A 35-year-old man is brought to the emergency department following a motor vehicle accident. He lost consciousness for 2 minutes, then regained consciousness and appeared well. After 4 hours, he develops severe headache, vomiting, and altered mental status. Non-contrast CT head shows a lens-shaped (biconvex) hyperdensity in the epidural space with mass effect. Which investigation should be performed next to assess for ongoing bleeding and guide urgent intervention?

Explanation

## Clinical Presentation & Imaging Findings The patient presents with a **classic "talk and die" syndrome** — initial loss of consciousness, lucid interval, then rapid deterioration. The lens-shaped (biconvex) hyperdensity in the epidural space indicates **acute epidural hematoma**, typically from tearing of the **middle meningeal artery**. ## Why CTA is the Next Investigation of Choice **Key Point:** In acute epidural hematoma with mass effect and clinical deterioration, CTA of the head and neck is essential to identify the source of bleeding (usually middle meningeal artery) and assess for active arterial bleeding, which determines urgency of surgical intervention. ### Role of CTA in Epidural Hematoma Management: | Investigation | Purpose | Findings in Epidural Hematoma | |---------------|---------|-------------------------------| | **Non-contrast CT** | Initial diagnosis, assess mass effect | Lens-shaped hyperdensity, midline shift | | **CTA (Arterial phase)** | Identify bleeding source, active extravasation | Middle meningeal artery injury, contrast pooling | | **CTA (Venous phase)** | Assess venous drainage, thrombosis | Dural sinus patency | | **MRI** | Subacute/chronic characterization | Not indicated in acute setting with mass effect | | **Repeat CT** | Monitor progression | Useful for conservative management, not acute intervention | **High-Yield:** Active arterial bleeding on CTA ("contrast blush") indicates ongoing hemorrhage and mandates **immediate surgical evacuation**. This finding directly impacts triage and operative urgency. **Clinical Pearl:** Epidural hematomas are **neurosurgical emergencies** when associated with mass effect and neurological deterioration. CTA identifies the arterial source (usually middle meningeal artery at the pterion) and confirms active bleeding, which is the key determinant for emergent burr hole drainage or craniotomy. ## Mermaid: Acute Epidural Hematoma Management Algorithm ```mermaid flowchart TD A[Acute epidural hematoma on CT]:::outcome --> B{Mass effect present?}:::decision B -->|Yes| C[CTA head and neck]:::action B -->|No, small| D[Conservative management]:::action C --> E{Active arterial bleeding?}:::decision E -->|Yes, contrast blush| F[Emergent surgical evacuation]:::urgent E -->|No active bleeding| G[Assess hematoma volume]:::action G --> H{Volume > 30 mL or midline shift > 5 mm?}:::decision H -->|Yes| I[Surgical evacuation]:::action H -->|No| J[Close monitoring + repeat CT]:::action D --> K[Serial CT imaging]:::action K --> L{Expansion or deterioration?}:::decision L -->|Yes| M[Delayed surgical evacuation]:::action L -->|No| N[Discharge with precautions]:::outcome ``` **Reasoning:** CTA is the gold standard next investigation because it identifies the arterial source of bleeding (middle meningeal artery) and detects active extravasation (contrast blush), which directly determines the urgency and type of surgical intervention required in this patient with acute epidural hematoma and mass effect.