Introduction: Acute brain infarction (BI) topology determined by diffusion weighted imaging - Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) on post-treatment magnetic resonance imaging (MRI) has been associated with clinical outcome in internal carotid artery (ICA) or proximal middle cerebral artery (MCA) occlusion treated by endovascular reperfusion therapy (EVRT).
Hypothesis: We hypothesize that among the same type of patients, the topology of acute BI captured by DWI ASPECTS on baseline MRI may be associated with 3 months functional outcome after EVRT.
Methods: Consecutive patients with an acute BI complicating ICA or proximal MCA occlusion treated by EVRT after a baseline MRI before treatment at a single center between April 2007 and March 2013 were enrolled. Poor functional outcome was defined by modified Rankin Scale (mRS) of 3 to 6 at 3 months. We used penalized logistic regression due to the multicollinearity between DWI-ASPECTS sites to assess the relationship between each DWI-ASPECTS sites and functional outcome after adjustment for age, sex, blood pressure, DWI lesion volume and infarct side. We estimated this relationship in the full cohort of patients and according to the achievement of a complete recanalization.
Results: We enrolled 206 patients [mean age 71 ± 16.5, median NIHSS 16 (IQR 10-21)]. Among them 58 (28%) had an ICA occlusion, 115 (56%) a MCA M1 occlusion and 33 (16%) a MCA M2 occlusion. Median DWI lesion volume was 13 mL (IQR 4-43), and median DWI ASPECTS score was 6 (IQR 4-8). A complete recanalization was achieved among 96 patients (47%), after a median time from onset of 237 min (IQR:185-282). The involvement of the lentiform nucleus was associated with poor functional outcome in the full cohort of patients [OR : 10; 95% CI (5-23); p<0.0001]. This relationship was observed in the subgroup of patients who did experience a complete recanalization [OR : 4; 95% CI (1.5-12); p=0.007] and among those who did not [OR : 21; 95% CI (5-92); p<0.0001].
Conclusions: In conclusion, the involvement of the DWI ASPECTS lentiform region on baseline MRI in patients experiencing an acute BI complicating an ICA or MCA occlusion treated by EVRT was associated with poor functional outcome, overall and despite a complete recanalization.