The following is a summary of “Diagnostic workup of acute headache and subarachnoid hemorrhage in a Norwegian population: An observational study,” published in the June 2024 issue of Neurology by Aaseth, et al.
Due to the limitations of past studies on diagnosing subarachnoid hemorrhage (SAH) with computed tomography (CT) in general emergency departments, researchers aimed to assess the effectiveness of CT and cerebrospinal fluid (CSF) analysis in a real-world setting.
Researchers conducted a retrospective study to investigate the past performance of head CT and CSF spectrophotometry in diagnosing SAH among a primary population of hospitals presenting with acute headaches.
They conducted the study at a large primary hospital serving about 10% of the population of Norwegia. Diagnostic workup data from patients consecutively assessed for acute headache (2009–2020) were collected. All CSF spectrophotometry reports were standardized, and the same CT scanner was used throughout the study.
The results showed 3,227 patients, with a median age of 45 and 63% being women. Among the patients, 170 (5.3% of all patients with acute headache) had SAH. Of the 3,071 patients with CT -negative, 2,852 (93%) underwent lumbar puncture, with 2,796 (98%) CSF reports negative for xanthochromia. The detection rate of aneurysmal SAH by positive xanthochromia was 9 in 2,852 cases (3‰). The miss rate for aneurysmal SAH detection by CT scan was 0 within 6 hours and 1 in 2,852 cases (0.3‰) within 12 hours.
Investigators found head CT scans within 6 hours of acute headache onset to be near-perfect in detecting SAH.