A Randomized Trial Comparing Two Tongue-Pressure Resistance Training Protocols for Post-Stroke Dysphagia

Abstract

The objective of this study was to compare the outcomes of two tongue resistance training protocols. One protocol ("tongue-pressure profile training") emphasized the pressure-timing patterns that are typically seen in healthy swallows by focusing on gradual pressure release and saliva swallowing tasks. The second protocol ("tongue-pressure strength and accuracy training") emphasized strength and accuracy in tongue-palate pressure generation and did not include swallowing tasks. A prospective, randomized, parallel allocation trial was conducted. Of 26 participants who were screened for eligibility, 14 received up to 24 sessions of treatment. Outcome measures of posterior tongue strength, oral bolus control, penetration-aspiration and vallecular residue were made based on videofluoroscopy analysis by blinded raters. Complete data were available for 11 participants. Significant improvements were seen in tongue strength and post-swallow vallecular residue with thin liquids, regardless of treatment condition. Stage transition duration (a measure of the duration of the bolus presence in the pharynx prior to swallow initiation, which had been chosen to capture impairments in oral bolus control) showed no significant differences. Similarly, significant improvements were not seen in median scores on the penetration-aspiration scale. This trial suggests that tongue strength can be improved with resistance training for individuals with tongue weakness following stroke. We conclude that improved penetration-aspiration does not necessarily accompany improvements in tongue strength; however, tongue-pressure resistance training does appear to be effective for reducing thin liquid vallecular residue.

Keywords: Deglutition; Deglutition disorders; Dysphagia; Rehabilitation; Tongue.

Figures

Figure 1

CONSORT diagram of participant flow through the study.

Figure 2

An example of a tongue-pressure waveform collected by the Iowa Oral Performance Instrument during a series of 5 maximum isometric tongue-palate pressure tasks, with the bulb in the posterior position. In the study, participants were able to view waveforms like this on a computer screen for visual biofeedback.

Figure 3

Outline of the treatment protocols for the two arms in this study. TPPT = Tongue-Pressure Profile Training. TPSAT = Tongue-Pressure Strength and Accuracy Training. MIP = maximum isometric pressure.

Figure 4

Pre- and post-treatment measures of tongue strength (posterior maximum isometric tongue-pressures). A significant treatment effect was found in both conditions (p < 0.01). There were no significant differences between the treatment arms with respect to the increase in tongue-pressure seen post-treatment. TPPT = Tongue-Pressure Profile Training. TPSAT = Tongue-Pressure Strength and Accuracy Training.