Obstruction-related dysphagia in inclusion body myositis: Cricopharyngeal bar on videofluoroscopy indicates risk of aspiration.

OBJECTIVE

To show the predictive risk factors for aspiration pneumonia and prognostic importance of a cricopharyngeal bar (CPB) on videofluoroscopic examination of swallowing (VFS) in inclusion body myositis (IBM).

METHODS

In this retrospective study, we examined a consecutive series of 37 patients with clinico-pathologically defined IBM based on the European Neuromuscular Center diagnostic criteria for IBM from 2013. The Swallowing Disturbance Questionnaire was used for the evaluation of dysphagia. A standard VFS was performed at diagnosis. The primary outcome was aspiration pneumonia. Secondary outcomes included IBM Functional Rating Scale score, forced vital capacity (FVC), and body mass index.

RESULTS

Aspiration pneumonia occurred in 10 of 37 IBM patients (27%). Based on univariate analysis, 4 factors increased aspiration pneumonia risk: BMI < 18.5 (n = 5; hazard ratio [HR], 10.7; 95% CI, 2.50-46.0; p = .001); aspiration (n = 7; HR, 7.57; 95% CI, 1.82-31.6; p = .005); insufficient opening of the upper esophageal sphincter (n = 11; HR, 4.53; 95% CI, 1.12-18.3; p = .03); and CPB presence (n = 15; HR, 11.6; 95% CI, 1.46-91.8; p = .02). Clinical features of IBM-CPB(+) were elderly onset, obstruction-related dysphagia, and mild decreases in FVC, resulting in aspiration pneumonia in 1.3 years (interquartile range, 0.9-5.2); 67% of IBM-CPB(+) patients underwent interventional procedures for dysphagia. IBM-CPB(+) patients had a lower FVC than IBM-CPB(-).

CONCLUSIONS

A CPB in IBM largely contributes to obstruction-related dysphagia and is a risk factor that predicts aspiration pneumonia and refractory dysphagia requiring aggressive therapy.