TY - JOUR T1 - EMQ answers <a href="pending:yes" l:rel="in-this-issue" l:ref-type="journal" hwp:journal="emermed" hwp:volume="25" hwp:fpage="394">394</a> JF - Emergency Medicine Journal JO - Emerg Med J SP - 464 LP - 464 VL - 25 IS - 7 A2 - , Y1 - 2008/07/01 UR - http://emj.bmj.com/content/25/7/464.abstract N2 - True. The frequency of sentinel headaches preceding confirmed subarachnoid haemorrhage ranges widely in studies from 10–43%.1 This variability is only partly explained by recall bias. A recent review recommends that the term sentinel bleed should be abandoned: “people have either had a subarachnoid haemorrhage or not and the important task is to recognise when they have.”2False. The false negative rate is approximately 2% when performed within 12 h, increasing to 7% by 24 h. Subarachnoid blood is almost completely reabsorbed at 10 days.2False. There is currently no sound … ER -