Risk of ischemic stroke after third, fourth, and sixth cranial nerve palsies in type 2 diabetes

The aim of this study was to define the risk of ischemic stroke among newly diagnosed type 2 diabetes (T2D) patients who developed ocular motor cranial nerve (CN) palsies.

From the National Health Insurance Service - National Sample Cohort database (2002-2013) of a random sample of 1 025 340 Koreans, patients with newly diagnosed T2D aged ≥20 years were included in the study. The incidence of ocular motor CN palsies was identified using diagnostic codes for third, fourth, and sixth CN palsies. To determine the effect of incident ocular motor CN palsy on subsequent ischemic stroke, covariate Cox regression was used (Model 1 included only ocular motor CN palsy as a time-varying covariate; Model 2 included ocular motor CN palsy and demographic information; Model 3 included all variables in Model 2 as well as comorbidity, concomitant medication, and the Charlson comorbidity index score).

Of 45 820 T2D patients, 75 developed ocular motor CN palsy and 1411 had ischemic stroke. Four patients experienced ischemic stroke after the development of ocular motor CN palsy. Incident ocular motor CN palsy was associated with the subsequent risk of ischemic stroke in Models 1, 2 and 3 (hazard ratios [95% confidence intervals] 3.74 [1.40-9.98], 3.33 [1.25-8.89], and 2.96 [1.11-7.92], respectively). Male sex, older age, and lower income were associated with an increased risk of ischemic stroke. Among confounders, hypertension, atrial fibrillation, and congestive heart failure were associated with the risk of ischemic stroke.

Physicians should pay more attention to manageable risk factors of ischemic stroke when diabetic patients suffer from ocular motor CN palsies.