Incidence, outcomes and risk factors of rebound neurological deterioration after initial improvement following intravenous thrombolysis: a retrospective cohort study

Introduction In clinical practice, a substantial number of acute ischemic stroke (AIS) patients experience neurological deterioration following by initial early neurological improvement (ENI) after intravenous thrombolysis (IVT), a pattern we define as rebound neurological deterioration (REND). However, the incidence and clinical implications of REND remain unclear. Methods This retrospective study included AIS patients who achieved ENI, defined as ≥ 4-point reduction of National Institutes of Health Stroke Scale (NIHSS) score from baseline to 2 h after IVT. REND was defined as a ≥ 2-point increase in NIHSS score within 24 h from last known well, occurring after ENI and in the absence of symptomatic intracranial hemorrhage. The association between REND and functional outcomes was assessed using multivariable logistic regression models and the independent risk factors of REND were identified through backward stepwise selection. Results A total of 1,025 AIS patients were screened in this retrospective study and 277 patients experienced ENI following IVT were included in the analysis. REND occurred in 19.9% of patients, which was negatively associated with favorable functional outcomes [adjusted OR (95%CI): 0.076 (0.031, 0.186), P < 0.001]. In stepwise logistic regression analysis, younger age [adjusted OR (95%CI): 0.966 (0.939, 0.994), P = 0.017], history of hypertension [adjusted OR (95%CI): 2.728 (1.165, 6.390), P = 0.021], and presence of large vessel occlusion/severe stenosis [adjusted OR (95%CI): 2.159 (1.076, 4.333), P = 0.030] were independent risk factors of REND. Conclusion REND occurred in approximately one-fifth of AIS patients with ENI after IVT and was strongly associated with poor functional outcomes. Younger age, history of hypertension, and large vessel occlusion or severe stenosis were independent risk factors of REND.