A previously fit and healthy 57 year old gentleman presented to hospital 2 weeks after a previous admission with acute severe headache. At the time of his previous admission the patient had reported that the headache was preceded by an unprovoked sharp pain in his back which had quickly resolved. The headache developed a few hours later and was noted to be markedly worsened by any attempt to sit upright, accompanied by intense nausea, and relieved by lying flat. [download-attachments container="div" style="list" display_icon="1" display_count="1" display__size="0"]