CT for Subarachnoid Hemorrhage

Subarachnoid Haemorrhage

A negative head CT in a neurologically normal patient, with a thunderclap headache presentation, a clear time of onset, and a modern CT scanner performed within 6 hours of onset read by an attending radiologist results in a post test risk of SAH of 1 – 2/1000 patients. A shared decision strategy should be used to balance the risk and benefits of performing a lumbar puncture versus a negative CT within 6 hours being sufficient to rule out SAH.

A Thunderclap Headache

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A thunderclap headache is defined as a very severe headache that reaches its maximum intensity within 1 minute. One of the most common causes is subarachnoid hemorrhage, but what else can cause a it?

Serious reasons why your patient fainted…

If your patient presents with…

  1. Symptoms of arm ischemia or paresthesias with syncope – Subclavian steal syndrome
  2. Chest pain that is acute, radiates, tearing/sharp, involves symptoms above and below diaphragm with syncope – Aortic dissection
  3. Tachypnea, pleuritic chest pain, shortness of breath with syncope – PE
  4. Neurologic deficit with syncope – TIA/stroke
  5. Headache that is sudden in onset, maximal at onset, worst of life with syncope – Subarachnoid hemorrhage
  6. Minor trauma with head or neck pain and syncope – Carotid/vertebral artery dissection
  7. Abdominal/flank pain in older patient with syncope – Ruptured AAA