Minor stroke is considered an acute ischemic stroke (AIS) that has a National Institute of Health Stroke Scale (NIHSS) score ≤ 5 points. About 1/3 patients with mild stroke have poor prognosis, whether patients with this type undergo thrombolysis has been a controversial issue. A pooled analysis published in the Lancet in 2014 included 9 high-quality RCT studies of intravenous thrombolysis such as NINDS and IST3, and a total of 666 (10%) patients with mild stroke were included in the analysis. For mild stroke, the proportion of good prognosis in the control group and the alteplase group was 58.9% and 68.7% (OR 1.48, 95%Cl 1.07-2.06), respectively. Therefore, guidelines recommended alteplase thrombolytic therapy for patients with mild stroke. However, PRISMS, a randomized controlled trial of intravenous thrombolytic therapy for mild stroke published in 2018, found that alteplase intravenous thrombolytic therapy did not improve clinical outcomes compared with aspirin in patients with mild non-disabled stroke (90-day mRS 0-1 ratio 78.2% vs 81.5%), and the incidence of symptomatic intracranial hemorrhage was higher. However, a major limitation of the PRISMS study was that more than 85% of patients had numbness and dysarticulation, so this conclusion cannot be extrapolated to patients with other mild stroke symptoms. Moreover, due to the early termination of the sponsorship of this trial, the number of enrolled cases did not reach the pre-designed number, resulting in a serious decline in the authenticity of the study results. Symptoms and outcomes of minor stroke are important criteria for assessment. However, there is currently no uniform standard for the assessment of disability.
Both international and domestic guidelines recommend IVT with alteplase for minor disabling stroke within 4.5h, but not routinely recommend intravenous thrombolysis for minor nondisabling stroke within 4.5h. It is important to underline that strokes with low NIHSS scores are not necessarily nondisabling. Despite, patients with mild stroke symptoms are often excluded from IVT due to safety concerns potentially outweighing the putative benefits of recanalization therapy.
Therefore, the investigators developed a new definition to refine the disability assessment of stroke symptoms. The purpose of this study was to investigate whether AIS patients with NIHSS ≤ 5, a limb-related NIHSS item score of 0, and with any of the following NIHSS item ≥2: Best Gaze, Visual, Facial palsy, Limb ataxia, Sensory, Best language, Dysarthria, Extinction and Inattention, could benefit from intravenous thrombolysis.