Asymptomatic Pontine Lesion and Diabetic Amyotrophy after Rapid Improvement of Poor Glycemic Control in a Patient with Type 1 Diabetes.

We herein report a 28-year-old woman with type 1 diabetes with an asymptomatic pontine lesion and diabetic amyotrophy. She had suffered from diabetes from 10 years old. Treatment in a hospital reduced the hemoglobin A1c level from 14.2% to 7.2% for approximately 2 months. She suffered from acute-onset pain and weakness of the lower limb muscles without central nervous system manifestations. Magnetic resonance imaging showed high-intensity lesions at the brainstem and lower limb muscles on T2-weighted images. These findings and symptoms gradually resolved. Rapid treatment of poor glycemic control might increase the risk of asymptomatic pontine lesions and diabetic amyotrophy.