Background: The objective of this study was to evaluate the diagnostic value of the head-up-tilt (HUT) test for detecting cerebral hemodynamic insufficiency in patients with major cerebral artery occlusion disease because such patients may benefit from extracranial - intracranial bypass surgery.
Methods and results: In 13 cases of transient ischemic attacks in patients with carotid or middle cerebral artery occlusive disease, the HUT test was used to determine whether or not the symptoms appear during induced hypotension before investigating cerebral hemodynamics with positron emission tomography. Three of the 13 patients showed focal symptoms such as hemiparesis and limb shaking during the HUT test. In all 3 patients, the oxygen extraction fraction (OEF) increased beyond 53.3% (ie, misery perfusion), whereas only 2 of the other 10 patients without focal symptoms showed an increase in OEF during HUT.
Conclusions: The HUT test was highly useful for screening patients with cerebral hemodynamic insufficiency in carotid occlusive disease.