Therapeutic Dilemma of Wake-up Stroke: Clinical and Brain Imaging Characteristics and Reperfusion as a Treatment Option

Wake-up stroke (WUS) comprises a significant proportion of ischemic strokes. However, due to unclear onset, these patients are often not considered for reperfusion therapy. The objective of this study was to investigate the clinical and imaging differences between WUS patients and those with clear-onset stroke, documenting any sex, age, or risk factor predilection for WUS.

This prospective observational cohort study used an ongoing stroke registry to identify patients with acute ischemic stroke admitted to a hospital in Saudi Arabia within 5 days of symptom onset from April 2018 to March 2020. Patients were classified into 2 groups: WUS and clear-onset stroke.

Among 645 patients, 448 met the criteria for acute ischemic stroke and were included in the study. WUS was identified in 112 (25%) patients. There were no differences in sex or median age between the 2 groups. Diabetes mellitus, hypertension, and dyslipidemia were higher in the WUS group, while atrial fibrillation, history of stroke and epilepsy were higher in the clear-onset stroke group. Bihemispheric stroke was higher in the clear-onset stroke group than in the WUS group (6.0% vs 2.7%).

Only minor dissimilarities between clinical and radiologic features of WUS and clear-onset stroke were found. Circadian patterns of stroke onset were observed in both groups. Stroke was more likely to occur during waking than during sleep, and a diurnal pattern of common occurrence during the morning was documented. Recognition of the acceptable timeframe for acute reperfusion therapy in unwitnessed strokes is crucial so that thrombolytic treatment can be started for these patients.