What are the complications of a chronic subdural hematoma?

Complications of Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) can lead to significant morbidity and mortality primarily due to intracranial hypertension, brain compression, and neurological deterioration, with recurrence rates of up to 21% following surgical evacuation. 1

Major Complications

Neurological Complications

• Intracranial hypertension - Can lead to brain herniation and death if untreated
• Cognitive decline - Commonly presents as confusion, memory problems, and decreased mental function 1
• Focal neurological deficits - Including hemiparesis, aphasia, and visual disturbances
• Seizures - Due to cortical irritation from the hematoma
• Headaches - Persistent and often worsening with increased intracranial pressure

Surgical Complications

• Recurrence - Occurs in approximately 21% of cases after surgical evacuation 1
  • Risk factors for recurrence include:
    • Presence of thick subdural membrane visualized during surgery
    • Brain remaining at depth after evacuation
    • Absence of subdural drain during surgery
• Acute bleeding - Can occur during evacuation procedures
• Infection - Including empyema or meningitis
• Pneumocephalus - Air entering the subdural space during surgery

Systemic Complications

• Mortality - Overall mortality rate around 5% 1
  • Statistically significant factors determining mortality:
    • Advanced age
    • Low Glasgow Coma Scale (GCS) at presentation
    • Associated illnesses (particularly cardiac and renal failure)

Special Considerations

Differential Diagnosis Challenges

CSDH requires differentiation from other conditions with similar presentations:

• Cerebral hemorrhage and edema
• Subdural hematoma (acute)
• Hyponatremia (particularly challenging as symptoms are similar and it can itself lead to CSDH) 2
• Dementia and other neurodegenerative conditions

Management Complications

• Anticoagulant/antiplatelet therapy - Increases risk of recurrence and expansion 3
• Surgical timing issues - Delayed intervention may lead to worse outcomes
• Drainage complications - Catheter placement failures, infections (particularly with intraventricular drains)

Prevention of Complications

• Postoperative drainage significantly reduces recurrence without increasing complications 4
• Surgical technique considerations:
  • Both burr hole and twist drill procedures show similar efficacy 4
  • Irrigation during surgery may lead to better outcomes 4
  • Frontal catheter placement appears to provide better outcomes 4
  • 48 hours of drainage is as effective as 96 hours 4

Emerging Treatment Options

Middle meningeal artery (MMA) embolization is showing promise as an adjunctive or alternative treatment for CSDH:

• May reduce recurrence rates compared to conventional surgical procedures 3
• Complete hematoma resolution observed in some patients treated with MMA embolization alone 3
• Particularly beneficial for patients with contraindications to surgery due to multiple comorbidities 5

Warning Signs of Serious Complications

• Development of anisocoria or bilateral mydriasis
• Rapid decline in GCS
• New onset seizures
• Progressive focal neurological deficits
• Signs of increased intracranial pressure (vomiting, severe headache, altered consciousness)

Early recognition and management of these complications are essential to improve outcomes in patients with chronic subdural hematoma.