[Magnetic resonance angiography in 12 patients with Wallenberg's syndrome].

Magnetic resonance angiography (MRA) was performed in 12 patients with Wallenberg's syndrome (WS) in chronic stage to investigate the lesion of the vertebral artery (VA). The laterality of infarction in the medulla oblongata was confirmed with MRI: the right in four patients and the left in eight. In this study, time-of-flight MRA was evaluated. Coronal and OM sections in MRA were examined, because the former is useful to observe asymmetry and curve of the cervical VA, and the latter is useful to observe asymmetry and stenosis of the intracranial VA. In nine out of 12 patients, the ipsilateral VA was rather hypoplastic compared to the contralateral VA, and the flow of the hypoplastic VA stopped before and after entering the intracranial region. The contralateral VA of the hypoplastic cases showed curve in the neck in five patients and stenosis in the intracranial portion in one patient. A comparative study was conducted between vertebral angiogram (VAG) and MRA in four patients. Both VAG and MRA were useful in detecting hypoplasia and stoppage of the flow. It was considered that VA hypoplasia is frequently responsible for WS, and that MRA is useful in screening the vascular lesion as a non-invasive procedure to reveal changes of the bilateral VA.