The study of the distribution of AMR in some patients was carried out repeatedly over several days. The SCP was recorded in 17 leads in accordance with the international scheme 10-20 with the reference electrode located on the wrist of the right hand. The spatial distribution of AMR in patients with stroke was characterized by the following features. The magnitude of SCP in monopolar leads was positive in all areas. The average SCP was increased, especially with the localization of the lesion in the left hemisphere .
The distribution of SCP in healthy people and patients with the consequences of an acute violation of cerebral circulation.
SMA is the middle cerebral artery, PMA is the anterior cerebral artery. Mapping of 17 leads UPP. Control – average values in the group of healthy subjects of the corresponding age. The distribution of SCP after stroke in individual patients is presented. z is the sagittal line, d, s are the right and left parasagittal lines. Fp – frontal pole, F – frontal, C – central, T – temporal, P – parietal, O – occipital region
Compared with the norm, the average SCP in patients after a stroke was increased approximately twice and was 11.9 + 1.2 mV. In the sagittal direction, the nature of the distribution of SCP did not differ from the norm: the SCP was minimal in the frontal areas, increased to the vertex, and somewhat decreased to the back of the head. In the parasagittal directions, the SCP distribution was generally similar, but the SCP values over the nidus were significantly less than normal. In addition, in the healthy hemisphere
, a mirror focus was often visible with higher UCP values .
Local SCPs were significantly reduced over the affected area compared with local SCPs in the symmetric region of the healthy hemisphere. Reduced capacity over a lesion on the surface of the head is similar to changes in SCP, revealed during abduction from the surface of the brain in conditions of acute ischemia. In the present study, registration was carried out after a considerable time, from 2 weeks to 4 years after a stroke. During this period, after an increase in necrotic changes in the area of the lesion, large connective tissue scars or cysts-cavities develop, the walls of which are represented by connective tissue (A.N. Koltover, 1975; and others). Given the timing of cerebrovascular accident, it can be assumed that the registration of AMR in most patients was carried out at the stage of gliomesodermal scars or cysts. Obviously, the large size of these formations, violate the normal structure of the BBB, which leads to a decrease in UPP. Probably,A decrease in SCP is also associated with impaired blood supply and a significant decrease in energy metabolism in the damaged area. It is possible that the decrease in SCP, recorded on the surface of the head, is to some extent due to the absence of a constant potential gradient created by the membrane potentials of vertically ordered cortical neurons.
Thus, the use of SCP showed the presence of local and cerebral changes in patients with the consequences of an acute violation of cerebral circulation. Cerebral changes in patients with the effects of stroke manifest themselves in an increase in the amount of AMR averaged over all leads, which apparently reflects acidification of the blood flowing from the brain as a result of the accumulation of lactate and other products of anaerobic energy metabolism due to insufficient blood circulation to the brain.
Local changes of SCP indicate a significant decrease in energy metabolism in the area of post-ischemic cysts and scars. The decrease in SCP is obviously associated with a drop in the BBB potentials and a violation of the structure of the vascular bed. The use of SCP allows to estimate the magnitude of the local brain damage and the degree of cerebral changes.