[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-studies-list:{\"conditionNormalized\":\"cerebrovascular-circulation\",\"overallStatus\":[\"RECRUITING\",\"AVAILABLE\",\"NOT_YET_RECRUITING\"],\"orderBy\":\"LastUpdateSubmitDate:desc\",\"size\":25,\"offset\":0}":3,"health-study-condition:cerebrovascular-circulation":27},{"pageToken":4,"total":5,"offset":6,"count":5,"results":7},null,6,0,[8,44,74,108,127,159],{"id":9,"slug":10,"hasResults":11,"nctId":12,"briefTitle":13,"officialTitle":14,"acronym":4,"eligibilityCriteria":15,"healthyVolunteers":11,"sex":16,"minAge":17,"maxAge":18,"enrollmentInfo":19,"targetDuration":4,"studyType":22,"phases":23,"briefSummary":25,"conditions":26,"keywords":29,"overallStatus":31,"whyStopped":4,"lastUpdateSubmitDate":32,"lastUpdatePostDateStruct":33,"startDateStruct":36,"completionDateStruct":38,"leadSponsor":40,"locationsCount":43},"100392549","assessment-of-the-relationship-between-cerebral-blood-flow-and-heart-rate-100392549",false,"NCT04391465","Assessment of the Relationship Between Cerebral Blood Flow and Heart Rate","Assessment of the Relationship Between Cerebral Blood Flow and Heart Rate: An Electrophysiology Based Study","Inclusion Criteria:\n\n* Male or female\n* Age 18-70 years, inclusive\n* Scheduled for clinically indicated elective electrophysiological studies where temporary pacing catheters are being placed in the right atrium\n* Left ventricular ejection fraction ≥50%\n* Able and willing to provide informed consent\n* Able to travel to the Cardiac Electrophysiology Laboratory at the Foothills Medical Centre, Calgary, Alberta, Canada\n\nExclusion Criteria:\n\n* Unable or unwilling to provide informed consent\n* Other factors which in the investigator's opinion would prevent the participant from completing the protocol","ALL","18 Years","70 Years",{"count":20,"type":21},20,"ESTIMATED","INTERVENTIONAL",[24],"NA","The investigators will seek to determine the relationship between heart rate and middle cerebral artery (MCA) cerebral blood flow (CBF), as well as better understand the hemodynamic determinants of MCA CBF velocity. In order to manipulate heart rate, the investigators will recruit patients already scheduled for clinically indicated elective electrophysiological studies, where temporary pacing catheters placed in the right atrium can be used to artificially pace the heart at controlled rates. MCA CBF will be measured by transcranial Doppler ultrasound.",[27,28],"Cerebrovascular Circulation","Physiology",[30],"Cerebral Blood Flow","RECRUITING","2026-04-30",{"date":34,"type":35},"2026-05-07","ACTUAL",{"date":37,"type":35},"2021-08-11",{"date":39,"type":21},"2027-12",{"name":41,"class":42},"University of Calgary","OTHER",1,{"id":45,"slug":46,"hasResults":11,"nctId":47,"briefTitle":48,"officialTitle":49,"acronym":4,"eligibilityCriteria":50,"healthyVolunteers":51,"sex":16,"minAge":52,"maxAge":53,"enrollmentInfo":54,"targetDuration":4,"studyType":22,"phases":56,"briefSummary":58,"conditions":59,"keywords":61,"overallStatus":31,"whyStopped":4,"lastUpdateSubmitDate":65,"lastUpdatePostDateStruct":66,"startDateStruct":68,"completionDateStruct":70,"leadSponsor":72,"locationsCount":43},"100564430","phase-2-brain-blood-vessel-responses-to-changes-in-blood-flow-100564430","NCT06629077","Brain Blood Vessel Responses to Changes in Blood Flow","Cerebrovascular Responses to Acute Hypoperfusion","Inclusion Criteria:\n\n* Between the ages of 55-69 years\n* Have a BMI less than or equal to 34.5 kg\u002Fm2\n* Nonsmoker\n* are less than 72 in (182.88 cm) height\n* Females must be postmenopausal\n\nExclusion Criteria:\n\n* Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)\n* History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis\n* History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia\n* Uncontrolled hypertension\n* History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease\n* Severe untreated obstructive sleep apnea\n* History of diabetes with HbA1c greater than 9.5%\n* Major neurologic disorders other than dementia (e.g., MS, ALS, brain surgery, etc.)\n* Current or recent (\\<1 year) major psychiatric condition (Axis I) or addictive disorders\n* Significant surgical history\n* Other significant medical conditions at investigators' discretion\n* Contraindications to MRI\n* Prescribed medications that interfere with prazosin\n* Lactose allergy\n* lower body will not fit in lower body negative pressure (LBNP) chamber (regardless of overall height and BMI).",true,"55 Years","69 Years",{"count":55,"type":21},36,[57],"PHASE2","Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging.",[60,27],"Magnetic Resonance Imaging",[60,62,63,64],"Brain Blood Flow","Lower Body Negative Pressure","Carbon Dioxide","2026-02-27",{"date":67,"type":35},"2026-03-02",{"date":69,"type":35},"2026-02-26",{"date":71,"type":21},"2027-01",{"name":73,"class":42},"University of Wisconsin, Madison",{"id":75,"slug":76,"hasResults":11,"nctId":77,"briefTitle":78,"officialTitle":79,"acronym":80,"eligibilityCriteria":81,"healthyVolunteers":11,"sex":16,"minAge":17,"maxAge":4,"enrollmentInfo":82,"targetDuration":4,"studyType":22,"phases":84,"briefSummary":85,"conditions":86,"keywords":91,"overallStatus":31,"whyStopped":4,"lastUpdateSubmitDate":99,"lastUpdatePostDateStruct":100,"startDateStruct":102,"completionDateStruct":104,"leadSponsor":106,"locationsCount":43},"100621941","hyper-mind---hyperoxia-effects-on-cerebral-hemodynamics-100621941","NCT07377162","HYPER MIND - Hyperoxia Effects on Cerebral Hemodynamics","HYPERMIND - Hyperoxia Effects on Cerebral Hemodynamics","HYPER-MIND","Inclusion Criteria\n\n* Adult patients aged ≥18 years\n* Admitted to the intensive care unit (ICU)\n* Intubated and mechanically ventilated for ≤72 hours\n* Receiving volume-controlled mechanical ventilation\n* Arterial partial pressure of carbon dioxide (PaCO₂) between 35 and 45 mmHg\n* Invasive arterial blood pressure monitoring in place\n* Adequate transcranial Doppler (TCD) acoustic window\n* Clinically judged to be suitable for a brief normobaric hyperoxic stimulus\n* Expected to receive one or two hyperoxic steps based on baseline FiO₂ requirements: a) Baseline FiO₂ \\\u003C 0.5: two-step hyperoxic stimulus (FiO₂ 0.5 followed by FiO₂ 1.0); b) Baseline FiO₂ ≥ 0.5: one-step hyperoxic stimulus (FiO₂ 1.0)\n\nExclusion Criteria:\n\n* Age \\\u003C18 years\n* Pregnancy\n* Extracorporeal membrane oxygenation (ECMO)\n* Continuous renal replacement therapy (CRRT)\n* Contraindications to hyperoxia, as judged by the treating physician\n* Severe hemodynamic instability requiring changes in vasopressor dose during the recording period\n* Inability to obtain a reliable transcranial Doppler signal through the temporal acoustic windows\n* Any clinical condition deemed by the treating physician to pose unacceptable risk during hyperoxic exposure",{"count":83,"type":21},80,[24],"This study aims to better understand how short periods of exposure to high oxygen levels affect blood flow in the brain of patients who are intubated and mechanically ventilated in the Intensive Care Unit (ICU). Many ICU patients receive more oxygen than strictly necessary, and high blood oxygen levels (hyperoxemia) are very common. However, the immediate effects of short hyperoxic exposures on cerebral circulation and autoregulation remain poorly understood.\n\nIn this study, patients who already require mechanical ventilation for medical reasons will undergo a brief and controlled increase in the oxygen delivered through the ventilator (FiO₂). During this time, we will continuously monitor blood flow in one of the main brain arteries using a non-invasive ultrasound technique called transcranial Doppler (TCD). The goal is to evaluate how cerebral blood flow, pulsatility, and autoregulatory capacity change during and after a short hyperoxic stimulus.\n\nNo additional invasive procedures are required beyond standard ICU monitoring, except for the temporary adjustment of the ventilator's oxygen settings and arterial blood gas sampling, which are part of usual care in critically ill patients. Participation does not provide direct clinical benefit but may help improve future oxygen management in ICU patients. The study involves minimal risk, as short hyperoxic exposures are already common in routine care and will be interrupted immediately in case of any adverse event.",[87,27,88,89,90],"Hyperoxemia","Cerebral Autoregulation","Critical Illness","Mechanical Ventilation",[92,93,94,95,89,96,97,98],"hyperoxemia","brain hemodynamics","tcd","cerebral autoregulation","intensive care unit","hyperoxia","oxygen","2026-01-22",{"date":101,"type":35},"2026-01-29",{"date":103,"type":35},"2024-01-01",{"date":105,"type":21},"2028-12-31",{"name":107,"class":42},"Erasme University Hospital",{"id":109,"slug":110,"hasResults":11,"nctId":111,"briefTitle":112,"officialTitle":49,"acronym":4,"eligibilityCriteria":113,"healthyVolunteers":51,"sex":16,"minAge":114,"maxAge":115,"enrollmentInfo":116,"targetDuration":4,"studyType":22,"phases":117,"briefSummary":58,"conditions":118,"keywords":119,"overallStatus":31,"whyStopped":4,"lastUpdateSubmitDate":120,"lastUpdatePostDateStruct":121,"startDateStruct":123,"completionDateStruct":124,"leadSponsor":126,"locationsCount":43},"100564431","phase-2-brain-blood-vessel-responses-to-changes-in-blood-flow-younger-cohort-100564431","NCT06629090","Brain Blood Vessel Responses to Changes in Blood Flow: Younger Cohort","Inclusion Criteria:\n\n* Between the ages of 20-40 years\n* Have a BMI ≤34.5 kg\u002Fm2\n* are less than 72 in (182.88 cm) height\n* Nonsmoker\n\nExclusion Criteria:\n\n* Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)\n* History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis\n* History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia\n* Uncontrolled hypertension\n* History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease\n* Severe untreated obstructive sleep apnea\n* History of diabetes with HbA1c greater than 9.5 percent\n* Major neurologic disorders other than dementia (e.g., MS, ALS, brain surgery, etc.)\n* Current or recent (less than1 year) major psychiatric condition (Axis I) or addictive disorders\n* Significant surgical history\n* Other significant medical conditions at investigators' discretion\n* Contraindications to MRI\n* Prescribed medications that interfere with prazosin\n* Lactose allergy\n* lower body will not fit in lower body negative pressure (LBNP) chamber (regardless of overall height and BMI)","20 Years","40 Years",{"count":55,"type":21},[57],[60,27],[60,62,63,64],"2025-12-17",{"date":122,"type":35},"2025-12-18",{"date":120,"type":35},{"date":125,"type":21},"2026-12",{"name":73,"class":42},{"id":128,"slug":129,"hasResults":11,"nctId":130,"briefTitle":131,"officialTitle":132,"acronym":133,"eligibilityCriteria":134,"healthyVolunteers":11,"sex":16,"minAge":17,"maxAge":4,"enrollmentInfo":135,"targetDuration":4,"studyType":22,"phases":137,"briefSummary":138,"conditions":139,"keywords":143,"overallStatus":31,"whyStopped":4,"lastUpdateSubmitDate":150,"lastUpdatePostDateStruct":151,"startDateStruct":153,"completionDateStruct":155,"leadSponsor":157,"locationsCount":43},"100443207","phase-2-co2-modulation-in-endovascular-thrombectomy-for-acute-ischemic-stroke-100443207","NCT05051397","CO2 Modulation in Endovascular Thrombectomy for Acute Ischemic Stroke","Evaluation of the Effect of Moderate and Controlled Hypercapnia on Ischemic Penumbra Vascular Collaterality During General Anesthesia for Anterior Circulation Acute Ischemic Stroke Mechanical Thrombectomy","COMET-AIS","Inclusion Criteria:\n\n• Large vessel occlusion anterior circulation stroke (terminal carotid artery and\u002For middle cerebral artery M1-M2 segment) eligible to mechanical thrombectomy under general anesthesia\n\nExclusion Criteria :\n\n* Active smoker\n* Chronic respiratory failure with ambulatory oxygen supplementation\n* Obesity with BMI\\>40Kg\u002F m2\n* Intubation before the procedure\n* Heart failure with intolerance to decubitus\n* Severe renal failure\n* Suspected elevated intracranial pressure\n* Pregnant or breastfeeding women",{"count":136,"type":21},50,[57],"Acute ischemic stroke due to large vessel occlusion is responsible of cerebral blood flow impairment with a progressive and extensive ischemic process. Cerebral collateral circulation may preserve an ischemic penumbra that could recover providing timely reperfusion of the occluded vessel. Mechanical thrombectomy is the standard of care for anterior circulation large vessel reperfusion. Strategy to promote cerebral blood flow in collateral circulation before reperfusion is scarce and rely mainly on blood pressure maintenance. Carbon dioxide is a potent cerebral vasodilator that could enhance collateral circulation blood flow and cerebral protection before reperfusion. General anesthesia with endotracheal mechanical ventilation could be used for thrombectomy and give the opportunity to modulate and control carbon dioxide tension in the blood. This study will test the effect of moderate hypercapnia on penumbral collateral circulation before reperfusion during mechanical thrombectomy for anterior circulation acute ischemic stroke under general anesthesia.",[140,141,142,27,64],"Ischemic Stroke, Acute","Thrombectomy","Anesthesia, General",[144,145,146,147,148,149],"mechanical thrombectomy","large vessel occlusion stroke","carbon dioxide tension","cerebral blood flow","general anesthesia","cerebral collateral circulation","2025-09-30",{"date":152,"type":35},"2025-10-06",{"date":154,"type":35},"2022-07-20",{"date":156,"type":21},"2026-10-19",{"name":158,"class":42},"University Hospital, Clermont-Ferrand",{"id":160,"slug":161,"hasResults":11,"nctId":162,"briefTitle":163,"officialTitle":164,"acronym":165,"eligibilityCriteria":166,"healthyVolunteers":11,"sex":16,"minAge":17,"maxAge":4,"enrollmentInfo":167,"targetDuration":4,"studyType":169,"phases":4,"briefSummary":170,"conditions":171,"keywords":176,"overallStatus":31,"whyStopped":4,"lastUpdateSubmitDate":191,"lastUpdatePostDateStruct":192,"startDateStruct":194,"completionDateStruct":196,"leadSponsor":198,"locationsCount":43},"100507900","brain-perfusion-evaluation-by-contrast-enhanced-ultrasound-100507900","NCT05893407","Brain PERfusion Evaluation by Contrast-Enhanced UltraSound","Quantification of Cerebral Perfusion at the Patient's Bedside When Performing Contrast-enhanced Ultrasound in Neurointensive Care Patients","PerCEUS","Inclusion Criteria:\n\n* Age ≥18\n* Intensive care unit admission for acute brain injury\n* Proven acute brain injury by CT and\u002For MRI\n* Requiring a contrast ultrasound imaging\n* Informed consent of patient or relative\n\nExclusion Criteria:\n\n* Pregnancy\n* Not sufficient temporal window\n* Contraindications to Sonovue ® : acute coronary syndromes, severe ischemic heart disease (requiring revascularization), pulmonary arterial hypertension \\> 90 mmHg, right-left shunt, ARDS, dobutamine's use, known allergy or adverse reaction to Sonovue®\n* Patient on State Medical Assistance",{"count":168,"type":21},60,"OBSERVATIONAL","The objective of the study is to assess brain tissue perfusion by contrast-enhanced ultrasound perfusion imaging (PerCEUS) in acute brain injuries. More precisely, it aims :\n\n* to evaluate the heterogeneity of brain perfusion and thus diagnose brain tissue hypoperfusion with contrast-enhanced ultrasound.\n* to correlate contrast-enhanced ultrasound with perfusion measurements by usual multimodal monitoring.",[172,173,174,27,175],"Cerebral Hemorrhage","Subarachnoid Hemorrhage","Ischemic Stroke","Perfusion",[177,178,179,180,181,182,183,184,185,186,187,188,189,190],"Brain perfusion","Cerebral blood flow","Diagnostic imaging","Ultrasonography Doppler","Doppler ultrasound","Transcranial Doppler","Contrast enhanced ultrasound","Contrast-enhanced ultrasonography","Contrast ultrasound","Ultrasound perfusion imaging","Ultrasound contrast agent","Intra-cranial pressure","Intracerebral hematoma","Neurocritical care","2025-06-16",{"date":193,"type":35},"2025-06-19",{"date":195,"type":35},"2023-07-21",{"date":197,"type":21},"2025-07",{"name":199,"class":42},"Assistance Publique - Hôpitaux de Paris"]