Neuro Emergencies

Subarachnoid Hemorrhage

• Definitions:
  • "Thundercalp Headache", "Worst headache of life"
  • Defined as: Severe headache that reaches maximum intensity within 60s of onset. 
  • 25% of "Thunderclap Headache" is SAH --> Neurosurgical Emergency
• Other Dx:
  • dural sinus
  • thrombosis
  • meningitis
  • migraine
• Diagnosis:
  • 1st test: Non-Contrast Head CT
  • 2nd test: (if CT negative) --> Lumbar Puncture
    • Evaluate for erythrocytes or xanthochromia.
    • Xanthochromia describes a yellow discoloration of the CSF from breakdown of erythrocytes, which may not develop for at least 6 hours after the initial event.
  • Normal CSF has a very good negative predictive value (generally excludes)
  • 3rd Test: (If all normal) --> rule out other causes:
    • MRI Head
    • MRI Angiography: Cervicocephalic arterial dissection, internal carotid artery dissection (often Horners)
    • MRI Venography:  Deep venous thrombosis and cerebral venous sinus thrombosis. 
• Treatment:
  • Neurosurgical referral