Acute stroke: therapeutic transcranial color duplex sonography.

The enhancement of thrombolysis by ultrasound energy (sonothrombolysis) is an emerging field of interest in the treatment of acute ischemic stroke. Recent in vitro and clinical studies have investigated the effects of using transcranially applied 'diagnostic' ultrasound for this purpose. Using transcranial color duplex sonography (TCDS) allows an examiner to identify the site of occlusion and focus the ultrasound beam on it. Clinical studies using TCDS to enhance thrombolysis in acute middle cerebral artery occlusions have revealed an accelerating effect on recanalization, as well as a tendency for a better outcome. Data from small sample studies suggest that this effect on recanalization is present not only in combination with recombinant tissue plasminogen activator (rt-PA), but also with any thrombolytic drug. However, when TCDS was used in combination with rt-PA, an increase in the rate of asymptomatic and symptomatic intracerebral hemorrhages tended to occur compared to patients treated with thrombolysis alone. Larger sample-sized clinical studies should be conducted in the future to evaluate the safety and efficacy of using TCDS for sonothrombolysis. This method should also be further developed to determine its effect when used in combination with other types of ultrasound and thrombolytic drugs.