Upward Effortful Pitch Glide as a Predictor of Pharyngeal Constriction in Individuals With Upper Versus Lower Motor Neuron Lesions

This study tested the validity of using nasoendoscopy ratings of volitional maximum pharyngeal constriction (PCmax) during nasoendoscopy recordings of effortful upward pitch glide to predict pharyngeal area at maximum constriction (PAM) during swallowing recordings (VFSSs) in individuals with upper motor neuron (UMN) versus lower motor neuron (LMN) lesions.

Retrospective analysis of electronic medical records identified individuals with UMN or LMN lesions who underwent both VFSS and nasoendoscopy within 3 months. Blinded expert judges rated the degree and symmetry of PCmax in paired nasoendoscopic images of quiet breathing (minimum pharyngeal constriction) and highest pitch production (PCmax). Sixty-five percent of paired images were rated twice for intra- and interrater reliability estimates of agreement; consensus-based ratings were used when disagreement occurred. Comparisons between PCmax ratings and dichotomized VFSS PAM measures from 3-cc and 20-cc liquid bolus trials within UMN and LMN groups were assessed using univariate logistic regression.

Forty-six individuals (N = 24 LMN, 22 UMN) met inclusion criteria. Judge 1 achieved an intraclass correlation coefficient of .76, while Judge 2 achieved .71 intrarater agreement on PCmax measures; interrater agreement was .73 prior to reaching consensus. Nasoendoscopic ratings of PCmax did not differentiate "normal" and "abnormal" VFSS PAM measures in the UMN group (p = .89). In contrast, the odds ratio for correspondence between high PCmax scores (i.e., greater pharyngeal constriction) and normal PAM measures was 1.91 (95% confidence interval [1.14, 4.52]; p = .053) in the LMN group.

Those with LMN lesions show predictable correspondence between PCmax and PAM outcomes, while the PCmax measures of a volitional task may not predict PAM in UMN lesioned individuals.