Value of Whole Brain Computed Tomography Perfusion for Predicting Outcome after TIA or Minor Ischemic Stroke

Abstract

Introduction: About 15% of patients with transient ischemic attack (TIA) or minor ischemic stroke have functional impairment after 3 months. We studied the role of whole brain computed tomography perfusion (WB-CTP) in the emergency diagnosis of TIA or minor stroke in predicting disability at 3 months.

Methods: We included patients with ongoing symptoms of a TIA or minor stroke with a National Institutes of Health Stroke Scale (NIHSS) score less than 4 who were evaluated with noncontrast CT (NCCT), CT angiography (CTA), and WB-CTP within 24 hours of symptom onset. Patients treated with thrombolysis or a premorbid modified Rankin Scale (mRS) score greater than 1 were excluded. The association between clinical or imaging features and disability (mRS score ≥2) at 3 months was analyzed with Poisson regression. Potential additional prognostic value of WB-CTP was assessed with logistic regression.

Results: We included 115 patients in 2012 to 2013. Median age was 68 years, and 66% were men. At 3 months, 20 patients (17%) were disabled. NIHSS score on admission (relative risk [RR], 3.6; 95% confidence interval [CI], 1.4-9.3), female sex (RR, 2.4; 95% CI, 1.1-5.3), early ischemic changes on NCCT (RR, 5.0; 95% CI, 2.6-9.9), extracranial or intracranial vessel stenosis ≥50% on CTA (RR, 3.0; 95% CI, 1.4-6.4), and perfusion abnormalities on WB-CTP (RR, 11.4; 95% CI, 4.6-28.2) were associated with disability at 3 months. In multivariable analysis, the relation between perfusion abnormalities and poor outcome remained essentially the same. WB-CTP showed prognostic value in addition to proved clinical and imaging predictors of disability.

Conclusions: WB-CTP is useful to identify patients with TIA or minor ischemic stroke at high risk of functional impairment at 3-month follow-up.

Keywords: Minor ischemic stroke; computed tomography perfusion; disability; transient ischemic attack.