Acute bilateral thalamic infarction as a cause of acute dementia and hypophonia after occlusion of the artery of Percheron.

The thalami of the human brain obtain their blood supply from many perforating arteries, which exhibit complex distribution and many variations. One rare variation is the artery of Percheron that supplies the paramedian thalami bilaterally. This artery arises from the first segment of the posterior cerebral artery and gives rise to bilateral medial thalamic perforants. Occlusion of the artery of Percheron none rarely results in bilateral thalamic and mesencephalic infarctions. We describe the case of a 38-year-old male patient with a presumed occlusion of this artery in which MR imaging revealed characteristic symmetrical bilateral paramedian thalamic infarctions. The unique characteristics of this case are based on the young age of the patient, the absence of any risk factors or other diseases and even more on the rare clinical manifestations consisted of hypophonia, memory dysfunction, time disorientation and apathy.