Ultrasound: Validity of a Pocket-Sized System in the Assessment of Swallowing

Adequate hyoid and laryngeal displacement facilitate safe and efficient swallowing. Although videofluoroscopy is commonly used for assessment of this biomechanical event, ultrasound provides benefits as a radiation-free modality for this purpose. This study investigated validity of a pocket-sized ultrasound system (Clarius™) in the assessment of hyoid and laryngeal excursion. Hyoid excursion and thyrohyoid approximation were concurrently assessed in 20 healthy adults using ultrasound and videofluoroscopy during saliva, liquid, and puree swallowing. Correlation analyses were performed to evaluate validity. There was a strong and moderate positive association between ultrasound and videofluoroscopic measurements of hyoid excursion during dry and liquid swallowing, respectively. No evidence for a significant association was found for ultrasound and videofluoroscopic measurements of hyoid excursion for puree swallowing and of thyrohyoid approximation for any bolus type. Further work towards improved validity is necessary prior to clinical transfer of the pocket-sized Clarius™ system in clinical swallowing assessment.

Effect of topical nasal anesthetic on swallowing in healthy adults: A double-blind, high-resolution manometry study

OBJECTIVE

Topical nasal anesthetic (TNA) is used when evaluating pharyngeal swallowing with high-resolution manometry (HRM). It is unclear if desensitizing the nasal mucosa improves procedure tolerability or affects pharyngeal pressure. This study evaluated the effects of TNA on comfort and pharyngeal pressure using HRM.

METHODS

A double-blinded study was conducted with 20 healthy participants ( x¯ = 27 years). Participants performed five saliva and five 10-mL swallows during two exams with ManoScan HRM ESO catheter (Medtronic, Minneapolis, MN) randomized under placebo (nonanesthetic lubricant) and anesthetized (0.4 mL of 2% viscous lidocaine hydrochloride) conditions. Comfort was rated using a 100-mm visual analog scale (VAS). Pharyngeal HRM amplitude and timing were analyzed.

RESULTS

VAS ratings were similar under placebo (mean = 38.4, standard deviation [SD] = 19.92) and TNA conditions (mean = 33.78, SD = 18.9), with no significant differences between placebo and anesthetized conditions (t[19] = 1.23, P = 0.23) or tolerability at first and second procedure (t[19] = 1.38, P = 0.18). Lower maximum and mean pharyngeal pressure were found for the TNA condition when compared to placebo (dry: maximum [-15.45 mmHg, standard error (SE) = 5.06 mmHg, P = 0.021]; mean [-5.22 mmHg, SE = 1.58 mmHg, P = 0.005]), and (liquid: maximum [-14.79 mmHg, SE = 5.01 mmHg, P = 0.010]; mean [-2.79 mmHg, SE = 1.99 mmHg, P = 0.008]).

CONCLUSION

This double-blind, randomized study is the first to investigate effects of TNA on tolerability and pharyngeal pressure using HRM. Results indicate TNA offered no significant difference in procedure comfort while affecting the magnitude of pharyngeal swallowing.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:1335-1339, 2018.

A Systematic Review of Rehabilitation for Corticobulbar Symptoms in Adults with Huntington's Disease

Background:

Corticobulbar symptoms have been reported in all stages of Huntington’s disease (HD); aspiration pneumonia associated with swallowing impairment has been identified as the most common cause of death. Whilst recent research has described positive effects of corticobulbar rehabilitation in other neurodegenerative conditions, it is unclear if this is similarly effective in HD. Preliminary evidence in corticospinal rehabilitation has revealed physical therapy and exercise could be beneficial for individuals with HD.

Objective:

This systematic review will explore the literature relative to rehabilitation of corticobulbar symptoms in adults with HD.

Methods:

Two investigators independently searched relevant electronic databases for literature related to corticobulbar rehabilitation in HD, published in English until October 2019. Included studies were critically appraised using the Oxford Centre for Evidence-based Medicine Levels of Evidence, Cochrane Risk of Bias Tool and Scottish Intercollegiate Guidelines Network checklists. Study outcomes included measurements of function, quality of life or neuromuscular physiology.

Results:

Seventy-seven publications were screened with eight studies meeting the inclusion criteria – two randomised control trials and six intervention studies. Validated and objective outcome measures of corticobulbar symptoms were infrequently used. There was a high risk of bias identified in 7/8 studies. The data suggested positive clinical outcomes, no adverse effects and no deterioration observed across longitudinal studies.

Conclusions:

This systematic review documented a lack of high-quality evidence to support the use of rehabilitation to treat corticobulbar symptoms in HD. However, the suggestion of potential positive effects based on available, albeit limited, studies provides justification for further research in this area.

Potential for Behavioural Pressure Modulation at the Upper Oesophageal Sphincter in Healthy Swallowing

Supratentorial structures are known to be involved in the neural control of swallowing, thus the potential for volitional manipulation of pharyngeal swallowing is of rehabilitative interest. The extent of volitional control of the upper oesophageal sphincter (UOS) during swallowing remains unclear. Prior research has shown that the UOS opening duration can be volitionally prolonged during execution of the Mendelsohn manoeuvre, which does not change the UOS opening time in isolation but the swallowing response in its entirety. This study explored the capacity of healthy adults to increase the period of pressure drop in the region of the UOS (UOS-Pdrop) during swallowing, through volitional UOS pressure modulation in the absence of altered pharyngeal pressure. The period of UOS-Pdrop was used as a proxy of UOS opening duration that is associated with a pressure decrease at the region of the UOS. Six healthy adults were seen 45 min daily for 2 weeks and for one follow-up session. During training, high-resolution manometry contour plots were provided for visual biofeedback. Participants were asked to maximally prolong the blue period on the monitor (period of UOS-Pdrop) without altering swallowing biomechanics. Performance was assessed prior to training start and following training. There was evidence within the first session for task-specific volitional prolongation of the period of UOS-Pdrop during swallowing with biofeedback; however, performance was not enhanced with further training. This may suggest that the amount to which the period of UOS-Pdrop may be prolonged is restricted in healthy individuals. The findings of this study indicate a potential of healthy adults to volitionally prolong UOS opening duration as measured by the period of pressure drop at the region of the UOS. Further research is indicated to evaluate purposeful pressure modulation intra-swallow in patient populations with UOS dysfunction to clarify if the specificity of behavioural treatment may be increased.

Pharyngeal Swallowing During Wake and Sleep

Sleep is associated with stages of relative cortical quiescence, enabling evaluation of swallowing under periods of reduced consciousness and, hence, absent volition. The aim of this study was to measure and characterize changes in the characteristics of pharyngeal swallows during sleep and wake using high-resolution manometry (HRM). Pharyngeal swallows were recorded with a ManoScan™ HRM in wake-upright, wake-supine, and sleep conditions in 20 healthy participants (mean 27 years; range 21-52). Velopharyngeal and hypopharyngeal segments were analysed separately. Contractile integral, mean peak pressure, inverse velocity of superior-to-inferior pharyngeal pressure, and time to first maximum pressure were analysed with custom-designed software. The supine-wake condition was compared to both upright-wake and sleep conditions using linear mixed effects models. No significant differences were found between supine-wake and upright-wake conditions on any measures. The mean peak pharyngeal pressure was lower during sleep than during the supine-wake condition for both the velopharynx (- 60 mmHg, standard error [SE] = 11, p < 0.001) and hypopharynx (- 59 mmHg, SE = 9, p = 0.001), as was the pharyngeal inverse velocity (- 12 ms/cm, SE = 4, p = 0.012) for the hypopharyngeal segment and the pharyngeal contractile integral (- 32 mmHg s cm, SE = 6, p < 0.001). No significant differences were found in time to the first pharyngeal maximum pressure. This study used HRM to characterize and compare pharyngeal pressures during swallowing in both wake and sleep conditions. No differences were found between upright and supine awake conditions, a finding important to pharyngeal manometric measures made during supine positioning, such as in fMRI. Higher pressures and longer time-related measures of volitional pharyngeal swallowing when awake indicate that cortical input plays an important role in modulation of pharyngeal swallowing.

Ultrasound: Reliability of a Pocket-Sized System in the Assessment of Swallowing

Purpose Ultrasound imaging offers a noninvasive adjunct to clinical swallowing assessment. Published reliability of sophisticated ultrasound systems is promising; however, no data exist for reliability using more affordable, pocket-sized devices. This study explored intrarater, interrater, and test-retest reliability of swallowing measures acquired with pocket-sized ultrasound technology. Method Five participants collected measures of swallowing from 20 healthy individuals using the Clarius ultrasound. Hyoid excursion and thyrohyoid approximation were derived during saliva, liquid, and puree swallowing. The cross-sectional area of the floor of mouth muscles and tongue thickness were obtained at rest. Measures were collected at two occasions minimum 11 days apart. Reliability was assessed for the entire process of data acquisition including scanning and online measurement, and for offline measurement of saved images. Results For most measures, reliability was poor (ICC [intraclass correlation coefficient] < .50) to moderate (ICC = .50-.75) for the entire process of data acquisition and poor to good (ICC > .75) when measuring saved images. Conclusion Further work is needed to elucidate whether our study findings apply to the Clarius system only or the data suggest a general limitation of pocket-sized ultrasound technology.

Effect of Topical Nasal Anesthetic on Comfort and Swallowing in High-Resolution Impedance Manometry

OBJECTIVES/HYPOTHESIS

Use of topical nasal anesthetic (TNA) is common in high-resolution impedance manometry (HRIM). This study investigated the effect of TNA on swallowing and procedure tolerability during HRIM with a 4.2-mm catheter, a more commonly used catheter size with impedance capabilities.

STUDY DESIGN

Randomised experimental study with blinding of participants.

METHODS

Twenty healthy participants (mean age = 33 years, 16 female) were randomized to undergo HRIM using the ManoScan™ ESO Z 4.2-mm catheter twice, 1 week apart, under two conditions: with TNA (viscous lidocaine) and with placebo. Analyses included esophageal data of three saliva, three saline (5 mL), and three bread swallows (2 cm × 2 cm) performed while reclined 45°, and pharyngeal data under the same conditions while seated upright. Pharyngeal and upper esophageal sphincter (UES) HRIM parameters were analyzed using the Swallow Gateway analysis platform. Visual analogue scale (VAS) scores rating procedural comfort were analyzed.

RESULTS

There were no significant physiological differences in pharyngeal and UES parameters between conditions. There were also no significant differences in VAS scores under placebo (mean = 54.8, standard deviation (SD) = 19.3) and TNA (mean = 60.0, SD = 21.9) (t[19] = -0.9, P = .4) conditions; however, there was a significant difference in the first versus second session (t[19]) = 5.1, P < .05).

CONCLUSIONS

TNA did not improve comfort, but it also did not significantly affect swallowing behavior. There was, however, a practice effect regardless of TNA use with improved tolerance of the 4.2-mm catheter and likely more natural swallowing behavior during the second session of HRIM.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Potential for Volitional Control of Resting Pressure at the Upper Oesophageal Sphincter in Healthy Individuals

Resting pressure at the upper oesophageal sphincter (UOS) has been reported to be susceptible to factors such as emotional stress or respiration. This exploratory study investigated the potential for behavioural modulation of UOS resting pressure in healthy adults to increase our understanding of volitional control of UOS pressure, and the potential development of rehabilitation approaches. Six healthy adults were seen one hour daily for two weeks (10 days) and for one post-training session after a training break of two weeks. Manipulation of UOS resting pressure was practised during a protocol of alternating increased and decreased pressure. A high-resolution manometry contour plot was used as a biofeedback modality. Participants were asked to explore how to achieve warmer and cooler colours (pressure increase and decrease, respectively) at the UOS resting pressure band, without changing head position or manipulating activity of other muscles. Performance was analysed prior to training start and following daily training. Participants were able to increase resting pressure following one week of practice; however, there was no evidence for purposeful pressure decrease. The increased resting pressure achieved by participants indicates a capacity for purposeful pressure modulation given intensive biofeedback training. The lack of volitional reduction in pressure may be explained by sustained pressure generation due to the intrinsic muscular characteristics of the UOS and a flooring effect in healthy subjects, in whom physiology mandates a minimum degree of resting pressure to fulfil the barrier function. Distention caused by the presence of the intraluminal catheter cannot be ruled out.

Co-design of a therapeutic virtual reality tool to increase awareness and self-management of cognitive fatigue after traumatic brain injury

PURPOSE

The symptom of cognitive fatigue is reported as one of the longest lasting and most debilitating symptoms of traumatic brain injury (TBI). Virtual reality may be one of the most suitable technologies for neurorehabilitation, able to integrate evidence-based neuroscientific principles into motivating rehabilitation simulations. The purpose of this study was to seek perspectives of individuals with lived experience of TBI and experienced rehabilitation clinicians in the co-design of a novel technology-based tool for cognitive fatigue after TBI.

MATERIALS AND METHOD

Co-design focus groups with a sample of clinicians and individuals with lived experience of TBI were used to identify the design parameters. A prototype was developed using inter-disciplinary design iterations. Focus groups were repeated with participants testing the prototype. Qualitative data were analysed using a general inductive approach.

RESULTS

Feasibility of VR in this population was well tolerated. The focus groups guided development of domains including environment, tasks, level progression, outcome measures and considerations about clinical implementation of VR.

CONCLUSIONS

By merging advancements in VR science with a translational approach, a co-designed virtual reality tool to increase awareness and self-management of cognitive fatigue has been developed, suitable for use in persons with TBI.Implications for rehabilitationImmersive virtual reality tools show promise for addressing awareness of cognitive fatigue after traumatic brain injury in rehabilitation settings.Early engagement with consumers is recommended to produce a usable rehabilitation product.