ObjectiveTo explore the relevance of an increase in neutrophil count and early neurological deterioration (END) after intravenous thrombolysis in patients with acute ischemic stroke.MethodsA retrospective study was conducted on the patients who received thrombolysis treatment of alteplase within 4.5 hours after onset between January 2017 and November 2018. Based on the existence of END, the patients were divided into the END group and the non-END group. Univariate and multivariate logistic regression, and receiver operating characteristic curves were used to analyze the relevances between END and the indexes such as neutrophil count, lymphocyte count, and neutrophil to lymphocyte ratio (NLR) after thrombolysis. Paired sample t test and Wilcoxon signed-rank test were used to compare the changes of neutrophil and lymphocyte before and after thrombolysis.ResultsA total of 187 patients were included, including 48 in the END group and 139 in the non-END group. Before thrombolysis, the differences of total protein (t=2.130, P=0.035) and albumin (t=2.777, P=0.007) between the two groups were statistically significant, but the differences in other clinical indexes between the two groups were not statistically significant (P>0.05). After thrombolysis, white blood cell count, neutrophil count, NLR, fibrinase degradation product, baseline and change of National Institute of Health Stroke Scale score, proportion of cardiogenic embolism, degree of responsible vascular stenosis and anterior circulation cortical infarction site were all higher in the END group than those in the non-END group (P<0.05). The total protein, albumin, lymphocyte count and prealbumin in the END group were lower than those in the non-END group (P<0.05). Neutrophil in the END group increased significantly (Z=−2.314, P=0.021) after thrombolysis. Neutrophil count [odds ratio=1.288, 95% confidence interval (1.069, 1.552)] was one of the independent influencing factors of venous thrombolysis END, and the specificity was the highest (the sensitivity was 62.5%, and the specificity was 71.9%).ConclusionsAfter thrombolysis, elevated neutrophil count has some relevance to END. Dynamic monitoring on neutrophil count after intravenous thrombolysis treatment can predict the occurrence of END.