Effect of a Cooling Sensation Flavor on the Swallow Response in Post-stroke Patients With Oropharyngeal Dysphagia

REFRESH Study: Therapeutic Effect of a Cooling Sensation Flavor in Pre-thickened ONS Products on the Swallow Response in Post-stroke Patients With Oropharyngeal Dysphagia

Current oropharyngeal dysphagia (OD) treatment in older patients is based on compensatory strategies (fluid thickening and texture modified diets) that improve swallow safety but do not improve the swallowing function. One of these strategies is thickening products, which are used to reduce pharyngeal bolus velocity by increasing viscosity of fluids. There are several studies demonstrating the therapeutic effect of thickeners in reducing the prevalence of penetrations and aspirations, and their use has been correlated with reduced prevalence of respiratory infections, aspiration pneumonia and hospital readmissions.

In recent years, new neurorehabilitation treatment strategies for OD have been developed such as peripheral (electrical or chemical stimulation) or central stimulation (transcranial direct current stimulation or repetitive transcranial magnetic stimulation).

The investigators suggest that new generation treatments for OD have to combine thickened fluids and about peripheral stimulation using transient receptor potential (TRP) channels agonists. The aim of this study is to evaluate the therapeutic effect of a cooling sensation (CS) flavor in a pre-thickened oral nutritional supplement (ONS) drink on the biomechanical mechanism of the swallow response in chronic post-stroke patients with OD.

The investigators designed a randomized, crossover, interventional and open-label clinical study. The study includes 2 groups: 1) n=25: 1st visit: stimulation with Control, 2nd visit: stimulation with CS; and 2) n=25: 1st visit: stimulation with CS, 2nd visit: stimulation with Control. Each patient will attend a total of 2 visits, with a washing period of at least 7 days between visits. The procedures to be performed during each visit are: clinical assessment of swallowing with V-VST, spontaneous swallowing frequency measurement using electromyography, and collection of a sample of saliva using a Salivette®.

Inclusion Criteria:

• ≥18 years
• Patients with chronic OD as a consequence of stroke (more than 3 month since stroke diagnostic)
• Patients with impaired safety and/or efficacy of swallow (V-VST)
• Patients that can swallow safely the investigation and control product according to the viscosity of the product and the results of the V-VST
• Patients able to follow the protocol and give informed consent

Exclusion Criteria:

• Pregnancy
• Life expectancy <3 months or palliative care
• OD diagnosis prior to stroke
• Dementia (GDS 4 or higher)
• Allergy to the investigation and/or control product or to any of its components
• Participation in another interventional study in the month prior to inclusion
• Current users of a pre-thickened ONS drink with cooling sensation flavor