Thunderclap headache in a patient with Giant Cell Arteritis: think Aortic Dissection

We report a case of a patient with giant cell arteritis, which was thought to be in remission at the time, who presented with thunderclap headache. He died eight hours later and was found at autopsy to have a type A aortic dissection. At no point during this short history did he develop chest pain, back pain or breathlessness. There was no focal neurology. We note that six recent reviews of thunderclap headache do not mention aortic dissection as a possible cause, but have found four case reports of patients like ours whose thunderclap headache was a consequence of aortic dissection in the absence of chest pain. We believe our case, together with those previously reported, supports the view that aortic dissection should be added to the differential diagnosis of thunderclap headache, particularly if the patient also happens to have a history of GCA.