Subdural hemorrhage

Background

• Bleeding between the dura mater and arachnoid membrane, typically from bridging vein rupture
• Three types by timing:
  • Acute (<3 days) — hyperdense (white) on CT
  • Subacute (3-21 days) — isodense (may be difficult to see)
  • Chronic (>21 days) — hypodense (dark) on CT
• Most common in elderly and anticoagulated patients
• Acute SDH mortality: 50-90% (highest of all traumatic intracranial lesions)
• May occur with minimal or no trauma in the elderly and anticoagulated

Risk Factors

• Advanced age (cerebral atrophy stretches bridging veins)
• Anticoagulation / antiplatelet therapy
• Chronic alcohol use (cerebral atrophy, coagulopathy)
• Coagulopathy or thrombocytopenia
• Prior falls or head trauma (even minor)
• CSF shunt (overdrainage)

Clinical Features

Acute SDH

• Headache, altered mental status, decreasing GCS
• Ipsilateral fixed/dilated pupil (uncal herniation)
• Contralateral hemiparesis
• May present with coma from onset
• Associated with high-energy mechanism or fall in anticoagulated patients

Chronic SDH

• Insidious onset over weeks to months
• Headache, cognitive decline, confusion, personality changes
• Gait disturbance, falls
• Fluctuating neurologic symptoms (may mimic stroke or dementia)
• History of trauma often absent or trivial

Differential Diagnosis

• Epidural hemorrhage
• Subarachnoid hemorrhage
• Intracerebral hemorrhage
• Ischemic stroke
• Meningitis
• Dementia (chronic SDH)

Evaluation

• Non-contrast CT head — test of choice
  • Acute: hyperdense, crescent-shaped collection crossing suture lines
  • Chronic: hypodense, crescent-shaped; may have mixed density if rebleeding
  • Evaluate for midline shift, mass effect, herniation
• Labs: CBC, coagulation studies (PT/INR, PTT), type and screen
• If on anticoagulation: specific reversal levels (e.g., anti-Xa for DOACs)

Management

Acute SDH

• ABCs — intubate if GCS <=8
• Emergent neurosurgical consultation
• Reverse anticoagulation immediately:
  • Warfarin: 4-factor PCC (25-50 units/kg) + Vitamin K 10 mg IV
  • Dabigatran: Idarucizumab 5 g IV
  • Rivaroxaban/Apixaban: Andexanet alfa or 4-factor PCC
  • Antiplatelet agents: platelet transfusion if surgical candidate
• ICP management: head of bed elevation, osmotherapy (Mannitol or Hypertonic saline)
• Surgical indications: clot thickness >10 mm, midline shift >5 mm, GCS drop >=2 points

Chronic SDH

• Neurosurgical consultation for possible burr hole drainage
• Reverse anticoagulation
• Many small, asymptomatic chronic SDH may be observed with serial imaging
• Symptomatic chronic SDH: typically surgical (burr hole or craniotomy)

Disposition

• All acute SDH: admit, neurosurgical evaluation, ICU for operative or declining patients
• Chronic SDH: admit if symptomatic, new, or enlarging; small stable chronic SDH may have outpatient neurosurgery follow-up

See Also

• Epidural hemorrhage
• Head trauma (main)
• Subarachnoid hemorrhage
• Anticoagulation reversal