Ultrasound and neurosonographic examination of the facial nerve was performed in 60 patients with hemifacial spasm and 40 healthy controls. The aim was to identify structural and hemodynamic changes of the nerve associated with neurovascular conflict. Patients with hemifacial spasm showed a significant decrease in facial nerve diameter (1.9 ± 0.3 mm vs. 2.4 ± 0.2 mm; p < 0.01), reduced echogenicity, and altered perineural blood flow. These findings indicate compressive changes and early demyelination of nerve fibers. A positive correlation was established between the degree of neurosonographic changes and the severity of spasm (r = 0.62; p < 0.05), confirming the diagnostic value of the method.