Acetazolamide Challenge With Perfusion in the Prediction of Cerebral Vasospasm
| Status: | Recruiting |
|---|---|
| Conditions: | Neurology |
| Therapuetic Areas: | Neurology |
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 4/6/2019 |
| Start Date: | April 2019 |
| End Date: | July 2021 |
| Contact: | Azam Ahmed, MD |
| Email: | azam.ahmed@neurosurgery.wisc.edu |
| Phone: | 608-263-0485 |
C-arm Cone Beam CTA and CTP With Acetazolamide Challenge in Aneurysmal Subarachnoid Hemorrhage: Evaluating Predictability for Early Ischemia in Cerebral Vasospasm
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.
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.
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.
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.
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.
We found this trial at
1
site
Madison, Wisconsin 53792
(608) 263-2400
Principal Investigator: Azam Syed Ahmed, MD
University of Wisconsin In achievement and prestige, the University of Wisconsin–Madison has long been recognized...
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