The value of acetazolamide challenge test in the evaluation of acute stroke

The acetazolamide (ACZ) challenge test provides a useful information about compromised hemodynamic state in chronic stroke. However, there is no consensus whether this test is of any value in the evaluation of acute ischemic stroke. The purpose of this study is to examine the value of ACZ challenge test in the management of acute ischemic stroke. Study 1: Nineteen patients with acute embolic stroke were subjected to the Xe CT with and without ACZ (17 mg/kg, i.v.) within 6 hours from the onset. The cases included 12 middle cerebral artery (MCA) occlusions and 7 internal carotid artery (ICA) occlusions. The baseline cerebral blood flow (CBF) values and cerebrovascular reserve (CVR) (% increase in CBF after ACZ) were analyzed in 53 affected regions of interest (ROI). The study indicated that the CBF threshold of subsequent permanent infarction was 15 ml/100 g/min and the ROI with negative CVR had a higher incidence of hemorrhagic infarction. Study 2: Xe-CT with and without ACZ was performed in 32 patients with acute occlusion of the main trunks of cerebral arteries within 6 hours after the onset. Occluded arteries were MCA in 20 patients, ICA in 7, both ICA and MCA in 4 and anterior cerebral artery (ACA) in one. The abnormal hemispheric CBF (< 20 ml/100 g/min) and CVR (< 10%) were correlated with the Glasgow outcome scales of the patients. The predictability of Good Recovery, Moderately Disabled, Severely Disabled, Vegetative Survival and Dead were 80%, 50%, 50%, 100% and 100% by CBF criteria, and 80%, 60%, 80%, 100% and 100% by CVR criteria, respectively. There was no significant increase in the predictability of final outcome of the patients by adding the CVR information of the acute stage. The ACZ challenge test has a potential value in the prediction of hemorrhagic transformation of the ischemic regions. It does not increase the predictability of the long-term outcome. We do not recommend performing ACZ challenge test on routine basis in the evaluation of acute ischemic stroke.