Cerebral neural networks in cases of concomitant chronic cerebral ischemia and type 2 diabetes mellitus

About authors

Research Center of Neurology, Moscow, Russia

Correspondence should be addressed: Vitaly Fedorovich Fokin
Volokolamskoye shosse, 80, Moscow, 125367, Russia; ur.liam@fvf

About paper

Funding: the study was supported through the grant by RSF 22-15-00448.

Author contribution: Fokin VF — article authoring; Ponomareva NV — design of physiological and neuropsychological tests, general design of the study; Konovalov RN — design of neuroimaging evaluation; Shabalina AA — biochemical tests; Medvedev RB — dopplerogaphy; Lagoda OV — clinical tests; Boravova AI — psychophysiological tests; Krotenkova MV — management of neuroimaging evaluation; Tanashyan MM — management of clinical tests, general design of the study.

Compliance with ethical standards: the study was approved by the local Ethical Committee of the Research Center of Neurology (Minutes #5-6/22 of June 1, 2022). All participants submitted signed informed consent forms.

Received: 2023-09-14 Accepted: 2023-09-22 Published online: 2023-10-31

With type 2 diabetes mellitus (DM2) as a concomitant disease, chronic cerebral ischemia (CCI) has a more severe course because of chronic hyperglycemia. Using resting state functional MRI (fMRI) data, this study aimed to investigate connectivity of cerebral neural networks in patients that have CCI with DM2 and without DM2. The study involved 257 CCI patients (81 male and 176 female, aged 50-85 years) some of whom had DM2. We assessed metabolic parameters, state of cerebral circulation, and cognitive functions. Resting fMRI was used for the analysis of structure of connectivity of cerebral neural networks. With false discovery rate (FDR) factored in, CCI patients with DM2 had values of some indicators of connectivity of cerebral neural networks at a level significantly lower than CCI patients without DM2 (p (FDR) < 0.05). Namely, the indicators in question were those of connectivity of right hemisphere's speech neural network, left hemisphere's parahippocampal region, and angular gyrus of the right hemisphere, which is an integral part of the brain's passive mode network. Also, CCI patients with DM2 had significantly poorer connectivity of anterior cingulate gyrus, part of the salient neural network, and superior temporal gyrus. There are significant changes in the cerebellar networks, too. Overall, the size and intensity of most of the neural networks studied in resting state are lower in CCI patients with DM2.

Keywords: type 2 diabetes mellitus, connectivity, chronic cerebral ischemia, resting state functional MRI, size and intensity of neural networks