Published online by Cambridge University Press: 09 October 2017
Put simply, the sun should not set on an undiagnosed thunderclap headache.JF Rothrock
A person presenting with a thunderclap headache is at high risk of a life-threatening condition – 4–5 times greater risk than those who are in the “rule-out MI” or “rule-out pulmonary embolism” category. Of those who do have a high-risk condition, 30–50 percent will not have a subarachnoid hemorrhage (SAH). Many emergency physicians discharge people with thunderclap headaches after a computed tomography (CT) and a lumbar puncture (LP) have ruled out an SAH, but this strategy needs to change and encompass consultation and additional imaging if that first series of investigations is negative. There are many other conditions that can present with a thunderclap headache. This chapter will review the differential diagnosis, and the signs and symptoms of each; it will conclude with recommendations on a comprehensive approach in the emergency department (ED) for someone presenting with a thunderclap headache.