Subarachnoid Hemorrhage (SAH): NEET PG Essentials
1. Clinical Presentation
Classic presentation: “Thunderclap headache” (the worst headache of life, reaching peak intensity within seconds/minutes). Often associated with meningism, photophobia, and decreased level of consciousness.
2. Etiology & Risk Factors
- Most Common: Trauma.
- Most Common Non-Traumatic: Rupture of a saccular (berry) aneurysm.
- Associations: Polycystic Kidney Disease (ADPKD), Ehlers-Danlos syndrome, and Coarctation of the aorta.
3. Imaging & Diagnostics
| Step | Clinical Utility |
|---|---|
| Non-Contrast CT | First-line diagnostic. Look for hyperdense blood in the basal cisterns and sulci. |
| Lumbar Puncture | Required if CT is negative but suspicion is high. Look for xanthochromia (yellowish appearance of CSF due to bilirubin). |
4. Management & Complications
- Vasospasm: The most significant complication (usually days 4–14). Prevented with Nimodipine.
- Hydrocephalus: Caused by the obstruction of CSF reabsorption by blood products.
- Rebleeding: Highest risk within the first 24–48 hours. Aggressive BP control is mandatory.