Predicting postoperative voice characteristics of spastic dysphonia patients.

Current treatment of spastic dysphonia may involve unilateral RLN section preceded by a temporary chemical paralysis of one RLN as a diagnostic test. This study compared the immediate postchemical paralysis and postsurgical paralysis voice and speech qualities of 33 spastic dysphonic patients using perceptual, acoustic, and temporal measurements and found that following section of the RLN, there was a decrease in overpressure and aperiodicity, an increase in vocal range, and a reduction of breathiness. Vocal tremor and speech rate were variably affected. It appears that chemical paralysis of the RLN is a fairly accurate means of previewing the postsurgical voice.