COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

Acetazolamide Challenge With Perfusion in the Prediction of Cerebral Vasospasm

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03377049
Recruitment Status : Suspended (due to COVID-19)
First Posted : December 19, 2017
Last Update Posted : April 1, 2020
Information provided by (Responsible Party):
University of Wisconsin, Madison

Brief Summary:
The investigators propose a technique using cone beam CT perfusion (CBCTP) imaging with an acetazolamide challenge as a potential diagnostic tool to detect a defect in cerebral autoregulation at a time when it has not yet caused clinically apparent signs or symptoms. The Acetazolamide or vasodilatory challenge should identify subjects having a abnormal cerebrovascular reactivity capacity at a time before this response is needed i.e. before significant vasospasm has occurred. More specifically, after receiving the drug there will not be the expected increase in cerebral blood flow in some of the subjects because they are already suffering from a disturbance in the vasculature's ability to respond to the signal for vasodilation. The investigators believe that ultimately the presence of this deficit will be helpful in identifying patients who are at risk for potential brain ischemia due to this decreased capacity to autoregulate if/when clinically significant vasospasm occurs. The investigators predict that the technique described will be more sensitive in this regard than the presently available methods e.g. the severity of subarachnoid bleeding. If this is correct, the cone beam CT perfusion measurements would be a better predictor of those patients at risk for cerebral infarction due to delayed vasospasm. Identifying these individuals prior to the onset of clinically apparent symptoms would result in modification of their management and potentially provide the opportunity to reduce the morbidity and mortality associated with ischemic brain injury.

Condition or disease
Subarachnoid Hemorrhage, Aneurysmal Vasospasm, Cerebral

Detailed Description:
The objective of this proposal is to conduct a feasibility study of acetazolamide activated C-arm cone beam CT perfusion (CBCTP) to determine its application in the prediction of symptomatic cerebral vasospasm (i.e. ischemia or stroke) in patients with aneurysmal subarachnoid hemorrhage. The initial plan is to obtain C-arm CBCTP pre- and post-intravenous infusion of 1g acetazolamide within 24 hours of symptom onset in aneurysmal subarachnoid hemorrhage patients. The hypothesis is that some of these patients that will later develop clinical vasospasm of a degree sufficient to cause cerebral ischemia. These, we believe, will demonstrate altered cerebrovascular reactivity during the acetazolamide challenge at a time before there is either angiographic evidence of vasospasm or clinical evidence of abnormal perfusion. The pilot study will enroll 10 subjects. If analysis of this data demonstrates that C-arm CBCTP with an acetazolamide challenge yields reproducible data and can be obtained with clinical ease and safety then a proposal for further research in a larger cohort will be submitted. This will aim to assess the utility of the CBCT perfusion measurement with an acetazolamide challenge to serve as a screening diagnostic tool to predict the subsequent occurrence of delayed vasospasm in subjects with an acute aneurysmal subarachnoid hemorrhage.

Layout table for study information
Study Type : Observational [Patient Registry]
Estimated Enrollment : 10 participants
Observational Model: Cohort
Time Perspective: Prospective
Target Follow-Up Duration: 1 Year
Official Title: C-arm Cone Beam CTA and CTP With Acetazolamide Challenge in Aneurysmal Subarachnoid Hemorrhage: Evaluating Predictability for Early Ischemia in Cerebral Vasospasm
Actual Study Start Date : July 28, 2019
Estimated Primary Completion Date : August 2021
Estimated Study Completion Date : August 2021

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Bleeding

Acetazolamide Challenge
Subjects entered into the study as a cohort, will because of their participation, undergo only two additional digital subtraction angiogram (DSA) imaging acquisitions. These will be done in conjunction with their standard diagnostic DSA evaluation and consist of two CBCTPs, one before and one after administration of 1 g acetazolamide through a peripheral IV line. Each CBCTP will require administration of 75-100 mL iodinated contrast medium also through an intravenous line. Neither of these imaging studies will be used for clinical decision making, but would be processed and evaluated at later date for a formal analysis of the results. Following completion of diagnostic imaging subjects will receive the usual standard of care for treatment of their ruptured aneurysm i.e. endovascular embolization or open surgical clipping.

Primary Outcome Measures :
  1. Development of delayed cerebral vasospasm [ Time Frame: Day 1-14 during the hospitalization. ]
    Clinical neurological deterioration not attributable to other causes, mores specifically not due to re-bleeding, hydrocephalus, or metabolic changes.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Adult patients, 18 years or older with subarachnoid hemorrhage due to a ruptured aneurysm

Inclusion Criteria:

  • Patients with aneurysmal subarachnoid hemorrhage presenting to our institution within 24 hours of symptom onset
  • Adults, 18 years of age or older
  • Women of childbearing potential must not be pregnant (negative urine pregnancy test)

Exclusion Criteria:

  • Contraindication to acetazolamide (i.e. sulfonamide allergy, renal or liver failure)
  • Contraindication to contrast media (Allergy or abnormal serum Cr and/or GFR based on current UW guidelines for IV contrast)
  • Renal insufficiency, history of renal failure or renal transplant
  • Hunt and Hess grade 1 and 5 (Attached protocol provides details on the grading scale. Grade 1 have lowest yield for vasospasm and Grade 5 are by definition critically ill and unstable patients)
  • Critically ill patients who are unstable and who cannot undergo scans within the proposed timeline i.e. within 24 hours of the onset of their symptoms.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03377049

Layout table for location information
United States, Wisconsin
University of Wisconsin
Madison, Wisconsin, United States, 53792
Sponsors and Collaborators
University of Wisconsin, Madison
Layout table for investigator information
Principal Investigator: Azam Ahmed, MD University of Wisconsin, Madison
Additional Information:


Layout table for additonal information
Responsible Party: University of Wisconsin, Madison Identifier: NCT03377049    
Other Study ID Numbers: 2017-1510
SMPH/NEURO SURG/NEURO SURG ( Other Identifier: UW Madison )
A535700 ( Other Identifier: UW Madison )
First Posted: December 19, 2017    Key Record Dates
Last Update Posted: April 1, 2020
Last Verified: August 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: Yes
Keywords provided by University of Wisconsin, Madison:
acetazolamide challenge
cerebral vasospasm
aneurysmal subarachnoid hemorrhage
Additional relevant MeSH terms:
Layout table for MeSH terms
Subarachnoid Hemorrhage
Vasospasm, Intracranial
Pathologic Processes
Intracranial Hemorrhages
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases