Prevalence and Clinical Predictors of Stroke Mimics in the Extended Thrombectomy Window: A Cross-Sectional Study in Vietnam

BackgroundStroke mimics pose diagnostic challenges in the emergency department, particularly in patients presenting within the 4.5-24 hour thrombectomy window. Misdiagnosis may result in unnecessary interventions or delayed stroke treatment. This study aimed to determine the prevalence, clinical characteristics, and predictors of stroke mimics among suspected stroke patients in this timeframe. MethodsWe conducted a cross-sectional study at Peoples Hospital 115, Vietnam (February-June 2024). Patients presenting with acute neurological deficits underwent standardized magnetic resonance imaging. Logistic regression identified independent predictors of stroke mimics. ResultsAmong 1,180 patients (mean age 62.6 years; 58.6% male), 346 (29.3%) were diagnosed with SMs. Compared to stroke patients, stroke mimics were more likely to be male (77.2% vs. 50.8%, P < 0.001), had lower NIHSS scores (median 8 vs. 12.5, P = 0.013), and shorter hospital stays (median 2 vs. 4 days, P < 0.001). Independent predictors included bilateral leg weakness (OR 23.9; 95% CI, 6.9-33.8), quadriparesis (OR 25.4; 95% CI, 7.8-35.1), dizziness (OR 14.6; 95% CI, 7.1-32.7), headache (OR 13.2; 95% CI, 6.5-26.8), seizures (OR 13.9; 95% CI, 6.7-28.5), altered consciousness (OR 4.9; 95% CI, 2.4-9.8), numbness (OR 6.4; 95% CI, 2.1-12.5), and male sex (OR 3.3; 95% CI, 2.5-4.4). Atrial fibrillation was a negative predictor (OR 0.33). ConclusionsStroke mimics account for nearly one-third of suspected strokes within the extended thrombectomy window. Recognizing specific clinical predictors can improve diagnostic accuracy, reduce unnecessary interventions, and optimize ED resource allocation. Integration of these predictors into triage protocols could support faster, safer decision-making in clinical practice. Key PointsO_ST_ABSWhat is already known on this topicC_ST_ABSStroke mimics are common and complicate triage in the era of thrombectomy; prevalence varies widely but data from Southeast Asia are scarce. What this study addsIn this large Vietnamese cohort, nearly one-third were stroke mimics; distinct clinical predictors were identified. How this study might affect research, practice or policyIncorporating these predictors into triage could reduce unnecessary interventions and optimize ED resources.