Abnormal spontaneous brain activity in type 2 diabetes with and without microangiopathy revealed by regional...

To investigate whether global spontaneous brain activity changes in type 2 diabetes mellitus (T2DM) patients and these changes vary according to the degree of microangiopathy.

T2DM patients with (M(+), n=26) and without (M(-), n=22) microangiopathy as well as 28 healthy nondiabetic subjects were enrolled in this study. All the subjects completed a resting-state functional magnetic resonance imaging (rs-fMRI) examination and neuropsychological assessment. Regional homogeneity (ReHo) values, representing spontaneous brain activity, were calculated and compared between M(+) and M(-) T2DM patients and nondiabetic controls.

In both M(+) and M(-) T2DM patients, ReHo values were decreased in the occipital lobe, temporal lobe, postcentral gyrus, and cerebellum, while increased in the bilateral precuneus, superior/middle frontal gyrus, and insula. Compared with the M(-) group, M(+) patients showed decreased ReHo values in the left cuneus and superior occipital gyrus. The ReHo values in the lingual gyrus/calcarine cortex and MTG were related to clinical parameters in T2DM patients.

The abnormalities of spontaneous brain activity revealed by ReHo values in both M(+)and M(-) T2DM patients may provide insights into the neurological pathophysiology underlying diabetes-related cognitive impairments. M(+) patients showed more decreased brain activity related to severely impaired function of visual processing and visual memory.