Should IV Thrombolysis be given in Patients with Suspected Ischemic Stroke but Unknown Symptom Onset and Without Diffusion-Weighted Imaging Lesion? - Results of a Case-Control Study.

Background: Many acute ischemic stroke (AIS) patients present with unknown time of symptom onset (UTO). In these situations, wake-up MRI protocols can guide treatment decisions: patients with DWI (diffusion-weighted imaging) but no fluid-attenuated inversion recovery lesion were shown to benefit from IVT (intravenous thrombolysis). However, initial MRI of some stroke patients is DWI negative, leaving it unclear whether this subgroup profits from IVT. Therefore, we aimed to compare the safety and efficacy of IVT in wake-up AIS patients with or without a DWI lesion in initial imaging.

Methods: We performed a case-control study. All AIS patients with UTO who underwent wake-up MRI and were treated with IVT at a German University Hospital from 2013 to 2017 were included. Patients without (DWI-) were compared to patients with DWI lesion (DWI+) regarding clinico-radiological characteristics, adverse events, and outcome at discharge. Likely stroke mimics were excluded.

Results: Eleven DWI- and 32 DWI+ patients were included. There were no statistically significant differences regarding functional scores, age, sex, door-to-needle time, bleeding complications, and death. DWI+ patients more frequently had anterior circulation stroke (P = .049) and higher modified Rankin Scale (mRS) scores at discharge (P = .048). Solely in the DWI+ group 3 bleeding complications (2 asymptomatic hemorrhagic transformations, 1 muscle hematoma) and 3 deaths occurred (P = .29). A favourable outcome (mRS≤ 2) was achieved in 82% of the DWI- and in 58% of the DWI+ group (p > .05).

Conclusions: Our data suggest that IVT may be used in DWI- patients with UTO with acute neurological symptoms very likely to be related to AIS.