Circadian variation in acute ischemic stroke: a hospital-based study

Area of Science:

• Neurology
• Chronobiology
• Epidemiology

Background:

• Investigated circadian rhythm in ischemic stroke onset.
• Differentiated between first-ever and recurrent stroke subtypes.

Purpose of the Study:

• To analyze the circadian patterns of ischemic stroke onset.
• To compare these patterns across different stroke subtypes.
• To assess differences between first-ever and recurrent strokes.

Main Methods:

• Analyzed 1223 ischemic stroke patients from two hospitals.
• Recorded symptom onset time, distinguishing between asleep and awake onset.
• Compared circadian rhythms across stroke types and recurrence status.

Main Results:

• 914 patients had known onset times; 25.6% awoke with stroke symptoms.
• Thrombotic and lacunar strokes showed higher onset incidence upon awakening.
• All subtypes exhibited diurnal variation, with a morning peak, minimized when accounting for awakenings. No circadian rhythm differences were observed between first-ever and recurrent strokes.

Conclusions:

• A circadian rhythm exists for all ischemic stroke types, with higher daytime incidence.
• The morning peak may be overestimated due to stroke onset upon awakening.
• Circadian patterns do not differ between first-ever and recurrent ischemic strokes.