[Determinants for the prognosis of median cerebral artery processes--a retrospective analysis of 90 patients].

The data of 825 consecutive patients with ischemic stroke or TIA were retrospectively reviewed for ultrasound findings of stenoses or occlusions of the middle cerebral artery (MCA). Using survival statistics,we studied the influence of various factors on the prognosis of MCA findings. We identified 90 subjects with MCA stenosis or occlusion. Microembolic signals were demonstrated in 33% and spontaneous flow variations in 7%. Symptomatic MCA findings normalized more quickly than asymptomatic findings. Microembolic signals occurred only in symptomatic stenoses. Spontaneous flow variations strongly predicted the disappearance of a stenosis. Atherogenic risk factors were associated with stable ultrasound findings. These data suggest that different types of MCA findings exist: (1) dynamic, emboligenic stenoses or occlusions with early normalization and a high risk for ischemic events and (2) static, nonemboligenic stenoses with rare normalization and a low risk of ischemic events. A high percentage of the former may be of embolic origin, and the latter may be atherosclerotic plaques.