Daily Variation in the Occurrence of Different Subtypes of Stroke.

Luciana Ripamonti,Roberto Riva,Fabiola Maioli,Gaetano Procaccianti,Corrado Zenesini

doi:10.1155/2017/9091250

Abstract

Three thousand two hundred and ninety-eight patients admitted to our Stroke Unit with hemorrhagic, large artery atherosclerosis, cardioembolic, small-vessel occlusion, and undetermined etiology-cryptogenic strokes were included in the study. The circadian variability in onset in each stroke subgroup and the associations with various risk factors were analyzed. In each subgroup, a significant minority of patients suffered from stroke during sleep. In the ischemic group, hypercholesterolemia, paroxysmal atrial fibrillation, and previous myocardial infarction facilitated the onset during waking. During waking, stroke onset was significantly higher in the morning compared to the afternoon both in the hemorrhagic and in the ischemic type. In hemorrhagic stroke, a previous stroke was associated with a lower early morning occurrence. In large artery atherosclerosis stroke, males were at higher risk of early morning occurrence (p < 0.01). In small-vessel occlusion stroke, hypertension is significantly more present in the morning compared to the afternoon onset (p < 0.005). Circadian patterns of stroke onset were observed both in hemorrhagic and in ischemic stroke, irrespective of the ischemic subgroup. In all groups, stroke was more likely to occur during waking than during sleep and, in the diurnal period, during morning than during afternoon. Moreover, sex and some clinical factors influence the diurnal pattern.

Highlights

Circadian variation in stroke onset has been analyzed since the early 1970s, but until the beginning of the new millennium data were very discordant [1, 2]
Our study has the strength of considering the stroke onset in relation to patient characteristics in a large cohort of patients drawn from a well-defined catchment area
In all cases considered there was indication of precise stroke onset and if it was reported on awakening we considered it as asleep onset

Summary

Introduction

Circadian variation in stroke onset has been analyzed since the early 1970s, but until the beginning of the new millennium data were very discordant [1, 2]. Risk factors have been given little consideration in relation to daily onset in stroke subtypes and mostly without significant results [4, 5, 10, 17, 32,33,34,35,36,37]. Most authors have not studied the subtype simultaneously or, when done, the number of patients was too small to investigate the difference in circadian onset or the association between circadian rhythms and risk factors in the various stroke subtypes

Objectives

Methods

Discussion

Conclusion