Evaluation of Cerebral Vasospasm after Subarachnoid Hemorrhage Based on Serial 3D-CTA Findings

Abstract

We assess the usefulness of serial three-dimensional CT angiography (CTA) in the diagnosis of cerebral vasospasm (VS), and evaluate the contribution of VS to symptomatic vasospasm (SVS), cerebral infarction, and modified Rankin scale (mRS) in patients with aneurysmal subarachnoid hemorrhage (SAH). Within 3 hours after the onset of symptoms, CTA was performed in 48 patients with SAH. CTA was repeated on Day 5-8 (median 7) and Day 12-15 (median 14) to assess VS. Vasospasm was defined as ≥25% vascular narrowing, and rated with the following criteria (degree of VS): moderate spasm (25-50% decrease in vessel diameter), and severe spasm (≥50% decrease). Vasospasm was also categorized as follows (CTA grade): no VS, local VS, and diffuse VS. By local VS we mean an area of narrowing of the vessel in continuity with an aneurysm and not extending more than 2 cm to the aneurysm, or limited to the A-1, A -2 portion (≤2 cm). Diffuse VS means any stenosis affecting either a long segment of vessel or distal segments of cerebral arteries.Aggressive treatments for the VS including triple H therapy were started, when either SVS was revealed or Diffuse VS was detected on CTA. We statistically investigate correlations of Hunt and Kosnik grade, Fisher CT group, degree of VS, and CTA grade, with SVS, cerebral infarction, and mRS. Of the 48 patients, 32 (67%) showed VS and 19 (40%) revealed SVS by the 3rd CTA.Cerebral infarction on CT was detected in 13 (27%) patients. With logistic regression analysis, CTA grade significantly correlated with SVS and infarction, while Hunt and Kosnik grade and age of the patients significantly correlated with mRS.Prospective evaluation of CTA following SAH might allow early recognition of VS and promote aggressive treatment and improved neurological outcomes.