A Case of Hyperglycemia-Induced Epileptic Homonymous Hemianopsia

Hyperglycemia sometimes initially presents with neurological manifestations, including seizures, visual hallucinations, choreoathetosis, hemiballismus, myoclonus, tremor, and consciousness disturbance. Epileptic seizures induced by hyperglycemia are reported to occur predominantly in the occipital lobe, and the epileptic form is mainly epilepsia partialis continua. Of the two patterns of hyperglycemia (ketotic or nonketotic), nonketotic hyperglycemia is more commonly associated with seizures because ketosis has an anticonvulsive effect, so hyperglycemia-induced seizures are generally seen in nonketotic patients. Here, we report a 51-year-old Japanese male with intermittent homonymous hemianopsia who presented high hemoglobin A1c (19.1%). He had been drinking 3 L of the sugared soft beverage every day. After admission, he showed left-sided hemiconvulsion. Anti-seizure medications and insulin treatment were administered, and his seizure was aborted. The magnetic resonance imaging (MRI) showed a high-intensity lesion in the diffusion-weighted image and fluid-attenuated inversion recovery with gadolinium enhancement in the occipital lobe. In hyperglycemic convulsions, MRI sometimes shows leptomeningeal or parenchymal gadolinium enhancement. In addition, most hyperglycemic seizures are associated with nonketotic hyperglycemia and show occipital-dominant imaging abnormalities. We report this case by reviewing the differential diagnosis.