scholarly journals The Role of Arterioles and the Microcirculation in the Development of Vasospasm after Aneurysmal SAH

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Masato Naraoka ◽  
Naoya Matsuda ◽  
Norihito Shimamura ◽  
Kenichiro Asano ◽  
Hiroki Ohkuma

Cerebral vasospasm of the major cerebral arteries, which is characterized by angiographic narrowing of those vessels, had been recognized as a main contributor to delayed cerebral ischemia (DCI) in subarachnoid hemorrhage (SAH) patients. However, the CONSCIOUS-1 trial revealed that clazosentan could not improve mortality or clinical outcome in spite of successful reduction of relative risk in angiographic vasospasm. This result indicates that the pathophysiology underlying DCI is multifactorial and that other pathophysiological factors, which are independent of angiographic vasospasm, can contribute to the outcome. Recent studies have focused on microcirculatory disturbance, such as microthrombosis and arteriolar constriction, as a factor affecting cerebral ischemia after SAH. Reports detecting microthrombosis and arteriolar constriction will be reviewed, and the role of the microcirculation on cerebral ischemia during vasospasm after SAH will be discussed.

2011 ◽  
Vol 15 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Bhavani P. Thampatty ◽  
Paula R. Sherwood ◽  
Matthew J. Gallek ◽  
Elizabeth A. Crago ◽  
Dianxu Ren ◽  
...  

2001 ◽  
Vol 95 (3) ◽  
pp. 393-401 ◽  
Author(s):  
Tõnu Rätsep ◽  
Toomas Asser

Object. In this study the authors evaluated the relative role of cerebral hemodynamic impairment (HDI) in the pathogenesis of delayed cerebral ischemia and poor clinical outcome after aneurysmal subarachnoid hemorrhage (SAH). Methods. Cerebral hemodynamics were assessed daily with transcranial Doppler (TCD) ultrasonography in 55 consecutive patients with verified SAH. Hemodynamic impairment was defined as blood flow velocity (BFV) values consistent with vasospasm in conjunction with impaired autoregulatory vasodilation as evaluated using the transient hyperemic response tests in the middle cerebral arteries. A total of 1344 TCD examinations were performed, in which the evaluation of HDI was feasible during 80.9% and HDI was registered during 12% of the examinations. It was found that HDI occurred in 60% of patients and was frequently recorded in conjunction with severe vasospasm (p < 0.05) and a rapid increase of BFV values (p < 0.05). Detection of HDI was closely associated with the development of delayed ischemic brain damage after SAH (p < 0.05). Furthermore, because delayed ischemia was never observed in cases in which vasospasm had not led to the development of HDI, its occurrence increased significantly the likelihood of subsequent cerebral ischemia among the patients with vasospasm (p < 0.05). Detection of HDI was independently related to unfavorable clinical outcome according to Glasgow Outcome Scale at 6 months after SAH (p < 0.05). Conclusions. The results showed that HDI is common after SAH and can be evaluated with TCD ultrasonography in routine clinical practice. Detection of HDI could be useful for identifying patients at high or low risk for delayed ischemic complications and unfavorable clinical outcome after SAH.


2017 ◽  
Vol 97 ◽  
pp. 199-204 ◽  
Author(s):  
Abdulrahman Aldakkan ◽  
Alireza Mansouri ◽  
Blessing N.R. Jaja ◽  
Naif M. Alotaibi ◽  
R. Loch Macdonald ◽  
...  

2019 ◽  
Vol 32 (3) ◽  
pp. 179-188 ◽  
Author(s):  
Isabel Fragata ◽  
Marta Alves ◽  
Ana Luísa Papoila ◽  
Ana Paiva Nunes ◽  
Patrícia Ferreira ◽  
...  

Background Computed tomography (CT) perfusion has been studied as a tool to predict delayed cerebral ischemia (DCI) and clinical outcome in spontaneous subarachnoid hemorrhage (SAH). The purpose of the study was to determine whether quantitative CT perfusion performed within 72 hours after admission can predict the occurrence of DCI and clinical outcome as measured with a modified Rankin scale (mRS) at 3 months after ictus. Methods Cerebral perfusion was assessed in a prospective cohort of patients with acute SAH. CT perfusion parameters at <72 h post SAH were quantitatively measured in the main vascular territories and represented as whole-brain means. Spearman rank correlation coefficient and generalized additive regression models for binary outcome were used. Results A total of 66 patients underwent CT perfusion at <72 h. Poor clinical grade on admission was correlated with worse cerebral perfusion in all parameters. Multivariable analysis yielded an association of time to peak (TTP; odds ratio (OR) = 0.89; 95% confidence interval (CI): 0.77, 1.02; p = 0.083) with the occurrence of DCI. We also found an association of TTP values with poor outcome, with an 8% increase in the odds of mRS > 3 for each one second increase in TTP at admission (OR = 1.08; 95% CI: 1.00, 1.17; p = 0.061). Conclusions We identified an association of early TTP changes with DCI and poor clinical outcome. However, there were no associations with cerebral blood flow or mean transit time and DCI/clinical outcome. CT perfusion still remains to be validated as a tool in predicting outcome in SAH.


Neurosurgery ◽  
1992 ◽  
Vol 30 (1) ◽  
pp. 17???22 ◽  
Author(s):  
Padraic O??Neill ◽  
Steven Walton ◽  
Patrick M. Foy ◽  
Malcom D. M. Shaw

2011 ◽  
Vol 115 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Bartosz T. Grobelny ◽  
Andrew F. Ducruet ◽  
Peter A. DeRosa ◽  
Ivan S. Kotchetkov ◽  
Brad E. Zacharia ◽  
...  

Object Cystathionine β-synthase (CBS) is an enzyme that metabolizes homocysteine to form H2S in the brain. Hydrogen sulfide functions as a vasodilator as well as a regulator of neuronal ion channels and multiple intracellular signaling pathways. Given the myriad effects of H2S, the authors hypothesized that patients possessing gain-of-function polymorphisms of the CBS gene will experience a decreased incidence of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH). Methods Patients were enrolled in a prospective observational database of aSAH outcomes. DNA was extracted from buccal swabs and sequenced for 3 functional polymorphisms of the CBS gene (699C→T, 844ins68, and 1080C→T) by polymerase chain reaction. Serum homocysteine levels (μmol/L) were assayed. Multivariate analysis was used to determine the relationship between CBS genotype and occurrence of both angiographic vasospasm and DCI. Results There were 87 patients included in the study. None of the polymorphisms investigated were significantly associated with the incidence of angiographic vasospasm. However, after controlling for admission hypertension, patients with the gain-of-function 844 WT/ins genotypes were less likely to experience DCI relative to those with the 844 WT/WT genotype (86 patients, p = 0.050), while the decrease-in-function genotype 1080 TT was more likely to experience DCI relative to those with 1080 CC and CT genotypes (84 patients, p = 0.042). Serum homocysteine levels did not correlate with the extent of either angiographic vasospasm or DCI in this analysis. Conclusions Polymorphisms of the CBS gene that impart gain-of-function may be associated with a reduced risk of DCI after aSAH, independent of serum homocysteine. Signaling through H2S may mediate protection from DCI following aSAH through a mechanism that does not involve macrovascular vasodilation.


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