Master of Dental Surgery / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au

Thesis (M(Communication Pathology))--University of Pretoria, 2003. / Includes bibliographical references.

Safe and efficient swallowing requires integrity of both motor and sensory systems. Prior studies have established that motor impairment in individuals with PD frequently manifests as abnormalities in swallowing biomechanics. In contrast, very few studies have investigated the contribution of sensory impairment towards pharyngeal biomechanics and airway protection in this patient cohort. This area should be addressed in light of evidence that the severity of limb motor dysfunction in PD does not reliably predict severity of dysphagia. Emerging data suggests that dysphagia in PD cannot be solely attributed to motor impairment, but may also be influenced by deficits in sensory aspects of airway protection. As an example, silent aspiration in up to 100% has been reported in individuals with PD due to laryngopharyngeal sensory deficits have. Even so, current research lacks information on the integration of both motor and sensory components that make up the swallowing process. The aim of this study was to document changes in airway protection with age, in PD and across severity levels of PD. The project was comprised of two parts. In part one, three parallel studies were conducted to assess a series of both motor and sensory airway mechanism (Chapters 4 to 9). In the first study, 16 young (8 males, age range 21.3 - 32.4) and 16 elder adults (8 males, age range 61.5 - 84.7), were assessed to investigate changes in airway protection that accompany ageing. In the second study, data from individuals diagnosed with PD across severity levels (Hoehn-Yahr 1 - 4, age range 64.2 - 84.5) were age and gender-matched to 16 healthy elders in order to examine the effects of PD on airway protection. In the third, the impact of disease severity was studied with data from 16 individuals in the earlier stages (Hoehn-Yahr ≤ 2, 13 males, age range 51.3 - 82.5, ) compared to 16 individuals in the later stages (Hoehn-Yahr ≥ 2.5, 10 males, age range 61.5 - 78.9). In part two of this project, two smaller, pilot studies were completed to probe the influence of pharmacologic and behavioural treatments on airway protection mechanisms. In the first pilot study, the effect of pharmacotherapy on airway protection was investigated in 10 patients 'on' and 'off' levodopa (Chapter 10). In the second study, 5 patients were assessed before and after completing the Lee Silverman Voice Treatment (LSVT) to document effects of speech rehabilitation on airway protection (Chapter 11). Multimodality assessment elicited data from all participants on both motor and sensory components of airway protection (Chapter 3). Specifically, breathing-swallowing coordination (BSC) and swallowing apnoea (SA) were captured using simultaneous directional nasal airflow and surface electromyography (sEMG). Standard, closed-loop spirometry was used to assess pulmonary function. Swallowing biomechanics were screened using a validated timed test of swallowing efficiency and further evaluated using fibreoptic endoscopic evaluation of swallowing (FEES). Finally, chemo-sensation of the laryngopharynx was determined with the administration of the inhalation cough challenge while mechanosensation was examined using FEES. Results suggest that motor control for airway protection is reasonably robust in PD, although sensory response is impaired. The predominant pattern for swallowing respiratory coordination was mid-expiration for all participants regardless of age and disease severity (Chapter 4). Individuals with PD demonstrated a reduction in average time and volume per swallow, leading to an overall decrease in swallowing capacity (Chapter 5). No difference was found for swallowing efficiency between those in early and later stages of PD. Pulmonary function measures were not significantly different as a function of age, PD or PD severity (Chapter 6). In summary, results from motor assessments contributing to airway protection support the robustness of breathing-swallowing coordination (BSC) and pulmonary function across research groups, but identify a reduction in overall swallowing efficiency in PD. Results from sensory assessments contributing to airway protection revealed that chemosensation was not different between age groups but base of tongue mechano-sensation was diminished in individuals with PD. Natural cough thresholds did not differ between young adults and elders but when asked to stifle coughing, elders were less able to do so compared to young adults (Chapter 7). For the first time, a reduction in mechano-reception at the base of tongue was recorded in individuals with PD (Chapter 8). These patients also demonstrated increased post swallow residual (Chapter 5), which offers an explanation for the complaint of globus in this population. These assessments highlight some compromise to sensory aspects of airway protection in PD. Overall, dysphagia had a negative impact on the quality of life of individuals with PD and even more as disease severity progresses (Chapter 9). Results from part two of the study looking at the effects of therapeutic interventions on airway protection revealed some unexpected findings. In chapter 10, results showed a reduction in pulmonary function when 'on' levodopa, but no differences in swallowing efficiency, BSC, or laryngopharyngeal chemo- and mechano-reception were observed. These results suggested a reduction in pulmonary function with levodopa without any increase in risk of airway protection compromise1. Unexpectedly and documented for the first time, the percentage of post swallow inspiration increased after LSVT (Chapter 11) but as with the levodopa study, this was also not accompanied by any apparent increase in aspiration risk. An increase in submental surface electromyography (sEMG) amplitude across all 5 participants may serve as a proxy measure of improvement in hyolaryngeal excursion. Finally, participants reported an overall improvement in social functioning and communication after LSVT. In conclusion, this study provided evidence that mechano-sensory aspect of airway protection is diminished in individuals with PD, possibly compromising airway protection. Patients not only demonstrated increased residue but the lack of sensation may prevent clearing or spontaneous multiple swallows. Overall, airway protection is maintained in ageing but swallowing efficiency declines in the presence of PD. This study contributes significantly to current research efforts in PD by expanding on existing reports regarding motor aspects of airway protection. Specifically, BSC, swallowing efficiency and evaluation of biomechanics using FEES research have never before been investigated exclusively in the PD population. Finally, the chemo- and mechano-sensation evaluated in this study are an important addition to the limited evidence that sensory impairment in individuals with PD potentially compromises airway protection. Results of the present study will serve as a platform upon which future studies may compare and expand.

The relationship between respiratory muscle fatigue and the function of swallowing is examined here. The main objective of this study is to examine the effects of respiratory muscle fatigue on swallowing physiology in healthy young adults. Specifically, this study aims to determine if differences exist in several swallowing-related parameters (a. the muscle recruitment pattern of the submentals and infrahyoids associated with swallowing, b. the pattern of breathing and swallowing coordination, c. the duration of the breath phases associated with swallowing, d. the duration of swallowing apnea, and e. the secondary swallow frequency) during several different swallowing conditions before, following respiratory muscle fatigue and following recovery. Fifty-four healthy young adults were randomly assigned into two groups, either an inspiratory (MIP) or an expiratory (MEP) muscle fatigue group. Respiratory and swallowing measurements were obtained, during 3 experimental conditions: a baseline condition, after exercise-induced fatigue, and finally, after a 15min rest period. A loaded breathing device was used in order to induce fatigue to the respiratory muscles. Presence of fatigue was determined with the assessment of Maximum Expiratory (PEmax)/Maximum Inspiratory (PImax) Pressures measured with a mouth pressure manometer. Electrophysiologic data were obtained with the use of sEMG on the submental and infrahyoid muscle groups, and with the use of three respiratory belt transducers, placed around the thorax, abdomen and neck. The Borg Scale was used to behaviourally assess perceived sense of breathing effort. Descriptive and inferential statistics were conducted to allow for detailed analysis of differing measures and variances between individuals. Results revealed significant differences between the three experimental conditions in the muscle recruitment patterns of the submental and infrahyoids, in the pattern of breathing and swallowing coordination, in the duration of the swallow-related respiratory cycle and in the frequency of secondary swallows. The duration of the deglutitive apnea was not affected by the presence of respiratory muscle fatigue. In particular, the sEMG Integral of the infahyoids was significantly reduced during the fatigued condition compared to the baseline and post-rest conditions, as opposed to an increase in sEMG integral of the submental muscles observed only in the MEP subject group. Additionally, the occurrence of swallows followed by inspiration was significantly increased during the fatigued condition. Secondary swallow frequency was significantly increased during the fatigued condition. These results suggest an effect of respiratory muscle fatigue on selective swallowing related parameters. These results are of great clinical importance since the observed patterns may increase the risk of aspiration. Results will be discussed with respects to the implications for patients and their therapeutic interventions.

Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-22Bitstream added on 2014-06-13T19:27:14Z : No. of bitstreams: 1 fioravanti_mp_me_botfm.pdf: 623692 bytes, checksum: 5ec64d660f1df53219efc1f3b21de315 (MD5) / Fundação para o Desenvolvimento Médico e Hospitalar (Famesp) / O aumento da expectativa de vida preocupa os profissionais de saúde quanto à qualidade da mesma em idosos. Entre os problemas que surgem com o envelhecimento estão aqueles relacionados com as condições orais e os distúrbios da deglutição. Os distúrbios da deglutição orofaríngea em idosos, particularmente naqueles institucionalizados, causam desnutrição, desidratação e disfagia, aspiração e pneumonia. A dificuldade para deglutir pode ser avaliada inicialmente por testes clínicos fonoaudiológicos da deglutição, os quais apresentam grande heterogeneidade quanto aos sinais clínicos observados e às consistências e volume de alimentos usados. Objetivo: Caracterizar e classificar a deglutição orofaríngea do idoso institucionalizado. Pacientes e Métodos: Foram estudados 47 moradores de uma casa de repouso que ingeriram 4 consistências de alimentos e foram observados quanto à presença de 7 sinais clínicos sugestivos risco de disfagia e de aspiração. As condições oral e nutricional foram determinadas, foram estabelecidas correlações entre consistências e presença de alterações clínicas e foi criada classificação das alterações segundo grau de severidade. Resultados: Foram encontrados 43 indivíduos desdentados, 40% deles com prótese dentária, 38 dos quais com alteração à mastigação para sólido entre 78 alterações nas 4 consistências. Dos 47 indivíduos, cerca de 69% apresentaram alterações à mastigação de sólidos, enquanto que alteração na elevação da laringe e alteração na qualidade vocal foram apresentados, cada uma, por 15,6% deles. Na consistência pastoso grosso cerca de 19% dos idosos apresentavam deglutições múltiplas, enquanto que alteração na elevação da laringe e da qualidade vocal estiveram presentes, cada uma, em 13%. Foram classificados como portadores de alteração de grau leve a moderado... / The increase in life expectancy concerns health care professionals with regard to the quality of life of the elderly population. Problems arising from ageing include those related to oral condition and deglutition disorders. Oropharyngeal swallowing disorders particularly in institutionalized elderly individuals, cause malnutrition, dehydration, aspiration and pneumonia. Swallowing impairment can be initially evaluated by clinical tests, which present great heterogeneity regarding the clinical signs observed and the consistency and volume of the food used. Objective: To characterize and classify oropharyngeal deglutition in institutionalized elderly individuals by means the bedside clinical evaluation. Patients and methods: Forty-seven nursing home residents were evaluated during ingestion of foods of four consistencies. They were assessed for the presence of 7 clinical signs suggestive of risk dysphagia. Oral and nutritional conditions were determined; correlations between the consistencies and the presence of clinical changes were established and a classification of the alterations according to levels of severity was done. Forty-three toothless individuals were found, of whom 40% had dental prostheses and 38 presented alteration in mastication for solid food among the 78 alterations found for the 4 consistencies. Of the 47 individuals, approximately 69% showed alteration for solid food and impairment of larynx elevation and of vocal quality were each found in 15.6% of the subjects. In thick consistency 19% of the elderly showed repetitive swallowing and alteration in larynx elevation and vocal quality were each present in 13% of the elderly. Seventy-four percent of the individuals were classified as presenting mild to moderate alteration, and 38% of them were malnourished, without differences between age ranges. Discussion: The presence... (Complete abstract click electronic access below)

Aim: The aim of this research was to measure functional intraoral pressures using a newly developed method; specifically, three areas were examined. Firstly, this new approach to measurement allowed the equilibrium theory of tooth position to be re-addressed. Secondly, it allowed investigation the patterns of pressure change in the palatal midline during water swallowing. Lastly, this approach allowed a preliminary investigation of the affect of the viscosity of the food ingested on the pressures generated in the mouth. Methods: The participants were 6 healthy volunteers (4 males, 2 females) recruited from the post-graduate students at the University of Otago, School of Dentistry. The age range was 25 to 35 years. All had full permanent dentitions, Angle Class I occlusions (normal) with acceptable overbite and overjet relationship, and none of them had a history of previous orthodontic treatment. For each of the subjects a cast chrome-cobalt baseplate was constructed to house 8 miniature strain gauge pressure transducers (Precision Measurement Co. Michigan). The location of the sensors were standardised as follows: Three sensors were paired on the buccal and lingual surfaces of the central, canine and first molar. Two palatal vault sensors were placed in the midline of the palate, one at level of the distal of the first premolar, and the second slightly anterior to the junction of the hard and soft palate. Simultaneous recordings were taken during a set of tasks including water swallows, saliva swallows and food ingestion. Results: The results showed that swallowing was a highly complex wellcoordinated event, and that each individual had their own unique signature pattern of swallowing, characterised by pressure changes of high frequency, in excess of �1000 kPa/s. Conclusions: The analysis of the pressure acting on the teeth showed that although the pattern and magnitude of pressure generated varied among the group, the observation of waveforms would suggest a tendency for no inherent balance between the buccal and the palatal pressures on the teeth during swallowing for any of the individuals tested. This investigation of the pressure in the midline revealed an aspect previously not fully explored; these experiments showed that there were large and persistent negative pressures generated during swallowing, that preceded the positive pressures and which appear important in bolus propulsion The patterns of swallowing and the magnitudes of pressure generated, changed with the different consistency of the various substances ingested. There was a general trend for increased pressures during swallowing of substrates that are more viscous; water showed the lowest pressures, followed by saliva and finally jelly. Keywords: Tongue pressure, Intraoral pressures, Tongue dynamics, Swallowing.

Dysphagia (swallowing disorder) is a common health problem that degrades the quality of life of many people. The videofluoroscopic swallowing study (VFSS) is the current gold standard in dysphagia assessment but is associated with high cost, long wait times, and a lack of portability. As a result, there is a pining need for an alternative technique that can serve day-to-day monitoring of dysphagia as well as screening for VFSS referral. The primary objective of this thesis was to investigate three non-invasive signal modalities, namely dual-axis accelerometry, submental mechanomyography (MMG), and nasal airflow, for their potential as alternatives to VFSS. To this end, signals were acquired from 17 healthy individuals and 24 patients with dysphagia, with various stimuli. In a characterization study, the anterior-posterior (A-P) and superior-inferior (S-I) axes in dual-axis accelerometry were found to contain non-overlapping information about swallowing, justifying the extension of single-axis (A-P only) to dual-axis (A-P and S-I) accelerometry. Also, several dual-axis accelerometry signal features were found to be stimulus dependent, and the observed stimulus effects were linked to slower swallowing function with increasing bolus viscosity. Age and stimulus effects on submental MMG were scrutinized, as an analogy to previous electromyography (EMG) studies of similar design. Similarities to EMG confirmed the validity of MMG as a muscle activity measurement tool in swallowing research. Automatic swallow segmentation, which is a crucial precursory step to swallow diagnosis, was investigated with artificial neural networks. Segmentation performance was shown to improve as more signal modalities were included, verifying the value of multi-sensor fusion. When all signal modalities were utilized, an adjusted accuracy of 89.6% was achieved. Automatic discrimination between healthy and abnormal swallows was investigated in two studies. Using previously collected pediatric data, a radial basis classifier based only on A-P accelerometry resulted in an adjusted accuracy of 81.3% in aspiration detection. In an adult study, linear discriminant classifiers resulted in adjusted accuracies of 74.7%, 83.7%, and 84.2% for aspiration, valleculae residue, and pyriform sinus residue detection, respectively. It was concluded that the three signal modalities analyzed in this thesis possess promising potential for abnormal swallow detection.

Dysphagia (swallowing disorder) is a common health problem that degrades the quality of life of many people. The videofluoroscopic swallowing study (VFSS) is the current gold standard in dysphagia assessment but is associated with high cost, long wait times, and a lack of portability. As a result, there is a pining need for an alternative technique that can serve day-to-day monitoring of dysphagia as well as screening for VFSS referral. The primary objective of this thesis was to investigate three non-invasive signal modalities, namely dual-axis accelerometry, submental mechanomyography (MMG), and nasal airflow, for their potential as alternatives to VFSS. To this end, signals were acquired from 17 healthy individuals and 24 patients with dysphagia, with various stimuli. In a characterization study, the anterior-posterior (A-P) and superior-inferior (S-I) axes in dual-axis accelerometry were found to contain non-overlapping information about swallowing, justifying the extension of single-axis (A-P only) to dual-axis (A-P and S-I) accelerometry. Also, several dual-axis accelerometry signal features were found to be stimulus dependent, and the observed stimulus effects were linked to slower swallowing function with increasing bolus viscosity. Age and stimulus effects on submental MMG were scrutinized, as an analogy to previous electromyography (EMG) studies of similar design. Similarities to EMG confirmed the validity of MMG as a muscle activity measurement tool in swallowing research. Automatic swallow segmentation, which is a crucial precursory step to swallow diagnosis, was investigated with artificial neural networks. Segmentation performance was shown to improve as more signal modalities were included, verifying the value of multi-sensor fusion. When all signal modalities were utilized, an adjusted accuracy of 89.6% was achieved. Automatic discrimination between healthy and abnormal swallows was investigated in two studies. Using previously collected pediatric data, a radial basis classifier based only on A-P accelerometry resulted in an adjusted accuracy of 81.3% in aspiration detection. In an adult study, linear discriminant classifiers resulted in adjusted accuracies of 74.7%, 83.7%, and 84.2% for aspiration, valleculae residue, and pyriform sinus residue detection, respectively. It was concluded that the three signal modalities analyzed in this thesis possess promising potential for abnormal swallow detection.

Thesis (Ph.D.)--University of Canterbury, 2009. / Typescript (photocopy). "29th April 2009." Includes bibliographical references (p. 256-277). Also available via the World Wide Web.

Thèse : Botanique : Faculté des sciences de Paris : 1877. Thèse : Zoologie : Faculté des sciences de Paris : 1877. / Titre provenant de l'écran-titre. Bibliogr. p. 93-94.