Anterior temporal artery sign in CT angiography predicts reduced fatal brain edema and mortality in acute M1 middle cerebral artery occlusions.

ABSTRACT

BACKGROUND: Mortality in acute ischemic middle cerebral artery (MCA) stroke ranges from 5% to 45%. We identify a vascular imaging sign, presence of "prominent anterior temporal artery" on computed tomography (CT) angiography (CTA) and investigate whether it predicts mortality in acute M1-MCA occlusions. METHODS: One hundred and two patients with acute M1-MCA occlusions from 2003-to 2007 were included in the study. A prominent anterior temporal artery arising from proximal M1 MCA was identified by two readers blinded to clinical outcome. Primary clinical outcome was survival (modified Rankin Scale [mRS] 0-5) at 3 months. RESULTS: An anterior temporal artery arising from M1 MCA was present in 20/102 (20%). Eighteen of 20 (90%) patients with this sign survived at 3 months (mRS 0-5) when compared to 66/82 (80.4%) patients without the sign (odds ratio 2.2 CI(95) .5-10.4). The sign has a sensitivity of 21% (CI(95) .13-.25) but specificity of 89% (CI(95) .64-.98) in predicting survival at 3 months. Positive predictive value was 90% with likelihood ratio of 1.9 (CI(95) .9-7.6). CONCLUSION: Presence of prominent anterior temporal artery in M1-MCA occlusions on CTA identifies a group of patients with reduced case fatality. The mechanism is likely related to a reduced chance of malignant cerebral edema.