ELECTROENCEPHALOGRAPHIC ASSESSMENT OF CEREBRAL ACTIVITY NEURODYNAMIC COMPONENTS AND THEIR POSSIBLE ROLE IN THE DEVELOPMENT OF NEUROCOGNITIVE DEFICIENCY

Abstract

The relevance of this article is due to the variability of scientific ideas about the mechanisms of development of neurocognitive deficit associated with a line of psychopathological conditions. Many questions remain about the functions of individual brain structures and systems, as well as central neurodynamics in the development of cognitive defects. The question of the influence of the disorganization of vertically oriented structures of the first brain functional block (BFB) on the formation of neurocognitive deficit in mental pathology of the schizophrenic spectrum remains the least studied in modern neuroscience. The present research was aimed to assess the functional state of the first brain energy block and to determine the role of disorders in the neurodynamic components of activity in the development of neurocognitive deficit in psychopathology. Materials and methods. 40 patients with paranoid schizophrenia and 38 healthy subjects matched in age, gender ratio and educational level were examined. EEG by monopolar according to the international system 10/20 using a 21-channel system “Telepat-1” was registered. With the help of visual and spectral methods of analysis, both nonspecific physical parameters of the α-rhythm — index, frequency and amplitude, and physiological features of α-oscillations — reactivity, regularity, autorhythm (modulation) and stability of the α-rhythm were studied. The functional state of the RF was determined by the parameters of the latent periods of synchronization, desynchronization, and the depth of desynchronization in the eye opening/closing test. The tonus of the cortex by the ratio of the values of the indices of alpha- and delta-rhythms was determined. The threshold of convulsive readiness of the brain was calculated from the number of recorded flashes in the background EEG. Fluctuations in the frequency of the basic alpha rhythm exceeding 0.5 Hz were regarded as a sign of instability in the oscillatory activity of the brain. Results. It has been established that impairment of cognitive functions in schizophrenia is associated not only with cortical dysfunction (II and III BFB), but also with disorganization of vertically oriented structures of the I BFB. Revealed disorganization of the reticular formation and alpha-regulating system, decreased tone and activation of the cerebral cortex. The possible pathogenetic influence of these pathophysiological factors on the formation of neurocognitive deficit
has been substantiated. The most informative diagnostic EEG-signs of disorders in the neurodynamic components of brain activity were determined.