[A peculiar MRI findings in a case with slowly progressive cerebral ischemia caused by internal carotid artery stenosis possibly due to fibromuscular dysplasia].

A 47-year-old man developed progressive muscular weakness in the left arm. MR images revealed low intensity signal lesions with ring enhancement by Gd-DTPA in right fronto-parietal lobes. At that time cerebral angiography was not performed because he refused. A tuberculin skin test showed strongly positive reaction and then administration of anti-tuberculous drugs was started. His symptom had remained stable for one year, but left facial palsy and dysarthria added about two years later. MR images revealed expansion of the lesions in right parietal lobe, adding cortical high intensity signal lesions with Gd-DTPA enhancement on T1-weighted images. Angiography disclosed tubular stenosis of right internal carotid artery at the portion of cervical to petrous segment and the local stenosis at right renal artery. These lesions were considered to be caused by fibromuscular dysplasia, but not atherosclerosis, because we could not find any atherosclerotic lesions in other arteries including right carotid bifurcation. His manifesting symptoms were ascribed to slowly progressive cerebral ischemia. And peculiar MRI findings in his early stage resembled those of inflammatory granulomatous diseases.