E kstrapyramidnoy system, which is characterized by the so-called parkinson syndrome: akinesia, rigidity, tremor. At present, primary parkinsonism, or Parkinson’s disease, secondary parkinsonism (vascular, post-encephalitic, drug, traumatic, etc.) and parkinson syndrome are distinguished in various forms of multisystem degeneration.
Parkinsonism, like Alzheimer’s disease, is a neurodegenerative disease associated with pathological aging (GN Kryzhanovsky et al., 1995). In parkinsonism, degenerative changes are detected primarily in the dopaminergic neurons of the nigro-striatal system and in the blue spot. Atrophic changes in cortical structures can also be observed, mainly in the frontal area (AM Wayne et al., 1981).
The pathogenesis of Parkinson’s syndrome is associated with an impaired phase-tonic relationship in the motor system as a result of an imbalance in the balance of dopamine – acetylcholine – serotonin mediators. Degeneration of the dopaminergic neurons of the substantia nigra and their axons, which innervate the striatum and exert a inhibitory effect on the cholinergic neurons of the caudate nucleus, leads to the hyperactivation of the striated cholinergic neurons. With an increase in the level of acetylcholine, tonic motions increase and phasic motor manifestations decrease, that is, muscular rigidity increases, and the speed of movements decreases. When the dopamine level increases (for example, when taking drugs of the l-dopa group), on the contrary, the speed of movement increases, and the rigidity decreases (R. Hassler, 1972; LR Zenkov, 1974).
The pathogenesis of akinesia is associated with impaired activation of the cortical prefrontal and additional motor regions, which is caused by the disintegration of these parts of the cortex and subcortical structures as a result of the defeat of the dopaminergic formations of the nigrostricular system (DJ Brooks, 1997).