Progressive supranuclear palsy in the course of subclavian steal syndrome.

A 70-year-old man manifested during four years a progressive clinical picture consisting in palsy of gaze, axial rigidity, disorders of standing and gait, dysarthria, dysphagia. Neuroradiological investigations demonstrated proximal thrombosis of the left subclavian artery with subclavian steal. At necropsy, degenerative changes in several areas of the basal ganglia and brain stem, with presence of globose neurofibrillary tangles, were found, consistently with the pathologic pattern of the Progressive Supranuclear Palsy (PSP). The association of PSP and subclavian steal syndrome has not been previously reported, to our knowledge. We hypothesize that chronic ischemia, due to subclavian steal syndrome, in the vertebral basilar system and its watershed versus carotid system may have favoured the appearance, in these same areas, of the changes of the PSP.