Headache
Official guideline from the American College of Emergency Physicians.
summary by Eric Steinberg, DO
Diagnosis
Use the Ottawa Subarachnoid Hemorrhage Rule (>40 years, complaint of neck pain or stiffness, witnessed loss of consciousness, onset with exertion, thunderclap headache, and limited neck flexion on examination) as a decision rule that has high sensitivity to rule out subarachnoid hemorrhage, but low specificity to rule in subarachnoid hemorrhage, for patients presenting to the emergency department with a normal neurologic examination result and peak headache severity within 1 hour of onset of pain symptoms.
Perform lumbar puncture or computed tomography angiography to safely rule out subarachnoid hemorrhage in the adult emergency department patient who is still considered to be at risk for subarachnoid hemorrhage after a negative noncontrast head computed tomography result.