Capillary flow disturbances after experimental subarachnoid hemorrhage: A contributor to delayed cerebral ischemia?

2019 ◽  
Vol 26 (3) ◽  
pp. e12516 ◽  
Author(s):  
Maryam Anzabi ◽  
Hugo Angleys ◽  
Rasmus Aamand ◽  
Maryam Ardalan ◽  
Kim Mouridsen ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cerebral Ischemia ◽  
Capillary Flow ◽  
Delayed Cerebral Ischemia ◽  
Flow Disturbances ◽  
Experimental Subarachnoid Hemorrhage

Scavenging Free Iron Reduces Arteriolar Microvasospasms After Experimental Subarachnoid Hemorrhage

Stroke ◽  
2021 ◽  
Author(s):  
Hanhan Liu ◽  
Julian Schwarting ◽  
Nicole Angela Terpolilli ◽  
Kathrin Nehrkorn ◽  
Nikolaus Plesnila
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cerebral Ischemia ◽  
Delayed Cerebral Ischemia ◽  
Neurological Deficits ◽  
Free Iron ◽  
Acute Cerebral Ischemia ◽  
Experimental Subarachnoid Hemorrhage ◽  
Underlying Mechanisms ◽  
Novel Therapeutic Strategies

Background and Purpose: Subarachnoid hemorrhage (SAH) is associated with acute and delayed cerebral ischemia resulting in high acute mortality and severe chronic neurological deficits. Spasms of the pial and intraparenchymal microcirculation (microvasospasms) contribute to acute cerebral ischemia after SAH; however, the underlying mechanisms remain unknown. We hypothesize that free iron (Fe 3+ ) released from hemolytic red blood cells into the subarachnoid space may be involved in microvasospasms formation. Methods: Male C57BL/6 mice (n=8/group) received 200 mg/kg of the iron scavenger deferoxamine or vehicle intravenously and were then subjected to SAH by filament perforation. Microvasospasms of pial and intraparenchymal vessels were imaged three hours after SAH by in vivo 2-photon microscopy. Results: Microvasospasms occurred in all investigated vessel categories down to the capillary level. Deferoxamine significantly reduced the number of microvasospasms after experimental SAH. The effect was almost exclusively observed in larger pial arterioles (>30 µm) covered with blood. Conclusions: These results provide proof-of-principle evidence that Fe 3+ is involved in the formation of arteriolar microvasospasms after SAH and that arteriolar and capillary microvasospasms are triggered by different mechanisms. Deciphering the mechanisms of Fe 3+ -induced microvasospasms may result in novel therapeutic strategies for SAH patients.

scholarly journals Association of transcranial Doppler blood flow velocity slow waves with delayed cerebral ischemia in patients suffering from subarachnoid hemorrhage: a retrospective study

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Vasilios E. Papaioannou ◽  
Karol P. Budohoski ◽  
Michal M. Placek ◽  
Zofia Czosnyka ◽  
Peter Smielewski ◽  
...  
Keyword(s):  
Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Cerebral Ischemia ◽  
Flow Velocity ◽  
Transcranial Doppler ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Delayed Cerebral Ischemia ◽  
Area Under The Curve ◽  
Slow Waves

Abstract Background Cerebral vasospasm (VS) and delayed cerebral ischemia (DCI) constitute major complications following subarachnoid hemorrhage (SAH). A few studies have examined the relationship between different indices of cerebrovascular dynamics with the occurrence of VS. However, their potential association with the development of DCI remains elusive. In this study, we investigated the pattern of changes of different transcranial Doppler (TCD)-derived indices of cerebrovascular dynamics during vasospasm in patients suffering from subarachnoid hemorrhage, dichotomized by the presence of delayed cerebral ischemia. Methods A retrospective analysis was performed using recordings from 32 SAH patients, diagnosed with VS. Patients were divided in two groups, depending on development of DCI. Magnitude of slow waves (SWs) of cerebral blood flow velocity (CBFV) was measured. Cerebral autoregulation was estimated using the moving correlation coefficient Mxa. Cerebral arterial time constant (tau) was expressed as the product of resistance and compliance. Complexity of CBFV was estimated through measurement of sample entropy (SampEn). Results In the whole population (N = 32), magnitude of SWs of ipsilateral to VS side CBFV was higher during vasospasm (4.15 ± 1.55 vs before: 2.86 ± 1.21 cm/s, p < 0.001). Ipsilateral SWs of CBFV before VS had higher magnitude in DCI group (N = 19, p < 0.001) and were strongly predictive of DCI, with area under the curve (AUC) = 0.745 (p = 0.02). Vasospasm caused a non-significant shortening of ipsilateral values of tau and increase in SampEn in all patients related to pre-VS measurements, as well as an insignificant increase of Mxa in DCI related to non-DCI group (N = 13). Conclusions In patients suffering from subarachnoid hemorrhage, TCD-detected VS was associated with higher ipsilateral CBFV SWs, related to pre-VS measurements. Higher CBFV SWs before VS were significantly predictive of delayed cerebral ischemia.

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