Efficacy of Continuous Positive Airway Pressure for Treatment of Hypernasality

Abstract

Objective: To determine whether speech hypernasality in subjects born with cleft palate can be reduced by graded velopharyngeal resistance training against continuous positive airway pressure (CPAP). Design: Pretreatment versus immediate posttreatment comparison study. Setting: Eight university and hospital speech clinics. Patients: Forty-three subjects born with cleft palate, aged 3 years 10 months to 23 years 8 months, diagnosed with speech hypernasality. Intervention: Eight weeks of 6 days per week in-home speech exercise sessions, increasing from 10 to 24 minutes, speaking against transnasal CPAP increasing from 4 to 8.5 cm H2O. Main Outcome Measure: Pretreatment to immediate posttherapy change in perceptual nasality score based on blinded comparisons of subjects’ speech samples to standard reference samples by six expert clinician-investigators. Results: Participating clinical centers treated from two to nine eligible subjects, and results differed significantly across centers (interaction p = .004). Overall, there was statistically significant reduction in mean nasality score after 8 weeks of CPAP therapy, whether weighted equally across patients (mean reduction = 0.20 units on a scale of 1.0 to 7.0, p = .016) or across clinical centers (mean = 0.19, p = .046). This change was about one-sixth the maximum possible reduction from pretreatment. Nine patients showed reductions of at least half the maximum possible, but hypernasality of eight patients increased at least 30% above pretreatment level. Most improvement was seen during the second month when therapy was more intense (p = .045 for nonlinearity). No interactions with age or sex were detected. Conclusion: Patients receiving 8 weeks of velopharyngeal CPAP resistance training showed a net overall reduction in speech hypernasality, although response was quite variable across patients and clinical centers. The net reduction in hypernasality is not readily explainable by random variability, subject maturation, placebo effect, or regression to the mean. CPAP appears capable of substantially reducing speech hypernasality for some subjects with cleft palate.