Thunderclap Headache

What is Thunderclap Headache?

Thunderclap headache is a sudden severe headache which reaches its peak intensity within one minute or less. It is sometimes described as "the worst headache of my life." Once present, the headache can last from an hour to days.

Causes of Thunderclap Headache  

Causes of thunderclap headache are subarachnoid hemorrhage, a syndrome called reversible cerebral vasoconstriction syndrome (RCVS), cerebral aneurysms (even unruptured),  cerebral venous sinus thrombosis, cervial artery dissection, spontaneous intracranial hypotension, third ventricle colloid cyst, pituitary apoplexy, epidural cervical hematoma, and hypertensive crisis. Not all cases of thunderclap headache have one of these potentially serious underlying causes, and can be idiopathic, meaning there is no identifiable cause. Idiopathic thunderclap headache is what is known as a diagnosis of exclusion, which means that underlying problems with the blood vessels in the brain or neck should be ruled out first.

Unruptured aneurysms are present in 3.6-6% of the general population. It is thus unclear whether thunderclap headache is always due to an unruptured aneurysm in an individual who has both.

Primary cough headache, exertional headache, and headache associated with sexual activity can also present as thunderclap headache. As mentioned, idiopathic thunderclap headache, in which no underlying problem is identified, can occur. In the past, this has been referred to as "crash migraine."

80% of those with primary thunderclap headache (with no underlying cause) have a triggering event, such as exertion, defecation, coughing, sexual activity, bathing, or emotional disturbance. Although it is not entirely clear why thunderclap headaches occur, it is thought that a sudden change in sympathetic tone of the blood vessels may cause sudden vasodilation resulting in the headache pain.

What Should You Do If You Have a Thunderclap Headache?

If you have a thunderclap headache, you should seek evaluation. You may simply have idiopathic thunderclap headache, or thunderclap headache associated with exertional headache, cough headache, or headache associated with sexual activity. However, no one will know whether there is a more serious and treatable underlying condition unless it is looked for.


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by Christina Peterson, M.D.

edited 7/1/2012