Effects of aural stimulation with capsaicin ointment on swallowing function in elderly patients with non-obstructive dysphagia

Abstract

ObjectiveIn the present study, an attempt was made to examine the effects of aural stimulation with ointment containing capsaicin on swallowing function in order to develop a novel and safe treatment for non-obstructive dysphagia in elderly patients.DesignA prospective pilot, non-blinded, non-controlled study with case series evaluating a new treatment.SettingSecondary hospitals.Patients and methodsThe present study included 26 elderly patients with non-obstructive dysphagia. Ointment containing 0.025% capsaicin (0.5 g) was applied to the external auditory canal with a cotton swab under otoscope only once or once a day for 7 days before swallowing of a bolus of colored water (3 mL), which was recorded by transnasal videoendoscopy and evaluated according to the endoscopic swallowing score.ResultsAfter a single application of 0.025% capsaicin ointment to the right external auditory canal, the endoscopic swallowing score was significantly decreased, and this effect lasted for 60 minutes. After repeated applications of the ointment to each external auditory canal alternatively once a day for 7 days, the endoscopic swallowing score decreased significantly in patients with more severe non-obstructive dysphagia. Of the eight tube-fed patients of this group, three began direct swallowing exercises using jelly, which subsequently restored their oral food intake.ConclusionThese findings suggest that stimulation of the external auditory canal with ointment containing capsaicin improves swallowing function in elderly patients with non-obstructive dysphagia. By the same mechanism used by angiotensin-converting enzyme inhibitors to induce cough reflex, which has been shown to prevent aspiration pneumonia, aural stimulation with capsaicin may reduce the incidence of aspiration pneumonia in dysphagia patients via Arnold’s ear-cough reflex stimulation.

Effects of Capsaicin on Older Patients with Oropharyngeal Dysphagia: A Double-Blind, Placebo-Controlled, Crossover Study

“…TRPV1 is considered to be a therapeutic target of OD [21]. Capsaicin is a specific agonist to TRPV1, and it has occasionally been reported that administration of capsaicin improves OD [22,23,24,25]. However, there are no randomized, double-blind, placebo-controlled trials on the effect of capsaicin on OD to date.…”

Aural stimulation with capsaicin ointment improved swallowing function in elderly patients with dysphagia: a randomized, placebo-controlled, double-blind, comparative study

“… 20 However, in our previous study, repeated alternative application with ointment containing 0.025% capsaicin to each external auditory canal once a day for 7 days still improved swallowing function in patients with dysphagia. 4 Therefore, once-a-day alternative application to each external auditory canal with low-dose capsaicin may be a useful method to prevent capsaicin defunctionalization, although it is still uncertain how long the effects of single application with capsaicin ointment last. Furthermore, multicenter studies are required to explore whether repeated aural stimulation with 0.025% capsaicin ointment in such a way to prevent capsaicin defunctionalization really reduces the incidence of aspiration pneumonia in patients with dysphagia.…”

“…As a subset of neurons in the vagal nodose ganglion expresses TRPV1, 6 our previous study suggested that ointment containing capsaicin activates TRPV1 in vagal Arnold’s nerve of the external auditory canal, resulting in improvement of the swallowing function. 4 However, we cannot exclude the possibility that a nonspecific mechanical stimulation of the external auditory canal with a cotton swab rather than the TRPV1-mediated stimulation with capsaicin improves swallowing function in dysphagic patients. To exclude this possibility, we designed a randomized, placebo-controlled, double-blind, comparative study to compare the effects of ointment containing capsaicin on swallowing function to those of placebo in elderly patients with dysphagia.…”

“…In our previous study, we indeed showed that aural stimulation with capsaicin ointment improved swallowing function in elderly patients with dysphagia, suggesting that aural stimulation with capsaicin ointment may be a safer therapy for dysphagia. 4 …”

Targeting Chemosensory Ion Channels in Peripheral Swallowing-Related Regions for the Management of Oropharyngeal Dysphagia

“…Application of a TRPV1 agonist into the ear canal can also improve swallowing performance [ 138 ]. A pilot study reported that acute or chronic (once daily for 7 days) application of capsaicin-containing ointment (around 1 mM) in the external auditory canal improved swallowing function in older patients with dysphagia, as assessed by endoscopic swallowing scores [ 138 ]. In this study, the effects lasted for 60 min after an acute application [ 138 ].…”