Isolated INO as a presentation of midbrain paramedian area lacunar infarction in patients with diabetes

The clinical features and pathogenesis of the pure midbrain infarction need to be described. Of 4257 stroke patients who were on the stroke registry between January 2000 and December 2015, 25 patients with pure midbrain infarctions, as demonstrated on diffusion-weighted magnetic resonance imaging, were enrolled. We analyzed the clinical features, MRI findings, and etiologic mechanisms of the infarctions. According to the distribution of each penetrating artery of the midbrain, we classified all the infarctions into paramedian (PM) area (13 patients), lateral area (10 patients), and PM and lateral areas (2 patients). In the lacunar infarction of the PM area group (8 patients), 6 patients had diabetes mellitus (DM), and 5 patients showed isolated anterior internuclear ophthalmoplegia (INO)-the ratio was much higher than that of the non-PM-lacunar infarction group. Patients with DM were more likely to develop lacunar infarction of the midbrain PM area than that of non-diabetics. Data suggest that isolated INO is a presentation of midbrain PM area lacunar infarction in patients with DM.