Diagnostic value of "dysphagia limit" for neurogenic dysphagia: 17years of experience in 1278 adults

PubMed ID: 25088732Objective: Neurogenic dysphagia (ND) is a prevalent condition that accounts for significant mortality and morbidity worldwide. Screening and follow-up are critical for early diagnosis and management which can mitigate its complications and be cost-saving. The aims of this study are to provide a comprehensive investigation of the dysphagia limit (DL) in a large diverse cohort and to provide a longitudinal assessment of dysphagia in a subset of subjects. Methods: We developed a quantitative and noninvasive method for objective assessment of dysphagia by using laryngeal sensor and submental electromyography. DL is the volume at which second or more swallows become necessary to swallow the whole amount of bolus. This study represents 17. years experience with the DL approach in assessing ND in a cohort of 1278 adult subjects consisting of 292 healthy controls, 784 patients with dysphagia, and 202 patients without dysphagia. A total of 192 of all patients were also reevaluated longitudinally over a period of 1-19. months. Results: DL has 92% sensitivity, 91% specificity, 94% positive predictive value, and 88% negative predictive value with an accuracy of 0.92. Patients with ALS, stroke, and movement disorders have the highest sensitivity (85-97%) and positive predictive value (90-99%). The clinical severity of dysphagia has significant negative correlation with DL = r = -0.67, p < 0.0001). Conclusions: We propose the DL as a reliable, quick, noninvasive, quantitative test to detect and follow both clinical and subclinical dysphagia and it can be performed in an EMG laboratory. Significance: Our study provides specific quantitative features of DL test that can be readily utilized by the neurologic community and nominates DL as an objective and robust method to evaluate dysphagia in a wide range of neurologic conditions. © 2014 International Federation of Clinical Neurophysiology