Abnormal corpus callosum induced by diabetes impairs sensorimotor connectivity in patients after acute stroke

ObjectivesTo test the hypothesis that abnormal corpus callosum (CC) induced by diabetes may impair inter-hemispheric sensorimotor functional connectivity (FC) that is associated with poor clinical outcome after stroke.MethodsForty-five patients with acute ischaemic stroke in the middle cerebral artery territory and 14 normal controls participated in the study. CC was divided into five subregions on three-dimensional T1-weighted image. The microstructural integrity of each subregion of CC was analysed by DTI and the inter-hemispheric FCs in primary motor cortex (M1-M1 FC) and primary sensory cortex (S1-S1 FC) were examined by resting-state functional magnetic resonance imaging.ResultsDiabetic patients (n = 26) had significantly lower fractional anisotropy (FA) in the isthmus of CC (CCisthmus) when compared with non-diabetic patients (n = 19) and normal controls (p < 0.0001). In addition, diabetic patients had the lowest M1-M1 FC (p = 0.015) and S1-S1 FC (p = 0.001). In diabetic patients, reduced FA of CCisthmus correlated with decreased M1-M1 FC (r = 0.549, p = 0.004) and S1-S1 FC (r = 0.507, p = 0.008). Decreased M1-M1 FC was independently associated with poor outcome after stroke in patients with diabetes (odds ratio = 0.448, p = 0.017).ConclusionsCC degeneration induced by diabetes impairs sensorimotor connectivity and dysfunction of motor connectivity can contribute to poor recovery after stroke in patients with diabetes.Key points center dot Abnormal isthmus of corpus callosum in stroke patients with diabetes.center dot Abnormal isthmus of corpus callosum correlated with decreased inter-hemispheric sensorimotor connectivity.center dot Decreased motor connectivity correlated with poor stroke outcome in diabetic patients.