A 68-year-old man was admitted to our department because of left incomplete homonymous hemianopia accompanied by hyperglycemia. Both T2-weighted and diffusion-weighted imaging revealed a low signal intensity along the subcortex and high signal intensity along the cortex on the right parietal and occipital lobes. Furthermore, arterial spin labeling and single-photon emission computed tomography showed hyperperfusion at the right parieto-occipital lobe. However, the electroencephalography result was normal. Hyperperfusion improved after controlling the blood glucose levels; nevertheless, homonymous hemianopia remained. We suspect that the irreversible brain damage was attributable to hyperperfusion associated with long-term hyperglycemia.
Keywords: epilepsy; homonymous hemianopia; hyperglycemia; hyperperfusion; single-photon emission computed tomography.