Transcranial Doppler ultrasound findings in middle cerebral artery occlusion.

We evaluated the efficacy of transcranial Doppler ultrasonography in 23 patients suffering from acute middle cerebral artery occlusion. The diagnosis of occlusion was most suggestive when all basal arteries except the affected middle cerebral artery were detectable. Enhanced blood flow velocity in the anterior cerebral artery due to leptomeningeal collateralization was used as a corroborating criterion. With frequent follow-up examinations, we monitored reperfusion of the M1 segment resulting from recanalization or embolus migration in 16 patients. Those patients undergoing recanalization within days after onset of the first symptoms revealed variable clinical courses and lesion patterns on computed tomography, indicating the crucial importance of early and efficient leptomeningeal collateral blood supply. Transcranial Doppler ultrasonography was able to exclude middle cerebral artery occlusion with accuracy, which provides important clinical information. However, distal branch occlusions could not be detected with sufficient exactness.