Abstract

Thunderclap headache (TCH) is an acute severe headache that is maximal in intensity at onset. TCH may be the first sign of such sometimes life-threatening situations as subarachnoid haemorrhage, sentinel headache, cerebral venous sinus thrombosis, cervical artery dissection, spontaneous intracranial hypotension, pituitary apoplexy, ischemic stroke, acute hypertensive crisis and other less frequent causes. In these cases TCH is defined as secondary. Primary TCH is a diagnosis of exclusion. It is based on the clinical presentation of typical headache with all secondary causes excluded by thorough visualizing and laboratory investigations. The pathogenesis of TCH is unclear at the present time. Hypothetically secondary TCH is related to irritation of the intracranial pain-sensitive structures. The production of headache in primary TCH might be explained by a heightened response to endogenous circulating catecholamines, exaggerated stimulation of sympathetic receptors by exogenous drugs, or abnormal antidromic discharge of sympathetic afferents, which all can induce acute vasoconstriction and headache. Using visualizing methods in TCH should be obligatory.