Effortful upward pitch glide as a predictor of non-volitional swallow function in individuals with upper versus lower motor neuron lesions

Objective: This study addressed the correspondence between maximum pharyngeal constriction (PCmax) during effortful upward pitch glide task using nasoendoscopy compared with measures from videofluoroscopic swallow studies (VFSS) of swallowing function in individuals with upper (UMN) vs lower motor neuron (LMN) lesions. The nasoendoscopy task is considered to predict pharyngeal function during swallowing although neural pathways for pitch glide differs for some populations. Methods: Comparisons were made between PCmax measures from VFSS and nasoendoscopy in 26 individuals with UMN (N = 13) or LMN (N = 13) etiologies of dysphagia. Two judges rated the degree and symmetry of PCmax in paired nasoendoscopic images contrasting quiet breathing (i.e. minimum pharyngeal constriction) and highest pitch production (i.e. PCmax). Judges rated each subject twice in a randomized order to obtain intra- and inter-rater reliability estimates. Judge 1 achieved 96% and Judge 2 achieved 92% intra-rater agreement. Inter-rater agreement was 63% overall. Judges reached consensus on items with differing ratings prior to final analysis. Final nasoendoscopy PCmax ratings were compared to VFSS measures within and between UMN and LMN groups using univariate linear regression analysis. Results: A significant difference occurred between nasoendoscopic ratings and VFSS PCmax measures between UMN and LMN groups (p<.054). Stronger correspondence was shown for the LMN group than the UMN group. Nasoendoscopic ratings did not accurately predict VFSS PCmax measurement outcomes in 1/3 of the UMN group. Conclusions: Nasoendoscopic ratings of PCmax during upward pitch glide may not accurately predict VFSS measures in 1/3 of individuals with UMN lesions.