Temporal lobe atrophy as a potential predictor of functional outcome in older adults with acute ischemic stroke

Background: To explore whether temporal lobe atrophy predicts 3-month functional outcome in a population of patients with anterior circulation acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT). Methods: We retrospectively selected patients > 65 years from our prospective endovascular stroke registry between June 2013 and August 2018. According to 3-month modified Rankin Scale (mRS), patients were divided in two groups, named good (mRS ≤ 2) and poor (mRS > 2) outcome. Measures of temporal lobe atrophy (i.e., interuncal distance [IUD], medial temporal lobe thickness [mTLT] and radial width of temporal horn [rWTH]) were assessed on pre-treatment CT scan. Cutoff values for good outcome were obtained for IUD, mTLT and rWTH by means of non-parametric ROC curve analysis. Multivariate analysis was performed to identify predictors of outcome. Ordinal shift analysis based on cutoff values was built to evaluate differences in 3-month mRS. Results: Among 340 patients, 130 (38.2%) had good and 210 (61.8%) had poor outcome. We found the following cutoff values for good outcome: < 25 mm for IUD, > 15 mm for mTLT and < 4 mm for rWTH. Lower IUD (OR 0.71; 95% CI 0.63–0.80; p < 0.0001) and rWTH (OR 0.73; 95% CI 0.61–0.87; p < 0.0001) and higher mTLT (OR 1.30; 95% CI 1.14–1.49; p < 0.0001) were independently associated with good outcome. Ordinal shift analysis based on cutoff values revealed significant differences in the rate of good outcome for rWTH (49 vs 27%; p < 0.0001), mTLT (52 vs 21%; p < 0.0001) and IUD (57 vs 17%; p < 0.0001). Conclusions: Assessment of temporal lobe atrophy may predict functional outcome in patients with AIS treated with MT.