Thunderclap headache and benign angiopathy of the central nervous system: a common pathogenetic basis.

Thunderclap headache (TCH) is a head pain that begins suddenly and is severe at onset; TCH might be the first sign of different neurological illnesses, and primary TCH is diagnosed when no underlying cause is discovered. Patients with TCH who have evidence of reversible, segmental, cerebral vasoconstriction of circle of Willis arteries and normal or near-normal results on cerebrospinal fluid assessment are thought to have reversible cerebral vasoconstriction syndrome (RCVS). Herein, we discuss the differential diagnosis of TCH and offer pathophysiological considerations for TCH and RCVS.