A 68-year-old man with chronic alcoholism and on warfarin for atrial fibrillation presents to the emergency department with a 3-day history of progressive headache and confusion. His wife reports a minor head trauma from a fall 5 days ago, which he did not initially think was serious. On examination, he is drowsy with a Glasgow Coma Scale of 13/15. Blood pressure is 160/95 mmHg, heart rate 88/min. CT head (non-contrast) shows a crescent-shaped hyperdense collection that crosses the midline and compresses the lateral ventricle. What is the most likely diagnosis?

Explanation

## Clinical Presentation & Imaging Correlation **Key Point:** The crescent-shaped hyperdense collection that crosses the midline is pathognomonic for acute subdural hematoma. The delayed presentation (5 days post-trauma) in a patient with coagulopathy (warfarin) and chronic alcoholism (coagulopathy + brain atrophy) is classic. ## Subdural vs Epidural Hematoma: Distinguishing Features | Feature | Subdural Hematoma | Epidural Hematoma | |---------|-------------------|-------------------| | **Location** | Between dura and brain (subdural space) | Between skull and dura | | **Shape on CT** | Crescent-shaped (concave inner margin) | Lens-shaped/biconvex (convex inner margin) | | **Crosses midline?** | YES (does not respect dural attachments) | NO (respects dural attachments like falx) | | **Typical vessel** | Bridging veins (tearing) | Middle meningeal artery | | **Mechanism** | Minor/trivial trauma (esp. elderly, alcoholics) | Significant trauma; fracture common | | **Lucid interval** | Rare | Classic (50–80% of cases) | | **Age group** | Elderly, chronic alcoholics, anticoagulated | Younger patients | | **Prognosis** | Worse (higher mortality) | Better if treated promptly | **High-Yield:** Subdural hematomas cross the midline because they lie in the subdural space, which is continuous across the brain. Epidural hematomas do NOT cross the midline because the dura is firmly adherent to the skull at the falx and tentorium. ## Why This Patient Has Subdural Hematoma 1. **Delayed presentation (5 days):** Subdural hematomas can present acutely, subacutely (3–20 days), or chronically (>20 days). Epidural hematomas present acutely (within 24–48 hours). 2. **Minor trauma:** This elderly patient with brain atrophy and coagulopathy suffered only a trivial fall. Bridging veins are easily torn in brain atrophy. 3. **Coagulopathy:** Warfarin increases bleeding risk and slows clot formation, allowing subdural collections to expand over days. 4. **Imaging findings:** Crescent shape + midline crossing = subdural. **Clinical Pearl:** Chronic alcoholics have brain atrophy, which stretches bridging veins and makes them prone to subdural hematoma even from minor trauma. Always suspect subdural in elderly patients with delayed neurological decline after trivial head injury. ## Management Implications - **Acute subdural (>3 mm or mass effect):** Surgical evacuation (burr holes or craniotomy) - **Chronic subdural:** Burr hole drainage (often bilateral) - **Coagulopathy reversal:** INR correction with vitamin K / fresh frozen plasma / prothrombin complex concentrate [cite:Robbins 10e Ch 28]