[Transcranial Doppler ultrasonic examination in vertebro-basilar circulatory pathology]

Vertebrobasilar ischemic disease cannot be adequately explored by echo-Doppler ultrasonic investigating procedures, since they do not permit the study of the intracranial arteries. The transcranial pulsed Doppler (2 MHZ) velocity detection method developed by R. Aaslid now offers such possibilities, although it has not yet been validated in this field. The authors relate their experience and methodological criteria (patient's position, deepness of access, flow direction, response to compression tests). They conducted 2 studies, one bearing on the detection of 14 cases of 75% stenosis of the superior segment, or of arteriographically-confirmed endocranial vertebral/basilar artery occlusion; the other one was concerned with assessing the basilar hemodynamic consequences of vertebral-subclavian steal syndromes. Out of 17 steal syndrome cases, of which 5 were symptomatic (4 pre-steal cases, 7 permanent, 6 intermittent), basilar flow determined spontaneously or following postischemic hyperemic test of the upper limb, was moderately changed in 30% of cases. Transcranial pulsed Doppler ultrasonic examination could be recommended in addition to the regular echo-Doppler velocity detection test, and thus contribute to exploring and monitoring transient or full-blown ischemic accidents of the vertebrobasilar circulation, in expectation of medical, surgical or angioplastic management.