7

• Subarachnoid hemorrhage


  5% of strokes, 3rd cause
• Causes of spontaneous subarachnoid hemorrhage


  • Rupture of saccular berry aneurysm (70%)
  • Congenital AVM (10%)
  • Others: pituitary apoplexy, arterial dissection, mycotic (infective) aneurysm
• Rupture of saccular berry aneurysm


  • Most common locations are the anterior communicating artery & origin of the posterior communicating artery (branching point)
  • Risk factors for rupture: smoking, family history, HTN, alcohol & drugs
• Congenital AVM


  • Risk of 1st bleed is 2-3% per year and rebleed is 10% per year
• Presentation of subarachnoid hemorrhage


  • Abrupt onset of severe worst ever headache, occipital, max intensity w/in minutes
  • Meningeal irritation (neck stiffness & Kernig)
  • N/V
  • Sub-hyaloid hemorrhage ± papilledema
  • May have sentinel bleeding or worsening headache
  • Brief LOC±seizures
  • If no bleeding: aneurysm may be asymptomatic or produce mass effect (painful 3rd CN palsy)
• Most common cause of SAH is head injury (traumatic SAH)
• Diagnosis


  1. Non-contrast CT within 24 hours ASAP

  2. If normal CT and strong suspicion of SAH à must do lumbar puncture (12 hours after symptom onset)

  3. Findings on LP:

  4. Increased opening pressure

  5. RBC in CSF

  6. Xanthochromia (bilirubin in CSF)

  7. After confirming the diagnosis à must determine the etiology: MR angiography (DSA)
• Non-contrast CT


  • Positive bleeding in 75% of cases
• Lumbar puncture must be done if normal CT and strong suspicion of SAH
• Lumbar puncture findings include increased opening pressure, RBC in CSF, and xanthochromia (bilirubin in CSF)
• After confirming the diagnosis, must determine the etiology using MR angiography (DSA)
• Treatment


  1. Bed rest & analgesia

  2. BP control: maintain SBP <160 (IV Labetalol or Nicardipine)

  3. Nimodipine (CCB) oral or IV: to decrease cerebral artery spasm & further ischemia

  4. Maintain euvolemia

  5. Hyponatremia (due to SIADH & urinary salt loss): may contribute to delayed cerebral ischemia - large volume of IV 0.9% NS needed

  6. Only effective Tx to prevent rebleed: obliteration of aneurysm by surgical clipping or endovascular coiling - best done within 24 hours & immediately if rebleeding occurs

  7. Secondary prevention: control HTN & stop smoking
• Prognosis


  Prediction of the likely course and outcome of a disease or injury
• Most prognostic significance


  • GCS >12 (conscious level on admission)
  • Age
  • Amount of blood visible on CT
• Outcomes


  • 50% die suddenly/soon after hemorrhage
  • The rest may have variable neurological deficits