[Classical cortical superficial siderosis presenting as extensive higher brain dysfunction with hypoperfusion in the frontoparietal lobe on the 123I-IMP-SPECT: a case report].

A 72-year-old male developed neurological symptoms such as difficulty in charging his electronic money card and making his mobile-phone call ten months before admission. On admission, neurological examination revealed extensive higher brain dysfunction such as impairment in recent memory, executive function disorders, constructional disturbance, agraphia and acalculia. Brain MRI revealed a low intensity lesion on the surface of the cerebral cortex diffusely and symmetrically on T2*-weighted images. MRI images are consistent with superficial siderosis. However, the lack of hemosiderin deposition in the brain stem and cerebellar hemisphere was atypical of the classical type of superficial siderosis. 123I-IMP-SPECT revealed hypoperfusion dominantly in the left hemisphere, particularly in the left frontal and parietal lobes. According to the Boston criteria, the patient with the cerebral microbleeds and cortical superficial siderosis was diagnosed with probable CAA (cerebral amyloid angiopathy).