title: Acute headache and subarachnoid haemorrhage: a retrospective review of CT and lumbar puncture findings.
abstract: OBJECTIVE
  Assess and correlate the clinical presentation, cranial CT and lumbar puncture (LP) findings in patients presenting with acute headache, clinically suspicious of subarachnoid haemorrhage, from the Accident and Emergency (A/E) department of a main teaching hospital.
  
  
  METHODS
  We retrospectively reviewed over a 1-year period all patients referred for cranial CT from the A/E department, with clinically suspected non-traumatic SAH. Patients with a negative CT, with a diagnosis of SAH on LP, had their initial CT examination reassessed in a double blind review.
  
  
  RESULTS
  116 consecutive patients were included in the study. Patients were divided into 3 groups post CT results: diagnostic of SAH (19), abnormal without evidence of SAH (16) and normal (81). The clinical management of the latter group was analysed with particular emphasis on the performance and results of lumbar puncture (LP). 81 patients, clinically suspicious of SAH in our study had a normal cranial CT and were eligible for LP 49% had an LP, which was positive in 15% and contributed 24% to the total number diagnosed with SAH. LP was not performed in 51% of eligible patients.
  
  
  CONCLUSIONS
  This study reviews the varying clinical presentations of SAH and the difficulty in clinically diagnosing SAH where headache is the only symptom. We review the wide differential diagnosis on cranial CT and on discharge of patients presenting with symptoms clinically suspicious of SAH. In addition this study identfies a high proportion of patients without detailed clinical notes and discharged without a diagnosis. The study reaffirms that a significant proportion of patients are diagnosed on LP and stress the importance of performing a LP in all cases with clinically suspected SAH with a negative CT This latter point requires highlighting in the medical literature as over half of eligible patients did not have a LP performed despite this being accepted diagnostic protocol.
authors.affiliation: Department Clinical Radiology, Royal Infirmary Edinburgh. johnandal101@hotmail.com
authors.forename: J
authors.initials: J
authors.lastname: O'Neill
authors.forename: S
authors.initials: S
authors.lastname: McLaggan
authors.forename: R
authors.initials: R
authors.lastname: Gibson
mesh_terms: D006801:Humans; D012189:Retrospective Studies; D013129:Spinal Puncture; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed