Transcranial doppler findings during spontaneous recanalization of vertebrobasilar occlusions.

Transcranial Doppler sonography (TCD) is of recognized value in the noninvasive detection of intracranial stenosis and occlusion. Serial TCD studies can detect recanalization of middle cerebral artery occlusion. Little information exists on TCD findings during vertebrobasilar recanalization. We report a 25-year-old woman with chronic meningitis who developed severe pontine and cerebellar infarctions due to bilateral distal vertebral and proximal basilar artery occlusion. Initial TCD showed a high-resistance signal from the distal right vertebral artery and no signal from the basilar artery. Evolutionary changes in flow velocities detected by seven TCD studies over a 5-week period suggested spontaneous recanalization of the distal vertebral and proximal basilar artery occlusion. These findings were accompanied by dramatic clinical improvement. Recurrent symptoms and TCD on day 73 suggested reocclusion, confirmed by repeat angiography. TCD may be useful for monitoring posterior circulation hemodynamics during recanalization of vertebrobasilar occlusions in selected patients.