Safety and Outcomes of Intravenous Thrombolysis in Stroke Mimics

Abstract

Background and Purpose— Efforts to increase the availability and shorten the time delivery of intravenous thrombolysis in patients with acute ischemic stroke carry the potential for tissue plasminogen activator administration in patients with diseases other than stroke, that is, stroke mimics (SMs). We aimed to determine safety and to describe outcomes of intravenous thrombolysis in SM. Methods— We retrospectively analyzed stroke registry data of consecutive acute ischemic stroke admissions treated with intravenous thrombolysis over a 6-year-period. The admission National Institutes of Health Stroke Scale score, vascular risk factors, ischemic lesions on brain MRI (routinely performed as part of diagnostic work-up), and discharge modified Rankin Scale scores were documented. Initial stroke diagnosis in the emergency department was compared with final discharge diagnosis. SM diagnosis was based on the absence of ischemic lesions on diffusion-weighted imaging sequences in addition to an alternate discharge diagnosis. Symptomatic intracranial hemorrhage was defined as brain imaging evidence of intracranial hemorrhage with clinical worsening by National Institutes of Health Stroke Scale score increase of ≥4 points. Results— Intravenous thrombolysis was administered in 539 patients with acute ischemic stroke (55% men; mean age, 66±15 years). Misdiagnosis of acute ischemic stroke was documented in 56 cases (10.4%; 95% CI, 7.9% to 13.3%). Conversion disorder (26.8%), complicated migraine (19.6%), and seizures (19.6%) were the 3 most common final diagnoses in SM. SMs were younger (mean age, 56±13 years) and had milder baseline stroke severity (median National Institutes of Health Stroke Scale, 6; interquartile range, 4) compared with patients with confirmed acute ischemic stroke (mean age, 67±14 years; median National Institutes of Health Stroke Scale, 8; interquartile range, 10; P<0.001). There was no case of symptomatic intracranial hemorrhage in SMs (0%; 95% CI, 0% to 5.5%); 96% of SMs were functionally independent at hospital discharge (modified Rankin Scale, 0 to 1). Conclusions— Our single-center data indicate favorable safety and outcomes of intravenous thrombolysis administered to SM.