Transcranial Doppler sonographic findings in middle cerebral artery disease.

The transcranial Doppler sonographic findings of 61 patients with middle cerebral artery (MCA) disease were compared with those of 535 controls. According to computed tomographic, angiographic, and/or autopsy findings, the patients were classified as having MCA occlusive lesions in the central (sphenoidal) part or in peripheral branches or MCA stenosis. With MCA lesions, the MCA flow velocity (FV) was reduced. At the same time the anterior cerebral artery FV increased because of collateral flow over leptomeningeal anastomoses. Central MCA lesions showed less marked changes than did peripheral lesions. In MCA stenosis a steep rise of MCA FV appeared inside the stenotic segment. If there was a high-grade stenosis or occlusion of the internal carotid artery, a collateral circulation over the anterior part of the circle of Willis was seen in addition to the changes caused by the MCA disease. From these hemodynamic changes, transcranial Doppler sonographic diagnostic criteria for MCA occlusive and stenotic lesions were established.