The Effects of Sensory Stimulation on Neurogenic Oropharyngeal Dysphagia

Abstract

Sensory input is crucial for the initiation and modulation of the swallow response. Patients with neurogenic oropharyngeal dysphagia present severe impairments in oropharyngeal sensitivity associated with impaired motor responses. Several strategies have been used with the aim to modulate the swallow response by modifying the sensorial properties of the bolus (either chemically or physically) or by directly stimulating the sensory and motor neurons of the pharynx and larynx. Most of the stimuli described as swallow sensory stimulants (such as acid, capsaicin or piperine) are integrated by receptors of the multimodal transient receptor potential (TRP) channel family, mostly expressed in sensory nerves. Enhancing the sensorial stimuli may increase the sensorial input to the swallowing centre of the brain stem, thus triggering the swallow response earlier and protecting the respiratory airway. Moreover, sensorial stimuli may promote brain plasticity, facilitating the recovery of deglutition. The aim of this review is to briefly summarize the effects of swallow therapies focused on sensory stimulation and discuss their effects, rationality, action mechanism and perspectives in patients with neurogenic oropharyngeal dysphagia.