Favorable Bridging Therapy Based on DWI-FLAIR Mismatch in Patients with Unclear-Onset Stroke

Abstract

Background and purpose: Standard selection criteria for revascularization therapy usually exclude patients with unclear-onset stroke. Our aim was to evaluate the efficacy and safety of revascularization therapy in patients with unclear-onset stroke in the anterior circulation and to identify the predictive factors for favorable clinical outcome.

Materials and methods: We retrospectively analyzed 41 consecutive patients presenting with acute stroke with unknown time of onset treated by intravenous thrombolysis and/or mechanical thrombectomy. Only patients without well-developed fluid-attenuated inversion recovery changes of acute diffusion lesions on MR imaging were enrolled. Twenty-one patients were treated by intravenous thrombolysis; 19 received, simultaneously, intravenous thrombolysis and mechanical thrombectomy (as a bridging therapy); and 1 patient, endovascular therapy alone. Clinical outcome was evaluated at 90 days by using the mRS. Mortality and symptomatic intracranial hemorrhage were also reported.

Results: Median patient age was 72 years (range, 17-89 years). Mean initial NIHSS score was 14.5 ± 5.7. Successful recanalization (TICI 2b-3) was assessed in 61% of patients presenting with an arterial occlusion, symptomatic intracranial hemorrhage occurred in 2 patients (4.9%), and 3 (7.3%) patients died. After 90 days, favorable outcome (mRS 0-2) was observed in 25 (61%) patients. Following multivariate analysis, initial NIHSS score (OR, 1.43; 95% CI, 1.13-1.82; P = .003) and bridging therapy (OR, 37.92; 95% CI, 2.43-591.35; P = .009) were independently associated with a favorable outcome at 3 months.

Conclusions: The study demonstrates the safety and good clinical outcome of acute recanalization therapy in patients with acute stroke in the anterior circulation and an unknown time of onset and a DWI/FLAIR mismatch on imaging. Moreover, bridging therapy versus intravenous thrombolysis alone was independently associated with favorable outcome at 3 months.

Fig 1.

A 49-year-old woman presented with right hemiplegia and dysarthria (NIHSS score, 13). The patient arrived at the emergency department 72 minutes after symptom detection. MR imaging showed an acute ischemic lesion in the left MCA territory on DWI (A and B) without parenchymal signal changes on FLAIR (C and D) and occlusion of the left MCA (M1 segment) with collateral blood flow in the distal cerebral artery territory on MRA (E). Intravenous thrombolysis was started (0.9 mg/kg) 140 minutes after symptom detection. On DSA, the left MCA was still occluded on the M1 segment (F) and was recanalized after mechanical thrombectomy (TICI 3) (G). Time from symptom detection to recanalization was 189 minutes (3 hours 9 minutes). The mRS score at 3 months was zero.