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Design: A multisite, prospective, and randomized within-subject design study. Setting: Five university settings in varied geographical areas in the United States. Purpose: The purpose of this study was to compare lingual pressure generation using the Tongueometer (TO) and the Iowa Oral Performance Instrument (IOPI) in typically aging, community-dwelling adults during three measurement tasks: maximum isometric pressure (MIP), regular effort saliva swallow (RESS) pressure, and effortful saliva swallow pressure (ESP). Participants: Eighty-seven typically aging, community-dwelling adults (aged 55 years and over) with no self-reported history of swallowing or neurological disorders were recruited to complete this study. Results: Strong positive associations were found between the lingual pressure generation measures from the TO and IOPI in all tasks in typically aging adults, with Pearson correlations ranging from r = .780 to .874, p < .001. Agreement between the devices (Lin’s concordance correlation coefficient) ranged from moderate for the MIP (ρc = .78) and ESP (ρc = .61) tasks to weak agreement for the RESS task (ρc = .47). MIP, RESS pressure, and ESP were lower when measured by the TO compared with the IOPI, p < .001. Conclusions: The TO measures lingual pressure generation similarly to the IOPI but pressures register lower when using the TO than the IOPI in typically aging persons. This supports the need for developing normative values specific to the TO device or development of a valid and reliable conversion formula from TO to IOPI normative values. At this time, the clinical use of reference values from the TO should not be generalized to IOPI normative values. [ABSTRACT FROM AUTHOR]

Purpose: Changes in voice quality after consuming food or drink have been used as a clinical indicator of dysphagia during the clinical swallowing evaluation (CSE); however, there is conflicting evidence of its efficacy. This study investigated if dysphonia and/or voice change after swallowing are valid predictors of penetration, aspiration, or pharyngeal residue. Our approach aimed to improve current methodologies by collecting voice samples in the fluoroscopy suite, implementing rater training to improve interrater reliability and utilizing continuous measurement scales, allowing for regression analyses. Method: In this prospective study, 30 adults (aged 49-97 years) referred for a videofluoroscopic swallowing study (VFSS) were audio-recorded completing a sustained /i/ prior to VFSS and again after swallowing each bolus during the VFSS. Swallowing function was measured using the reorganized Penetration-Aspiration Scale and the Normalized Residue Ratio Scale. Following listener training, 84 voice samples were perceptually rated using the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V). Ordinal and logistic regression were used to determine whether voice quality and voice quality change after swallowing were predictors of airway invasion and pharyngeal clearance. Results: Results indicated that the presence of dysphonia at baseline during a sustained /i/ task as measured by the CAPE-V predicted airway invasion but not pharyngeal residue. Voice change after swallowing associated with vowel /i/ production as measured by the CAPE-V did not predict either dysphagia measure. Conclusion: These results indicate that voice change during a sustained /i/ after swallowing appears unrelated to airway invasion or pharyngeal residue; however, in the absence of known laryngeal pathology, dysphonia prior to a CSE should alert speech-language pathologists of a possible comorbid dysphagia. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to determine the effect of intensity dosing during tongue exercise on tongue pressure generation, adherence, and perceived effort. Design: This was a five-site, prospective, randomized clinical trial. Outcome measures were obtained across multiple baselines, biweekly during exercise, and 4-weeks post-intervention. Setting: The general community at each study site. Participants: Typically aging adults between 55-82 years of age with no history of neurological or swallowing disorders. Eighty-four volunteers completed the study. Interventions: Participants were randomly assigned to one of four exercise groups: (a) maximum intensity/no biofeedback, (b) progressive intensity/no biofeedback, (c) maximum intensity/biofeedback, and (d) progressive intensity/biofeedback. Half of the participants completed a maintenance exercise program. Outcome measures: Maximum isometric pressure (MIP), regular effort saliva swallow pressure, adherence, and the Borg Rating of Perceived Exertion Scale. Results: All exercise protocols were efficacious for gains in MIP (large effect sizes; Cohen's d). Group 3 made gains in regular effort saliva swallow pressure (medium effect size). There was a significant change in perceived exertion for regular effort saliva swallow pressure at 8 weeks. Tongue pressure gains were maintained at 1 month, regardless of maintenance group status. Mean adherence across groups was high. Conclusions: All groups improved pressure generation. Intensity dosing differences did not affect strength gains, adherence, or detraining. Regular effort saliva swallow pressure may be most responsive to maximum intensity with biofeedback. The findings suggest flexibility in approach to tongue exercise protocols. Tongue muscles may differ from limb muscles in terms of dose response and neuroplasticity principles. [ABSTRACT FROM AUTHOR]

This investigation assessed the effect of side-lying position on infant oropharyngeal swallow physiology. Infant modified barium swallow studies (MBS) recordings were retrospectively examined in matched-pairs comparing at-risk infants swallowing in both an upright/cradled position and a side-lying position. Swallow parameters were measured independently and through a consensus coding approach. Infants fed in side-lying position showed a decrease in airway invasion severity as compared with when those same infants were fed in an upright/cradled position (P =.009). Bolus location at the time of swallow initiation was higher when infants were fed in side-lying position as compared with cradle position (P =.024), representing decreased risk of airway invasion. Infants fed in side-lying position demonstrated fewer swallows per breaths (P =.032). This pilot study validates the need for additional research to further define the mechanisms related to this improvement, and to determine how diagnosis and medical stability moderate these findings. [ABSTRACT FROM AUTHOR]

Purpose: Previously, externally placed vibratory laryngeal stimulation increased rates of swallowing in persons with and without dysphagia. This study examined the feasibility of using a vibratory device on the skin over the thyroid cartilage for home-based swallowing rehabilitation in long-standing dysphagia. Method: Only participants with long-standing dysphagia (> 6 months) following cerebrovascular accident or head/neck cancer who had not previously benefited from dysphagia therapy participated. The device had two modes used daily for 90 days. In automatic mode, participants wore the device when awake, which vibrated for 4–8 s every 5 min to trigger a volitional swallow. In manual mode, participants practiced by activating vibration while swallowing rapidly. Study related adverse events, such as pneumonia, and device-recorded adherence were tracked. Swallowing function on a modified barium swallow study was assessed at baseline and after 3 months of device use. Outcome measures included the Dysphagia Outcome and Severity Scale (DOSS), Penetration– Aspiration Scale (PAS), and swallowing timing measures. Participants’ perceptions of the vibratory device and training were obtained. Results: The intent to treat analysis showed seven of 11 participants completed the study, all with severe chronic dysphagia. Of those seven participants completing the study, two developed respiratory complications (possibly due to pneumonia) that cleared after antibiotic intervention. For prescribed practice trials, adherence was 80% or greater in four of seven participants (57%) whereas prescribed automatic stimulations were met in only two of seven participants (29%). Three participants (43%) had a modest benefit on DOSS. The time to vestibule closure after the bolus passed the ramus was reduced in five participants (71%) on the modified barium swallow study. Conclusion: Overall, the results have indicated that intensive home-based practice with stimulation may provide limited functional benefits in severe chronic dysphagia. [ABSTRACT FROM AUTHOR]

Purpose: Mental practice using motor imagery (MP) improves motor strength and coordination in the upper and lower extremities in clinical patient populations. Its effectiveness as a rehabilitation tool for patients with lingual weakness is not yet well understood, nor are the underlying mechanisms within the context of swallow or lingual MP. Using previously published data on a lingual and MP exercise program, the objective of this study was to explore how MP of lingual exercise affects cortical activation in healthy older adults over time and how neural changes correlate with functional oral pressure outcomes. Method: A prospective randomized controlled study was previously completed; older healthy participants were randomized to one of four treatment groups receiving lingual MP, lingual physical practice, a combination of both, and a sham control. This paper reports descriptive data on cortical activation during both the physical and mental forms of lingual resistance in a subgroup of 13 participants using functional near-infrared spectroscopy at baseline and after 6 weeks of the assigned exercise regimen. Results: Aggregated data indicates that participants who completed 6 weeks of lingual exercise, either in physical or in MP form, had decreased oxygenated hemoglobin when completing a maximal lingual pressure task. Conclusions: Some participants in a lingual resistance MP program demonstrated trends similar to those seen after strength training. Combining MP with physical training may lead to greater changes in oxygenation compared to a physical or mental training program alone, although given the small number of participants, it is important not to overinterpret the results. MP is a promising, innovative approach that may enhance traditional exercise-based swallowing rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: Chronic obstructive pulmonary disease (COPD) limits respiration, which may negatively impact airway safety during swallowing. It is unknown how differences in lung volume in COPD may alter swallowing physiology. This exploratory study aimed to determine how changes in lung volume impact swallow duration and coordination in persons with stable state COPD compared with older healthy volunteers (OHVs). Method: Volunteers = 45 years with COPD (VwCOPDs; n = 9) and OHVs (n = 10) were prospectively recruited. Group and within-participant differences were examined when swallowing at different respiratory volumes: resting expiratory level (REL), tidal volume (TV), and total lung capacity (TLC). Participants swallowed self-administered 20-ml water boluses by medicine cup. Noncued (NC) water swallows were followed by randomly ordered block swallowing trials at three lung volumes. Estimated lung volume (ELV) and respiratory-swallow patterning were quantified using spirometry and respiratory inductive plethysmography. Manometry measured pharyngeal swallow duration from onset of base of tongue pressure increase to offset of negative pressure in the pharyngoesophageal segment. Results: During NC swallows, the VwCOPDs swallowed at lower lung volumes than OHVs (p = .011) and VwCOPDs tended to inspire after swallows more often than OHVs. Pharyngeal swallow duration did not differ between groups; however, swallow duration significantly decreased as the ELV increased in VwCOPDs (p = .003). During ELV manipulation, the COPD group inspired after swallowing more frequently at REL than at TLC (p = .001) and at TV (p = .002). In conclusion, increasing respiratory lung volume in COPD should improve safety by reducing the frequency of inspiration after a swallow. [ABSTRACT FROM AUTHOR]

Saliva accumulation in the oropharynx generates an automatic pattern of swallowing in the brainstem in animals. Previous fMRI studies have found that spontaneous saliva and water swallows in humans evoked activation following swallow onset in both precentral motor and postcentral somatosensory cortical regions. Using event-related averaging of continuous functional near infrared spectroscopy (fNIRS), we examined cortical hemodynamic responses (HDR) from 5 s before to 35 s after spontaneous reflexive saliva swallow onset in the lateral postcentral somatosensory and precentral motor regions in both hemispheres in healthy volunteers. Three HDR changes from baseline were detected. First, the onset of HDR occurred 2 s before swallow onset in the left postcentral somatosensory area and 0.67 s before swallow onset in the right postcentral somatosensory area. Second, an early HDR peak amplitude occurred 3-4 s after swallow onset in all four regions. Z scores relative to baseline pre-swallow cortical activity levels averaged 20 and 22.7 s in the right and left somatosensory regions and 10 and 15.8 s in left and right motor areas, respectively. Finally, a late HDR peak occurring between 22 and 23 s after swallow onset in the somatosensory regions and 17-19 s in the motor areas likely resulted from esophageal peristalsis. Overall, cortical activation timing relative to swallow onsets showed activation began before the pharyngeal phase of swallowing in the somatosensory areas. This indicates that somatosensory triggering of swallowing occurs not only in the brainstem but also in the cortex for reflexive saliva swallowing in awake humans. [ABSTRACT FROM AUTHOR]

Sour stimuli have been shown to upregulate swallowing in patients and in healthy volunteers. However, such changes may be dependent on tasteinduced increases in salivary flow. Other mechanisms include genetic taster status (Bartoshuk LM, Duffy VB, Green BG, Hoffman HJ, Ko CW, Lucchina LA, Weiffenbach JM. Physiol Behav 82: 109-114, 2004) and differences between sour and other tastes. We investigated the effects of taste on swallowing frequency and cortical activation in the swallowing network and whether taster status affected responses. Three-milliliter boluses of sour, sour with slow infusion, sweet, water, and water with infusion were compared on swallowing frequency and hemodynamic responses. The sour conditions increased swallowing frequency, whereas sweet and water did not. Changes in cortical oxygenated hemoglobin (hemodynamic responses) measured by functional near-infrared spectroscopy were averaged over 30 trials for each condition per participant in the right and left motor cortex, S1 and supplementary motor area for 30 s following bolus onset. Motion artifact in the hemodynamic response occurred 0-2 s after bolus onset, when the majority of swallows occurred. The peak hemodynamic response 2-7 s after bolus onset did not differ by taste, hemisphere, or cortical location. The mean hemodynamic response 17-22 s after bolus onset was highest in the motor regions of both hemispheres, and greater in the sour and infusion condition than in the water condition. Genetic taster status did not alter changes in swallowing frequency or hemodynamic response. As sour taste significantly increased swallowing and cortical activation equally with and without slow infusion, increases in the cortical swallowing were due to sour taste. [ABSTRACT FROM AUTHOR]

The objective of this review is to gather available evidence regarding the role of the cerebellum in swallowing-related functions. We reviewed literature on cerebellar functions related to healthy swallowing, patterns of dysphagia in individuals with cerebellar lesions, and the role of the cerebellum in therapeutic intervention of neurogenic dysphagia since 1980. A collective understanding of these studies suggests that both hemispheres of the cerebellum, predominantly the left, participate in healthy swallowing. Also, it appears that the cerebellum contributes to specific physiological functions within the entire act of swallowing, but this is not clearly understood. The understanding of patterns of dysphagia in cerebellar lesions remains ambiguous with equivocal results across a small number of studies. The cerebellum appears to be involved in oral exercises for dysphagia in the relationship between oral movements in such exercises, and deglutition remains uncertain. There is increasing evidence to suggest successful use of transcranial magnetic stimulation of the cerebellum to improve neuromotor control of swallowing. Future studies should address activation of the cerebellum with swallowing of different consistencies and tastes in healthy adults to gain better insights. Studies should also investigate dynamics of neural activation during different stages of recovery from dysphagia following strokes to cortical centers to determine if the cerebellum plays a compensatory role during instances of increased neural demands. [ABSTRACT FROM AUTHOR]