Makindo Medical Notes

Related Subjects: |Subarachnoid Haemorrhage |Perimesencephalic Subarachnoid haemorrhage |Haemorrhagic stroke |Cerebellar Haemorrhage |Putaminal Haemorrhage |Thalamic Haemorrhage |ICH Classification and Severity Scores |Saccular aneurysms

⚡ Note: Any new, severe headache with onset to maximum severity within 5 minutes, lasting ≥60 minutes, should be treated as a possible Subarachnoid Haemorrhage (SAH). ❗ 50% of patients die within 48 hours irrespective of therapy. 🧠 Early clipping or coiling, ideally within 72 hours, is now the goal for all grades of SAH. Also see Saccular aneurysms.

🚑 Initial Management of Suspected Aneurysmal SAH (on CT)

🧾 About

• Definition: Bleeding into the subarachnoid space from ruptured vessels.
• Distribution: Blood tracks into sulci, ventricles, and cisterns. Convexity SAH may mimic trauma or RCVS.

📊 Incidence

• 1–2% of population harbour unruptured aneurysms.
• SAH incidence ≈ 6 per 100,000/year, mostly <60 yrs.

🔎 Tip: Differentiating traumatic vs aneurysmal SAH is vital. 👉 Traumatic bleeds: external signs, convexity blood, no thunderclap headache. 👉 Aneurysmal bleeds: sudden headache, basal cistern blood, CTA needed.

🩸 Causes

• Aneurysmal rupture: 85% (berry/saccular aneurysm).
• Perimesencephalic SAH: 10%, often benign course.
• Traumatic SAH: Common in elderly post-fall.
• Dissection: Vertebral artery dissection ± lateral medullary signs.
• AVM/vascular malformations: Rare, usually with parenchymal bleed.
• Others: RCVS, vasculitis, amyloid angiopathy, infections.

🧬 Berry/Saccular Aneurysms

• Sites: Ant. communicating (35%), ICA–PCom (35%), MCA bifurcation (20%), basilar tip (5%), PICA.
• Risk factors: Smoking 🚬, binge alcohol 🍺, cocaine/illicit drugs, ADPKD, Marfan, Ehlers–Danlos, sickle cell, SLE.

🩺 Clinical Presentation

• Sudden thunderclap headache (“worst ever”).
• Peak within 60s; collapse then transient recovery possible.
• Photophobia, meningism, ↓GCS/coma.
• CN III palsy or monocular blindness = local aneurysm compression.

⚠️ Complications

• Vasospasm: 3–12 days; delayed infarction → Nimodipine + fluid balance.
• Re-bleeding: 20% within 2 weeks; especially day after bleed.
• Hydrocephalus: Obstructed CSF outflow → EVD or VP shunt.
• Seizures: ~6% at presentation.
• Hyponatraemia: Renal salt wasting/SIADH.

🔍 Investigations

• CT Head: 95% sensitive within 6h; sensitivity drops thereafter.
• LP (xanthochromia): If CT negative but suspicion persists, do ≥6h after onset.
• CTA/MRA: Localises aneurysm; DSA if equivocal.
• TCD: Daily monitoring for vasospasm.

🧠 Treatment

• Vasospasm: Nimodipine 60 mg q4h × 21d. ICU may use Triple-H (HTN, hypervolaemia, haemodilution) but balance re-bleeding risk.
• Aneurysm repair:
  • Endovascular coiling = preferred (esp. high surgical risk).
  • Clipping = neurosurgical alternative if anatomy unsuitable.
  • Timing: ideally <72h to reduce re-bleed risk.
• Hydrocephalus: EVD acutely; VP shunt for chronic cases.
• Seizures: Treat if they occur (levetiracetam preferred). No routine prophylaxis.
• BP control: SBP 140–160 mmHg pre-treatment.
• Supportive: Maintain euvolaemia, prevent hyponatraemia, ICU/HDU monitoring.

📌 Exam Pearls

✅ Thunderclap headache + meningism = SAH until proven otherwise. ✅ If CT negative → LP after 6h for xanthochromia. ✅ Nimodipine reduces vasospasm risk, not re-bleeding. ✅ Early coiling/clipping <72h saves lives.

📚 References

• van Gijn & Rinkel. Subarachnoid haemorrhage. Brain 2001
• Subarachnoid haemorrhage. Lancet 2007

Cases — Subarachnoid Haemorrhage (SAH) with Complications

• Case 1 — Classic Presentation with Vasospasm: A 48-year-old woman develops a sudden “thunderclap” headache while exercising, described as the “worst headache of my life.” She vomits and collapses. CT head confirms diffuse SAH. On day 7, she becomes confused and hemiparetic. CT angiography shows cerebral vasospasm. Diagnosis: SAH with delayed cerebral ischaemia from vasospasm. Management: Nimodipine (calcium channel blocker) for 21 days, maintain euvolaemia, neurosurgical/neuroradiology input for aneurysm coiling or clipping.
• Case 2 — Hydrocephalus: A 55-year-old man presents with sudden severe occipital headache and neck stiffness. CT shows perimesencephalic SAH. Two days later, he becomes drowsy and develops papilloedema. CT head now shows dilated ventricles. Diagnosis: SAH complicated by acute hydrocephalus due to obstruction of CSF flow. Management: External ventricular drain (EVD) or ventriculoperitoneal shunt; neurocritical care monitoring.
• Case 3 — Rebleeding: A 40-year-old woman presents with sudden collapse and severe headache. CT head shows aneurysmal SAH. While awaiting transfer for endovascular coiling, she deteriorates acutely with coma and extensor posturing. Repeat CT shows larger volume of blood. Diagnosis: Early rebleeding of unsecured aneurysm. Management: Immediate neurosurgical input; strict blood pressure control; urgent definitive treatment (coiling/clipping); supportive neuro-ICU care.

Teaching Commentary 🧠

SAH is most often due to rupture of a berry aneurysm (e.g., anterior communicating artery). Classic presentation = thunderclap headache ± meningism, reduced GCS, vomiting. Major complications to remember: - Rebleeding (first 24h, prevent with early aneurysm securing). - Vasospasm (days 3–10, causes delayed ischaemia; prevent with nimodipine). - Hydrocephalus (acute or delayed, treat with CSF diversion). - Hyponatraemia (SIADH or cerebral salt wasting). Management is supportive + definitive aneurysm occlusion (endovascular coiling preferred in UK practice) + vigilant monitoring for complications in neuro-ICU.