Do All ASPECT Score Regions have the Same Predictive Power for Functional Outcomes?

ABSTRACT

BACKGROUND AND PURPOSE: ASPECTS (Alberta Stroke Program Early CT Score) is a 10-point topographic CT scan score that has been shown to be a strong prognostic factor in acute ischemic stroke. We investigated whether all ASPECTS regions have the same prognostic value. METHODS: Clinical characteristics, ASPECTS, and 3-month modified Rankin Scale (mRS) data were retrospectively collected in 350 patients who were diagnosed with middle cerebral artery (MCA) territory stroke. To describe the 3-month mRS data, an ordered categorical approach was applied using a proportional odds model. Furthermore, external validation was performed using additional data from 30 patients. RESULTS: As expected, ASPECTS was an independently important predictor. However, when 10 regions were analyzed separately, the M1, M2, and M3 regions, related to MCA cortex, were not found to predict 3-month mRS scores in the final model. The odds ratios for ischemic change in other regions (except M1, M2, and M3) ranged from 2.6 to 3.8. Moreover, among clinical characteristics, only age was identified as a significant predictor. The sensitivity and specificity of the final model in the external validation were 91% and 88%, respectively. CONCLUSIONS: All ASPECTS regions did not have the same predictive power for functional outcomes, defined as the 3-month mRS. The implementation of a proportional odds model allowed a proper description of the ordered categorical nature of the mRS and the identification of relevant predictors.