A 35-year-old man is brought to the emergency department 4 hours after a motor vehicle collision with loss of consciousness. He is now alert but drowsy. CT head shows a lens-shaped hyperdensity in the right frontoparietal region that does not cross the midline, with 8 mm midline shift. What is the most appropriate immediate next step?

Explanation

## Clinical Diagnosis: Acute Extradural Hematoma The **lens-shaped** hyperdensity that **does not cross the midline** (respects the dural attachment at sutures) is pathognomonic for **extradural (epidural) hematoma**. The 8 mm midline shift indicates significant mass effect and increased intracranial pressure. ## Why Immediate Neurosurgical Intervention Is Required **Key Point:** Acute extradural hematoma is a **neurosurgical emergency**. The classic presentation is: - Arterial bleeding (middle meningeal artery) → rapid accumulation - "Talk and die" syndrome: initial lucidity followed by rapid deterioration - Midline shift >5 mm warrants urgent surgical evacuation **High-Yield:** Extradural hematoma has the best prognosis of all intracranial bleeds IF treated promptly. Delays in surgery dramatically increase mortality and morbidity. ## Management Algorithm ```mermaid flowchart TD A["Acute extradural hematoma on CT"]:::outcome --> B{"Midline shift & symptoms?"}:::decision B -->|"Yes (>5 mm or symptomatic)"|C["Mannitol IV + emergency neurosurgery consult"]:::action B -->|"No (small, asymptomatic)"|D["Observe in ICU with serial CT"]:::action C --> E["Burr hole evacuation"]:::action E --> F["Good outcome if <4 hrs"]:::outcome D --> G{"Expansion on follow-up CT?"}:::decision G -->|"Yes"|C G -->|"No"|H["Continue observation"]:::action ``` ## Extradural vs Subdural: Key Distinctions | Feature | Extradural | Subdural | |---------|-----------|----------| | **Shape** | Lens-shaped, respects sutures | Crescent, crosses sutures | | **Crosses midline?** | No | Yes | | **Vessel injured** | Arterial (middle meningeal) | Venous (bridging veins) | | **Speed of accumulation** | Rapid (hours) | Slower (hours to weeks) | | **Typical presentation** | "Talk and die" syndrome | Gradual deterioration | | **Midline shift >5 mm** | Surgical emergency | Depends on acuity | | **Prognosis if treated early** | Excellent | Good to fair | **Clinical Pearl:** The "talk and die" syndrome occurs because initial arterial bleeding may be contained by dural adhesions, but continued bleeding leads to sudden decompensation. Time from diagnosis to surgery is the single most important prognostic factor. **Warning:** Do NOT delay surgery for additional imaging (MRI) in a symptomatic patient with significant midline shift. CT diagnosis is sufficient; neurosurgery should be contacted immediately while mannitol is being administered. ## Immediate Supportive Measures 1. **Mannitol 1 g/kg IV** — osmotic diuretic to reduce ICP acutely 2. **Head elevation to 30°** — improves cerebral venous drainage 3. **Avoid hypoxia and hypercapnia** — maintain PaO₂ >100 mmHg, PaCO₂ 35–40 mmHg 4. **Emergency neurosurgical consultation** — for burr hole evacuation **Mnemonic:** **EDH = Lens + Emergency** — Extradural hematoma is lens-shaped and a neurosurgical emergency.