Transcranial Doppler And Magnetic Resonance Finding In Patients With Atherosclerotic Middle Cerebral Artery Infarcts

Objective:Through Observed the transcranial Doppler in patients with atherosclerotic middle cerebral artery stenotic or occlutive disease(MCAOD), analyze the probable mechanism of the hemodynamic change. Investigated the infartion patterns in patients with MCAOD,explore the pathogenesis and compensation of collateral flowMethods:68 cases with MCAOD were dignosed by Magnetic Resonance Angio-graphy (MRA) or computer tomography angiography(CTA),25 cases were also dignosed by digital subtraction angiography. Excluded the patients accompanied by artial fibrillation, internal carotid artery stenosis>50%, infractions suspious caused by cardiac embolus.Recorded age, past history, include hypertention, diabetes, hypercholesterolemia, hyperglyceridemia. Recoded history of smoking and alcoholic. MCAOD were degreed into:1) occlution; 2) severe stenosis; 3) moderate stenosis based on MRA/CTA/DSA.Transcranial Doppler in 46/68, calculated the radio of bilateral anterior cerebral artery(ACA) mean velocity (rVmACA) and the radio of bilateral posterior cerebral artery(PCA) mean velocity (rVmPCA),and compared with the healthy controls. Transient ischemic attack (TIA) in 3 cases with normal MRI, observed acute infarct patterns in last 65 patients underwent diffusion weighted imaging(DWI). A. Territorial Infarction;B Watersheld Infarction; C. Semiovale Infarction; D. Deep penetrator branch Infarction:striatocapsular infarction(SCI), and lacunar Infarction;及E. Multiple Scattered Spotty Infarction. Evaluate clinical and radiological features in these patients.Results:Through MRA/CTA/DSA,16 patients were founded middle cerebral artery occlution,52 were founded middle cerebral artery stenotis. The average age in patients with MCA occlution was significantly lower than patients with MCA stenotis.The rVmACA in patient group was significantly higher than those controls.Among these patients, territorial infarcts were seen in 7/65, watershed infarcts in 27/65,1 of those progressived to territorial infarct; semioval infarcts in 11/65,3 coexisted mutiple scatted spotty infarcts,2 of those progressived to territorial infarct; deep penetrator branch infarcts in 18/65. Multiple scattered spotty infarction in Conclusion:A variety of infarct patterns can occur in patients with MCAOD.The artery-artery cerebral embolism and low perfusion are important mechanisms of cerebral infarcts in patients with MCAOD.1) Patients with hyperglyceridemia are easily suffer from MCAOD. In sympotomatic MCAOD patients, radio of MCA occlution in youngers is higher.2) Contrastive PCA, mean velocity of ACA increased in sympotom lateral patients with MCAOD, prompted the opening of leptomeningeal anastomoses vessel is the important way collateral of circulation, and the collateral flow between MCA and ACA is dominant.3) Ischemic lesions in patients with MCAOD does not in accord with the degree of MCA Stenosis. MCAOD could result various infarct patterns. The main infarct patterns is watersheld infarction, semiovale infarction and deep penetrator branch infarction.4) 16 patients with watersheld infarction.6/16 were showed multiple cortical lesions in MRI, speculated MCAOD caused local low perfution, then impaired clearance of embolus, artery-artery embolism prodused multiple watersheld infarction.5) 15 patients with semiovale infarction.3/15 were indicated multiple scattered spotty infarctions in MRI, support that contemporaneously with low perfution caused by MCAOD, microemboli from artery may exist.