Thunderclap headaches are sudden headaches with severe intensity, peaking within one minute. The term was first used in a patient who had three episodes of “intense sentinel headache of sudden onset” before an unruptured aneurysm was found. Reversible cerebral vasoconstriction syndrome (RCVS), a recently recognized syndrome characterized by continuous thunderclap headache attacks has been proposed to account for most of these cases. This research was published in The Journal of Headache and Pain.

RCVS is a clinical emergency linked with potential clinical worsening, morbidity and even mortality.

In this study, patients experiencing sudden headaches in Taiwan’s Far Eastern Memorial Hospital were monitored between the period July 2010 to June 2013. They were requested to fill out a detailed headache intake form, have their medical and headache histories recorded, receive a neurological examination and were suggested to keep a headache diary. Neuroimaging studies, including brain computed tomography (CT),  magnetic resonance imaging (MRI) with 3-dimensional reformatting angiography (CTA and/or MRA), were arranged to identify vasoconstriction.

Patients were also more likely to report bathing as their headache trigger, and less likely to cite exertion. They were also found among older patients who had longer headache duration.

According to the study, RCVS is unifying term which encompasses a group of recurrent headache syndromes including: Call-Fleming syndrome, thunderclap headache with reversible vasospasm, benign angiopathy of the central nervous system, postpartum cerebral angiopathy, among others.

Read the full article: A common cause of sudden and thunderclap headaches: reversible cerebral vasoconstriction syndrome.