Consider at the beginning “local” interactions between the characteristics of SCP and SGP in the three groups of healthy subjects tested by us of both sexes and different ages (young — 20-39 years old, average — 39-59, elderly — 60-75), as well as in patients with BA . All subjects underwent neurological and psychiatric examination. The assignment of the SGP was carried out in a bipolar and monopolar manner. In the case of monopolar and bipolar registration, the active electrodes were located in the occipital regions (points O,) and the reference electrodes were located in the central regions during bipolar leads (points C and C by system 10-20); with a unipolar lead, the reference electrodes were attached to the earlobes. The registration of SGP was carried out according to a standard method on a specialized device for registration of Neuropack-2 airspace (Nihon Kohden, Japan). The registration procedure is described in detail earlier (VF Fokin et al., 1989).
When comparing the SGP in groups of young and elderly healthy subjects, it was found that the latency of the first positive component P1 increases significantly with age from 55.5 + 1.4 to 60.4 + 1.0 ms, the latency of the other components has a certain tendency to increase, however for subsequent components, differences in latent periods are not statistically significant. The latency of all components, except the first, in the group of patients with BA is significantly higher than in the first and second groups. Thus, the latent period of the first negative component N1 in the group of elderly subjects was 83.1 + 1.5 ms, in patients with BA – 94.3 + 4.4 ms.
The components did not significantly differ in amplitude in healthy people of young and old age. In the case of BA, the components P3 and N3 had a significantly lower amplitude compared with the corresponding parameters in healthy subjects of the corresponding age. The amplitudes of the remaining components in patients with BA were not significantly different from the norm.
In older subjects, the distribution of SCP over the surface of the head is smoother than in middle-aged people (Chapter 5, “Energy metabolism during brain development and aging”). In patients with BA, the distribution of SCP over the surface of the head had a distinct relief, but with significantly higher SCP values (for more details, see section 7.3 “Energy metabolism of the brain in Alzheimer’s disease”).
Statistical analysis showed that the largest number and most significant pair correlations are observed between local and monopolarly registered SCPs in the occipital region, exclusively with the amplitude characteristics of the SGP in all groups.
Consider the values of the correlation coefficients between the local and monopolar SCP in the occipital region with the amplitudes of the components of the SGP in the right and left hemispheres .