Original Article

Neurocritical Care

, Volume 16, Issue 2, pp 219-223

First online:

Circadian Variation in Ictus of Aneurysmal Subarachnoid Hemorrhage

  • Richard E. TemesAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center Email author 
  • , Thomas BleckAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Siddharth DugarAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Bichun OuyangAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Yousef MohammadAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Sayona JohnAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Pratik PatelAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Vivien LeeAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
  • , Shyam PrabhakaranAffiliated withDivison of Cerebrovascular Disease and Neurocritical Care, Rush University Medical Center
    • , Mark QuiggAffiliated withDepartment of Neurology, University of Virginia

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Background

Temporal patterns in aneurysmal subarachnoid hemorrhage (aSAH) may provide insight into modulation, and therefore, prevention of hemorrhage. We investigated the time of hemorrhage and its relationship to traditional risk factors among patients admitted with aSAH.

Methods

Admitted patients with aSAH were prospectively followed through outcomes and baseline demographics were abstracted through chart review. The group temporal distribution by hour of onset was summarized with cosinor nonlinear least squares. aSAH onset was gathered into night (2300–0500), morning (0500–1100), afternoon (1100–1700), and evening (0500–2300) daily phases. The odds ratio (OR) with 95% CI was calculated for having an aSAH during the morning, afternoon, and evening hours using night as a reference. Multinomial logit models were fitted using aSAH cases across time blocks to determine their associations with different risk factors.

Results

202 patients had the hour of hemorrhage available, and 49 had phase identifiable [total 251: 38 (15%) night, 98 (39%) morning, 58 (23%) afternoon, 57 (23%) evening]. The peak hours of aSAH were between 0700 and 0800 representing 13% of the sample, with a significant cosinor-fitted phase of 7.33(95% CI 5.30, 9.36). For all aSAH cases, morning onset was significantly more common than night onset (OR = 2.58, 95% CI = 1.77–3.75). Nonsmokers were more likely to have aSAH in the morning than smokers (P = 0.043, OR = 3.10, 95% CI = 1.33–7.23).

Conclusions

aSAH occur in a diurnal, morning prevalent pattern regardless of traditional aSAH risk factors. The association of these risk factors with existing onset patterns should be investigated in future studies.

Keywords

Circadian rhythm Subarachnoid hemorrhage Risk factors Neurocritical Care Ictus