scholarly journals Adaptation of the cerebrocortical circulation to carotid artery occlusion involves blood flow redistribution between cortical regions and is independent of eNOS

2016 ◽  
Vol 311 (4) ◽  
pp. H972-H980 ◽  
Author(s):  
Andreas Polycarpou ◽  
László Hricisák ◽  
András Iring ◽  
Daniel Safar ◽  
Éva Ruisanchez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Blood Supply ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Laser Speckle ◽  
Collateral Vessels ◽  
The Right

Cerebral circulation is secured by feed-forward and feed-back control pathways to maintain and eventually reestablish the optimal oxygen and nutrient supply of neurons in case of disturbances of the cardiovascular system. Using the high temporal and spatial resolution of laser-speckle imaging we aimed to analyze the pattern of cerebrocortical blood flow (CoBF) changes after unilateral (left) carotid artery occlusion (CAO) in anesthetized mice to evaluate the contribution of macrovascular (circle of Willis) vs. pial collateral vessels as well as that of endothelial nitric oxide synthase (eNOS) to the cerebrovascular adaptation to CAO. In wild-type mice CoBF reduction in the left temporal cortex started immediately after CAO, reaching its maximum (−26%) at 5–10 s. Thereafter, CoBF recovered close to the preocclusion level within 30 s indicating the activation of feed-back pathway(s). Interestingly, the frontoparietal cerebrocortical regions also showed CoBF reduction in the left (−17–19%) but not in the right hemisphere, although these brain areas receive their blood supply from the common azygos anterior cerebral artery in mice. In eNOS-deficient animals the acute CoBF reduction after CAO was unaltered, and the recovery was even accelerated compared with controls. These results indicate that 1) the Willis circle alone is not sufficient to provide an immediate compensation for the loss of one carotid artery, 2) pial collaterals attenuate the ischemia of the temporal cortex ipsilateral to CAO at the expense of the blood supply of the frontoparietal region, and 3) eNOS, surprisingly, does not play an important role in this CoBF redistribution.

scholarly journals Neurovascular Coupling Varies with Level of Global Cerebral Ischemia in a Rat Model

2012 ◽  
Vol 33 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Wesley B Baker ◽  
Zhenghui Sun ◽  
Teruyuki Hiraki ◽  
Mary E Putt ◽  
Turgut Durduran ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Ischemia ◽  
Carotid Artery ◽  
Electrical Response ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Laser Speckle ◽  
Global Cerebral Ischemia ◽  
Functional Responses ◽  
Bilateral Carotid

In this study, cerebral blood flow, oxygenation, metabolic, and electrical functional responses to forepaw stimulation were monitored in rats at different levels of global cerebral ischemia from mild to severe. Laser speckle contrast imaging and optical imaging of intrinsic signals were used to measure changes in blood flow and oxygenation, respectively, along with a compartmental model to calculate changes in oxygen metabolism from these measured changes. To characterize the electrical response to functional stimulation, we measured somatosensory evoked potentials (SEPs). Global graded ischemia was induced through unilateral carotid artery occlusion, bilateral carotid artery occlusion, bilateral carotid and right subclavian artery (SCA) occlusion, or carotid and SCA occlusion with negative lower body pressure. We found that the amplitude of the functional metabolic response remained tightly coupled to the amplitude of the SEP at all levels of ischemia observed. However, as the level of ischemia became more severe, the flow response was more strongly attenuated than the electrical response, suggesting that global ischemia was associated with an uncoupling between the functional flow and electrical responses.

scholarly journals Ablation of Vitamin D Signaling Compromises Cerebrovascular Adaptation to Carotid Artery Occlusion in Mice

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1457
Author(s):  
Éva Pál ◽  
László Hricisák ◽  
Ágnes Lékai ◽  
Dorina Nagy ◽  
Ágnes Fülöp ◽  
...  
Keyword(s):  
Vitamin D ◽  
Blood Flow ◽  
Carotid Artery ◽  
Collateral Circulation ◽  
Temporal Cortex ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Arterial Blood Flow ◽  
Blood Flow Increase ◽  
Vitamin D Signaling

Vitamin D insufficiency has been associated with increased incidence and severity of cerebrovascular disorders. We analyzed the impact of impaired vitamin D signaling on the anatomical and functional aspects of cerebrovascular adaptation to unilateral carotid artery occlusion (CAO), a common consequence of atherosclerosis and cause of ischemic stroke. Cerebrocortical blood flow (CoBF) showed a significantly increased drop and delayed recovery after CAO in mice carrying a functionally inactive vitamin D receptor (VDR) with the most sustained perfusion deficit in the temporal cortex. To identify the cause(s) for this altered adaptation, the extent of compensatory blood flow increase in the contralateral carotid artery and the morphology of pial collaterals between the anterior and middle cerebral arteries were determined. Whereas VDR deficiency had no significant influence on the contralateral carotid arterial blood flow increase, it was associated with decreased number and increased tortuosity of pial anastomoses resulting in unfavorable changes of the intracranial collateral circulation. These results indicate that VDR deficiency compromises the cerebrovascular adaptation to CAO with the most sustained consequences in the temporal cortex. The dysregulation can be attributed to the altered development and function of pial collateral circulation whereas extracranial vessels may not be impaired.

Assessing the Effects of Antihypertensive Medication on Cerebral Blood Flow: Demonstration in Internal Carotid Artery Occlusion

DICP ◽  
1991 ◽  
Vol 25 (12) ◽  
pp. 1299-1301 ◽  
Author(s):  
Susan C. Fagan ◽  
James R. Ewing ◽  
Steven R. Levine ◽  
Gretchen E. Tietjen ◽  
Nabih M. Ramadan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Antihypertensive Medication ◽  
Internal Carotid ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Internal Carotid Artery Occlusion ◽  
Bilateral Carotid

Dynamic cerebral blood flow (CBF) studies using acetazolamide or hypercapnia as a vasodilatory challenge have attempted to evaluate intracranial hemodynamics. We report two patients with asymptomatic internal carotid artery occlusion in whom the vasodilatory stimulus was a single oral dose of antihypertensive medication (prazosin hydrochloride or enalapril maléate). In both patients, changes in regional CBF occurred that were larger than those seen in nine normal controls. One patient experienced an improvement in regional CBF with a reduction in probe pair asymmetry. In the other patient, who had bilateral carotid artery disease, a decrease in regional CBF in all 16 probes (mean decrease 12 percent) and an accentuation of the predose asymmetry were observed. Both patients remained asymptomatic throughout the study. Assessing these effects on cerebral circulation may help identify patients at risk for iatrogenic focal cerebral ischemia and provide information regarding the functional status of the cerebral vasculature.

Mechanism of intrarenal blood flow redistribution after carotid artery occlusion

1977 ◽  
Vol 232 (2) ◽  
pp. F167-F172 ◽  
Author(s):  
E. H. Prosnitz ◽  
E. J. Zambraski ◽  
G. F. DiBona
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Renal Blood Flow ◽  
Perfusion Pressure ◽  
Renal Perfusion ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Outer Cortex ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Perfusion Pressure

Bilateral carotid artery occlusion results in an increase in mean arterial pressure, an increase in renal sympathetic nerve activity, and a redistribution of renal blood flow from inner to outer cortex. To elucidate the mechanism of the renal blood flow redistribution, carotid artery occlusion was performed in anesthetized dogs with the left kidney either having renal perfusion pressure maintained constant (aortic constriction) or having alpha-adrenergic receptor blockade (phenoxybenzamine); the right kidney of the same dog served to document the normal response. When renal perfusion pressure was maintained constant, renal blood flow distribution (microspheres) was unchanged by carotid artery occlusion. In the presence of renal alpha-adrenergic receptor blockade, carotid artery occlusion elicited the usual redistribution of renal blood flow from inner to outer cortex. The redistribution of renal blood flow observed after carotid artery occlusion is mediated by the increase in renal perfusion pressure rather than the increase in renal sympathetic nerve activity.

Axilloaxillary Bypass for the Treatment of Subclavian Artery Stenosis Complicated by Bilateral Common Carotid Artery Occlusion: Technical Case Report

Neurosurgery ◽  
2003 ◽  
Vol 53 (2) ◽  
pp. 444-447 ◽  
Author(s):  
Masahiro Ogino ◽  
Masashi Nagumo ◽  
Toru Nakagawa ◽  
Masashi Nakatsukasa ◽  
Ikuro Murase
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Vertebral Artery ◽  
Subclavian Artery ◽  
Bypass Surgery ◽  
Left Subclavian Artery ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Bilateral Common Carotid Artery ◽  
Common Carotid Artery Occlusion

Abstract OBJECTIVE AND IMPORTANCE We successfully treated a patient with stenosis of the left subclavian artery, complicated by bilateral common carotid artery occlusion, via axilloaxillary bypass surgery. CLINICAL PRESENTATION A 67-year-old patient with a history of hypertension and cerebral infarction underwent neck irradiation for treatment of a vocal cord tumor. Three months later, he began to experience transient tetraparesis several times per day. The blood pressure measurements for his right and left arms were different. Supratentorial blood flow was markedly low. The common carotid arteries were bilaterally occluded, and the right vertebral artery was hypoplastic. Therefore, only the left vertebral artery contributed to the patient's cerebral circulation; his left subclavian artery was severely stenotic. INTERVENTION The patient underwent axilloaxillary bypass surgery because the procedure avoids thoracotomy or sternotomy, manipulation of the carotid artery, and interruption of the vertebral artery blood flow. The patient has been free of symptoms for more than 5 years. CONCLUSION Neurosurgeons should be aware that extra-anatomic bypass surgery is an effective treatment option for selected patients with cerebral ischemia.

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