Subdural Hematoma

Summary

Subdural hematomas describe a bleed under the dura and above the arachnoid mater of the brain. They are a result of ruptured bridging veins. There are two main types of subdural hematomas: acute and chronic. Acute subdural hematomas are most often seen in young, healthy individuals, and are caused by high-energy trauma to the head. In comparison, chronic subdural hematomas are often seen in older individuals or those with a history of alcohol abuse. They can be caused by mild head trauma. Finally, subdural hematomas can be seen in babies who have been shaken.

Acute subdural hematomas present with elevated intracranial pressure and usually cause headaches and vomiting. Subdural hematomas are often diagnosed with CT scan, where the bleed appears as concave and crescent-shaped hyperdensity that crosses suture lines.

Key Points

• Subdural Hematoma
  • Cause
    • Bleeding into confined space (hematoma) below dura mater (sub = below, dural = dural mater) but above the arachnoid mater
    • Rupture of cortical bridging veins
    • Acutely due to high-energy trauma
    • Chronically due to mild trauma in susceptible patients
      • elderly with cerebral atrophy
      • history of chronic alcohol abuse
    • Also seen in shaken babies
  • Presentation
    • Acute
      • Increased ICP
    • Chronic
      • Subtle and variable presentation
        • Often undiagnosed because all the symptoms are non-specific
      • Mild headache
      • Cognitive impairment
      • Unsteady gait
      • Seizures
      • Focal neurological deficits
  • Diagnosis
    • CT Head without Contrast
      • Crescent-shaped hematoma
      • CROSSES suture lines