[Electromyography of external laryngeal muscles in diagnosis of dysphonia]

Bioelectrical parameters of two groups of external laryngeal muscles, viz. superior muscles pulling up and inferior muscles pulling down the thyroid cartilage, were measured. Hypokinetic dysphonia was indicated by 1.2-1.6-fold increase of the pulse amplitude of superior muscles and hyperkinetic dysphonia was evidenced by 1.4-2.0-fold increase of that of inferior muscles. When the amplitude was identical on differed by less than 1.2 times, mixed dysphonia was suspected. In healthy people, the pulse amplitude of inferior muscles exceeded that of superior muscles by 1.2-1.4 times. This approach helps to improve the accuracy and reliability of dysphonia diagnosis, to better understand mechanisms of the pathology, and to develop the most efficient methods of voice recovery. Altogether 60 patients and 30 normal subjects were examined.