Cerebral Vasoreactivity in Carotid Stenosis or Occlusion Cases: A Transcranial Doppler Study with Acetazolamide (Diamox) Test

Park, Seong Min; Lee, Kwang Soo; Choi, Jae Young; Kim, Yeong In

Abstract

BACKGROUND: The aim of this trial was to evaluate the acetazolamide induced vasoreactivity of the cerebral vasculature in patients with carotid stenosis/occlusion, relative changes of blood flow velocity within the middle cerebral artery were measured by transcranial doppler ultrasonography during acetazolamide challenge. To evaluate the effectiveness of extracranial-intracranial bypass surgery in patients with ICA stenosis/occlusion with decreased vasoreactivity, we studied whether the vasoreactivity could show a significant difference between the territorial infarction and borderzone infarction cases.
METHODS
To test vasoreactivity in 21 patients with unilateral carotid stenosis or occlusion, we measured blood flow velocity in the middle cerebral artery by transcranial doppler sonography both at rest and after injection of acetazolamide. Among 21 patients, 13 patients are MCA territorial and 8 patients are borderzone infarction which are angiographically confirmed symptomatic cases.
RESULTS
The increase in blood flow velocity (%Vm) after acetazolamide stimulation was significantly different between the both hemisphere (affected side: 24.01+/-24.44%, contralateral side: 49.39+/-19.38%, p<0.05). In patients with carotid stenosis/occlusion, vasoreactivity of the borderzone infarction cases was lower than territorial infarction cases(mean+/-SD: 12.25+/-11.20% and 29.92+/-26.42%, p=0.13), but it is not significant statistically.
CONCLUSION
We concluded that TCD with acetazolamide challenge is a useful method for assessment of the adequacy of hemodynamic reserve in patients with severe stenosis or occlusive cerebrovascular disease but it is very difficult problem apply to EC-IC bypass surgery directly.