Electrophysiological evaluation of pharyngeal phase of swallowing in patients with Parkinson's disease

LRRK2G2019S Gene Mutation Causes Skeletal Muscle Impairment in Animal Model of Parkinson's Disease

BACKGROUND

While the gradually aggravated motor and non-motor disorders of Parkinson's disease (PD) lead to progressive disability and frequent falling, skeletal muscle impairment may contribute to this condition. The leucine-rich repeat kinase2 (LRRK2) is a common disease-causing gene in PD. Little is known about its role in skeletal muscle impairment and its underlying mechanisms.

METHODS

To investigate whether the mutation in LRRK2 causes skeletal muscle impairment, we used 3-month-old (3mo) and 14-month-old (14mo) LRRK2G2019S transgenic (TG) mice as a model of PD, compared with the age-matched littermate wild-type (WT) controls. We measured the muscle mass and strength, ultrastructure, inflammatory infiltration, mitochondrial morphology and dynamics dysfunction through behavioural analysis, electromyography (EMG), immunostaining, transmission electron microscopy (TEM) and other molecular biology techniques.

RESULTS

The 3mo-TG mice display mild skeletal muscle impairment with spontaneous potentials in EMG (increased by 130%, p < 0.05), myofibre necrosis (p < 0.05) and myosin heavy chain-II changes (reduced by 19%, p < 0.01). The inflammatory cells and macrophage infiltration are significantly increased (CD8a+ and CD68+ cells up 1060% and 579%, respectively, both p < 0.0001) compared with the WT mice. All of the above pathogenic processes are aggravated by aging. The 14mo-TG mice EMG examinations show a reduced duration (by 31%, p < 0.01) and increased polyphasic waves of motor unit action potentials (by 28%, p < 0.05). The 14mo-TG mice present motor behavioural deficits (p < 0.05), muscle strength and mass reduction by 37% and 8% (p < 0.05 and p < 0.01, respectively). A remarkable increase in inflammatory infiltration is accompanied by pro-inflammatory cytokines in the skeletal muscles. TEM analysis shows muscle fibre regeneration with the reduced length of sarcomeres (by 6%;p < 0.05). The muscle regeneration is activated as Pax7+ cells increased by 106% (p < 0.0001), andmyoblast determination protein elevated by 71% (p < 0.01). We also document the morphological changes and dynamics dysfunction of mitochondria with the increase of mitofusin1 by 43% (p < 0.05) and voltage-dependent anion channel 1 by 115% (p < 0.001) in the skeletal muscles of 14mo-TG mice.

CONCLUSIONS

Taken together, these findings may provide new insights into the clinical and pathogenic involvement of LRRK2G2019 mutation in muscles, suggesting that the diseases may affect not only midbrain dopaminergic neurons, but also other tissues, and it may help overall clinical management of this devastating disease.

Mechanisms of Swallowing, Speech and Voice Disorders in Parkinson's Disease: Literature Review with Our First Evidence for the Periperal Nervous System Involvement

The majority of patients with Parkinson's disease (PD) develop swallowing, speech, and voice (SSV) disorders. Importantly, swallowing difficulty or dysphagia and related aspiration are life-threatening conditions for PD patients. Although PD treatments have significant therapeutic effects on limb motor function, their effects on SSV disorders are less impressive. A large gap in our knowledge is that the mechanisms of SSV disorders in PD are poorly understood. PD was long considered to be a central nervous system disorder caused by the death of dopaminergic neurons in the basal ganglia. Aggregates of phosphorylated α-synuclein (PAS) underlie PD pathology. SSV disorders were thought to be caused by the same dopaminergic problem as those causing impaired limb movement; however, there is little evidence to support this. The pharynx, larynx, and tongue play a critical role in performing upper airway (UA) motor tasks and their dysfunction results in disordered SSV. This review aims to provide an overview on the neuromuscular organization patterns, functions of the UA structures, clinical features of SSV disorders, and gaps in knowledge regarding the pathophysiology underlying SSV disorders in PD, and evidence supporting the hypothesis that SSV disorders in PD could be associated, at least in part, with PAS damage to the peripheral nervous system controlling the UA structures. Determining the presence and distribution of PAS lesions in the pharynx, larynx, and tongue will facilitate the identification of peripheral therapeutic targets and set a foundation for the development of new therapies to treat SSV disorders in PD.

Therapeutic singing-induced swallowing exercise for dysphagia in advanced-stage Parkinson's disease

Background

With longer life spans and medical advancements, the rising number of patients with advanced-stage Parkinson's disease (PD) warrants attention. Current literature predominantly addresses dementia and fall management in these patients. However, exploring the impact of swallowing function on patients with advanced PD is crucial. Previous research has demonstrated notable enhancements in the quality of life related to voice for participants following a group singing-intervention program. To further elucidate the effect of individual singing-induced swallowing exercises, our study aimed to investigate the quantitative and qualitative effects of therapeutic singing on swallowing function in patients with advanced PD in comparison to a matched usual care control group. The hypothesis of this study is that therapeutic singing-induced swallowing exercises can assist to maintain swallowing function in patients with advanced PD.

Methods

This prospective matched control study compared the effects of a 6-week therapeutic singing-based swallowing intervention on swallowing function and quality of life in patients with advanced PD. The intervention group received individual sessions with a music therapist and conventional individual physical therapy. The control group received the same standard physical therapy for 6 weeks without music intervention. The primary outcome measure was Video Fluoroscopic Dysphagia Scale (VDS).

Results

The study revealed that the intervention group maintained swallowing function, whereas the control group experienced deterioration, indicating significant time-dependent changes in Penetration-Aspiration Scale (PAS), National Institutes of Health-Swallowing Safety Scale (NIH-SSS), and VDS. Analysis of PAS and NIH-SSS liquid food scores in both groups showed significant time effects. However, the intervention group exhibited no significant differences between the pre- and post-tests, indicating preservation of the swallowing function. VDS of liquid food indicated an interaction effect between time and group in the pharyngeal phase and total scores. The Swallowing-Quality of Life showed significant time-effect improvement in the intervention group.

Conclusion

Therapeutic singing exercises may help maintain swallowing function in advanced PD patients, potentially enhancing quality of life related to swallowing in those with advanced-stage diseases.

Clinical trial registration

https://cris.nih.go.kr/cris/search/listDetail.do, identifier KCT0008644.

Differentiation of Bolus Texture During Deglutition via High-Density Surface Electromyography: A Pilot Study

OBJECTIVE

Swallowing is a complex neuromuscular task. There is limited spatiotemporal data on normative surface electromyographic signal during swallow, particularly across standard textures. We hypothesize the pattern of electromyographic signal of the anterior neck varies cranio-caudally, that laterality can be evaluated, and categorization of bolus texture can be differentiated by high-density surface electromyography (HDsEMG) through signal analysis.

METHODS

An HDsEMG grid of 20 electrodes captured electromyographic activity in eight healthy adult subjects across 240 total swallows. Participants swallowed five standard textures: saliva, thin liquid, puree, mixed consistency, and dry solid. Data were bandpass filtered, underwent functional alignment of signal, and then placed into binary classifier receiver operating characteristic (ROC) curves. Muscular activity was visualized by creating two-dimensional EMG heat maps.

RESULTS

Signal analysis results demonstrated a positive correlation between signal amplitude and bolus texture. Greater differences of amplitude in the cranial most region of the array when compared to the caudal most region were noted in all subjects. Lateral comparison of the array revealed symmetric power levels across all subjects and textures. ROC curves demonstrated the ability to correctly classify textures within subjects in 6 of 10 texture comparisons.

CONCLUSION

This pilot study suggests that utilizing HDsEMG during deglutition can noninvasively differentiate swallows of varying texture noninvasively. This may prove useful in future diagnostic and behavioral swallow applications.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2695-2703, 2023.

Electrokinesiographic Study of Oropharyngeal Swallowing in Neurogenic Dysphagia

Electrokinesiographic study of swallowing (EKSS) can be useful for the assessment of patients with suspected or overt neurogenic dysphagia. EKSS consists of multichannel recording of the electromyographic (EMG) activity of the suprahyoid/submental muscle complex (SHEMG), the EMG activity of the cricopharyngeal muscle (CPEMG), and the laryngopharyngeal mechanogram (LPM). The LPM is an expression of the mechanical changes that the laryngopharyngeal structures undergo during the pharyngeal phase of swallowing. This method allows detailed evaluation of the magnitude, duration and temporal relations of the different events that characterize oropharyngeal swallowing, and thus in-depth exploration both of physiological deglutition mechanisms and of pathophysiological features of swallowing in neurogenic dysphagia. Furthermore, EKSS can guide dysphagia treatment strategies, allowing identification of optimal solutions for single patients. For instance, CPEMG recording can identify incomplete or absent relaxation of the upper esophageal sphincter during the pharyngeal phase of swallowing, thus suggesting a therapeutic approach based on botulinum toxin injection into the cricopharyngeal muscle. More recently, the 'shape' of SHEMG and the reproducibility of both SHEMG and LPM over repeated swallowing acts have been implemented as novel electrokinesiographic parameters. These measures could be valuable for straightforward non-invasive investigation of dysphagia severity and response to dysphagia treatment in clinical practice.

Behavioural interventions for swallowing in subjects with Parkinson's disease: A mixed methods systematic review

BACKGROUND

Dysphagia is prevalent in subjects with Parkinson's disease (PD). Swallowing intervention to improve or maintain swallowing function is of major importance as dysphagia may considerably impact physical and psycho-social health.

AIMS

A mixed methods systematic review was conducted to summarize and appraise literature reporting (1) effects of behavioural interventions for swallowing in individuals with PD; and (2) participants' perspectives of swallowing interventions.

METHODS & PROCEDURES

Electronic databases were searched systematically in July 2020 for articles published between 2014 and 2020. In addition, studies published between 2000 and 2014 were identified non-systematically through previous reviews. Peer-reviewed quantitative and qualitative research in English or German documenting behavioural interventions for swallowing in individuals with a diagnosis of PD was eligible for inclusion. Participants at all disease stages were included. Behavioural interventions included rehabilitative and compensatory strategies. Studies reporting swallowing outcomes with and without a comparative group were included. For each study, the National Health and Medical Research Council level of evidence was defined. Included studies were critically appraised using the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields. An integrated synthesis was performed after separate analysis of effect data and data reflecting participants' experiences. This review was conducted based on published JBI methodology and the guideline from the Preferred Reporting Items for Systematic Reviews and Meta-Analysis system was followed.

MAIN CONTRIBUTION

A total of 33 studies published in English met the inclusion criteria. Thirty-one studies reported quantitative data, one was qualitative and one was mixed methods. Intervention effects on swallowing function, swallowing safety and swallowing-related quality of life were reported for various treatment approaches. Three studies explored how participants perceived the intervention. Overriding themes including subjects' views regarding treatment schedules and levels of effort or comfort associated with the intervention were identified across these studies. Combining evidence of intervention effects and subjects' experiences was possible for one rehabilitative and one compensatory intervention.

CONCLUSIONS & IMPLICATIONS

Beneficial effects of swallowing interventions have been reported; however, most experiments were case studies of variable methodological quality. Randomized-controlled trials with robust methodology to explore treatment effects in larger samples is needed to guide clinical practice. Research reporting subjects' views is scarce. More studies exploring how individuals perceive behavioural interventions for swallowing are necessary to inform clinical decision-making.

WHAT THIS PAPER ADDS

What is already known on the subject Dysphagia is common in individuals with PD. Swallowing intervention is of major importance as dysphagia may negatively affect physical and psycho-social health of subjects with PD. What this study adds Beneficial effects of behavioural interventions for swallowing, including rehabilitative and compensatory strategies, have been reported; however, available data are mostly based on case studies of variable quality. Data on how participants perceive specific behavioural interventions are lacking. Based on the available data, integration of efficacy data and individuals' experiences is limited. What are the clinical implications of this work? Given the current evidence of intervention effects and individuals' views on behavioural treatment strategies, interventions implemented into clinical practice require careful evaluation on a case-by-case basis. More high-quality research is needed to examine interventions' short- and long-term effects in larger samples to guide clinical practice. In addition to studies evaluating intervention effects, research exploring participants' experiences with interventions is required as a foundation for clinical decision-making.

Relationship between motor dysfunction and chewing movement in patients with Parkinson's disease: A transversal study

Objective

To assess the impact of chewing movement in patients with Parkinson's disease (PD), we examined the relation between chewing movement and motor dysfunction in association with PD progression.

Methods

Thirty patients with PD (mean age, 68.9 ± 9.0 years; mean Hoehn and Yahr stage, 3.0 ± 0.7) were recruited. The PD condition was assessed in each patient by using the score of Movement Disorder Society Unified PD Rating Scale (MDS-UPDRS) part III score, body mass index (BMI), serum albumin (Alb), and tongue pressure, number of chews, mealtime, and chewing speed were collected. The patients were divided into two groups (mild and moderate PD groups) based on an MDS-UPDRS part III cut-off value of 32.

Results

The chewing speed positively correlated with tongue pressure (rho = 0.69, p < 0.01) in the mild group, and with BMI (rho = 0.54, p = 0.03), serum Alb (rho = 0.63, p = 0.02), and number of chews (rho = 0.69, p < 0.01) in the moderate group. The MDS-UPDRS part III scores for all participants correlated negatively with chewing speed (rho = -0.48, p < 0.01), serum Alb (rho = -0.49, p < 0.01), and positively with mealtime (rho = 0.43, p = 0.01). Tongue pressure and serum Alb were identified to be as factors affecting the chewing speed (β= 0.560, p < 0.01; β= 0.457, p < 0.01, respectively).

Conclusions

These results indicated that the progression of motor dysfunction in patients with PD is likely to affect chewing speed and the nutritional status decline may be linked to the impairment of chewing movement in these patients.

Movement Disorders and the Gut: A Review

There is a close link between multiple movement disorders and gastrointestinal dysfunction. Gastrointestinal symptoms may precede the development of the neurologic syndrome or may arise following the neurologic presentation. This review will provide an overview of gastrointestinal accompaniments to several well-known as well as lesser known movement disorders. It will also highlight several disorders which may not be considered primary movement disorders but have an overlapping presentation of both gastrointestinal and movement abnormalities.

Evaluation of oropharyngeal deglutitive pressure dynamics in patients with Parkinson's disease

In Parkinson's disease (PD), oropharyngeal dysphagia is common and clinically relevant. The neurophysiology of dysphagia in PD is complex and incompletely understood. The aim of the study was to determine the changes in oropharyngeal deglutitive pressure dynamics in PD and to correlate these with clinical characteristics including dysphagia and PD severity. In prospective consecutive series of 64 patients with PD [mean age: 66.9 ± 8.3 (SD)], we evaluated dysphagia severity clinically as well as with Sydney Swallow Questionnaire (SSQ) and Swallow Quality-of-Life Questionnaire (SWAL-QOL). PD severity was assessed with Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). We used high-resolution pharyngeal impedance manometry (HRPIM) to objectively evaluate swallow function and compared data from 23 age-matched healthy controls [mean age 62.3 ± 9.1 (SD)]. Metrics assessed were upper esophageal sphincter (UES), integrated relaxation pressure (IRP), relaxation time (RT), maximum opening (MaxAdm), and pharyngeal intrabolus pressure (IBP) and pharyngeal contractility (PhCI). Mean MDS-UPDRS score was positively associated with dysphagia severity on SSQ and SWAL-QOL. HRPIM in PD compared with controls showed impaired UES relaxation parameters, with shorter RT, and elevated IRP and IBP. MaxAdm was not affected. The overall pharyngeal contractility was significantly higher in PD. Only the IBP and IRP were associated with PD severity and only IBP was significantly associated with dysphagia severity. UES dysfunction leading to increased flow resistance is common in patients with PD and correlates with dysphagia severity. Increased flow resistance may suggest impaired UES relaxation and/or impaired neuromodulation to bolus volume.NEW & NOTEWORTHY In Parkinson's disease, objective assessment of swallow function with high-resolution impedance manometry identifies upper esophageal sphincter dysfunction leading to increased flow resistance.

Role of Catechol-O-methyltransferase Val158Met Polymorphism on Transcranial Direct Current Stimulation in Swallowing

Transcranial direct current stimulation (tDCS) is one of the latest post-stroke dysphagia treatment modalities, and the effect of tDCS is known to be affected by various factors including genetic polymorphisms. However, the role of catechol-O-methyltransferase (COMT) polymorphisms on tDCS in swallowing is unclear. In this prospective pilot study, we aim to explore the effect of tDCS on the swallowing cortex and subsequent swallowing motor function according to COMT polymorphism. Twenty-four healthy participants received either anodal tDCS or sham mode tDCS on the mylohyoid motor cortex at random order, after inhibitory repetitive transcranial magnetic stimulation (rTMS) for preconditioning. The primary outcome was the changes of mylohyoid-motor-evoked potentials (MH-MEP) amplitude in each COMT polymorphism group, from the post-inhibitory rTMS baseline state to immediate, 30, and 60 min after tDCS. The secondary outcomes were the changes in swallowing function. The results showed that COMT Val/Val polymorphism showed improvement across time in the MH-MEP amplitudes and triggering time of swallowing after tDCS, whereas COMT Met carrier group did not show significant changes of MH-MEP or swallowing function across time. This therapeutic response variability of tDCS in the mylohyoid motor system according to COMT polymorphism support the importance of genetic analysis in individualized dysphagia treatment.

Hand Pronation–Supination Movement as a Proxy for Remotely Monitoring Gait and Posture Stability in Parkinson’s Disease

The Unified Parkinson’s Disease Rating Scale (UPDRS) is a subjective Parkinson’s Disease (PD) physician scoring/monitoring system. To date, there is no single upper limb wearable/non-contact system that can be used objectively to assess all UPDRS-III motor system subgroups (i.e., tremor (T), rigidity (R), bradykinesia (B), gait and posture (GP), and bulbar anomalies (BA)). We evaluated the use of a non-contact hand motion tracking system for potential extraction of GP information using forearm pronation–supination (P/S) motion parameters (speed, acceleration, and frequency). Twenty-four patients with idiopathic PD participated, and their UPDRS data were recorded bilaterally by physicians. Pearson’s correlation, regression analyses, and Monte Carlo validation was conducted for all combinations of UPDRS subgroups versus motion parameters. In the 262,125 regression models that were trained and tested, the models within 1% of the lowest error showed that the frequency of P/S contributes to approximately one third of all models; while speed and acceleration also contribute significantly to the prediction of GP from the left-hand motion of right handed patients. In short, the P/S better indicated GP when performed with the non-dominant hand. There was also a significant negative correlation (with medium to large effect size, range: 0.3–0.58) between the P/S speed and the single BA score for both forearms and combined UPDRS score for the dominant hand. This study highlights the potential use of wearable or non-contact systems for forearm P/S to remotely monitor and predict the GP information in PD.

Progression of Self-Perceived Speech and Swallowing Impairment in Early Stage Parkinson's Disease: Longitudinal Analysis of the Unified Parkinson's Disease Rating Scale

PURPOSE

The purpose of this study was to investigate the presence and progression of self-perceived speech and swallowing impairments in newly diagnosed people with Parkinson's disease (PD) longitudinally across 6 years.

METHOD

Longitudinal data from the Parkinson's Progression Markers Initiative were analyzed across six consecutive years in a cohort of 269 newly diagnosed people with PD, and a subset of those (n = 211) who were assessed at every time point across the 6 years. Dependent variables included self-perceived ratings of speech and swallowing impairment severity from the Unified Parkinson's Disease Rating Scale. Patient-centered factors of age at diagnosis and motor phenotype were also assessed to determine if they were related to the change in self-perceived speech and swallowing impairments.

RESULTS

Overall, self-perceived speech and swallowing impairments were present in newly diagnosed people with PD, although over time, the degree of severity for both remained in the mild range. However, the rate of change over time was significant for perceived speech impairment, F(5.5, 1158.8) = 21.1, p < .001), and perceived swallowing impairment, F(5.2, 1082.6) = 8.6, p < .001. Changes for speech and swallowing impairment were both in the direction of progressive severity. There were no effects of age at diagnosis or motor phenotype on the degree of change for either speech or swallowing.

CONCLUSIONS

Self-perceptions of speech and swallowing impairment changed significantly over time in newly diagnosed people with PD (PWPD). Consistent with existing literature, self-perceptions of speech impairment were rated as more severe than those of swallowing impairment. These findings reveal that even in the early years postdiagnoses, PWPD are experiencing changes to speech and swallowing function, albeit within the mildly severe range. The presence of self-perceived mild speech and swallowing impairments in the initial years postdiagnosis may support the need for intervention to improve and or sustain function over time.

A multinational consensus on dysphagia in Parkinson's disease: screening, diagnosis and prognostic value

Background

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by a combination of motor and non-motor dysfunction. Dysphagia is a common symptom in PD, though it is still too frequently underdiagnosed. Consensus is lacking on screening, diagnosis, and prognosis of dysphagia in PD.

Objective

To systematically review the literature and to define consensus statements on the screening and the diagnosis of dysphagia in PD, as well as on the impact of dysphagia on the prognosis and quality of life (QoL) of PD patients.

Methods

A multinational group of experts in the field of neurogenic dysphagia and/or PD conducted a systematic revision of the literature published since January 1990 to February 2021 and reported the results according to PRISMA guidelines. The output of the research was then analyzed and discussed in a consensus conference convened in Pavia, Italy, where the consensus statements were drafted. The final version of statements was subsequently achieved by e-mail consensus.

Results

Eighty-five papers were used to inform the Panel’s statements even though most of them were of Class IV quality. The statements tackled four main areas: (1) screening of dysphagia: timing and tools; (2) diagnosis of dysphagia: clinical and instrumental detection, severity assessment; (3) dysphagia and QoL: impact and assessment; (4) prognostic value of dysphagia; impact on the outcome and role of associated conditions.

Conclusions

The statements elaborated by the Consensus Panel provide a framework to guide the neurologist in the timely detection and accurate diagnosis of dysphagia in PD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10739-8.

A comparison of swallow-related submandibular contraction amplitude and duration in people with Parkinson's disease and healthy controls

PURPOSE

To compare the contraction amplitude and contraction duration of submandibular muscles during the pharyngeal stage of swallowing in people with Parkinson's disease (PD) compared to normal controls.

METHOD

A prospective cross-sectional study design was utilised to recruit 24 participants from the regional area. A total of 14 people with PD and 10 healthy controls (HC) were recruited. Participants swallowed three volumes of thin liquid (5mL, 10mL, 15mL) while the activity of the submandibular muscles was recorded using surface electromyography. Measurements of contraction amplitude ratio (normalised to a maximum voluntary contraction) and contraction duration were computed from recorded electromyographic signals. Receiver Operating Characteristics (ROC) were computed for variables associated with significant main effects.

RESULT

Analyses revealed a significant effect of group on contraction amplitude ratio but not contraction duration. There were no significant effects of bolus volume on the dependent variables. ROC analysis indicated that contraction amplitude ratio accurately predicted group assignment in 77% cases.

CONCLUSION

Findings revealed that a majority of people with PD in this study utilised a greater percentage of their maximum contraction force in submandibular muscles when swallowing compared to normal controls. Further research is needed to determine if this inefficiency is consistent across larger samples and whether it is due to elevated baseline muscle activity, a compensatory behaviour to accomplish a more effective swallow, or both.

Diagnosis and treatment of neurogenic dysphagia - S1 guideline of the German Society of Neurology

Introduction

Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality. Based on a systematic pubmed research of related original papers, review articles, international guidelines and surveys about the diagnostics and treatment of neurogenic dysphagia, a consensus process was initiated, which included dysphagia experts from 27 medical societies.

Recommendations

This guideline consists of 53 recommendations covering in its first part the whole diagnostic spectrum from the dysphagia specific medical history, initial dysphagia screening and clinical assessment, to more refined instrumental procedures, such as flexible endoscopic evaluation of swallowing, the videofluoroscopic swallowing study and high-resolution manometry. In addition, specific clinical scenarios are captured, among others the management of patients with nasogastric and tracheotomy tubes. The second part of this guideline is dedicated to the treatment of neurogenic dysphagia. Apart from dietary interventions and behavioral swallowing treatment, interventions to improve oral hygiene, pharmacological treatment options, different modalities of neurostimulation as well as minimally invasive and surgical therapies are dealt with.

Conclusions

The diagnosis and treatment of neurogenic dysphagia is challenging and requires a joined effort of different medical professions. While the evidence supporting the implementation of dysphagia screening is rather convincing, further trials are needed to improve the quality of evidence for more refined methods of dysphagia diagnostics and, in particular, the different treatment options of neurogenic dysphagia. The present article is an abridged and translated version of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/030-111l_Neurogene-Dysphagie_2020-05.pdf).

Pathophysiology of Swallowing Dysfunction in Parkinson Disease and Lack of Dopaminergic Impact on the Swallow Function and on the Effect of Thickening Agents

(1) Background: The effect of dopaminergic treatment on swallowing response in patients with Parkinson's disease (PD) suffering oropharyngeal dysphagia (OD) is not understood. Aim: To characterize OD pathophysiology in PD and to assess whether dopaminergic states affect swallow function and the effect of thickeners. (2) Methods: Fifty patients with PD (40 evaluated in OFF/ON states) and 12 healthy volunteers (HVs) were evaluated with videofluoroscopy (VFS) to assess the swallowing biomechanics and kinematics of the swallowing response at three different shear-viscosities (<50, 120, and 4000 mPa·s); (3) Results: Patients presented a mean age of 70.46 ± 10.03 years. Disease evolution was 5.09 ± 3.86 year and Hoehn-Yahr stage was 2.32 ± 0.81. For HVs, mean age was 40.20 ± 2.50 year. Penetrations were present in 37.50% of PD patients and were associated with delayed laryngeal vestibule closure (LVC = 293.33 ± 90.07 ms). In contrast, HVs presented a LVC = 164.00 ± 39.78 ms (p < 0.05). An LVC ≥ 260 ms cutoff predicted unsafe swallow (sensitivity ≥ 0.83, specificity ≥ 0.57, AUC = 0.80) in PD. Increasing bolus viscosity improved deglutition safety but increased oropharyngeal residue. There were no differences in swallowing between the OFF/ON states. (4) Conclusions: In initial PD stages, oropharyngeal swallow response is severely delayed, while mildly impaired swallow safety improves with increasing bolus viscosity, which increases residue. Dopaminergic treatment does not affect swallowing or the therapeutic effect of thickeners.

Predictors of Pharyngeal Dysphagia in Patients with Parkinson's Disease

BACKGROUND

Diagnosis of pharyngeal dysphagia in patients with Parkinson's disease is often difficult as reliable screening methods are lacking so far and clinical examination fails to adequately assess the pharyngeal phase of swallowing.

OBJECTIVE

To identify clinical predictors indicating the presence of pharyngeal dysphagia in patients at risk.

METHODS

We examined pharyngeal dysphagia in a large cohort of patients with Parkinson's disease (n = 200) divided in three clinical subtypes (tremor-dominant (TD), mainly bradykinetic (BK) and early postural instability and gait difficulty PIGD)) by using flexible endoscopic evaluation of swallowing. ANOVA-multivariance analysis and following t-tests as well as binary logistic regression analysis were performed to detect group differences and to identify clinical predictors for dysphagia.

RESULTS

Statistically significant differences were found in the dysphagic group: age, male gender, disease duration, stage of the disease, Levodopa equivalent dose and higher scores on the Unified Parkinson's disease rating scale III and II, item 7. The PIGD subtype was affected more frequently than the TD and BK subtype. In a logistic regression model higher age (>63.5 years p < 0.05) and Levodopa equivalent dose (>475 mg, p < 0.01) were identified to be independent predictors for the presence of pharyngeal dysphagia.

CONCLUSION

Particularly patients with an age > 63.5 years and a daily Levodopa equivalent dose >475 mg show an increased risk for pharyngeal dysphagia. These findings may partly be influenced by presbyphagia but are likely to represent disease progression. The PIGD subtype seems to be a risk factor due to more pronounced dyscoordination of oropharyngeal muscle movements.

Predicting Airway Invasion Using Screening Tools and Laryngeal Kinematics in People with Parkinson's Disease: A Pilot Study

BACKGROUND

Dysphagia in Parkinson's disease (PD) is a common manifestation, particularly in advanced disease stages. However, the pathophysiology and time course of dysphagia progression remains unclear in non-advanced disease stages (e.g., Hoehn & Yahr stages I-III). Conflicting reports from investigations of the perception of dysphagia in people with PD further complicates our understanding of dysphagia in this population.

OBJECTIVE

The objectives of this research were to evaluate the ability of screening tools to detect swallowing impairments and how laryngeal kinematics predict the occurrence of abnormal swallowing events.

METHODS

14 individuals with non-advanced PD, no previous history of dysphagia diagnosis, and self-reported difficulty swallowing participated. The Swallow Disturbance Questionnaire (SDQ) and 3-oz water swallow test (WSST) were administered, along with a videoflouroscopic swallow study (VFSS). Laryngeal kinematics were represented by laryngeal vestibule closure reaction time (LVrt) and laryngeal vestibule closure duration (LVCd). The Penetration-Aspiration Scale (PAS) was used to quantify airway invasion.

RESULTS

A logistic regression indicated a significant model of predicting airway invasion from our predictors (p = 0.003). LVrt and SDQ (p < 0.05) provided the largest impact (OR = 1.11; 1.17). The WSST showed no significance in predicting swallow impairment (p > 0.05).

CONCLUSION

Decreased airway safety related to laryngeal kinematic function in PD may be manifesting at non-advanced disease stages to varied degrees. Our results support expectations of dysphagia manifestation in PD although screening practices may not adequately identify impairment. Future research should target specific laryngeal characteristics within this population to better understand the physiological cause of swallowing impairment and developof targeted interventions.

Management of Dysphagia in Patients with Parkinson's Disease and Related Disorders

Various methods of rehabilitation for dysphagia have been suggested through the experience of treating stroke patients. Although most of these patients recover their swallowing function in a short period, dysphagia in Parkinson's disease (PD) and Parkinson-related disorder (PRD) degenerates with disease progression. Muscle rigidity and bradykinesia are recognized as causes of swallowing dysfunction, and it is difficult to easily apply the strategies for stroke to the rehabilitation of dysphagia in PD patients. Disease severity, weight loss, drooling, and dementia are important clinical predictors. Silent aspiration is a pathognomonic sign that may lead to aspiration pneumonia. Severe PD patients need routine video fluoroscopy or video endoscopy to adjust their food and liquid consistency. Patients with PRD experience rapid progression of swallowing dysfunction. Nutrition combined with nasogastric tube feeding or percutaneous endoscopic gastrostomy feeding should be considered owing to the increased risk of aspiration and difficulty administrating oral nutrition.

Predictors of Penetration-Aspiration in Parkinson’s Disease Patients With Dysphagia: A Retrospective Analysis

Objective:

Penetration-aspiration is considered the most severe sign of dysphagia, with aspiration pneumonia as one of its consequences. More than half of Parkinson’s disease (PD) patients suffer from dysphagia, and aspiration pneumonia is among the primary causes of mortality in PD patients. However, the identification of predictors of penetration-aspiration in PD patients remains an understudied topic. The purpose of this study was to identify predictors of penetration-aspiration in patients with PD.

Methods:

The data of 89 PD patients with dysphagia who underwent routinely conducted videofluoroscopic studies of swallowing (VFSS) were included in this retrospective study. The occurrence of penetration-aspiration was defined as scores ≥3 on the Penetration-Aspiration Scale (PAS). Four commonly reported signs of dysphagia in PD patients were evaluated as possible predictors. Furthermore, the relationships between the occurrence of penetration-aspiration and liquid bolus volume as well as clinical severity of PD (modified Hoehn and Yahr scale) were examined.

Results:

Logistic regression showed that a delayed initiation of the pharyngeal swallow (odds ratio [OR] = 7.47, P = .008) and a reduced hyolaryngeal excursion (OR = 5.13, P = .012) were predictors of penetration-aspiration. Moreover, there was a strong, positive correlation between increasing liquid bolus volume and penetration-aspiration (γ = 0.71, P < .001). No correlation was found between severity of PD and penetration-aspiration (γ = 0.077, P = .783).

Conclusion:

Results of the present study allow for a better understanding of penetration-aspiration risk in PD patients. They are useful for treatment planning in order to improve safe oral intake and adequate nutrition.

Characterization of oromotor and limb motor dysfunction in the DJ1 -/- model of Parkinson disease

Parkinson disease (PD) is devastating to sensorimotor function that includes cranial/oromotor and limb motor deficits. However, the onset, progression, and neural correlates of PD-related dysfunctions are poorly understood. To address this gap, we used a genetic rat model of PD, DJ1 -/-, and hypothesized that motor deficits would manifest early in the disease process, be progressive in nature, and be related to pathologies in brainstem structures associated with sensorimotor function. The present study compares homozygous DJ1 -/- male rats to age-matched wild type controls. Progressive cranial sensorimotor function (ultrasonic vocalizations and tongue motor performance) and limb motor function (tapered balance beam) was analyzed at 2, 4, 6, and 8 months of age. Additionally, tyrosine hydroxylase cell counts were performed in the locus coeruleus and correlated to behavioral measures. We found that compared to wild type controls, DJ1 -/- show deficits in ultrasonic vocalizations as well as oromotor (tongue) deficits that were progressive. Overtime, DJ1 -/- rats cross a tapered balance beam with significantly decreased speed of traversal. Additionally, in the DJ1 -/-, tyrosine hydroxylase positive cells in the locus coeruleus are significantly reduced and are negatively correlated to oromotor behaviors. Characterizing the DJ1 -/- model of PD provides important foundational work necessary to define behavioral and early-onset biomarkers that parallels early-stage PD pathology in humans.

The Test of Masticating and Swallowing Solids (TOMASS): reliability, validity and international normative data

BACKGROUND

Clinical swallowing assessment is largely limited to qualitative assessment of behavioural observations. There are limited quantitative data that can be compared with a healthy population for identification of impairment. The Test of Masticating and Swallowing Solids (TOMASS) was developed as a quantitative assessment of solid bolus ingestion.

AIMS

This research programme investigated test development indices and established normative data for the TOMASS to support translation to clinical dysphagia assessment.

METHODS & PROCEDURES

A total of 228 healthy adults (ages 20-80+ years) stratified by age and sex participated in one or more of four consecutive studies evaluating test-retest and interrater reliability and validity to instrumental assessment. For each study the test required participants to ingest a commercially available cracker with instructions to 'eat this as quickly as is comfortably possible'. Further averaged measures were derived including the number of masticatory cycles and swallows per bite, and time per bite, masticatory cycle and swallow. Initial analyses identified significant differences on salient measures between two commercially available crackers that are nearly identical in shape, size and ingredients, suggesting the need for separate normative samples for specific regional products. Additional analyses on a single cracker identified that the TOMASS was sensitive at detecting changes in performance based on age and sex. Test-retest reliability across days and interrater reliability between clinicians was high, as was validation of observational measures to instrumental correlates of the same behaviours. Therefore, normative data are provided for the TOMASS from a minimum of 80 healthy controls, stratified by age and sex, for each of seven commercially available crackers from broad regions worldwide.

OUTCOMES & RESULTS

Analyses on a single cracker identified Arnott's Salada, and that TOMASS measures were sensitive for detecting changes in performance based on age and sex. Interrater and test-retest reliability across days were high, as was validation of observational measures to instrumental correlates of the same behaviours. Significant differences were identified between two commercially available crackers, nearly identical in shape, size and ingredients, thus normative samples for specific regional products were required. Normative data were then acquired for the TOMASS from a minimum of 80 healthy controls, stratified by age and sex, for each of seven commercially available crackers from broad regions worldwide.

CONCLUSIONS & IMPLICATIONS

The TOMASS is presented as a valid, reliable and broadly normed clinical assessment of solid bolus ingestion. Clinical application may help identify dysphagic patients at bedside and provide a non-invasive, but sensitive, measure of functional change in swallowing.

Critical Dysphagia is Common in Parkinson Disease and Occurs Even in Early Stages: A Prospective Cohort Study

To assess the prevalence of dysphagia and its typical findings in unselected "real-world" Parkinson patients using an objective gold-standard method. This was a prospective, controlled, cross-sectional study conducted in 119 consecutive Parkinson patients of all stages independent of subjective dysphagia. Patients and 32 controls were clinically and endoscopically examined by flexible endoscopic evaluation of swallowing (FEES) to evaluate the deglutition with regard to three consistencies (water, biscuit, and bread). Typical findings of dysphagia like penetration and aspiration, residues, and leakage were assessed. Dysphagia was common in Parkinson patients and occurred in all, even early, disease stages. Only 5% (6/119) of patients showed a completely unremarkable deglutition. Aspiration was seen in 25% (30/119) of patients and always related to water. Residues occurred in 93% (111/119), most commonly for bread. Leakage was much less frequent and was found in only 3-18%, depending on consistency. In a significant fraction of patients, objective dysphagia was not subjectively perceived. A total of 16% of asymptomatic patients suffered from critical aspiration. Significant swallowing deficiencies already occurred in early disease. Aspiration was found in 4 of 20 (20%) patients with disease duration of less than 2 years. Seven of 57 patients (12%) with Hoehn and Yahr stage 2 suffered from severe aspiration. Given the high frequency of critical aspiration in Parkinson disease, these patients should be evaluated early for dysphagia to avoid complications and recommend an adequate therapy. FEES is a simple, cost efficient, minimally invasive method that is ideally suited for this purpose.

Dysphagia in Perry Syndrome: Pharyngeal Pressure in Two Cases

Background

To investigate the impact of dysphagia in Perry syndrome (PS), an autosomal dominant parkinsonism caused by mutation of DCTN1, which is associated with hypoventilation, depression, and weight loss.

Case Presentation

We used tongue pressure measurements and manofluorography to investigate swallowing function in 2 patients with PS. Case 1, a 60-year-old male showing parkinsonism, and case 2, a 49-year-old male admitted with pneumonia, were diagnosed as having PS based on the DCTN1 gene analysis. Case 1 showed a pharyngeal retention of the bolus on videofluorography (VF) and a few swallows were required for its passage into the esophagus. However, tongue pressure and manometry were within the normal range. This patient could eat a normal diet under supervision. Case 2 required artificial ventilation and tube feeding on admission. The VF image showed a slow transfer of the bolus, delayed swallow reflex, and pharyngeal retention of the bolus that required several swallows for its passage into the esophagus. The tongue pressure was within the normal range, but manometry showed a significant decrease in pressure at the hypopharynx and upper esophageal sphincter. The oral intake of the patients was limited to 2 cups of jelly per day.

Conclusions

The investigation of swallowing dysfunction of 2 cases of PS showed that maintaining pharyngeal pressure within the normal range was very important for oral feeding success and prognosis.

Amplitude e velocidade dos movimentos mastigatórios em pacientes com doença de Parkinson

RESUMO Objetivo: caracterizar a amplitude e a velocidade dos ciclos mastigatórios avaliados por eletrognatografia em um grupo de indivíduos idosos e confrontar esses dados com outros dois grupos de sujeitos com doença de Parkinson (DP) diferenciados pela característica motora predominante. Métodos: os 42 participantes foram divididos em três grupos: A com 15 voluntários e média de idade de 62 anos, sendo 8 do sexo feminino; B com 14 voluntários Parkinsonianos com rigidez predominante e média etária de 58 anos, dos quais 7 eram mulheres; e o grupo C com 13 voluntários, com DP e tremor predominante, com média de idade de 64 anos, sendo 4 mulheres. Empregou-se o teste ANOVA para diferença de médias, com contraste post-hoc de Dunnett ou teste t de Student, todos em nível de significância de 0,05. Resultados: houve maiores diferenças entre as medias dos grupos A e B no numero total de ciclos mastigatórios (A= 23,13 ± 1,41 B=18,21 ± 1,70) [p=0,034] e nas amplitudes máxima de abertura de boca (A= 34,66 ± 2,04 B=26,72 ± 2,49) [p=0,018], lateralização para direita (A=7,02 ± 0,59 B=5,80 ± 0,97) [p=0,036] e para esquerda (A=6,44 ± 0,64 B=3,35 ± 0,80) [p=0,039]. Conclusão: tendo o grupo de idosos superado as medias, na movimentação mandibular durante a mastigação, do grupo de parkinsonianos com rigidez significativamente. Podemos concluir que, é provável que fatores como a rigidez parkinsoniana possam comprometer a mastigação de indivíduos com a doença de Parkinson.

Esophageal dysfunction in different stages of Parkinson's disease

BACKGROUND

Dysphagia is a clinically relevant symptom in patients with Parkinson's disease (PD) leading to pronounced reduction in quality of life and other severe complications. Parkinson's disease-related dysphagia may affect the oral and pharyngeal, as well as the esophageal phase of swallowing.

METHODS

To examine the nature and extend of esophageal dysphagia in different stages of PD and their relation to oropharyngeal dysfunction, we examined 65 PD patients (mean age 66.3±9.7 years, mean disease duration 7.9±5.8 years, mean Hoehn & Yahr [H&Y] stage 2.89±0.91) and divided into three groups (early [H&Y I+II; n=21], intermediate [H&Y III; n=25], and advanced stadium [H&Y IV+V; n=19]), using esophageal high-resolution manometry (HRM) to detect esophageal motor disorders. Oropharyngeal impairment was assessed using fiberoptic endoscopic evaluation of swallowing.

KEY RESULTS

Major esophageal motor disorders were detected in nearly one third of the PD patients. Minor impairment of the esophageal body was present in 95% of participants and throughout all disease stages with pathological findings especially in peristalsis and intrabolus pressure (IBP). The IBP was found to significantly increase in the advanced stadium. Although dysfunction of the upper and lower esophageal sphincters was observed in individual patients, alterations in these esophageal segments revealed no statistical significance compared with normative data. No clear association was found between the occurrence of oropharyngeal dysphagia and esophageal impairment.

CONCLUSIONS & INFERENCES

Esophageal body impairment in PD is a frequent phenomenon during all disease stages, which possibly reflects α-synucleinopathy in the enteric nervous system.

The Functional Dysphagia Scale Is a Useful Tool for Predicting Aspiration Pneumonia in Patients With Parkinson Disease

OBJECTIVE

To describe the correlation between the functional dysphagia scale and aspiration pneumonia and which characteristics influence the occurrence of aspiration pneumonia in patients with idiopathic Parkinson disease.

METHODS

Fifty-three patients with idiopathic Parkinson disease were prospectively evaluated in this study. Disease severity and functional status were measured by modified Hoehn and Yahr (H&Y) staging, Schwab and England activities of daily living (S-E ADL) scale and Korean version of Mini-Mental State Examination (K-MMSE). Swallowing function was evaluated by the functional dysphagia scale (FDS) and the penetration-aspiration scale (PAS) based on a videofluoroscopic swallowing study. The patients were followed up for 3 months and divided into two groups according to the occurrence of aspiration pneumonia. The correlation between the variables and aspiration pneumonia was analyzed.

RESULTS

Eight patients of the 53 patients were allocated to the aspiration pneumonia group and 45 patients to the non-aspiration pneumonia group. The patients in the aspiration pneumonia group had significantly higher H&Y staging, and scored lower on S-E ADL scale and K-MMSE. The patients in the aspiration pneumonia group had significantly higher scores on FDS and PAS. A multiple logistic regression analysis showed that the S-E ADL scale and the FDS were associated with the occurrence of aspiration pneumonia in the patients with Parkinson disease.

CONCLUSION

Given that the FDS can quantitatively assess the functional problems associated with dysphagia, it can be clinically effective in predicting the occurrence of aspiration pneumonia, and the FDS and the S-E ADL scale could be predictive variables for aspiration pneumonia in patients with Parkinson disease.

Dysphagia in Alzheimer's disease

OBJECTIVE

To investigate electrophysiological parameters of swallowing in all stages of Alzheimer's disease.

METHODS

Forty Alzheimer's disease patients, 20 age-matched normal controls and 20 young normal controls were included. Dysphagia limit (DL) and sequential water swallowing (SWS) tests were performed. Cardiac rhythm, respiration and sympathetic skin responses were concomitantly recorded.

RESULTS

Dysphagia was found in 30/40 (75%) of Alzheimer's disease patients. Mean volume at the DL test was significantly reduced (16.5±1.0mL) in the Alzheimer's disease group. Swallowing and apnea times in the SWS test were significantly prolonged in elderly controls, but even longer in Alzheimer's disease patients.

CONCLUSIONS

Alzheimer's disease patients had electrophysiological features of dysphagia, even in the early period of disease. The cortical involvement and severity of cognitive disorder can increase swallowing problems, but subclinical signs of dysphagia may be observed even in patients with mild or moderate Alzheimer's disease.

Características do percurso da movimentação mandibular dos diferentes tipos de Doença de Parkinson

RESUMO O objetivo deste trabalho foi caracterizar a amplitude e a velocidade dos movimentos mandibulares isolados e mastigatórios avaliados por eletrognatografia de dois indivíduos com Doença de Parkinson (DP) e confrontar esses dados com os de um voluntário sem a DP. Os três participantes foram divididos em três categorias: voluntário sem DP, paciente com DP e rigidez predominante (DP-rigidez) e paciente com DP e tremor predominante (DP-tremor). Foram encontradas diferenças entre as três categorias, porém com maior importância entre o indivíduo sem DP e o com DP-rigidez, na amplitude e na velocidade, quando da realização dos movimentos mandibulares e mastigatórios. Os fatores relacionados aos processos adaptativos e compensatórios derivados da diminuição da ação dopaminérgica pareceram explicar melhor as alterações observadas na movimentação mandibular no grupo com DP.

Spontaneous Swallowing during All-Night Sleep in Patients with Parkinson Disease in Comparison with Healthy Control Subjects

STUDY OBJECTIVES

Spontaneous saliva swallows (SS) appear especially during sleep. The rate of SS was rarely investigated in all-night sleep in patients with Parkinson disease (PD). Dysphagia is a frequent symptom in PD, but the rate of SS was never studied with an all-night sleep electroencephalogram (EEG).

METHODS

A total of 21 patients with PD and 18 age-matched healthy controls were included in the study. Frequencies of SS and coughing were studied in all-night sleep recordings of patients with PD and controls. During all-night sleep, video-EEG 12-channel recording was used including the electromyography (EMG) of the swallowing muscles, nasal airflow, and recording of vertical laryngeal movement using a pair of EEG electrodes over the thyroid cartilage.

RESULTS

The total number of SS was increased while the mean duration of sleep was decreased in PD when compared to controls. Sialorrhea and clinical dysphagia, assessed by proper questionnaires, had no effect in any patient group. The new finding was the so-called salvo type of consecutive SS in one set of swallowing. The amount of coughing was significantly increased just after the salvo SS.

CONCLUSIONS

In PD, the rate of SS was not sufficient to demonstrate the swallowing disorder, such as oropharyngeal dysphagia, but the salvo type of SS was quite frequent. This is a novel finding and may contribute to the understanding of swallowing problems in patients with dysphagic or nondysphagic PD.

Quantitative Measures of Swallowing Deficits in Patients With Parkinson's Disease

OBJECTIVE

Dysphagia and associated aspiration pneumonia are commonly reported sequelae of Parkinson's disease (PD). Previous studies of swallowing in patients with PD have described prolonged pharyngeal transit time, delayed onset of pharyngeal transit, cricopharyngeal (CP) achalasia, reduced pharyngeal constriction, and slowed hyolaryngeal elevation. These studies were completed using inconsistent evaluation methodology, reliance on qualitative analysis, and a lack of a large control group, resulting in concerns regarding diagnostic precision. The purpose of this study was to investigate swallowing function in patients with PD using a norm-referenced, quantitative approach.

METHODS

This retrospective study includes 34 patients with a diagnosis of PD referred to a multidisciplinary voice and swallowing clinic. Modified barium swallow studies were performed using quantitative measures of pharyngeal transit time, hyoid displacement, CP sphincter opening, area of the pharynx at maximal constriction, and timing of laryngeal vestibule closure relative to bolus arrival at the CP sphincter.

RESULTS

Reduced pharyngeal constriction was found in 30.4%, and a delay in airway closure relative to arrival of the bolus at the CP sphincter was the most common abnormality, present in 62% of patients. Previously reported findings of prolonged pharyngeal transit, poor hyoid elevation, and CP achalasia were not identified as prominent features.

Videofluoroscopic Predictors of Penetration-Aspiration in Parkinson's Disease Patients

Parkinson's disease (PD) patients show a high prevalence of swallowing disorders and tracheal aspiration of food. The videofluoroscopic study of swallowing (VFSS) allows clinicians to visualize the visuoperceptual and temporal parameters associated with swallowing disorders in an attempt to predict aspiration risk. However, this subject remains understudied in PD populations. Our aim was to identify the predictors of penetration-aspiration in PD patients using the VFSS. Consecutive patients were evaluated using VFSS with different consistencies and volumes of food. A speech-language pathologist measured the type of intra-oral bolus organization, loss of bolus control, bolus location at the initiation of the pharyngeal swallow, the presence of multiple swallows, piecemeal deglutition, bolus residue in the pharyngeal recesses and temporal measures. Scores ≥3 on the penetration-aspiration scale (PAS) indicated the occurrence of penetration-aspiration. Using logistic marginal regression, we found that residue in the vallecula, residue in the upper esophageal sphincter and piecemeal deglutition were associated with penetration-aspiration (odds ratio (OR) = 4.09, 2.87 and 3.83; P = 0.0040, 0.0071 and 0.0009, respectively). Penetration/aspiration occurred only with fluids (both of thin and thick consistency), and no significant differences were observed between fluid types or food volumes. The mechanisms underlying dysphagia and penetration/aspiration in PD patients and indications for further studies are discussed.

Electrophysiological Techniques to Evaluate Swallowing in Central and Peripheral Nervous System Disorders

Neurogenic dysphagia is a frequent condition that may result in serious complications. Despite high incidence of neurogenic dysphagia, the neurologist is not really interested in its clinical diagnosis and management. In this review, several neurophysiological methods are described to evaluate the neurogenic dysphagia. These kinds of assessment methods are important for early diagnosis and some management strategies against to progressive swallowing pathology. The longitudinal follow-up of the patients also provides data about the prognosis of dysphagia. In our opinion, the neurophysiological methods presented in this review are reliable, cheap, and easy applicable quantitative tests to detect and follow both clinical and subclinical dysphagia. All these electrophysiological techniques can be applied within the discipline of the EMG laboratory.

Electrophysiological association of spontaneous yawning and swallowing

Yawning and swallowing are fundamental physiological processes that are present from fetal stages throughout life and that involve sequential motor activities in the oropharyngo-larynx making it likely that they may share neuroanatomical pathways. We postulate that yawning and swallowing are controlled by a distributed network of brainstem regions including the central pattern generator of swallowing, and therefore spontaneous swallowing is frequently associated with spontaneous yawning. In this study, we sought to test this hypothesis by evaluating the elementary features of yawning in the facial, masseter and submental muscles, together with laryngeal movement sensor and respiratory recordings for spontaneous swallowing. We investigated 15 healthy, normal control subjects, 10 patients with Parkinson's disease (PD) and 10 patients with brainstem stroke (BSS). Apart from four subjects with PD and two with BSS, who had dysphagia, none of the other study subjects were dysphagic by published criteria. Twenty-five subjects (10 control, 10 BSS, 5 PD) were evaluated by 1-h polygraphic recording, and 10 (5 control, 5 PD) underwent whole-night sleep recordings. One hundred thirty-two yawns were collected, 113 of which were associated with spontaneous swallows, a clear excess of what would be considered as coincidence. The yawns related with swallows could be classified into the following three categories. The characteristics or the duration of swallows and yawns were similar between controls and disease subjects, with the exception of increased duration of yawning in subjects with BSS. Our findings support the presence of common neuroanatomico-physiological pathways for spontaneous swallows and yawning.

Gastrointestinal Symptoms in Parkinson Disease: Clinical Aspects and Management

Although it is now generally recognized that the clinical spectrum of Parkinson disease (PD) is broader than its defining motor aspects, its various non-motor symptoms are often not routinely assessed in the clinical setting. As most of these symptoms are amenable to treatment, improved recognition would lead to more comprehensive management of the disease, and ultimately improve the quality of life for PD patients. In an attempt to increase the general awareness of physicians caring for these patients, this article focuses on the clinical manifestations and treatment of the gastrointestinal symptoms most commonly experienced by PD patients, as well as on the gastrointestinal side effects of antiparkinsonian treatments.

Dysautonomia in Parkinson disease

Dysautonomias are conditions in which altered function of one or more components of the autonomic nervous system (ANS) adversely affects health. This review updates knowledge about dysautonomia in Parkinson disease (PD). Most PD patients have symptoms or signs of dysautonomia; occasionally, the abnormalities dominate the clinical picture. Components of the ANS include the sympathetic noradrenergic system (SNS), the parasympathetic nervous system (PNS), the sympathetic cholinergic system (SCS), the sympathetic adrenomedullary system (SAS), and the enteric nervous system (ENS). Dysfunction of each component system produces characteristic manifestations. In PD, it is cardiovascular dysautonomia that is best understood scientifically, mainly because of the variety of clinical laboratory tools available to assess functions of catecholamine systems. Most of this review focuses on this aspect of autonomic involvement in PD. PD features cardiac sympathetic denervation, which can precede the movement disorder. Loss of cardiac SNS innervation occurs independently of the loss of striatal dopaminergic innervation underlying the motor signs of PD and is associated with other nonmotor manifestations, including anosmia, REM behavior disorder, orthostatic hypotension (OH), and dementia. Autonomic dysfunction in PD is important not only in clinical management and in providing potential biomarkers but also for understanding disease mechanisms (e.g., autotoxicity exerted by catecholamine metabolites). Since Lewy bodies and Lewy neurites containing alpha-synuclein constitute neuropathologic hallmarks of the disease, and catecholamine depletion in the striatum and heart are characteristic neurochemical features, a key goal of future research is to understand better the link between alpha-synucleinopathy and loss of catecholamine neurons in PD.

Electrophysiological evaluation of oropharyngeal Dysphagia in Parkinson's disease

Parkinson’s disease (PD) is a chronic, neurodegenerative movement disorder that typically affects elderly patients. Swallowing disorders are highly prevalent in PD and can have grave consequences, including pneumonia, malnutrition, dehydration and mortality. Neurogenic dysphagia in PD can manifest with both overt clinical symptoms or silent dysphagia. Regardless, early diagnosis and objective follow-up of dysphagia in PD is crucial for timely and appropriate care for these patients. In this review, we provide a comprehensive summary of the electrophysiological methods that can be used to objectively evaluate dysphagia in PD. We discuss the electrophysiological abnormalities that can be observed in PD, their clinical correlates and the pathophysiology underlying these findings.

Diagnostic value of "dysphagia limit" for neurogenic dysphagia: 17 years of experience in 1278 adults

OBJECTIVE

Neurogenic dysphagia (ND) is a prevalent condition that accounts for significant mortality and morbidity worldwide. Screening and follow-up are critical for early diagnosis and management which can mitigate its complications and be cost-saving. The aims of this study are to provide a comprehensive investigation of the dysphagia limit (DL) in a large diverse cohort and to provide a longitudinal assessment of dysphagia in a subset of subjects.

METHODS

We developed a quantitative and noninvasive method for objective assessment of dysphagia by using laryngeal sensor and submental electromyography. DL is the volume at which second or more swallows become necessary to swallow the whole amount of bolus. This study represents 17 years experience with the DL approach in assessing ND in a cohort of 1278 adult subjects consisting of 292 healthy controls, 784 patients with dysphagia, and 202 patients without dysphagia. A total of 192 of all patients were also reevaluated longitudinally over a period of 1-19 months.

RESULTS

DL has 92% sensitivity, 91% specificity, 94% positive predictive value, and 88% negative predictive value with an accuracy of 0.92. Patients with ALS, stroke, and movement disorders have the highest sensitivity (85-97%) and positive predictive value (90-99%). The clinical severity of dysphagia has significant negative correlation with DL (r=-0.67, p<0.0001).

CONCLUSIONS

We propose the DL as a reliable, quick, noninvasive, quantitative test to detect and follow both clinical and subclinical dysphagia and it can be performed in an EMG laboratory.

SIGNIFICANCE

Our study provides specific quantitative features of DL test that can be readily utilized by the neurologic community and nominates DL as an objective and robust method to evaluate dysphagia in a wide range of neurologic conditions.

Attentional resource allocation and swallowing safety in Parkinson's disease: a dual task study

BACKGROUND

Aspiration pneumonia is a leading cause of death in persons with Parkinson's disease (PD). Despite this, the mechanisms underlying dysphagia in this population are unclear. To date, researchers have not investigated the effects of varying cognitive demand on objective measures of swallowing safety. This study assessed whether swallowing safety could be disrupted by increasing cognitive demands during the task of swallowing.

METHODS

Twenty participants with moderate PD and dysphagia were tested while completing a novel dual task experimental paradigm under videofluoroscopy. In the dual task condition, participants swallowed 10 cc of thin liquid barium while completing a digits forward task.

RESULTS

Four females and 16 males completed the study. Results revealed differential effects to swallowing safety based on baseline measures of cognitive flexibility and attention. Participants with mild impairment in cognitive flexibility and attention demonstrated cognitive-motor interference with worsening of both swallowing and cognitive performance. In contrast, participants who were most impaired in the domains of cognitive flexibility and attention improved swallowing safety in the dual task condition. Additionally, decreased swallow timing durations existed in the dual task condition compared to the single task condition.

CONCLUSIONS

The results of this study support the hypothesis that supramedullary drive can influence the swallowing plan. Additionally, this study highlights the need for cognitive taxing during swallowing evaluations.