The rCBF response to Diamox in normal subjects and cerebrovascular disease patients

Abstract

Age-related norms for the regional cerebral blood flow (rCBF) response to Diamox (acetazolamide) were based on studies of 55 normal subjects at rest and on studies of 33 of these 55 normal subjects following an intravenous injection of Diamox (22 mg/kg). After the Diamox injection, rCBF increased at all locations measured in all subjects. On average, rCBF increased 1.7 times. The following were found for rCBF in both resting and Diamox-treated subjects: 1) rCBF decreased significantly with increasing age; 2) slope and intercept for the regression of rCBF on age were largest for frontal detectors, intermediate for parietal detectors, and smallest for occipital detectors; 3) rCBF hyperfrontality was most noticeable in younger subjects; 4) in subjects of any age, 95% confidence intervals for rCBF were relatively large (expected value +/- 30%) and lower 95% confidence intervals for Diamox rCBF tended to overlap the upper 95% confidence intervals for resting rCBF; and 5) side-to-side percentage difference in rCBF did not have a significant regression on age and tended to be less than 10% to 20%. Diamox did not have an important effect on blood pressure, pulse rate, or respiratory rate. The normative data for the rCBF response to Diamox was used in evaluating 20 patients with cerebrovascular disease. Forty percent of these patients, all of whom exhibited angiographic evidence of potentially hemodynamically significant lesions, had normal rCBF at rest and after Diamox injection. Twenty percent had normal resting flows with abnormal Diamox-activated flows. Asymmetry in rCBF was the most sensitive indicator of a potential abnormality in cerebral perfusion. Thirty percent of the abnormal studies showed only significant asymmetry. It is suggested that rCBF studies at rest and after Diamox treatment, with age-related norms, may be useful in the management of patients with cerebrovascular disease.

The Acetazolamide Challenge: Techniques and Applications in the Evaluation of Chronic Cerebral Ischemia

“…Inhibition of carbonic anhydrase causes carbonic acidosis, which induces a considerable increase in CBF. 23 ACZ is safe to administer and is generally well tolerated. Systemic blood pressure, heart and respiratory rates, arterial pH, arterial CO 2 pressure, and CMRO 2 are unaffected.…”

“…Most common side effects are acute and transient, including transient circumoral numbness, paresthesias, malaise, and headache. 23,24 Reversible pontine ischemia caused by ACZ challenge has been discussed in a case report 25 ; however, Piepgras et al 26 reported no acute ischemic sequelae in more than 1000 studies with the use of ACZ.…”

Quantitative Cerebrovascular Reserve Measured by Acetazolamide-Challenged Dynamic CT Perfusion in Ischemic Adult Moyamoya Disease: Initial Experience with Angiographic Correlation

“…8,9 As a result, ACZ-challenged single-photon emission CT (SPECT) increases the contrast in radioactivity levels observed between regions of adequate vascular reserve and those of inadequate reserve. Cerebrovascular reserve (CVR) obtained by using SPECT provides important information on hemodynamic status in patients with chronic cerebrovascular occlusive diseases.…”

Acetazolamide Reactivity on 123I-IMP Single Photon Emission Computed Tomography in Patients with Major Cerebral Artery Occlusive Disease: Correlation with Positron Emission Tomography Parameters

“…Acetazolamide is a potent cerebral vasodilator (Mithoefer et aI., 1957) and is increasingly being used to assess hemodynamic reserve in the brain in combination with 133Xe inhalation, cold Xe com puted tomography (CT), single photon emission computed tomography (SPECT), or transcranial Doppler ultrasonography (Vorstrup et al , 1986;Sullivan et al, 1987;Sorteberg et al, 1989;Rogg et al , 1989;Knop et aI. , 1992;Hasegawa et al , 1992;Chimowitz et al , 1993).…”