radiologists

Subdural hemorrhage (SDH) is a collection of blood between the dura and the arachnoid layers of the meninges. They are common and can occur in any age range, usually related to a history of head trauma. Prognosis tends to depend on the extent of the bleed and associated mass effect.

Reference article

This is a summary article; read more in our article on subdural hemorrhage.

  • anatomy
  • epidemiology
    • children: non-accidental injury 1
    • adults: high energy trauma, e.g. road traffic collisions
    • elderly: falls (there may not be a clear history of trauma)
  • presentation
    • acute
      • usually associated with head injury
        • may be associated contusions or extradural hemorrhage
      • underlying vascular malformations
    • subacute or chronic
      • confusion and vague neurological change
      • a classic cause of pseudodementia
      • beware patients on anticoagulants, e.g. warfarin
  • pathophysiology
    • tearing of bridging veins found in the subdural space
    • veins are subject to shearing forces
      • occurs with lower forces in the elderly
  • investigation
    • non-contrast CT head
  • treatment
    • correction of abnormal coagulation
    • discussion with neurosurgical services
    • small subdural can be observed with repeated CT
    • surgical evacuation of the clot
      • may carry significant mortality and morbidity
  • role of imaging
    • initial diagnosis
    • assessment of the associated mass effect
    • look for an underlying cause
    • suggest further imaging
    • follow up
  • radiographic features
    • general
      • typically unilateral
      • crescent distribution around the periphery
      • not limited by sutures
      • fill dural reflections (falx cerebritentorium)
    • CT
      • acute
        • hyperdense crescent
        • central hypodensity represents active bleeding
        • acute bleed mixed with CSF may appear less dense
        • density is variable in coagulopathic patients, e.g. warfarinised
      • subacute
        • over the first couple of weeks, the blood is broken down
        • density approaches that of the brain
        • they may be tricky to see
      • chronic
        • over time, the hematoma approaches CSF density
    • MRI
      • may be used to assess the underlying brain parenchyma
      • aging blood on MRI is a complex process
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Article information

rID: 32796
Synonyms or Alternate Spellings:
  • SDH (summary)
  • Subdural haematoma (summary)

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Cases and figures

  • Figure 1: diagram of subdural bleed
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  • Case 1: left chronic SDH
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  • Chronic subdural ...
    Case 2: chronic subdural
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  • Case 3: left isodense SDH
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  • Case 4: right chronic SDH
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  • Case 5: right acute SDH
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  • Case 6: right acute SDH (on warfarin)
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