Effects of 6-month of Treatment With TRPV1 and TRPA1 Agonists in Older Patients With OD

Biomechanical, Neurophysiological and Clinical Effects of 6-month Stimulation Using TRPV1 and TRPA1 Agonists in Older Patients With Oropharyngeal Dysphagia

In recent years, the investigators have characterized the impairments in pharyngeal sensory function associated with swallowing disorders in older patients with oropharyngeal dysphagia (OD). The investigators have demonstrated the acute and sub-acute therapeutic effect of TRP agonists on mechanical and neural swallow responses in patients with OD. The present hypothesis is that 6-months treatment with TRPV1 (capsaicin) or TRPA1 (piperine) agonists will improve the biomechanics and neurophysiology of the swallow response without inducing desensitization. The aim of this study is to evaluate the effect on biomechanics assessed by videofluoroscopy (VFS), neurophysiology (pharyngeal evoked sensory potentials -pSEP- and motor evoked potentials -pMEP-), and clinical outcomes during a 6-month treatment with TRP agonists added to the alimentary bolus 3 times a day in older patients with OD. Design: 150 older patients (>70y) with OD will be included in a randomized clinical trial with three treatment arms, in which the effect of oral administration of 1) capsaicin 10µM (TRPV1 agonist), 2) piperine 150µM (TRPA1), and 3) placebo (Control), will be evaluated. Measurements: 1) VFS signs of swallowing safety and efficacy and timing of swallow response ; 2) Spontaneous swallowing frequency; 3) Latency, amplitude and cortical representation of pSEP and pMEP; 4) Concentration of substance P and CGRP in saliva, 5) Clinical outcomes (respiratory and nutritional complications). The results of this study will increase evidence for a new generation of pharmacological treatments for older patients with OD, moving from compensation to rehabilitation of the swallowing function.

Inclusion Criteria:

• ≥70 years
• With a positive Volume-Viscosity Swallow Test for oropharyngeal dysphagia
• Penetration-aspiration scale >1 in videofluoroscopy
• Able to follow the protocol and to give written informed consent.

Exclusion Criteria:

• Life expectancy < 3m or palliative care
• Allergy to iodinated contrast or to the components of the treatment solutions
• Cancer or active infection
• Implanted electronic device
• Epilepsy
• Metal in the head
• Participation in another clinical trial (previous month).