Related Experiment Video
Updated: Jan 13, 2026

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Relationship between stroke onset timing and clinical outcomes in ischemic and hemorrhagic strokes: a systematic
Paria Heidari1, Negar Heidari2, Habibolah Khazaie3
1Student Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Insights
Stroke timing impacts patient outcomes. Nighttime strokes, both ischemic and hemorrhagic, are linked to increased severity and poorer results, informing better prevention and treatment strategies.
Area of Science:
- Neurology
- Circadian Biology
- Public Health
Background:
- Cerebrovascular accident (CVA), or stroke, involves interrupted blood flow to the brain, causing neuronal damage.
- Strokes are primarily categorized as ischemic or hemorrhagic.
- Understanding circadian variations in stroke onset is crucial for patient management and research.
Purpose of the Study:
- To systematically review the relationship between stroke onset timing and patient outcomes.
- To analyze timing patterns in both ischemic and hemorrhagic stroke types.
Main Methods:
- Comprehensive search of Embase, PubMed, Scopus, WoS, ScienceDirect, and Google Scholar databases.
- Inclusion of English-based observational studies on CVA risk at various times, with no date restrictions.
- Data extraction and categorization from eligible studies.
Main Results:
- Ischemic strokes predominantly occur in the morning, with some showing bimodal patterns.
- Nighttime strokes (both ischemic and hemorrhagic) are associated with greater severity and unfavorable outcomes.
- Hemorrhagic stroke incidence shows varied patterns, with some studies noting early morning peaks and others late evening/nighttime occurrences.
Conclusions:
- Circadian patterns significantly influence stroke incidence and outcomes.
- These findings can enhance stroke prevention strategies and treatment management.
- Understanding stroke timing is key to improving patient outcomes.
Background:
Cerebrovascular accident (CVA) is a critical medical pathology caused by the interruption of cerebral blood flow and leads to neuronal injury or neurodegeneration. Generally, CVAs are classified into two primary categories of ischemic and hemorrhagic. Investigation of circadian rhythm variation at the time of CVA onset is a critical subject for patient management, clinical treatment, and further scientific research. This systematic review aimed to investigate the relationship between the timing of stroke onset and patient outcomes in both ischemic and hemorrhagic strokes.
Methods:
Following searching strategy designation, international databases of Embase, PubMed, Scopus, WoS, ScienceDirect, and Google Scholar were searched using the MeSH-based keywords. No time restrictions were applied in this regard (by December 8, 2024). All English-based observational studies reporting the risk of CVA at various daytimes were enrolled for screenings and quality control. Finally, eligible studies were selected for data extraction and categorization.
Results:
According to the reports, ischemic strokes strictly occur in morning hours (06:00 to 12:00) while some studies recorded a bimodal pattern (dual peaks during morning and evening). It was also established that the strokes at night were more severe and yielded more unfavorable results. Scattered reports were found regarding the hemorrhagic strokes; some papers revealed the highest incidence in the early morning hours, while others reported the late evening or nighttime occurrence. In addition, some studies showed that nighttime hemorrhagic strokes are usually associated with greater severity and unfavorable clinical outcomes.
Conclusion:
This study clarified the effect of cyclic pattern on the incidence and outcome of stroke. These trends seem greatly accounted for improvement of prevention strategies, management of treatments, and enhancement of patient outcomes.
Related Concept Videos
Ischemic Heart Disease: Overview
Atherosclerosis, the primary malefactor, orchestrates this dangerous condition. It manifests as the accumulation of fatty deposits, akin to insidious plaques, within arterial walls. As time elapses, these plaques metamorphose, hardening and...
Regulation of Stroke Volume
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...

