Репозиторий Университета

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Objectives. The amplitude and latency of the P300 wave are regarded as basic neurophysiological correlates in studies of cognitive functions. The characteristics of the event-related θ rhythm recorded in the same time period as the P300 wave are less well studied. The aim of the present work was to carry out a complex assessment of the neurophysiological parameters of cognitive processes in health and various degrees of cognitive dysfunction in patients with personality disorders, schizotypal disorders, and schizophrenia. Materials and methods. A total of 124 subjects were studied: 44 healthy subjects (normal), 40 patients with schizophrenia, 22 patients with personality disorder, and 18 with schizotypal disorder. Studies used a probabilistic presentation of significant and non-significant auditory signals. P300 amplitude and latency were determined for each subject, along with power and paired coherence in the event-related θ rhythm, on presentation of significant stimuli. Results and conclusions. All patients, as compared with healthy subjects, were found to have a tendency to decreases in P300 amplitude and increases in latency, with reductions in the power and coherence of the event-related θ rhythm. In schizophrenia, this trend was spatially generalized, while changes in personality disorder and schizotypal disorders were mostly localized and did not reach statistical significance on between-group comparisons. These data may be evidence of gradual weakening of cognitive functions going from normal through schizotypal disorder and personality disorder to schizophrenia, which may correspond to decreases in insight and the ability to foresee the consequences of actions.

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Objectives. The amplitude and latency of the P300 wave are regarded as basic neurophysiological correlates in studies of cognitive functions. The characteristics of the event-related θ rhythm recorded in the same time period as the P300 wave are less well studied. The aim of the present work was to carry out a complex assessment of the neurophysiological parameters of cognitive processes in health and various degrees of cognitive dysfunction in patients with personality disorders, schizotypal disorders, and schizophrenia. Materials and methods. A total of 124 subjects were studied: 44 healthy subjects (normal), 40 patients with schizophrenia, 22 patients with personality disorder, and 18 with schizotypal disorder. Studies used a probabilistic presentation of significant and non-significant auditory signals. P300 amplitude and latency were determined for each subject, along with power and paired coherence in the event-related θ rhythm, on presentation of significant stimuli. Results and conclusions. All patients, as compared with healthy subjects, were found to have a tendency to decreases in P300 amplitude and increases in latency, with reductions in the power and coherence of the event-related θ rhythm. In schizophrenia, this trend was spatially generalized, while changes in personality disorder and schizotypal disorders were mostly localized and did not reach statistical significance on between-group comparisons. These data may be evidence of gradual weakening of cognitive functions going from normal through schizotypal disorder and personality disorder to schizophrenia, which may correspond to decreases in insight and the ability to foresee the consequences of actions.

© 2018 by the authors; licensee Modestum Ltd., UK. Objective: Cognitive impairments (CIs) appear to be commonly encountered in patients with arterial hypertension (AH). Hence, our study was aimed at examining the frequency of cognitive impairments (CIs) in the physician’s outpatient practice, as well as at determining clinical and instrumental peculiarities of the course of AH in patients with and without CIs. Method: We carried out comprehensive examination of three hundred and fifty 50-to-80-year-old hypertensive patients followed up in the setting of a polyclinic and tested by means of neuropsychological scales (MMSE, Mini-Cog test, Montreal Cognitive Assessment Scale, Hospital Anxiety and Depression Scale), duplex scanning of extracranial vessels, and magnetic resonance tomography (MRT) of the brain. Results: The findings of neuropsychological testing demonstrated the presence of CIs in 83.5% of hypertensive patients, with CIs reaching the level of dementia in 16.9% and being combined with depressive symptoms in 40.3%. Hypertensive patients with CIs as compared with those without CIs were found to have more pronounced lesions to white matter of the brain: periventricular (71.1%) and/or subcortical (15.8%) leukoaraiosis. Subcortical leukoaraiosis of the frontal lobes of the brain was associated with an elevated level of systolic arterial pressure (SAP). It was confirmed that impaired circadian rhythm of AP with stable persistence of nocturnal hypertension resulted in the most pronounced structural and morphological damage of the brain. Conclusion: High incidence of CIs in hypertensive patients has been confirmed. Structural and morphological impairments of strategically important regions of the brain (subcortical leukoaraiosis of the frontal lobes) in hypertensive patients with CIs were associated with elevated SAP.