Fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST) in healthy controls

The purpose of this study was to introduce a new method of bedside assessment of both the motor and sensory components of swallowing called fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST). This approach combines the established bedside endoscopic swallowing evaluation with a more recently described technique that allows objective determination of laryngopharyngeal (LP) sensory discrimination thresholds by delivering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve via a flexible endoscope. A prospective study was conducted of FEESST in 20 healthy control subjects, mean age of 34 +/- 11 years. LP sensory thresholds were defined as either normal (<4.0 mmHg air pulse pressure [APP]), moderate deficit (4.0-6.0 mmHg APP), or severe deficits (>6.0 mmHg APP). Subsequent to LP sensory testing, food of varying consistencies, mixed with green food coloring, was given and attention was paid to spillage, laryngeal penetration, pharyngeal residue, aspiration, and reflux. Therapeutic maneuvers such as postural changes and airway protection techniques were performed on each subject to determine if the assessed swallowing parameters were affected by maneuvers. All patients completed the study; all had normal LP sensory discrimination thresholds (2.9 +/- 0.7 mmHg APP). There were no instances of spillage, laryngeal penetration, or aspiration. Two of 20 subjects had pharyngeal residue and 2 of 20 had reflux. Institution of therapeutic maneuvers resulted in a predictable change in the endoscopic view of the laryngopharyngeal anatomy. FEESST provides comprehensive, objective sensory and motor information about deglutition in the bedside setting and might have implications for the bedside diagnosis and management of patients with dysphagia.