[Differential diagnosis of unilateral paresis and paralysis of the larynx].

Differential diagnosis of laryngeal paresis and paralysis using electron glottography (EGG) was tried in 57 patients and 30 healthy controls. Measurements were made of speed quotient (SQ) and open quotient (OQ) at piano and forte. It was found that in patients and controls SQ and OQ were not similar. SQ and OQ differed also in paralysis and paresis. Tonicity of the inner laryngeal muscles seems to decline more in paralysis than in paresis. Aerodynamic properties of the larynx are damaged more in paralysis and remain unchanged in paresis. Reduced SQ and high OQ at forte indicate unilateral laryngeal paralysis. OQ should be measured both at piano and forte. Thus, EGG is an effective procedure for differential diagnosis of laryngeal paralysis and paresis. It is especially convenient when laryngostroboscopy is problematic.