All thunderclap headaches are equal but some are more equal than others

Abstract

Purpose Subarachnoid haemorrhage (SAH) is a life-threatening condition with a clear investigative pathway. Unlike the diagnosis, its principle symptom – thunderclap headache – is common. The aim of this study is to determine how SAH is investigated in our department and to analyse clinical characteristics of the proven SAH. Methods and materials Glasgow Royal Infirmary’s Emergency Department (ED) and Acute Assessment Unit (AAU) 2013 computed tomography (CT) data were pulled from the radiology information system (RIS), searched and manually reviewed to leave CT head examinations performed to investigate SAH. Clinical information about these cases was then accessed from Clinical Portal. Results The study identified 1,865 CT heads, 426 to exclude subarachnoid haemorrhage. Sixteen patients had subarachnoid haemorrhage, 13 of who had SAH on CT (all within 11 hours of headache); three had SAH on lumbar puncture (LP) (all greater than 21 hours since headache). Twenty-two patients refused investigation, 257 had normal CTs and negative LP and 131 had normal CTs and no negative LP. Forty-seven of these 131 were discharged without a diagnosis. Conclusion The near ubiquity of CT availability and the incidence of headache means that many people enter a SAH diagnostic pathway but never complete the journey, despite potential complications of a missed diagnosis. These data advocate early CT for SAH and offer some reassurance to the clinician managing a late-presenting thunderclap headache. Subarachnoid haemorrhage (SAH) is a life-threatening condition with a clear investigative pathway. Unlike the diagnosis, its principle symptom – thunderclap headache – is common. The aim of this study is to determine how SAH is investigated in our department and to analyse clinical characteristics of the proven SAH. Glasgow Royal Infirmary’s Emergency Department (ED) and Acute Assessment Unit (AAU) 2013 computed tomography (CT) data were pulled from the radiology information system (RIS), searched and manually reviewed to leave CT head examinations performed to investigate SAH. Clinical information about these cases was then accessed from Clinical Portal. The study identified 1,865 CT heads, 426 to exclude subarachnoid haemorrhage. Sixteen patients had subarachnoid haemorrhage, 13 of who had SAH on CT (all within 11 hours of headache); three had SAH on lumbar puncture (LP) (all greater than 21 hours since headache). Twenty-two patients refused investigation, 257 had normal CTs and negative LP and 131 had normal CTs and no negative LP. Forty-seven of these 131 were discharged without a diagnosis. The near ubiquity of CT availability and the incidence of headache means that many people enter a SAH diagnostic pathway but never complete the journey, despite potential complications of a missed diagnosis. These data advocate early CT for SAH and offer some reassurance to the clinician managing a late-presenting thunderclap headache.