[Ultrasonic diagnosis of the vertebrobasilar system. II. Transnuchal diagnosis of intracranial vertebrobasilar stenoses using a novel pulsed Doppler system].

This report deals with the non-invasive detection of haemodynamically non-significant stenoses of the intracranial part of the vertebrobasilar system. A new Doppler device transmitting pulsed 2 MHz ultrasound was used. Among 67 patients with transient or stable neurological deficits of the posterior circulation area, five were found to have stenoses of the distal vertebral artery or basilar artery, respectively. Transnuchal approach via the foramen magnum was used. The findings were confirmed by angiography. Twelve subjects with normal Doppler findings also underwent angiography. Three of them presented irregularities and plaquing of the vertebrobasilar trunk without circumscribed stenosing lesions. Transcranial pulsed Doppler sonography permits non-invasive detection of intracranially located stenoses of the vertebrobasilar system which, up to now, could not be diagnosed with the help of extracranial conventional continuous-wave Doppler alone. This new method allows early detection of basilar artery occlusive disease. The effectiveness of anticoagulation and fibrinolysis can be assessed non-invasively.