Phonation Quotient Using Three Aerodynamic Instruments in the Disordered Voice

Laryngeal dysfunction is prominent in asthmatic women treated by inhaled corticosteroids

BACKGROUND

Dysphonia is a frequent comorbidity of asthma and has been suggested to be a local side effect of inhaled corticosteroids due to laryngeal candidiasis. We hypothesized that dysphonia in asthmatics was not due to laryngeal organic lesions but to laryngeal dysfunction during phonation (LDP).

OBJECTIVE

We compared the frequency of LDP in female asthmatic patients treated with inhaled corticosteroids to female controls.

METHODS

We compared 68 asthmatic female patients to 53 female control subjects. Pulmonary function tests were performed and the asthmatic patients classified according to the level of inhaled corticosteroids. Dysphonia was defined as a Vocal Handicap Index ≥18 or GRBAS score ≥2. All patients underwent video laryngo-strobe examination, analyzed blindly and separately by two otolaryngologists, describing mucosal changes, LDP, or Organic lesions linked to Laryngeal Dysfunction during Phonation (OLDP).

RESULTS

66.2% of the asthmatic patients exhibited dysphonia and 11.3% of controls (p < 0.001). No laryngeal candidiasis was found, only 3 patients presented laryngeal mucosa inflammation. LDP was observed in 60.3% of asthmatic patients and 18.9% of controls (p < 0.001), and no difference was found for OLDP (11.8% vs. 13.2%). No association was made between LDP, the dosage of inhaled corticosteroid, and bronchial obstruction.

CONCLUSIONS

Asthmatic patients were more dysphonic than control subjects. This phenomenon was not explained by mucosal inflammation, laryngeal candidiasis or OLDP. Asthmatic patients had more LDP than controls. There was no relation between LDP, inhaled corticosteroids dosage or bronchial obstruction. These results change our view of inhaled corticosteroid side effects in female asthmatic patients.

A Comparison of the s/z Ratio to Instrumental Aerodynamic Measures of Phonation

OBJECTIVE

The purpose of this study was to examine how the s/z ratio and instrumental measures of laryngeal valving and voicing efficiency.

STUDY DESIGN

Prospective, cohort design.

METHODS

Fifteen adult males (mean age 28.3 years) and 15 adult females (mean age 29.2 years) with normal voice quality were recruited and compared on productions of the s/z ratio and instrumental aerodynamic measures. The aerodynamic measures included vital capacity, maximum phonation time, airflow rate during sustained and sentence production, subglottal pressure, and laryngeal airway resistance. These measures were obtained on the Phonatory Aerodynamic System Model 6600. Statistical analyses included a univariate analysis of variance to examine for differences between sexes for all the variables, and between the s/z ratios for each of the three trials. Pearson's Product Moment Correlations were performed to identify the strength and nature of any significant relationships between the s/z ratio and instrumental aerodynamics.

RESULTS

There were significant differences in the mean values between males and females only for the measures of vital capacity and maximum phonation time. There were no significant differences between the three trials for the s/z ratio. There was a significant moderate negative correlation between the s/z ratio and laryngeal airway resistance in females and between the s/z ratio and sentence airflow rate in males.

CONCLUSIONS

The s/z ratio demonstrated only a moderate correlation with limited instrumental measures of laryngeal valving. In the absence of clear evidence of its ability to accurately assess laryngeal valving, the s/z ratio should be used in combination with other instrumental measures of laryngeal aerodynamics for a better representation of aerodynamic functioning.