What is the recommended management for a subdural hematoma measuring 3 mm on the right convexity and 4 mm on the right anterior falx?

Management of Small Subdural Hematoma (3-4 mm)

For this small subdural hematoma (3 mm convexity, 4 mm parafalcine), discharge without repeat imaging is appropriate if the patient is not anticoagulated and has a stable neurologic examination. 1

Risk Stratification by Anticoagulation Status

Non-Anticoagulated Patients

• Patients not on anticoagulation with subdural hematomas ≤3 mm and stable neurologic examination do not require routine repeat head CT and can be discharged with return precautions. 1
• Research confirms that no patient with initial subdural hematoma ≤3 mm required surgery in either initial presentation or follow-up, though 11.1% showed enlargement (maximum 10 mm). 2
• Routine repeat CT changes management in only 9.6% of mild TBI cases, indicating substantial over-utilization of imaging resources. 1

Anticoagulated Patients (Warfarin, DOACs, or Antiplatelet Agents)

• A 24-hour observation period with serial neurologic examinations is mandatory. 1
• Perform repeat head CT at 20-24 hours after injury to detect hematoma progression. 1
• Anticoagulation increases hematoma expansion risk three-fold (26% vs 9% in non-anticoagulated patients). 1
• If repeat CT is stable and neurologic examination remains intact, discharge with return precautions is appropriate. 1

Location-Specific Considerations

Parafalcine Component (4 mm)

• Parafalcine subdural hematomas are a clinically benign entity with significantly lower incidence of radiographic progression compared to convexity lesions. 3
• Parafalcine subdural hematomas have no documented cases of neurologic deterioration, neurosurgical intervention, or mortality in isolated presentations. 3
• Isolated falcotentorial subdural hematomas average 2.8 mm and do not increase in size on short-term follow-up CT. 4
• These patients do not benefit from ICU admission; floor admission results in shorter length of stay (2.0 vs 3.8 days) with equivalent outcomes. 3

Convexity Component (3 mm)

• The 3 mm convexity component falls well below surgical thresholds and expansion risk thresholds. 2
• Convexity location is a predictor of expansion, but only when combined with other risk factors (hypertension, subarachnoid hemorrhage, midline shift). 2

Surgical Thresholds (Not Applicable to This Case)

• Surgical evacuation is indicated for subdural hematoma >10 mm thickness OR midline shift >5 mm, regardless of GCS score. 5
• An 8.5 mm initial size threshold best predicts need for surgical intervention (AUC 0.81). 2
• This patient's measurements (3-4 mm) are far below any surgical threshold. 2, 5

Discharge Instructions

• Educate patients on warning signs: worsening headache, new confusion, focal weakness, or seizures requiring immediate return. 1
• Provide explicit return precautions emphasizing neurologic deterioration symptoms. 1

Common Pitfalls to Avoid

• Do not over-image stable non-anticoagulated patients with small subdural hematomas, as this rarely alters management and increases radiation exposure and costs. 1
• Do not admit parafalcine subdural hematomas to ICU when neurologically stable, as this provides no benefit and increases length of stay. 3
• Do not discharge anticoagulated patients without 24-hour observation and repeat imaging, as their expansion risk is substantially higher. 1