A Systematic Review of the Influence of Bolus Characteristics on Respiratory Measures in Healthy Swallowing.

There have been a number of studies on the effect of bolus volume, consistency, texture, temperature and taste on the oropharyngeal swallowing physiology. However, its influence on the respiratory function associated with swallow is not well understood. This study aimed at systematically analysing and documenting the prevailing research literature on respiratory functions before, during, and after healthy swallows of boluses with varied characteristics. The PRISMA guidelines were followed for retrieval of relevant research. From among the 48,329 reports screened for inclusion criteria, 25 articles were included for data extraction. Each of these reports was evaluated for its design, methodology and reporting quality and also the level of evidence provided by them. The results revealed that the scientific evidence in this regard was restricted to level II. Majority of the studies included considered bolus volume as the variable than bolus consistency, taste or temperature. Expiratory phase was preferred surrounding the apnea irrespective of volume, consistency or taste but changed with temperature variations across age groups. The reports are equivocal on the duration of respiratory apnea, and length of respiratory cycles before and after the apnea. The temporal coordination of pharyngeal swallow events was found to be independent of bolus volume. This review concluded that bolus characteristics have differential effects on the respiratory functions during swallow beyond a 'central sensory threshold' level. Objective standardization of bolus characteristics may be the immediate requirement for generalization of future research findings in this direction.

Evaluating Nasalance Values Among Bilingual Mandarin-English Speakers.

OBJECTIVE: The goals of this research are (1) to establish normative nasalance values for bilingual Mandarin-English speakers and compare values to those of previously reported monolingual Mandarin speakers, and (2) to examine whether sex, age, dialect, and language proficiency affect levels of nasalance among Mandarin-English speakers in both English and Mandarin. DESIGN: All participants recorded the speech stimuli, constructed to include oral sentences, nasal sentences, oronasal sentences, and vowels /ɑ, i, u/ in Mandarin and English. Nasalance measurements were recorded using the Nasometer II 6450. PARTICIPANTS AND SETTING: A total of 45 (20 males and 25 females) native Mandarin speakers between 20 and 54 years of age from mainland China participated in the study. RESULTS: Mean nasalance scores of the Mandarin oral sentence (Mean [M] = 17.64, standard deviation [SD] = 7.33), oronasal sentence (M = 54.62, SD = 7.81), and nasal sentence (M = 68.73, SD = 8.09) are reported. Mean nasalance scores of the English oral sentence (M = 20.02, SD = 7.83), oronasal sentence (M = 58.71, SD = 7.59), and nasal sentence (M = 65.27, SD = 7.45) are reported. A repeated measures analysis of variance showed significant sex difference in nasalance scores for English stimuli ( P = .031) and Mandarin stimuli ( P = .040). There was no significant effects of age, dialect, and language proficiency on Mandarin or English stimuli. CONCLUSIONS: This is the first study to report normative values for Mandarin-English speakers using the Nasometer II. Values reported can be used for objective assessment of bilingual speakers.

Examining Velopharyngeal Closure Patterns Based on Anatomic Variables.

The purpose of this study was to use three-dimensional magnetic resonance imaging to correlate velopharyngeal closure patterns with velopharyngeal anatomic structural characteristics. Thirty-eight participants (18 females and 20 males) between 19 and 32 years of age participated in the study. Participants were evaluated using magnetic resonance imaging and nasopharyngoscopy to determine closure pattern type and their relationship to anatomic characteristics believed to influence velopharyngeal closure. Structural anatomic measures were completed in the vertical (nasopharyngeal length) and horizontal (nasopharyngeal width) planes. Anterior to posterior dimensions of pharyngeal depth, posterior pharyngeal wall thickness, velar length, effective velar length, and adenoid thickness were also completed. Velar length and adenoid thickness varied based on closure patterns, with coronal closure pattern demonstrating significantly larger values than circular closure pattern. There were no statistically significant differences for effective velar length, pharyngeal depth, nasopharyngeal length, posterior pharyngeal wall thickness, and nasopharyngeal width based on the type of closure pattern. Closure patterns varied by sex, with females demonstrating more circular closure patterns than males who demonstrated more coronal closure patterns. Nasopharyngeal length, velar length, and nasopharyngeal width also varied by sex, with males demonstrating significantly larger values than females. Statistically significant differences were observed in velopharyngeal anatomic structural measures and sex during evaluations of closure patterns. These preliminary findings indicate that the length of the velum and thickness of the adenoids may have the greatest impact on velopharyngeal closure patterns.

Utility of a Clinical Swallowing Exam for Understanding Swallowing Physiology.

A clinical swallowing examination (CSE) is generally believed to be inadequate for making judgments regarding swallowing physiology compared to objective assessments. A large volume of studies has heavily focused on identifying aspiration using a CSE and research addressing physiologic information gathered from a CSE is sparse. The purpose of this study was to examine the utility of the CSE for assessing physiology compared to videofluoroscopic swallowing studies (VFSS). Data were derived from a prior investigation of sixty adult patients post-stroke tested with CSE and VFSS. The CSE included an examination of historical measures, oral motor/speech/voice, and trial swallows. The VFSS consisted of swallows of controlled portions of thin, thick, puree, and solid boluses. Previous results from these patients demonstrated significant accuracy in making binary estimates of aspiration and the presence of dysphagia. This analysis of data focused on physiologic measures, as well as overall dysphagia severity and diet recommendations. Significant associations between CSE and VFSS ratings were observed for hyolaryngeal elevation, overall swallowing severity, and diet recommendations. These findings were specific for certain bolus consistencies. These data suggest that the CSE may not provide significant physiological information other than hyolaryngeal excursion. This does not preclude the fact that the CSE is important in providing substantial information about overall dysphagia severity. It appears that the CSE is more powerful than simply a "screening" tool. More prospective research designs are warranted to substantiate the strengths of the CSE.

Role of cerebellum in deglutition and deglutition disorders.

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.

A randomized controlled trial of the effects of flow phonation voice treatment for primary muscle tension dysphonia.

OBJECTIVE: The purpose of the study was to investigate the effects of flow phonation voice therapy on laryngeal physiology and vocal quality in persons with primary Muscle Tension Dysphonia (MTD1). METHODS: Seventeen participants with a diagnosis of MTD1 completed the study. Participants were randomized to two groups. Group 1 (9 participants) received flow phonation treatment and individualized vocal hygiene education for 12 sessions over six weeks. Group 2 (8 participants) received vocal hygiene education only for three weeks (6 sessions), followed by another three weeks (6 sessions) of both vocal hygiene instruction and flow phonation therapy. Treatment consisted of cup-bubble blowing, gargling, and stretch and flow exercises. Visual-perceptual. auditory-perceptual, acoustic, aerodynamic and voice-related quality-of-life measures were obtained at three time points: before treatment, three weeks after initiation of treatment and after completion of treatment. RESULTS: Voice quality was perceived to be significantly improved in both groups. Voice related quality-of-life trended toward improvement for both groups across time points. Changes in aerodynamic and acoustic measures did not reach statistical significance compared to baseline for both groups. Visual comparisons of laryngeal closure patterns demonstrated comparably better outcomes for Group 1. CONCLUSIONS: Results of this study indicate flow phonation exercises can potentially be favorably employed for individuals with MTD1. In particular, it appears that the exercises aid in alleviating vocal hyperfunction, as evidenced by visual perceptual stroboscopic analysis, and clinically improved auditory-perceptual measures.

Effects of dual-task interference on swallowing in healthy aging adults.

A wide body of literature has demonstrated that the neural representation of healthy swallowing is mostly bilateral, with one hemisphere dominant over the other. While several studies have demonstrated the presence of laterality for swallowing related functions among young adults, the data on older adults are still growing. The purpose of this paper is to investigate potential changes in hemispheric dominance in healthy aging adults for swallowing related tasks using a behavioral dual-task paradigm. A modified dual-task paradigm was designed to investigate the potential reduction in hemispherical specialization for swallowing function. Eighty healthy right-handed participants in the study were divided into two groups [Group 1: young adults (18-40 years) and Group 2: older adults (65 and above)]. All the participants performed a timed water swallow test at baseline and with two interference conditions (silent word repetition, and facial recognition). The results of the study revealed the following 1) a statistically significant effect of age on swallow performance; 2) statistically significant effect of each of the interference tasks on two of the swallow measures (VPS and VPT) in younger adults; and 3) no significant effect of the interference tasks on the swallowing performance of older adults. These findings suggest that aging substantially affects swallowing in older individuals, and this potentially accompanies a reduction in the hemispheric specialization for swallowing related tasks.

"Prologues to a Bad Voice": Effect of Vocal Hygiene Knowledge and Training on Voice Quality Following Stage Performance.

PURPOSE: The purpose of this investigation was to determine the effects of intensive stage rehearsal and performance on perceptual, acoustic, and aerodynamic measures of voice, and to determine the impact of knowledge and practice of vocal hygiene on measures of voice during intensive vocal performance. METHODS: Nineteen stage actors who were participating in the Arkansas Shakespeare Theatre festival took part in the study. Each participant completed auditory-perceptual, acoustic, aerodynamic, and quality of life measures before and after 1 month of intensive rehearsals and stage performances. They also completed a questionnaire documenting their vocal use, vocal hygiene, and previous vocal training, if any. RESULTS: Subjects demonstrated statistically significant deterioration in auditory-perceptual measures and mean expiratory airflow. Other acoustic measures trended toward poorer outcomes after the performances; however, these were not statistically significant. Knowledge of vocal hygiene and vocal training did not have an impact on the change in vocal measures. CONCLUSIONS: Stage performances do impact vocal outcomes with reduction in quality and efficient use of airflow for voice production. Knowledge and practice of vocal hygiene have some impact on these changes; however, vocal hygiene may not be the best preventive strategy of potential phonotrauma in this subject population.

Telepractice Versus In-Person Delivery of Voice Therapy for Primary Muscle Tension Dysphonia.

PURPOSE: The purpose of this study was to investigate the utility of telepractice for delivering flow phonation exercises to persons with primary muscle tension dysphonia (MTD). METHOD: Fourteen participants with a diagnosis of primary MTD participated, 7 on site and 7 at remote locations. Each participant received 12 treatment sessions across 6 weeks. Treatment consisted of flow phonation voice therapy exercises. Auditory-perceptual, acoustic, aerodynamic, and quality-of-life measures were taken before and after treatment. RESULTS: Perceptual and quality-of-life measures were significantly better posttreatment and were statistically equivalent across groups. Acoustic and aerodynamic measures improved in both groups, but changes did not reach statistical significance. Results for the 2 service delivery groups were comparable, with no significant differences observed for perceptual and quality-of-life measures. CONCLUSIONS: Although the American Speech-Language-Hearing Association supports the use of telepractice for speech-language pathology services, evidence for the use of telepractice for providing behavioral treatment to patients with MTD has been lacking. The results of this study indicate that flow phonation exercises can be successfully used for patients with MTD using telepractice.