Swallowing apnea as a function of airway closure

The purpose of this research was to ascertain whether the existence of swallowing apnea (SA) was the sole result of glottic closure or the result of its own neural mechanism. Forty individuals served as participants. Groups 1 and 2 consisted of 10 individuals with laryngectomy less than one year and 10 individuals greater than one year, respectively. Groups 3 and 4 comprised 20 individuals who were age- and gender-matched to Groups 1 and 2. SA duration (SAD) was acquired during saliva swallows and 10-, 15-, 20-, and 25-ml water boluses. A repeated measures ANOVA was performed to determine mean differences in SAD as a function of group and bolus volume. Significant main effects of group and bolus volume were found and a significant interaction of group x bolus volume was found. In post-hoc analyses, both groups with laryngectomy exhibited statistically longer SADs than control groups. In single-df comparisons, the laryngectomy group over one year exhibited significantly shorter SADs on smaller versus larger bolus volumes. Even though SA is theoretically no longer needed in individuals with laryngectomy, the presence of SA remained in both groups with laryngectomy. Thus, these results support the hypothesis that SA is the result of its own neural command.