The article is devoted to the study of metabolic and neurochemical factors influencing the pathogenesis of hemifacial spasm (HFS).The levels of vitamin B₁₂, cortisol, and dopamine were determined in patients with HFS and compared with those in a control group. Significant correlations were established between decreased vitamin B₁₂ levels, hyperactivity of the hypothalamic–pituitary–adrenal axis, and disturbances in neurotransmitter processes. The findings confirm the involvement of vitamin B₁₂ deficiency in the disruption of neurovascular interactions, which contributes to the development of chronic pathological spasm of the facial muscles and defines directions for comprehensive patient rehabilitation.