Oropharyngeal dysphagia pathophysiology, complications and science-based interventions

Abstract

The etiology of oropharyngeal dysphagia can be broad, and includes aging with atrophy, debilitation, stroke, neurodegenerative and muscular diseases, tumor and postsurgical deformity, as well as effects due to medications and drying of the mucosal membranes. Pathophysiology depends on the multiple causative factors, including the cortex and neural connections to generate the swallow, as well as the oropharyngeal musculature. While chronic debilitation and age may result in nutritional deficiency and poor hydration, the other causes generally present with aspiration risk more acutely. Bacteriologically, aspiration pneumonia is usually polymicrobial with a predominance of Gram-negative enteric bacilli. However, there is emerging evidence to suggest that odontogenic sources may complicate the severity of bacterial load. The principles behind science-based interventions are primarily aspiration assessment with bedside evaluation, and ultimately modified barium swallow (videofluoroscopy) or functional endoscopic evaluation of swallowing (with or without sensory testing). Each has its advantages and logistical concerns. Intervention and rehabilitation is unique to the patient's needs, but may include reconditioning and therapy with a speech and language pathologist, and surgical options. The emerging roles of neuroplasticity and external neuromuscular stimulation are also discussed.