Computed Tomography Based Score of Early Ischemic Changes Predicts Malignant Infarction

Abstract

Background and Purpose: Identification of ischemic stroke patients at high risk of developing life-threatening malignant infarction at an early stage is critical to consider more rigorous monitoring and further therapeutic measures. We hypothesized that a score consisting of simple measurements of visually evident ischemic changes in non-enhanced CT (NEMMI score) predicts malignant middle cerebral artery (MCA) infarctions (MMI) with similar diagnostic power compared to other baseline clinical and imaging parameters.Methods: One hundred and nine patients with acute proximal MCA occlusion were included. Fifteen (13.8%) patients developed MMI. NEMMI score was defined using the sum of the maximum diameter (anterior-posterior plus medio-lateral) of the hypoattenuated lesion in baseline-CT multiplied by a hypoattenuation factor (3-point visual grading in non-enhanced CT, no/subtle/clear hypoattenuation = 1/2/3). Receiver operating characteristic (ROC) curve analysis and multivariable logistic regression analysis were used to calculate the predictive values of the NEMMI score, baseline clinical and other imaging parameters.Results: The median NEMMI score at baseline was 13.6 (IQR: 11.6–31.1) for MMI patients, and 7.7 (IQR: 3.9–11.2) for patients with non-malignant infarctions (p < 0.0001). Based on ROC curve analysis, a NEMMI score >10.5 identified MMI with good discriminative power (AUC: 0.84, sensitivity/specificity: 93.3/70.7%), which was higher compared to age (AUC: 0.76), NIHSS (AUC: 0.61), or ischemic core volume (AUC: 0.80). In multivariable logistic regression analysis, NEMMI score was significantly and independently associated with MMI (OR: 1.33, 95%CI: 1.13–1.56, p < 0.001), adjusted for recanalization status.Conclusion: The NEMMI score is a quick and simple rating tool of early ischemic changes on CT and could serve as an important surrogate marker for developing malignant edema. Its diagnostic accuracy was similar to CTP and clinical parameters.

Recanalization status and temporal evolution of early ischemic changes following stroke thrombectomy

“…15 Also, severity of hypoattenuation in infarcted tissue is correlated with worse prognosis, 16 and malignant edema. 17 In our study, no reversal of hypoattenuation was observed and all baseline ischemic changes were also detectable at 24 h (and also in any subsequent CT scan taken during the hospitalization). The same phenomenon was described in the early 2000s.…”

“…Their median age was 71 [IQR 62-79] years and 45% were females. Baseline NIHSS was median 14 [8][9][10][11][12][13][14][15][16][17][18]. Time from last-seen-well to arrival was median 170 [73-347] minutes.…”

“…15 Also, severity of hypoattenuation in infarcted tissue is correlated with worse prognosis, 16 and malignant edema. 17…”

Surgery for Malignant Acute Ischemic Stroke: A Narrative Review of the Knowns and Unknowns

“…41 Recently, a score calculated as the sum of the measurement of the maximum anteroposterior and mediolateral diameter of infarction multiplied by visually graded assessment of hypodensity on admission noncontrast CT (NEMMI score) was found to be useful to predict malignant MCA infarction. 42 In one study, the ability of the NEMMI score to predict malignant transformation was higher than patient's age, stroke severity, and infarct volume. 42 This could be important in an emergency, as the score is not dependent on any other clinical or laboratory characteristics.…”

“…42 In one study, the ability of the NEMMI score to predict malignant transformation was higher than patient's age, stroke severity, and infarct volume. 42 This could be important in an emergency, as the score is not dependent on any other clinical or laboratory characteristics. More research is needed to validate these results with interobserver agreement.…”