[A case of fibromuscular dysplasia presenting lateral medullary syndrome].

We reported a case of fibromuscular dysplasia (FMD) presenting lateral medullary syndrome accompanied with left truncal ataxia, left Horner's syndrome and superficial sensory deficit in the right extremities. He was 46-year-old man and had no remarkable risk factors for the cerebrovascular disease such as hypertension, diabetes mellitus and valvular heart disease. Cerebral angiography was performed and there was the string-of-beads-like shadow in the left vertebral artery, revealing a localized FMD. Wedge-shaped area of low signal intensity in the left lower medulla was recognized in magnetic resonance imaging (spin echo Tr/Te 600/30). It was suggested that the lesion of the lower medulla caused the patient's several symptoms. In Japan, there have been a few case reports of cervical or intracranial FMD, but we cannot find any report of FMD localizing in the unilateral vertebral artery. In general, it has been said that the etiology of lateral medullary syndrome under fifty years old differs from those of geriatric patients. The authors pointed out the significance of FMD as one of those risk factors causing lateral medullary syndrome and also discussed the mechanism of the sensory disturbance sparing face.