UMEM Educational Pearls

Category: Neurology

Title: Thunderclap Headache

Keywords: SAH, cerebral venous thrombosis, head CT (PubMed Search)

Posted: 9/23/2015 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

A thunderclap headache is defined as a very severe headache that reaches its maximum intensity within 1 minute.

One of the most common causes (and the one associated with this buzzword on board questions!) is subarachnoid hemorrhage, but what else can cause a it?

Reversible cerebral vasoconstriction syndrome (RCVS): suggested by recurrent thunderclap headaches (2-10) over 1 to 2 weeks. Normal CT and LP, with vasoconstriction on angiography. Can lead to SAH, ICH or ischemic stroke.

- Cervical artery dissection

- Cerebral venous sinus thrombosis

- Spontaneous intracranial hypotension: characterized by orthostatic HAs and auditory muffling.

- Intracerebral hemorrhage

Primary”: a diagnosis of exclusion

Bottom line? All patients with thunderclap HA should have a stat head CT with no contrast, then have SAH excluded with an LP, CTA or MRI/MRA. Just because you excluded SAH in a patient with thunderclap headache does not mean you’re done with the emergency workup. 


TJ Schwedt. Thunderclap Headache. Continuum 2015; 21(4): 1058-71