[Juvenile-onset multiple brain infarcts localized in the posterior circulation: a case report].

We report a 37-year-old male patient with multiple brain infarcts due to arterial lesions localized in the posterior circulation, who developed a paramedian pontine infarct on the left side. He had been treated as schizophrenia for 20 years. A cranial CT performed one year before showed old small infarcts in the territories of the bilateral thalamo-perforating and left thalamo-geniculate arteries and the right posterior inferior cerebellar artery. The vertebral and basilar arteries were small in diameter on MRI and MR angiography(MRA). Cerebral angiography revealed a narrow smooth basilar artery. In addition, the P2 segments of the bilateral posterior cerebral arteries were markedly narrow with irregular walls. Carotid arteriograms were normal and no atherosclerosis was found. The nature of these arterial lesions remains unknown in this case. Even if MRA shows vertebrobasilar artery hypoplasia, a known congenital risk factor of a posterior circulation infarct, we must rule out a possibility that some arterial pathology is going on.