Subdural Hematoma (SDH): NEET PG Essentials
1. Pathophysiology
- Mechanism: Rupture of the bridging veins that pass through the subdural space to drain into the dural venous sinuses.
- Risk Factors: Elderly patients (brain atrophy makes bridging veins more susceptible to stretching/tearing), alcoholics, and patients on anticoagulation/antiplatelet therapy.
2. Radiological Findings
| Feature | High-Yield Description |
|---|---|
| Shape | Crescent-shaped (concave-convex). |
| Suture Lines | Crosses suture lines (because it is limited by dural reflections, not sutures). |
| Density | Acute is hyperdense; subacute becomes isodense; chronic becomes hypodense. |
3. Clinical Pearls & Management
- Chronic SDH: Common in the elderly; often presents with non-specific symptoms like headache, confusion, or cognitive decline weeks after a minor fall.
- “Isodense” Trap: Subacute SDH can be isodense to brain parenchyma on non-contrast CT, potentially making it hard to detect. Look for mass effect (e.g., midline shift) if the scan looks “normal” despite clinical suspicion.
- Treatment: Small, asymptomatic hematomas may be managed conservatively. Symptomatic or large hematomas typically require surgical evacuation (e.g., burr hole or craniotomy).