The word “thunderclap” evokes a certain imagery—something sudden, intense, frightening. When it is associated with headache, the thunderclap is all those things. People who have experienced thunderclap headaches describe them as the worst pain they’ve ever had, equating the pain to being hit with a bat or by a bus. The pain ranks 10 on a severity scale of 1-10 and comes on quicker and with more intensity than other headaches. It can be accompanied by vomiting, numbness and other symptoms.
The thunderclap headache is scary enough on its own—but what does it mean?
Some researchers say the thunderclap headache is a warning sign of an impending rupture of an aneurysm or an aneurysm has ruptured. (An aneurysm is a bulging area in an artery and, if it ruptures, it can cause bleeding in the brain.) Other possible causes include brain infections, blood clots, leakage of spinal fluid and brain tumor.
According to research published in the July 2009 issue of the journal Cephalalgia, one under-recognized cause of the thunderclap headache is reversible cerebral vasoconstriction syndrome (RCVS). RCVS involves the reversible narrowing of cerebral arteries in the brain; if thunderclap headaches recur over a few days to two weeks, researchers say this is a hallmark sign that the patient has RCVS.1
In some cases, there may be no identifiable reason for the pain. But because it’s impossible to tell without a comprehensive diagnostic evaluation, the National Headache Foundation says “thunderclap headaches are medical emergencies that require immediate evaluation.” It will likely require an emergency CT scan or MRA and a lumbar puncture (commonly called a spinal tap) to see if there is blood in the spinal fluid.
References:
1. Cephalalgia. http://onlinelibrary.wiley.com/doi/10.1111/j.1468-2982.2008.01805.x/full
