Follow-Up Imaging in Angiography-Negative Spontaneous Subarachnoid Hemorrhage

The aim of this study was to assess the diagnostic yield of follow-up investigations in aneurysm-negative subarachnoid hemorrhage (SAH) patients.

In 109 (25%) of 435 patients with SAH and initial negative digital subtraction angiography (DSA), the diagnostic yield of repeat DSA and magnetic resonance imaging (MRI) of the brain and craniocervical junction was reviewed.

Of the 109 patients with an initial negative DSA, 51 (47%) had perimesencephalic (PM), 54 (50%) had nonperimesencephalic (NPM) blood distribution, and 4 (3.7%) had computed tomography-negative SAH. A delayed bleeding source was determined in 3 of 82 (3.7%) patients who underwent repeat DSA and in 1 of 5 patients who underwent a third DSA. The bleeding patterns of these patients were all NPM (n = 4). Repeat DSA did not identify a bleeding source in patients with PM-SAH. MRI of the brain and craniocervical junction after 2 days revealed a bleeding source in 1 of 105 patients (1%) in a computed tomography-negative SAH. When all diagnostic modalities, including exploratory craniotomy and MRI of the spinal axis, were considered, the rate of delayed diagnosis of the bleeding source was 6.4% (7/109). In addition to the bleeding pattern, patients with delayed diagnosis of the bleeding source were characterized by worse disease severity parameters, worse radiological grading scales, and more in-hospital complications than patients without delayed diagnosis of a bleeding source.

The results of this study support the use of repeat DSA in patients with NPM-SAH; however, routine repeat DSA may not be indicated in PM-SAH patients. The routine use of MRI remains controversial.