Abstract

Retinal migraine is a rare subtype of migraine characterized by recurrent monocular visual symptoms(MVS). Severe hyperglycemia can cause chorea, seizure, or coma, but its association with retinal migraine has rarely been reported. A 54-year-old migraineur with diabetes mellitus complained of bright light in his left eye. MVS lasted from 2 to 3 minutes, recurred 5 to 50 times a day, and sometimes were followed by severe right-side headaches. Three years ago, he had had recurrent MVS associated with a colorful rainbow in the left eye, after discontinuing oral hypogly- cemic agents by his own volition. Hyperglycemia (613 mg/dl) and elevated glycosilated haemoglobin(10.5%) were detected. Initial and second EEGs, brain MRIs and MR angiography did not reveal any significant abnormalities. MVS decreased with improved glycemic and headache control and finally ceased in 3 weeks. MVS can develop due to hyperglycemia, and may be related to neuronal hyperexcitability or spreading depression.