Videofluoroscopy Swallow Study: Technique and Protocol

Abstract

The video fluoroscopic swallow study (VFSS) or modified barium swallow study (MBSS) is the current gold standard for the diagnosis and management of dysphagia. Deglutition is a complex neuromuscular activity consisting of four phases: an oral preparatory, oral, pharyngeal, and esophageal phase. Each of the phases is controlled by a different neurological mechanism. The voluntary oral preparatory and oral phases are controlled by the medial part of the temporal lobes and the limbic system of the cerebral cortex with contributions from the motor cortex and other cortical areas. The pharyngeal part of swallow starts at the end of the oral phase and subsequently is coordinated by the swallowing center in the pons and medulla oblongata. The reflex is initiated by the touch receptors in the pharynx as a bolus of food is pushed to the back of the oral cavity by the tongue, and by stimulation of the palate (palatal reflex). The sophisticated function of deglutition is guided by sensory input from the upper aerodigestive tract, central processing in the brain, and harmonious contraction and relaxation of numerous skeletal (e.g., tongue) and smooth (e.g., pharynx and esophagus) muscles controlled by several cranial nerves and the autonomic nervous system (ANS). Evaluation of this plethora of events by a single test is quite challenging. Thus, pretest assessment of patient’s physical and psychosocial health is of paramount importance to maximize sensitivity, specificity, and accuracy of VFSS, as the test demands patient’s full cooperation. The VFSS provides a limited assessment of the esophageal phase of deglutition. Videofluoroscopic esophagogram is performed as a separate test for comprehensive evaluation of this phase of swallowing.