N J Giffin

Abstract

Sudden severe headache is a cardinal feature of subarachnoid haemorrhage (SAH) and other potentially life threatening neurological conditions. Early diagnosis and management improves the outcome of SAH. In general practice, benign thunderclap headache vastly outnumbers SAH as a cause of sudden headache. Thunderclap headache is a diagnosis of exclusion and all patients admitted with a first presentation of a severe headache lasting more than one hour should be investigated with a CT and lumbar puncture. It must be borne in mind that these investigations may miss diagnoses such as venous sinus thrombosis and Magnetic Resonance Angiography (MRA) should be performed if clinical suspicion remains high.