A 68-year-old man with chronic alcoholism presents to the emergency department 3 weeks after a minor head injury (fall at home). His wife reports progressive confusion, personality changes, and gait disturbance over the past 10 days. CT head (non-contrast) shows a crescent-shaped hypodense collection over the left convexity that crosses the midline. What is the most appropriate next step in management?

Explanation

## Clinical Presentation & Imaging Interpretation **Key Point:** This patient has a chronic subdural hematoma (cSDH) with acute-on-chronic features. The crescent-shaped hypodense collection that crosses the midline is pathognomonic for subdural hematoma (unlike epidural hematoma, which does NOT cross sutures). ### Why This Is Chronic Subdural Hematoma | Feature | Epidural | Subdural | | --- | --- | --- | | **Time from injury** | Hours to days | Days to weeks (chronic: >20 days) | | **Shape** | Lens-shaped, biconvex | Crescent-shaped, concave | | **Crosses midline** | NO (stops at sutures) | YES (crosses falx/tentorium) | | **Crosses dural attachments** | NO | YES | | **Typical source** | Middle meningeal artery | Bridging cortical veins | | **Risk factors** | Trauma (often severe) | Minor trauma, anticoagulation, coagulopathy, alcoholism | **Clinical Pearl:** Elderly and alcoholic patients are at high risk for cSDH because brain atrophy increases subdural space, stretching bridging veins. Even trivial trauma can cause venous bleeding that accumulates slowly over weeks. ### Management Algorithm for Chronic Subdural Hematoma ```mermaid flowchart TD A[Chronic Subdural Hematoma diagnosed]:::outcome --> B{Symptomatic?}:::decision B -->|Yes, progressive neurological deficit| C[Burr hole drainage]:::action B -->|Asymptomatic/minimal symptoms| D[Conservative management + serial imaging]:::action C --> E[Evacuation via burr hole or twist-drill]:::action E --> F[Recurrence rate ~10-15%]:::outcome D --> G[Repeat CT in 2-4 weeks]:::action G --> H{Progression?}:::decision H -->|Yes| C H -->|No| I[Continue observation]:::action ``` ### Why Burr Hole Drainage Is Correct **High-Yield:** This patient has **symptomatic** chronic SDH with clear neurological deterioration (confusion, personality change, gait disturbance). Symptomatic cSDH is a surgical emergency. 1. **Symptomatic status** = indication for drainage 2. **Progressive decline** over 10 days = acute decompensation 3. **Burr hole** is the standard minimally invasive approach for cSDH (lower morbidity than craniotomy) 4. **Local anesthesia** is safe and preferred in elderly patients to allow intraoperative monitoring **Mnemonic: DRAIN** — **D**eteriorating, **R**ecurrent bleeding, **A**cute expansion, **I**ncreasing mass effect, **N**eurological deficit = indications for drainage. ### Why Observation Is Wrong Here While asymptomatic or minimally symptomatic cSDH may be observed, this patient has **progressive neurological decline** — a clear red flag. Delaying surgery risks further deterioration, seizures, or herniation. [cite:Harrison 21e Ch 445]