Consensus on definitions, terminology, classification of dystonia, and clinical guidelines. Part 2. Etiology and pathogenesis (Axis II). Novel genetic classification

This article presents an adapted Russian-language version of the 2025 International Consensus on the Classification of Dystonia, with particular emphasis on etiology and pathogenesis (Axis II). The revised classification integrates recent advances in the understanding of the biological mechanisms underlying dystonia. Axis II distinguishes between genetic and acquired etiologies, clarifies the anatomical classification of nervous system lesions, and introduces a new category for pathogenetic mechanisms, including developmental, degenerative, metabolic, and immune or inflammatory processes. The article highlights the adoption of the modern genetic nomenclature (Movement Disorder Society — MDS), which replaces the previous DYT locus system. A detailed analysis is provided for the pathogenetic mechanisms of drug-induced, autoimmune, and neurodegenerative forms of dystonia. The final section outlines etiopathogenetic therapies, including incobotulinum toxin A and neurosurgical interventions. The proposed two-axis system aims to systematize clinical data and improve the accuracy of dystonia diagnosis for both specialists and physicians in related fields.