Oropharyngeal Dysphagia and Swallowing Dysfunction

Abstract

Oropharyngeal dysphagia (OD) is a disorder causing difficulty to form or move the alimentary bolus safely from the mouth to the esophagus. The three main populations at risk for OD are the elderly, patients with neurological diseases, and patients with head and neck diseases. OD may cause severe complications such as malnutrition and/or dehydration, choking and tracheobronchial aspiration which results in aspiration pneumonia with high mortality rates. OD may be caused by inability to mix the bolus and position it on the tongue in the oral phase. In the pharyngeal phase, OD is caused by delayed, prolonged or uncoordinated arrangement of oropharyngeal structures from a respiratory to a digestive pathway, and/or impaired transfer of the bolus from the mouth to the esophagus with reduced bolus propulsion and/or impaired upper esophageal sphincter (UES) relaxation. The sequential diagnostic procedure for patients at risk for OD includes: (a) screening of symptoms; (b) bedside clinical assessment, and (c) instrumental diagnosis. Videofluoroscopy can assess signs of safety and efficacy of deglutition, measure the swallow response and select therapeutic strategies. The Fiberoptic endoscopic evaluation of swallowing test studies pharyngeal/laryngeal anatomy, sensitivity and movement, aspirations, secretions, and the effect of treatments. Pharyngo-UES high-resolution manometry measures pharyngeal contraction and UES relaxation, and pharyngeal impedance detects postswallow residue and determines risk of aspirations. Therapeutic strategies for the treatment of OD include behavioral treatments, such as bolus modification (volume, viscosity), postural adjustment, motor behavioral techniques, swallow maneuvers, and sensory and neurophysiologic interventions. Alternative therapeutic strategies include surgical procedures at the UES, tube feeding and percutaneous endoscopic gastrostomy. New peripheral and central neuromodulation techniques have the potential to induce plastic changes in pharyngeal motor cortical areas that can be relevant for swallowing function.