INTRODUÇÃO: A demência ou comprometimento cognitivo avançado é um problema frequente e cada vez mais prevalente na população idosa. A maioria dos pacientes com demência desenvolve disfagia especialmente na fase avançada da doença e tem alto risco de morte por pneumonia aspirativa. Inúmeras são as discussões a respeito da funcionalidade dos idosos com quadros demenciais; todavia, a deglutição não faz parte das escalas de funcionalidade. Além disso, a avaliação da comunicação, segue critérios equivocados, como \"quantidade de palavras emitidas por dia\". OBJETIVOS: Traçar o perfil das dificuldades de deglutição e comunicação em pacientes com comprometimento cognitivo avançado, identificar indicadores de disfagia e distúrbios da comunicação que se associem com a classificação da funcionalidade global da escala FAST e propor a inclusão de parâmetros de disfagia e funcionalidade da comunicação na escala FAST. MÉTODOS: Foram coletados dados de 107 pacientes no banco de dados do Ambulatório de Comprometimento Cognitivo Avançado (ACCA) do Serviço de Geriatria do HCFMUSP. Foram realizadas análises descritivas dos perfis de funcionalidade e correlações entre funcionalidade global, da deglutição e da comunicação dos sujeitos. RESULTADOS: 67% da amostra era do sexo feminino, com idade média de 83 anos, destros, com 4 anos de escolaridade média. Quanto ao diagnóstico, 34% da amostra foi diagnóticada com DA, 32% com demência mista (DA e DV), 21% com DV e 13% com demências menos frequentes. Em relação ao estadiamento da demência, a maioria dos sujeitos foi classificada com CDR 3 e MEEM-g 9, que corresponde a demência grave. Em média, os pacientes apresentaram cinco ou mais comorbidades associadas à demência, além de sintomas neuropsiquiátricos e neuropsicológicos. Quanto à avaliação fonoaudiológica estrutural dos órgãos fonoarticulatórios, 100% apresentou alteração nos mecanismos de contenção oral e 77% apresentou alteração de proteção das vias aéreas. Em relação a funcionalidade da deglutição, 92% da amostra pode receber dieta por via oral de forma segura, desde que observadas restrições e adaptações na dieta, além de estratégias compensatórias. Quanto à funcionalidade da comunicação, 38% não utilizaram linguagem funcional; 48% apresentaram expressão oral fragmentada com necessidade de o ouvinte/cuidador assumir a responsabilidade pela comunicação; em 14% a responsabilidade da comunicação foi compartilhada com o ouvinte. CONCLUSÃO: Foram traçadas as características do perfil, das alterações de deglutição e de comunicação dos sujeitos com comprometimento cognitivo avançado. Todavia, ainda que os perfis de deglutição e comunicação declinem conforme a funcionalidade global, na população estudada, não foi possível identificar associação entre o nível da FAST e a gravidade da disfagia ou da comunicação. O estudo contribuiu com dados sobre a funcionalidade da deglutição e da comunicação dos sujeitos com comprometimento cognitivo avançado, desconsiderados pelas tradicionais escalas de funcionalidade / INTRODUCTION: Dementia with advanced cognitive impairment is a frequent and increasingly prevalent problem in the elderly population. Most patients with dementia develop dysphagia especially at an advanced stage of the disease and are at high risk of death from aspiration pneumonia. There are many discussions about the functionality of elderly people with dementia; however, swallowing is not part of the functionality scales. Furthermore, the evaluation of communication follows misguided criteria as quantities of words per day. OBJECTIVES: To outline the difficulties of swallowing and communication in patients with advanced cognitive impairment and to identify indicators of dysphagia and communication disorders associated with the classification of the global functionality of the FAST scale and propose the inclusion of dysphagia parameters and communication functionality in the FAST scale. METHODS: Data from 107 patients were collected from the Advanced Cognitive Compromising Ambulatory (ACCA) database of the Geriatric Service of the HCFMUSP from January to December 2016. Descriptive analyzes of functional profiles and correlations between global functionality of swallowing and the communication of the subjects. RESULTS: 67% of the sample was female, with a mean age of 83 years, right-handed, with 4 years of average schooling. Regarding the diagnosis, 34% was diagnosed with AD, 32% with mixed dementia (AD and DV), 21% with DV and 13% with less frequent dementias. Regarding staging of dementia, the majority of subjects were classified as CDR 3 and MMSE-g 9, which corresponds to severe dementia. On average, patients had five or more comorbidities associated with dementia, as well as neuropsychiatric and neuropsychological symptoms. Regarding the structural speech-language evaluation of the speech-language organs, 100% of the sample presented alterations in oral containment mechanisms and 77% presented alterations in airway protection. Regarding swallowing functionality, 92% of the sample can receive oral diet safely, provided dietary restrictions and adaptations are observed, as well as compensatory strategies.Regarding communication functionality, 38% did not use functional language; 48% have fragmented oral expression and the listener / caretaker assumes responsibility for communication; 14% the responsibility for communication was balanced with the listener. CONCLUSION: Characteristics of the subjects\' profile, the swallowing and communication changes of the subjects with advanced cognitive impairment were drawn. However, although the swallowing and communication profiles declined according to the global functionality, in this population it was not possible to identify an association between the global functional level of FAST and the severity of dysphagia and communication. The study contributed data on the functionality of swallowing and communication of subjects with advanced cognitive impairment, neglected by traditional scales of functionality

O tratamento do câncer de cabeça e pescoço acarreta consequências ao sistema estomatognático, à alimentação e à condição nutricional, porém pouco se sabe sobre a evolução dos pacientes em relação a tais aspectos após o término do tratamento antineoplásico. O presente estudo teve como objetivo verificar a relação entre a função de deglutição, o estado nutricional e o fluxo salivar em indivíduos após o tratamento do câncer de cabeça e pescoço. Foram incluídos no estudo 17 pacientes (14 homens e 03 mulheres) com média de 53 anos. A deglutição foi avaliada por meio dos exames de videofluoroscopia e eletromiografia de superfície (EMGs) dos músculos masseteres, orbicular da boca e supra-hioideos, o estado nutricional através da antropometria (IMC, CMB e %GC), a avaliação dietética com o recordatório alimentar de 24 horas e o fluxo salivar foi avaliado com estímulo mecânico. A análise dos exames demonstrou que 66,7% dos pacientes apresentaram deglutição com limitações funcionais, na escala de resíduos 58,3%, 66,7% e 58,3% com média de uma linha bário na estrutura para as consistências pudim, mel e liquida, respectivamente, enquanto a penetração laríngea esteve presente para 8,3% durante a deglutição de líquido. Na EMGs o tempo de atividade muscular durante a deglutição de pudim foi acima dos valores de normalidade, os valores da amplitude da atividade elétrica foram muito semelhantes para os músculos estudados, o que não é esperado em indivíduos sem alterações funcionais na deglutição. A avaliação antropométrica indicou que 41,2% estavam em eutrofia, segundo o IMC. As avaliações do tecido muscular e adiposo indicaram eutrofia em 52,9% e 41,2%, respectivamente. Na avaliação dietética foi verificado que 64,7% tinham seu consumo de energia acima do ideal, mas com ingestão de carboidratos, proteínas e lipídeos dentro da normalidade, sendo que 53,4% dos pacientes consumiam micronutrientes abaixo de suas necessidades. O exame de Fluxo Salivar com estímulo mecânico mostrou que 82,3% estavam com produção de saliva muito abaixo do adequado. Houve correlação significante entre a reserva de tecido muscular e o tempo da atividade muscular durante a deglutição, bem como entre o consumo de Sódio e Cálcio com a amplitude da atividade elétrica muscular para os músculos masseteres e orbicular da boca, nas consistências líquida e mel, respectivamente. Não foi encontrada correlação entre os dados das avaliações de deglutição e do fluxo salivar. Portanto, para os participantes da presente pesquisa foi verificada relação entre a deglutição e o estado nutricional, mostrando que a ingestão adequada de proteínas e dos micronutrientes sódio e cálcio influencia a atividade muscular durante a deglutição nos sobreviventes do câncer de cabeça e pescoço. / The treatment of head and neck cancer leads to consequences in the stomatognatic system, nourishment and nutritional condition. However, little is known concerning these factors in relation to the evolution of patients after the antineoplastic treatment is finished. The current study aimed to verify the connection among deglutition function, nutritional status and salivary flow in patients after treatment for head and neck cancer. The study has included 17 patients (14 men and 03 women), 53 years old average. The deglutition was evaluated through videofluoroscopy tests and surface electromyography on masseter muscles, orbicularis of the mouth and supra hyoids. The nutritional status was assessed through anthropometry (ICM, CMB and %GC) and diet evaluation by using a 24-hour food inventory, and the salivary flow was evaluated through mechanical stimuli. The analyses indicated that 66.7% of patients presented deglutition with functional limitations, with a waste scale of 58.3%, 66.7% and 58.3% with average of barium line in the structure to pudding, honey and liquid consistency, respectively, while laryngeal penetration reached 8.3% during liquid deglutition. For the surface electromyography, during flan deglutition, the time of muscle activity was above normal values. The values obtained from the electrical activity ampleness were similar to the studied muscles, which is not prospective in patients who do not have functional changes in deglutition. The anthropometric evaluation showed 41.2% of patients had eutrophy, according to ICM. The evaluation of muscle and adipose tissue showed eutrophy in 52.9% and 41.2%, respectively. The diet evaluation indicated that 64.7% had their energy consumption above the levels considered ideal, however, carbohydrates, proteins and lipids ingestion were normal, considering that 53.4% of patients ingested fewer micronutrients than necessary. The salivary flow test using mechanical stimulus showed that 82.3% had saliva production far below adequate. There was a significant correlation between muscle tissue reserve and time of muscle activity during deglutition, as well as Sodium and Calcium consumption with amplitude of muscular electrical activity for masseter muscles and orbicularis of the mouth, for liquid and honey consistency, respectively. No correlation between data of deglutition evaluations and salivary flow was found. Therefore, the relation between deglutition and nutritional status was established in the study, pointing that the adequate ingestion of proteins, sodium and calcium micronutrients affects muscle activities during deglutition in patients who survived head and neck cancer.

Introdução: A Síndrome de Sjögren (SS) é uma doença crônica, sistêmica, autoimune que afeta diversas glândulas, principalmente lacrimais e salivares, causando sensação de olhos e boca secos. Objetivo: Investigar as características miofuncionais orofaciais e a presença de sinais e sintomas de Desordem Temporomandibular (DTM) em portadores de Síndrome de Sjögren, comparativamente a um grupo controle. Metodologia: Estudo transversal, prospectivo descritivo e comparativo. Participaram 19 mulheres (média de idade: 33,2±8,7 anos), seis portadoras da forma primária da SS e treze portadoras da forma secundária da SS.Vinte mulheres saudáveis, pareadas por idade (média de idade 31,9±9,3 anos) compuseram o grupo controle (grupo C). As avaliações e os exames realizados foram: Protocolo de Avaliação Miofuncional Orofacial com Escores (AMIOFE), medida dos limites de movimentos mandibulares, pressão de língua e de lábios (Iowa Oral PerformanceInstrument- IOPI), palpação dos músculos e das articulações temporomandibulares (ATMs), Instrumento de Autoavaliação da Alimentação (EAT-10), questionário para investigação dos sinais e sintomas de desordem temporomandibular (ProDTMmulti), escala de dificuldade para mastigar, escala de funcionalidade mandibular (JFLS) e eletromiografia de superfície (EMG) dos músculos da mastigação e deglutição. Os dados categóricos ou com distribuição não normal foram analisados pelo teste estatístico não paramétrico de Mann-Whitney e aqueles com distribuição normal pela Análise de Variância (ANOVA), seguida do pós-teste. O nível de significância adotado foi P< 0,05. Resultados: O grupo SS apresentou diferenças estatisticamente significantes na comparação com o grupo C, com piores condições na avaliação miofuncional orofacial, quanto ao aspecto/postura das estruturas orais, a mobilidade de lábios, língua, bochechas e mandíbula, assim como nas funções de mastigação, deglutição e respiração. Foram também estatisticamente menores a abertura bucal, a distância interincisal horizontal, a pressão da língua na protrusão e elevação (valor da média e máximo), bem como no valor da deglutição. Os portadores de SS mostraram, por meio de escores,maior dificuldade para mastigar e risco de disfagia (EAT-10). Também foram maiores no grupo SS, comparado ao controle, os escores de dor à palpação, a severidade dos sinais e sintomas de DTM (ProDTMmulti) e a limitação funcional da mandíbula (JFLS). A atividade dos músculos mastigatórios nas provas de máxima contração voluntária (MCV) foi menor no grupo SS com um maior impacto por ciclo na mastigação unilateral esquerda. As mudanças temporais na deglutição, com duração aumentada para a consistência líquida e reduzida na deglutição de sólido também foram significantes no grupo SS, comparado ao grupo C. Conclusão: os resultados mostraram que os portadores de Síndrome de Sjögren apresentam prejuízos acentuados na musculatura e funções orofaciais e sinais e sintomas de DTM moderados, uma percepção de grande limitação funcional. Portanto, as consequências da SS não se resumem às queixas subjetivas, mas sim envolvem comprometimentos reais do sistema e funções estomatognáticas. / Introduction: Sjögren\'s syndrome (SS) is a chronic, systemic, autoimmune disease that affects several glands, mainly lacrimal and salivary, causing dry eyes and mouth. Objective: To investigate myofunctional orofacial characteristics and the presence of signs and symptoms of Temporomandibular Disorderers (TMD) in Sjögren\'s Syndrome patients compared to a control group. Methodology: Prospective descriptive and comparative cross-sectional study. Participants were 19 women (mean age: 33,2±8,7), with primary (n = 6) or secondary (n = 13) Sjögren Syndrome (SS group) and 20 healthy women, matched by age (mean age: 31,9 ±9,3-C group). The evaluations and examinations were performed with the Protocol of Orofacial Myofunctional Evaluation with Scores (OMES), measurement of limits of mandibular movements, tongue and lip pressure measure with Iowa Oral Performance Instrument (IOPI), Eating Assessment Tool (EAT-10), Temporomandibular Muscles and Temporomandibular Joint (TMJ) palpation, questionnaire for investigation of signs and symptoms of temporomandibular disorder (ProDTMmulti), difficulty of Chewing Scale, Jaw Functional Limitation Scale (JFLS), and Surface Electromyography (sEMG) of chewing and swallowing muscles. The categorical or non-normal distribution data were analyzed by nonparametric Mann-Whitney statistical test and data with normal distribution analyzed by Variance Analysis (ANOVA), followed by post-test. The level of significance was P<0.05. Results: The SS group presented statistically significant differences in comparison with group C, with worse conditions in the orofacial myofunctional evaluation, regarding the appearance / posture of oral structures, mobility of lips, tongue, cheeks and mandible, as well as in the functions of chewing, swallowing and breathing. The oral opening, horizontal interincisal distance, tongue pressure on protrusion and elevation (mean and maximum value), as well as the value of swallowing were also statistically lower. SS patients showed by scores greater difficulty in chewing and risk of dysphagia (EAT-10). There were also higher in the SS group, compared to control, pain scores at palpation, the severity of TMD signs and symptoms (ProDTMmulti) and functional limitation of the mandible (JFLS). The activity of the masticatory muscles in the tests of maximum voluntary contraction (MCV) was also lower in the SS group with a greater impact per cycle during the masticatory EMG. The temporal changes in swallowing, with increased duration for the liquid consistency and reduced for solid swallowing were also significant in the SS group, compared to the control. Conclusion: the results showed that patients with Sjögren\'s Syndrome present marked impairments in musculature and orofacial functions and moderate TMD signs and symptoms, a perception of great functional limitation. Therefore, the consequences of SS are not limited to subjective complaints, but rather involve real system compromises and stomatognatic functions.

Swallowing problems, and the often-associated sequelae including pneumonia, malnutrition, and dehydration are common, potentially life-threatening conditions suffered by many elderly individuals. The combination of cognitive, physical, and sensory impairments commonly seen in individuals with dementia and following stroke often results in eating needs going unmet, leading to increased morbidity and premature mortality. The functional limitations of many of these individuals frequently result in decreased mealtime independence and necessitate extensive or total assistance (i.e., dependence) with consuming food and liquids. Despite the implication of increased safety associated with feeding assistance, the influence and potential risk of absent pre-oral cues are unclear, especially in an already taxed system. This study investigated the cooperative relationships between the sequential sensorimotor acts involved in eating and swallowing, focusing on the anticipatory stage, under various sensory-loss conditions. Kinematic data from the lips, jaw, and hand were obtained from 24 healthy younger adults (ages 18-30) and 24 healthy older adults (ages 70-85) under four different conditions: typical self-feeding, typical assisted feeding (i.e., loss of proprioceptive cues), sensory loss self-feeding (i.e., loss of visual cues and degradation of auditory cues), and sensory loss assisted feeding (i.e., loss/degradation of auditory, proprioceptive, and visual cues). During typical self-feeding, all participants began the mouth opening gesture shortly after the onset of hand movement toward the mouth and prior to the onset of oral sensation. However, differences in the timing of anticipatory onset and offset lip movements were observed between older and younger adults and also on the basis of the presence/absence of feeding dependency and sensory loss. Older adults initiated lowering movement earlier than younger adults given the availability of proprioceptive and/or visual cues. In addition to demonstrating earlier lip lowering, during both self-feeding conditions older adults more consistently attended to the timing between lip lowering onset and hand movement onset as compared to both the younger adults and other relative timing pairs. Given the absence of proprioceptive cues (i.e., during assisted feeding), the onset of anticipatory lip movement was delayed. Sensory loss (i.e., loss of visual cues, reduction in auditory cues) alone did not negatively impact the onset of lip movement for either group as compared to typical self-feeding. Conversely, the presence of sensory loss more negatively impacted the offset of lip movement as compared to the absence of proprioception (e.g., the offset of lip movement was later given only visual/auditory loss as compared to assisted feeding). The presence of both feeding dependence and sensory loss had the greatest negative impact on the timing of both the onset and offset of anticipatory lip movement. These findings suggest that deglutition should be considered as beginning prior to the onset of oral sensation and highlight the necessity of better understanding the role that pre-oral, or anticipatory, sensorimotor information may play in the overall eating and deglutitory process. As older adults consistently demonstrated a "compensatory advantage" via earlier and less variable movement onset given the availability of proprioceptive and/or visual cues, continued investigation into these age-related differences is important. This study provides a first step in clarifying the relationship between these pre-oral cues and anticipatory oral posturing during eating and swallowing, allowing for a better understanding of the potential for increased risk assisted feeding recommendations may elicit. However, the differences observed between older and younger adults, particularly under conditions of sensory loss, may be further exacerbated in a taxed system, potentially increasing risk for various patient populations.

The use of neuromuscular electrical stimulation (NMES) for the treatment of swallowing disorders has become increasingly popular, yet little is known about its long-term effects on muscle physiology. This study indirectly assessed suprahyoid muscle physiology using electromyography (EMG) during a jaw-opening task that was completed before training, immediately after training, and two-weeks after training. Comparisons were made in muscle performance between control participants who engaged in effortful swallowing training and participants who received conjunctive NMES during effortful swallow training. All participants completed four weeks of swallowing exercises conducted five days a week (20 sessions) and consisting of 120 swallows each session. Results revealed that participants collectively improved their peak force production following training, but peak force and EMG median frequency did not vary as a function of training method. The observed high variability in median frequency between trials in addition to the documented improvement in function without a measured change in physiology suggests the need to consider alternate electrode placements during EMG or other tools of assessment. These findings suggests that both effortful swallow training and long-term conjunctive NMES with effortful swallowing improves jaw-opening strength of healthy adults, though adding NMES to the treatment was no more effective than training without it. Further research is necessary to determine the effects of long-term NMES training on swallowing physiology in vivo using other indirect measurements, or direct measurements such as muscle biopsy if possible.

Background: One of the common complications of stroke is dysphagia. Dysphagia can be a disabling problem with negative psycho-social consequences. The effect of dysphagia on quality-of-life is not well understood among the stroke survivors. The Chinese version of Swallow Quality-of-Life Questionnaire can be a reliable instrument to provide a multidimensional evaluation on the impact of post-stroke dysphagia in the population of Hong Kong Chinese older adults. Objective: To investigate factors associated with the swallowing-related quality-of-life in Hong Kong Chinese older adults with the history of stroke during the post-acute phase, using a disease-specific quality-of-life questionnaire (CSWAL-QOL). Method: This was a cross-sectional study of 92 stroke survivors, aged over 55. They were recruited from the inpatient wards and out-patient clinics. They were assessed for any dysphagia and its severity by the bedside swallow assessment. The Mini-Mental State Examination and the Chinese version of Swallow Quality-of-Life Questionnaire were used for cognitive and quality-of-life assessment respectively. Results: The test-retest reliability of the test was moderately correlated (Spearman’s rho 0.62).Participants on modified diet/fluid, on tube-feeding, older age and post-stroke for 1-2 years were observed to have lower CSWAL-QOL score across scales. Conclusion: The effect of ageing appeared to be a factor affecting swallowing-related QOL in stroke survivors, with better QOL in younger participants(age ranged from 55 to 69) and similar QOL in old (age ranged from 70 to 85) and very old (age above 85)participants. No gradual change of QOL was found as post-stroke duration increases. The oral feeding mode and normal food and fluid consistency resulted a better QOL in stroke survivors. / published_or_final_version / Medicine / Master / Master of Medical Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Neuromuscular electrical stimulation (NMES) has become an increasingly popular rehabilitative treatment approach for swallowing disorders (dysphagia). However, its precise effects on swallowing biomechanics and measures of swallowing neurophysiology are unclear. Clearly defined NMES treatment protocols that have been corroborated by thorough empirical research are lacking. The primary objective of this research programme was therefore to establish optimal NMES treatment parameters for the anterior hyo-mandibular (submental) musculature, a muscle group that is critically involved in the oral and pharyngeal phases of swallowing. Based on previous research, the primary hypothesis was that various NMES treatment protocols would have differential effects of either enhancing or inhibiting the excitability of corticobulbar projections to this muscle group. The research paradigm used to test this hypothesis was an evaluation of MEP amplitude and onset latency, recorded in the functional context of volitional contraction of the submental musculature (VC) and contraction of this muscle group during the pharyngeal phase of volitional swallowing (VPS, volitional pharyngeal swallow). Outcome measures were recorded before and at several time points after each NMES treatment trial. This methodology is similar to, but improved upon, research paradigms previously reported. Changes in corticobulbar excitability in response to various NMES treatment protocols were recorded in a series of experiments. Ten healthy research participants were recruited into a study that evaluated the effects of event-related NMES, whereas 15 healthy research participants were enrolled in a study that investigated the effects of non-event-related NMES. In a third cohort of 35 healthy research participants, task-dependent differences in corticobulbar excitability were evaluated during three conditions of submental muscle contraction: VC, VPS and submental muscle contraction during the pharyngeal phase of reflexive swallowing (RPS, reflexive pharyngeal swallowing). Event-related NMES induced frequency-depended changes in corticobulbar excitability. NMES administered at 80 Hz facilitated MEP amplitude, whereas NMES at 5 Hz and 20 Hz inhibited MEP amplitude. No changes were observed after NMES at 40 Hz. Maximal excitatory or inhibitory changes occurred 60 min post-treatment. Changes in MEP amplitude in response to event-related NMES were only observed when MEPs were recorded during the VC condition, whereas MEPs recorded during the VPS condition remained unaffected. Non-event-related NMES did not affect MEP amplitude in either of the muscle contraction conditions. Similarly, MEP onset latencies remained unchanged across all comparisons. MEPs were detected most consistently during the VC contraction condition. They were less frequently detected and were smaller in amplitude for the VPS condition and they were infrequently detected during pre-activation by RPS. The documented results indicate that event-related NMES has a more substantial impact on MEP amplitude than non-event-related NMES, producing excitatory and inhibitory effects. Comparison of MEPs recorded during VC, VPS and RPS suggests that different neural networks may govern the motor control of submental muscle activation during these tasks. This research programme is the first to investigate the effects of various NMES treatment protocols on the excitability of submental corticobulbar projections. It provides important new information for the use of NMES in clinical rehabilitation practices and our understanding of the neural networks governing swallowing motor control.

Swallowing impairment or dysphagia can be a consequence of several neurological and anatomical disorders such as stroke, Parkinson’s diseases, and head and neck cancer. Management of patients with dysphagia often involves diet modification, sensory stimulation, and exercise programme with the primary goal being safe swallowing to maintain nutrition. The aim of this project was to evaluate the effects of lemon odour and tastant on swallowing behaviour in healthy young adults. Specifically, the neural excitability and biomechanical characteristics of swallowing were measured in two studies. Neural excitability was evaluated by measuring motor-evoked potentials (MEPs) from the submental muscles which were evoked by transcranial magnetic stimulation (TMS) of the motor cortex. Biomechanical characteristics were evaluated through measures of submental muscle contraction, pressure changes in the oral cavity and pharynx, and the dynamics of the upper oesophageal sphincter (UES). Two groups of volunteers (16 in each group) participated in two separate studies. In the MEP study, 25% and 100% concentrations of lemon concentrate were presented separately as olfactory and gustatory stimuli. The four stimuli were randomly presented in four separate sessions. The olfactory stimulus was nebulized and presented via nasal cannula. Filter paper strips impregnated with the lemon concentrate placed on the tongue served as the gustatory stimulus. Tap water was used as control. TMS-evoked MEPs were measured at baseline, during control condition, during stimulation, immediately poststimulation, and at 30-, 60-, and 90-min poststimulation. Experiments were repeated using the combination of odour and tastant concentration that most significantly influenced the MEP. The biomechanical study used (a) surface electromyography (sEMG) to record contraction of the submental muscles, (b) lingual array with pressure transducers to record glossopalatal pressures, and (c) pharyngeal manometry to record pressures in the pharynx and the UES. Similar methods of presenting the stimuli were used to randomly present the 25% and 100% concentrations of lemon odour and tastant. All data were recorded concurrently during stimulation. The concentration of odour and tastant that produced the largest submental sEMG amplitude was selected for presentation of combined stimulation. Data were then recorded during combined stimulation and at 30-, 60-, and 90-min poststimulation. Results from the MEP study showed increased MEP amplitude at 30-, 60-, and 90-min poststimulation during swallowing compared to baseline, but only for the combined stimulation. Poststimulation results from the biomechanical study showed decreased middle glossopalatal pressure at 30 min and decreased anterior and middle glossopalatal contact duration at 60 min. No poststimulation changes were found in sEMG and pharyngeal manometry measures. During combined odour and tastant stimulation, there were increased pressure and contact duration at the anterior glossopalatal contact and decreased hypopharyngeal pressure. Generally, these changes correspond to increased efficiency of swallowing. In conclusion, these are the first studies to have measured the effects of flavour on neural excitability and biomechanics of swallowing and the first to have shown changes in MEP and several biomechanical characteristics of swallowing following flavour stimulation. These changes were present poststimulation, suggesting mechanisms of neural plasticity that may underlie potential value in the rehabilitation of patients with dysphagia.

Neuromuscular electrical stimulation (NMES) has become an increasingly popular rehabilitative treatment approach for swallowing disorders (dysphagia). However, its precise effects on swallowing biomechanics and measures of swallowing neurophysiology are unclear. Clearly defined NMES treatment protocols that have been corroborated by thorough empirical research are lacking. The primary objective of this research programme was therefore to establish optimal NMES treatment parameters for the anterior hyo-mandibular (submental) musculature, a muscle group that is critically involved in the oral and pharyngeal phases of swallowing. Based on previous research, the primary hypothesis was that various NMES treatment protocols would have differential effects of either enhancing or inhibiting the excitability of corticobulbar projections to this muscle group. The research paradigm used to test this hypothesis was an evaluation of MEP amplitude and onset latency, recorded in the functional context of volitional contraction of the submental musculature (VC) and contraction of this muscle group during the pharyngeal phase of volitional swallowing (VPS, volitional pharyngeal swallow). Outcome measures were recorded before and at several time points after each NMES treatment trial. This methodology is similar to, but improved upon, research paradigms previously reported. Changes in corticobulbar excitability in response to various NMES treatment protocols were recorded in a series of experiments. Ten healthy research participants were recruited into a study that evaluated the effects of event-related NMES, whereas 15 healthy research participants were enrolled in a study that investigated the effects of non-event-related NMES. In a third cohort of 35 healthy research participants, task-dependent differences in corticobulbar excitability were evaluated during three conditions of submental muscle contraction: VC, VPS and submental muscle contraction during the pharyngeal phase of reflexive swallowing (RPS, reflexive pharyngeal swallowing). Event-related NMES induced frequency-depended changes in corticobulbar excitability. NMES administered at 80 Hz facilitated MEP amplitude, whereas NMES at 5 Hz and 20 Hz inhibited MEP amplitude. No changes were observed after NMES at 40 Hz. Maximal excitatory or inhibitory changes occurred 60 min post-treatment. Changes in MEP amplitude in response to event-related NMES were only observed when MEPs were recorded during the VC condition, whereas MEPs recorded during the VPS condition remained unaffected. Non-event-related NMES did not affect MEP amplitude in either of the muscle contraction conditions. Similarly, MEP onset latencies remained unchanged across all comparisons. MEPs were detected most consistently during the VC contraction condition. They were less frequently detected and were smaller in amplitude for the VPS condition and they were infrequently detected during pre-activation by RPS. The documented results indicate that event-related NMES has a more substantial impact on MEP amplitude than non-event-related NMES, producing excitatory and inhibitory effects. Comparison of MEPs recorded during VC, VPS and RPS suggests that different neural networks may govern the motor control of submental muscle activation during these tasks. This research programme is the first to investigate the effects of various NMES treatment protocols on the excitability of submental corticobulbar projections. It provides important new information for the use of NMES in clinical rehabilitation practices and our understanding of the neural networks governing swallowing motor control.