Sector-related grey scale analysis of video ultrasound recorded tongue movements in swallowing

Abstract

Diseases of the oral cavity, floor of the mouth, and nervous system can be accompanied by disturbances in tongue movement during swallowing. These disturbances can be diagnosed by videosonography whereby the examiner has to evaluate extensive video documentation of lingual motion. It was the aim of this study to facilitate this evaluation by the application of a reproducible computer-assisted quantitative analysis procedure. Video sequences of 56 healthy adults and 19 patients with dysphagias of different etiologies were analysed. A numerical estimation of swallowing movements was carried out in abstraction from the structures imaged (bolus, air, muscles of the tongue, floor of the mouth, hyoid, etc.). Intensity changes of the pixels within previously defined radial image sectors were quantified in relationship to time and depicted as sector curves. The healthy adults demonstrated a characteristic pattern of two motion maxima that appeared within almost all sector curves. These maxima represented bolus transport movements and the reset movement of the tongue. Patients with diseases of the tongue or neuromuscular changes caused by disturbances of the central nervous system showed pathological deviations on videosonography. These appeared as local or general reductions in movement, slow speed motions, repetitive swallowing or unsorted additional movements of the tongue during swallowing.