Acetazolamide vasoreactivity in persistent vegetative state and vascular dementia evaluated by transcranial harmonic perfusion imaging and Doppler sonography.

UNLABELLED: To clarify the pathophysiological differences of the cerebrovascular reserve capacity in relation to cerebral cognitive impairments between persistent vegetative state (PVS) and vascular dementia (VD), we evaluated acetazolamide (ACZ) vasoreactivity testing by transcranial harmonic perfusion imaging (HPI) and Doppler sonography (TCD). METHODS: The subjects were 11 adult patients with severe cognitive impairments (4 PVS, 7 VD). TCD mean velocity (Vm) in the middle and posterior cerebral artery (MCA, PCA) and peak intensity (PI), area under curve (AUC), and mean transit time (MTT) analyzed by HPI time-intensity curves in the bilateral temporal lobe (TL), basal ganglia (BG), and thalamus (Th) were evaluated before and after ACZ administration. Resting values and relative changes (%delta) of TCD and HPI parameters were compared between PVS and VD. RESULTS: a) Resting values: There were no significant differences between the two groups. b) Vasoreactivity: 1) PVS: %delta Vm decreased in the left PCA and MCA. %delta PI/AUC/MTT decreased in the left TL and bilateral BG. 2) VD: %delta PI/AUC decreased in the right TL. %delta MTT tended to decrease in the right side. CONCLUSION: ACZ vasoreactivity tests by transcranial HPI and TCD allowed bedside, non-invasive, quantitative evaluation of the pathophysiology of cognitive function impairment and treatments, in relation to cerebrovascular reserve capacity in PVS and VD.

Acetazolamide vasoreactivity in vascular dementia and persistent vegetative state evaluated by transcranial harmonic perfusion imaging and Doppler sonography.

To clarify the pathophysiological differences of the cerebrovascular reserve capacity in relation to cerebral cognitive impairments between vascular dementia (VaD) and persistent vegetative state (PVS), we evaluated acetazolamide (ACZ) vasoreactivity testing by transcranial harmonic perfusion imaging (HPI) and Doppler sonography (TCD). Sixteen patients (age: 29-85 years; mean: 62) were divided into three groups: 7 VaD, 4 PVS, and 5 nondementia patients. Mean velocity (Vm) in the middle and posterior cerebral artery (MCA, PCA) was measured, and time-intensity curves of the HPI were evaluated at three regions of interest-the bilateral temporal lobe (TL), basal ganglia (BG), and thalamus (Th). TCD and HPI were evaluated before (resting state) and after ACZ administration, and vasoreactivity was compared among the three groups in terms of resting values and relative changes (%Delta) of Vm, peak intensity (PI), area under curve (AUC), and mean transit time (MTT). Results of the resting state: Decreased Vm, PI, and AUC of the VaD and PVS groups were more obvious in the right side. Results of vasoreactivity: In the PVS group, %DeltaVm decreased in the left PCA and MCA; %DeltaPI and %DeltaAUC decreased in the left TL and bilateral BG. In the VaD group, %DeltaPI and %DeltaAUC decreased in the right TL; %DeltaMTT tended to increase in the left side. ACZ vasoreactivity tests by transcranial HPI and TCD allowed bedside, noninvasive quantitative evaluation of the pathophysiology of cognitive function impairment in relation to cerebrovascular reserve capacity in VaD and PVS.