Type 2 diabetes and cognitive functions in patients with chronic cerebrovascular diseases

Background. Type 2 diabetes (T2DM) both directly and indirectly impacts the development of morphological and functional changes of the central nervous system. Aim. The study was to determine clinical and neurophysiological patterns of cognitive impairment (CI) in patients with chronic cerebrovascular diseases (CCD) and T2DM. Materials and methods. We examined 132 patients with CCD. First group included 58 patients without T2DM aged 64.5 [58; 72], second group 74 patients with CCD and T2DM 63 [57; 70]. Clinical, neurological, neuropsychological, neurophysiological (cognitive evoked potentials (EP) and neurovisualisation (brain MRI) examination was carried out to all patients. Results. Somatic and neurological characteristics of the patients were similar in both groups with the exception of more distinct metabolic changes in T2DM patients. Neurovisualisation study of the brain MRI in T2DM patients revealed more distinct changes in the form of white matter hyperintensity and subarachnoidal spaces enlargement. Neuropsychological examination in patients revealed the reduction of intellectual flexibility, constructive praxis disruption, optical spatial dysfunction and deteoration of delayed word recall. Significant disorders in the way of overall cognitive impairment, lobar dysfunction and impaired verbal associative productivity, proved by statistically lower amplitude and higher latency of P300 EP peak were noted in T2DM patients. Correlation links were detected: for P300 amplitude and direct and inverse number listing test (r=0.366 and r=0.520; p=0.006 and p<0.001 respectively); P300 latency and HbAi, (r=0.32; p<0.05) in group 2 and glucose levels in both groups (r=0.30; p<0.05); inverse relationship of latency with control functions evaluation (r=-0.34; p=0.008). Conclusion. CCD especially with T2DM manifests with neurocognitive imbalance, including control functions disruption and are accompanied by neurophysiological and neurovisualistion changes.