[A case of pseudoxanthoma elasticum showing various heteroptics due to infarction of right parieto-occipital lobe].

A case of pseudoxanthoma elasticum showing various heteroptics due to infarction of the right parieto-occipital lobe was reported. The patient was 48-year-old male. Angiography revealed an obstruction of the right internal carotid artery, aneurysmal dilation of the right posterior communicating artery, and obstructions of the right parieto-occipital artery and calcarine artery. A low density area was found in right occipital lobe by CT. MRI clearly identified lesions in the right cuneus and precuneus. Pseudopsia in the left homonymous quadrantanopsia, various types of visual illusion in the remaining visual field, and moreover, palinopsia were existed. Visual illusion was recognized in the early stage after the onset, while the pseudopsia was recognized about one month after the onset. Both abnormalities tended to improve from the peripheral region with the improvement of the defect in the visual field. Administration of phenytoin resulted in an improvement in the pseudopsia but it resulted in an aggravation in the visual illusion. Thus, the mechanisms of development of this phenomena were thought to be different from each other. It was found by dynamic CT that the blood flow in the primary visual cortex was rather increased in the affected site in comparison with that in the healthy site. It was speculated that the pseudopsia in the defective region of the visual field reflected a pathological repair process represented by a development of the collateral circulation. On the other hand, the visual illusion was thought to originate from visual unstability due to incomplete damage of the visual pathway at the affected site.