Respiratory dysfunction in Parkinson's disease

Dyspnea, the silent threat in Parkinson's: a mixed methods study

BACKGROUND

Dyspnea is considered a silent threat to people diagnosed with Parkinson's disease and may be a common concern in patients, however, little is known about how it affects quality of life. This study explored the experiences of independently mobile people who are affected by dyspnea in daily life.

METHODOLOGY

This was a cross-sectional mixed methods study that included an online questionnaire and semi-structured interviews. The participants were included if they were diagnosed with Parkinson's disease; had a self-reported Hoehn and Yahr Score I, II or III; were mobilizing independently; and were Arabic speakers. Participants were excluded if they had any other musculoskeletal, cardiac, respiratory, or neurological diseases; or were previous or current smokers; or had been previously hospitalized due to respiratory complications.

RESULTS

A total of 117 participants completed the Arabic version of the Dyspnea-12 Questionnaire. Dyspnea was reported in all participants and that it had an adverse effect on their quality of life, especially during activities of daily living. Additionally, participants reported a lack of knowledge about pulmonary rehabilitation and were unaware of the availability and potential benefits of participation in programs.

CONCLUSION

Dyspnea was reported in people in the early stages (Hoehn and Yahr Stages I, II, and III) of Parkinson's disease, and may benefit from routine assessment of lung function, dyspnea management and participation in pulmonary rehabilitation.

A Preliminary Study of Voluntary Cough Motor Performance and Learning With Skill Training and Biofeedback

PURPOSE

Sensorimotor cough skill training (CST) has been shown to improve cough strength, as well as facilitate changes during training (i.e., motor performance) and generalization to untrained tasks (i.e., motor learning). However, there is a gap in our understanding of the effects of voluntary CST (without sensory stimuli) on motor performance and learning. Furthermore, the contribution of physiologic factors, such as lung volume, a driver of cough strength in healthy adults, and treatment-specific factors, such as biofeedback, remains unexamined.

METHOD

Twenty individuals with Parkinson's disease (PD) completed pre- and post-CST single voluntary, sequential voluntary, and reflex cough testing. Participants were randomized to biofeedback or no biofeedback groups. They completed one CST session involving 25 trials of voluntary coughs, with the treatment target set 25% above baseline peak flow. Participants were instructed to "cough hard" to exceed the target. In the biofeedback group, participants received direct visualization of the target line in real time.

RESULTS

Cough peak flow showed positive improvements in motor performance (β = .02; 95% credible interval [CI]: 0.01, 0.03) and learning (β = .26; 95% CI: 0.03, 0.47). Changes in lung volume from pre- to post-CST did not predict treatment response. No differences in treatment response were detected between the biofeedback groups.

CONCLUSIONS

A single session of voluntary CST improved voluntary cough motor performance and learning. Although lung volume increased during CST, changes to lung volume did not predict treatment response. These findings demonstrate the potential of voluntary CST to improve motor performance and motor learning among individuals with PD and cough dysfunction.

SUPPLEMENTAL MATERIAL AND OPEN SCIENCE FORM

https://doi.org/10.23641/asha.25447444.

Apnea behavior in early- and late-stage mouse models of Parkinson's disease: Cineradiographic analysis of spontaneous breathing, acute stress, and swallowing

This study aimed to evaluate the timing and frequency of spontaneous apneas during breathing and swallowing by using cineradiography on mouse models of early/initial or late/advanced Parkinson's disease (PD). C57BL/6 J mice received either 6-OHDA or vehicle injections into their right striatum, followed by respiratory movement recordings during spontaneous breathing and swallowing, and a stress challenge, two weeks later. Experimental group animals showed a significantly lower respiratory rate (158.66 ± 32.88 breaths/minute in late PD, 173.16 ± 25.19 in early PD versus 185.27 ± 25.36 in controls; p<0.001) and a significantly higher frequency of apneas (median 1 apnea/minute in both groups versus 0 in controls; p<0.001). Other changes included reduced food intake and the absence of swallow apneas in experimental mice. 6-OHDA-induced nigrostriatal degeneration in mice disrupted respiratory control, swallowing, stress responsiveness, and feeding behaviors, potentially hindering airway protection and elevating the risk of aspiration.

State-dependent alteration of respiration in a rat model of Parkinson's disease

Parkinson's disease (PD) is the second most frequent neurodegenerative disorder. Besides major deficits in motor coordination, patients may also display sensory and cognitive impairments, which are often overlooked despite being inherently part of the PD symptomatology. Amongst those symptoms, respiration, a key mechanism involved in the regulation of multiple physiological and neuronal processes, appears to be altered. Importantly, breathing patterns are highly correlated with the animal's behavioral states. This raises the question of the potential impact of behavioral state on respiration deficits in PD. To answer this question, we first characterized the respiratory parameters in a neurotoxin-induced rat model of PD (6-OHDA) across three different vigilance states: sleep, quiet waking and exploration. We noted a significantly higher respiratory frequency in 6-OHDA rats during quiet waking compared to Sham rats. A higher respiratory amplitude was also observed in 6-OHDA rats during both quiet waking and exploration. No effect of the treatment was noted during sleep. Given the relation between respiration and olfaction and the presence of olfactory deficits in PD patients, we then investigated the odor-evoked sniffing response in PD rats, using an odor habituation/cross-habituation paradigm. No substantial differences were observed in olfactory abilities between the two groups, as assessed through sniffing frequency. These results corroborate the hypothesis that respiratory impairments in 6-OHDA rats are vigilance-dependent. Our results also shed light on the importance of considering the behavioral state as an impacting factor when analyzing respiration.

Your smartphone could act as a pulse-oximeter and as a single-lead ECG

In the post-covid19 era, every new wave of the pandemic causes an increased concern/interest among the masses to learn more about their state of well-being. Therefore, it is the need of the hour to come up with ubiquitous, low-cost, non-invasive tools for rapid and continuous monitoring of body vitals that reflect the status of one's overall health. In this backdrop, this work proposes a deep learning approach to turn a smartphone-the popular hand-held personal gadget-into a diagnostic tool to measure/monitor the three most important body vitals, i.e., pulse rate (PR), blood oxygen saturation level (aka SpO2), and respiratory rate (RR). Furthermore, we propose another method that could extract a single-lead electrocardiograph (ECG) of the subject. The proposed methods include the following core steps: subject records a small video of his/her fingertip by placing his/her finger on the rear camera of the smartphone, and the recorded video is pre-processed to extract the filtered and/or detrended video-photoplethysmography (vPPG) signal, which is then fed to custom-built convolutional neural networks (CNN), which eventually spit-out the vitals (PR, SpO2, and RR) as well as a single-lead ECG of the subject. To be precise, the contribution of this paper is twofold: (1) estimation of the three body vitals (PR, SpO2, RR) from the vPPG data using custom-built CNNs, vision transformer, and most importantly by CLIP model (a popular image-caption-generator model); (2) a novel discrete cosine transform+feedforward neural network-based method that translates the recorded video-PPG signal to a single-lead ECG signal. The significance of this work is twofold: (i) it allows rapid self-testing of body vitals (e.g., self-monitoring for covid19 symptoms), (ii) it enables rapid self-acquisition of a single-lead ECG, and thus allows early detection of atrial fibrillation (abormal heart beat or arrhythmia), which in turn could enable early intervention in response to a range of cardiovascular diseases, and could help save many precious lives. Our work could help reduce the burden on healthcare facilities and could lead to reduction in health insurance costs.

The incidence of deep venous thrombosis in Parkinson's disease

INTRODUCTION

Venous thromboembolism is one of the causes of sudden death in Parkinson's Disease (PD). Few studies have investigated the correlation between PD and deep venous thrombosis (DVT). This study aimed to investigate the frequency of DVT in PD patients prospectively.

MATERIAL AND METHOD

Demographic characteristics of 37 PD patients without known risk factors for DVT, disease duration, Hoehn-Yahr (H - Y) stage, oxygen saturation (SpO2) and heart rate values with pulse oximetry, use of assistive devices, waist and knee circumference measurements, and modified Medical Research Council (mMRC) dyspnea score was recorded. Both legs were evaluated for thrombus by Doppler venous ultrasound (US).

RESULTS

With the H-Y stage of the disease duration, a positive correlation was determined between the H-Y stage and mMRC. Disease duration was negatively correlated with BMI and positively correlated with the need for assistance. Assistive device use was positively associated with age and mMRC. DVT was detected in only one patient. When our patients' files were reviewed after 1.5 years, one patient was hospitalized with the diagnosis of submassive pulmonary embolism.

CONCLUSION

Attention should be paid to the development of DVT in elderly patients with advanced stages of PD, progression in the H-Y stage, use of assistive devices, and progression in dyspnea scoring. There is also a need for studies on the benefit of DVT prophylaxis in PD patients with a high risk of venous thromboembolism.

Ampakine CX614 increases respiratory rate in a mouse model of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia nigra compacta (SNpc). In a mouse model of PD induced by the injection of 6-hydroxydopamine (6-OHDA) into the caudate putamen (CPu) dyspnea events are very common. Neuroanatomical and functional studies show that the number of glutamatergic neurons in the pre-Bötzinger Complex (preBötC) are reduced. We hypothesize that the neuronal loss, and consequently loss of glutamatergic connections in the respiratory network previously investigated, are responsible for the breathing impairment in PD. Here, we tested whether ampakines (CX614), a subgroup of AMPA receptor positive allosteric modulators, could stimulate the respiratory activity in PD-induced animals. CX614 (50 µM) injected intraperitoneally or directly into the preBötC region reduced the irregularity pattern and increased the respiratory rate by 37% or 82%, respectively, in PD-induced animals. CX614 also increased the respiratory frequency in healthy animals. These data suggest that ampakine CX614 could become a tool to restore breathing in PD.

Validation of a comorbidity questionnaire in patients with neurological disorders

Rational

Several tools exist to assess comorbidities in neurological disorders, the most widely used being the Charlson Comorbidity Index (CCI), but it has several limitations. The Comorbidity and General Health Questionnaire (CGHQ) is a newly designed tool, which includes additional comorbidities associated with health-related quality of life (HR-QOL) and outcomes in neurological disorders.

Aims and objectives

To assess the feasibility and validity of the CGHQ in patients with neurological disease.

Method

Two hundred patients attending a general neurological clinic were invited to complete the CGHQ along with the EQ-5D-5L questionnaire. The CCI was simultaneously completed by the assessor. CGHQ comorbidity scores were compared with CCI, symptom burden and EQ-5D-5L scores.

Results

The CGHQ captured 22 additional comorbidities not included on the CCI and more comorbidities were endorsed on the CGHQ. The CGHQ correlated weakly to moderately with CCI comorbidity scores. While both the CGHQ and CCI correlated negatively with the EQ-5D-5L Visual Analogue Scale, only the CGHQ correlated negatively with the EQ-5D-5L summary index. The CGHQ but not the CCI correlated strongly and positively with symptom burden scores.

Conclusion

The CGHQ allows a more comprehensive assessment of comorbidities than the CCI and better correlates with patients' overall symptom burden and HR-QOL in neurological patients.

The Pedunculopontine Tegmental Nucleus is not Important for Breathing Impairments Observed in a Parkinson's Disease Model

Parkinson's disease (PD) is a motor disorder resulting from degeneration of dopaminergic neurons of substantia nigra pars compacta (SNpc), with classical and non-classical symptoms such as respiratory instability. An important region for breathing control, the Pedunculopontine Tegmental Nucleus (PPTg), is composed of cholinergic, glutamatergic, and GABAergic neurons. We hypothesize that degenerated PPTg neurons in a PD model contribute to the blunted respiratory activity. Adult mice (40 males and 29 females) that express the fluorescent green protein in cholinergic, glutamatergic or GABAergic cells were used (Chat-cre Ai6, Vglut₂-cre Ai6 and Vgat-cre Ai6) and received bilateral intrastriatal injections of vehicle or 6-hydroxydopamine (6-OHDA). Ten days later, the animals were exposed to hypercapnia or hypoxia to activate PPTg neurons. Vglut₂-cre Ai6 animals also received retrograde tracer injections (cholera toxin b) into the retrotrapezoid nucleus (RTN) or preBötzinger Complex (preBötC) and anterograde tracer injections (AAV-mCherry) into the SNpc. In 6-OHDA-injected mice, there is a 77% reduction in the number of dopaminergic neurons in SNpc without changing the number of neurons in the PPTg. Hypercapnia activated fewer Vglut₂ neurons in PD, and hypoxia did not activate PPTg neurons. PPTg neurons do not input RTN or preBötC regions but receive projections from SNpc. Although our results did not show a reduction in the number of glutamatergic neurons in PPTg, we observed a reduction in the number of neurons activated by hypercapnia in the PD animal model, suggesting that PPTg may participate in the hypercapnia ventilatory response.

Effects of an incentive spirometer versus a threshold inspiratory muscle trainer on lung functions in Parkinson's disease patients: a randomized trial

Upper airway obstruction, reduced maximal expiratory and inspiratory flows, reduced lung volumes, abnormal ventilatory control, and diaphragmatic dyskinesias are reported in patients with Parkinson's disease (PD). Inspiratory muscle training (IMT) has been reported to be effective in improving respiratory functions; however, no studies have compared the effects of the incentive spirometer (IS) with the threshold inspiratory muscle trainer (TIMT) in patients with PD. The study aimed to compare the effects of IS and TIMT on maximum inspiratory pressure (MIP), 6-min walk distance (6-MWD), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow rate (PEFR) in patients with stage 1-3 according to the Hoehn and Yahr scale. 18 patients were randomly assigned to two groups, i.e., incentive spirometer (IS) and threshold inspiratory muscle trainer (TIMT) group. The IS group received IMT with volume-based IS, and the TIMT group received IMT with TIMT. MIP, 6-MWD, FVC, FEV1, and PEFR were measured before and after six weeks of training. In IS group: A significant increase (p < 0.05) was observed in MIP and 6-MWD by 18.13 and 5%, respectively. In the TIMT group: A significant increase (p < 0.05) was observed in MIP and 6-MWD by 30.15 and 8.94%, respectively. Both groups observed no significant difference (p > 0.05) in FVC, FEV1, and PEFR. When the two groups were compared, a greater increase (p < 0.05) was observed in the MIP and 6-MWD in the TIMT group compared to IS group. IMT with IS or TIMT for six weeks effectively increased MIP and 6-MWD in patients with stage 1-3 (Hoehn and Yahr scale) of PD. No improvement was observed in FVC, FEV1, or PEFR with any of the techniques. TIMT is more effective than IS in improving MIP and 6-MWD.

Respiratory-Swallow Coordination in Individuals with Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Swallowing impairment, including altered physiology and aspiration, occur across the progression of Parkinson's disease (PD). The phase of respiration during which a swallow is initiated has been linked to swallowing impairment and aspiration in cohorts with dysphagia following stroke and head and neck cancer treatment, but has been understudied in PD. If similar findings are shown in individuals with PD, the implications for swallowing assessment and treatment are significant.

OBJECTIVE

The aim of this systematic review and meta-analysis of literature was to examine respiratory-swallow coordination measures and potential implications on swallowing physiology in individuals with PD.

METHODS

An extensive search of 7 databases (PubMed, EMBASE, Central, Web of Science, ProQuest Dissertations & Theses, Scopus, and CINAHL) with predetermined search terms was conducted. Inclusion criteria were individuals with PD and the use of objective evaluations of respiratory-swallow coordination.

RESULTS

Of the 13,760 articles identified, 11 met the inclusion criteria. This review supports the presence of atypical respiratory swallow patterning, respiratory pause duration and lung volume at swallow initiation in individuals with PD. The meta-analysis estimated an occurrence of 60% of non-expiration-expiration and 40% of expiration-expiration respiratory phase patterns surrounding swallowing.

CONCLUSION

Although this systematic review supports the occurrence of atypical respiratory-swallow coordination in individuals with PD, the evidence is limited by the variability in the methods of data acquisition, analysis, and reporting. Future research examining the impact of respiratory swallow coordination on swallowing impairment and airway protection using consistent, comparable, and reproducible methods and metrics in individuals with PD is warranted.

Pulmonary function and medication effect in mild-stage subjects with Parkinson's disease

BACKGROUND

Parkinson's disease (PD) causes a series of movement disorders, many of them starting in the early stage.

OBJECTIVE

To analyze the pulmonary function of mild-stage subjects with PD and to investigate the effects of levodopa on it.

METHODS

We included 21 patients with idiopathic PD and 20 healthy control subjects. The participants were submitted to spirometry and impulse oscillometry assessments. The PD patients were evaluated during the "off" and "on" phases of their anti-PD medication, which was was converted to levodopa in an equivalent daily dose. A statistical analysis was performed with cross-sectional (PD patients "off" medication versus controls) and paired (PD patients "off" medication versus PD patients "on" medication) tests. The effect of levodopa was calculated with partial Eta-squared (η² _ρ). Significance was set at 5%.

RESULTS

The PD patients presented normal values in the impulse oscillometry. Regarding spirometry, the results indicated an incipient obstructive ventilatory disorder in the PD group - confirmed by patients' flow-volume curves. The PD patients received a daily dose of 354.7 ± 148.2 mg of levodopa. The paired analyses showed a small effect of anti-PD medication on pulmonary parameters (η² _ρ= 0.197 for spirometry and η² _ρ= 0.043 for impulse oscillometry).

CONCLUSION

Patients with PD in the mild stage of the disease present pulmonary compliance and resistance compatible with normal parameters. The differences regarding the spirometric results indicate an incipient obstructive ventilatory disorder in patients with PD. Levodopa had small effect on pulmonary function in the mild stage of the disease.

After-effects of thixotropic conditionings on operational chest wall and compartmental volumes of patients with Parkinson's disease

Individuals with Parkinson's disease (PD) present respiratory dysfunctions, mainly due to decreased chest wall expansion, which worsens with the course of the disease. These findings contribute to the restrictive respiratory pattern and the reduction in chest wall volume. According to literature, inspiratory muscle thixotropic conditioning maneuvers may improve lung volumes in these patients. The study aimed to determine the after-effects of respiratory muscle thixotropic maneuvers on breathing patterns and chest wall volumes of PD. A crossover study was performed with twelve patients with PD (8 males; mean age 63.9±8.8 years, FVC%pred 89.7±13.9, FEV1%pred 91.2±15, FEV1/FVC%pred 83.7±5.7). Chest wall volumes were assessed using OEP during thixotropic maneuvers. Increases in EIVCW (mean of 126mL, p = 0.01) and EEVCW (mean of 150mL, p = 0.005) were observed after DITLC (deep inspiration from total lung capacity) due to increases in pulmonary (RCp) and abdominal (RCa) ribcage compartments. Changes in ICoTLC (inspiratory contraction from TLC) led to significant EIVCW (mean of 224mL, p = 0.001) and EEVCW (mean of 229mL, p = 0.02) increases that were mainly observed in the RCp. No significant changes were found when performing DERV (deep expiration from residual volume) and ICoRV (Inspiratory contraction from RV). Positive correlations were also observed between the degree of inspiratory contraction during ICoTLC and EEVRCp (rho = 0.613, p = 0.03) and EIVRCp (rho = 0.697, p = 0.01) changes. Thixotropy conditioning of inspiratory muscles at an inflated chest wall volume increases EIVCW and EEVCW in the ten subsequent breaths in PD patients. These maneuvers are easy to perform, free of equipment, low-cost, and may help patients improve chest wall volumes during rehabilitation.

Artificial intelligence-enabled detection and assessment of Parkinson's disease using nocturnal breathing signals

There are currently no effective biomarkers for diagnosing Parkinson's disease (PD) or tracking its progression. Here, we developed an artificial intelligence (AI) model to detect PD and track its progression from nocturnal breathing signals. The model was evaluated on a large dataset comprising 7,671 individuals, using data from several hospitals in the United States, as well as multiple public datasets. The AI model can detect PD with an area-under-the-curve of 0.90 and 0.85 on held-out and external test sets, respectively. The AI model can also estimate PD severity and progression in accordance with the Movement Disorder Society Unified Parkinson's Disease Rating Scale (R = 0.94, P = 3.6 × 10-25). The AI model uses an attention layer that allows for interpreting its predictions with respect to sleep and electroencephalogram. Moreover, the model can assess PD in the home setting in a touchless manner, by extracting breathing from radio waves that bounce off a person's body during sleep. Our study demonstrates the feasibility of objective, noninvasive, at-home assessment of PD, and also provides initial evidence that this AI model may be useful for risk assessment before clinical diagnosis.

Effects of an Aquatic Physical Exercise Program on Ventilatory Parameters in People with Parkinson’s Disease

Problems in the respiratory system are the main cause of death in Parkinson’s disease (PD). Ventilatory limitations can also be part of a vicious cycle involving physical-functional limitations (e.g., walking difficulties) and the patients’ perception of fatigue. The objective of this study was to analyze the effects of an aquatic physical exercise intervention program on ventilatory parameters, perception of fatigue, and gait capacity in participants with PD. This quasi-experimental study had a single group with repeated measures in four assessments, proposing an aquatic physical exercise intervention program. The inclusion criteria encompassed being in levels 1 to 4 on the Hoehn and Yahr scale and having a medical certificate for the activities. Assessments took place at 3-month intervals between them—the first period was the control, the second following the intervention, and the third period was the follow-up. The intervention had 25 biweekly sessions over 3 months. A total of 13 people (71.3 ± 5.61 years old) participated in the intervention, without significant differences in the control period. Between the intervention assessments, they had statistically significant differences in MIP, MEP, FVC, Tiffeneau index, MVV, and fatigue. The study demonstrated that the aquatic physical exercise intervention was effective for ventilatory outcomes and fatigue in people with PD.

COVID-19 and Parkinson's Disease: Possible Links in Pathology and Therapeutics

The outbreak of SARs-CoV-2 with emerging new variants is leading to global health crisis and has brought a major concern for patients with comorbidities. Parkinson's disease (PD) is a motor neurodegenerative disease involving various metabolic and psychological ailments along with the common occurrence of hyposmia as observed in COVID-19 patients. In addition, the observed surplus inflammatory responses in both diseases are also alarming. Alongside, angiotensin-converting enzyme 2 (ACE2) receptor, essentially required by SARS-CoV-2 to enter the cell and dopamine decarboxylase (DDC), required for dopamine synthesis is known to co-regulate in the non-neuronal cells. Taken together, these conditions suggested the probable reciprocal pathological relation between COVID-19 and PD and also suggested that during comorbidities, the disease diagnosis and therapeutics are critical and may engender severe health complications. In this review, we discuss various events and mechanisms which may have implications for the exacerbation of PD conditions and must be taken into account during the treatment of patients.

Respiratory Abnormalities in Parkinson's Disease: What Do We Know from Studies in Humans and Animal Models?

Parkinson’s disease (PD) is the second most common progressive neurodegenerative disease characterized by movement disorders due to the progressive loss of dopaminergic neurons in the ventrolateral region of the substantia nigra pars compacta (SNpc). Apart from the cardinal motor symptoms such as rigidity and bradykinesia, non-motor symptoms including those associated with respiratory dysfunction are of increasing interest. Not only can they impair the patients’ quality of life but they also can cause aspiration pneumonia, which is the leading cause of death among PD patients. This narrative review attempts to summarize the existing literature on respiratory impairments reported in human studies, as well as what is newly known from studies in animal models of the disease. Discussed are not only respiratory muscle dysfunction, apnea, and dyspnea, but also altered central respiratory control, responses to hypercapnia and hypoxia, and how they are affected by the pharmacological treatment of PD.

Effects of Bolus Holding on Respiratory-Swallow Coordination in Parkinson's Disease

PURPOSE

The aim of this study was to examine the effects of bolus holding on respiratory-swallow coordination (RSC) in people with Parkinson's disease (PD).

METHOD

People with PD were prospectively recruited to undergo RSC assessment using simultaneous respiratory inductive plethysmography and flexible laryngoscopy. During RSC assessment, participants swallowed 5-ml thin liquid boluses during held and nonheld swallowing tasks. Measures of RSC were analyzed for each swallow, which included respiratory pause duration, lung volume at swallow initiation, respiratory phase patterning, and the presence of paradoxical respiratory movements. Multilevel statistical modeling was used to determine if differences in RSC were present between the held and nonheld tasks.

RESULTS

Thirty-three participants were enrolled. When compared to the nonheld swallows, the held swallows exhibited shorter respiratory pauses (p = .001, R ² = .019), lower lung volumes at swallow initiation (p < .001, R ² = .116), more frequent exhale-swallow-exhale patterns (p < .001, OR = 4.30), and less frequent paradoxical respiratory movements (p = .001, OR = 0.43).

CONCLUSIONS

Findings from this study revealed that bolus holding significantly influences RSC in people with PD. This demonstrates that bolus holding may be an efficacious strategy to immediately improve RSC in PD. However, clinicians and researchers should consider avoiding bolus holding during swallowing evaluations if attempting to assess RSC behaviors that are most typical for the examinee.

Respiratory disorders of Parkinson's disease

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra, mainly affecting people over 60 yr of age. Patients develop both classic symptoms (tremors, muscle rigidity, bradykinesia, and postural instability) and nonclassical symptoms (orthostatic hypotension, neuropsychiatric deficiency, sleep disturbances, and respiratory disorders). Thus, patients with PD can have a significantly impaired quality of life, especially when they do not have multimodality therapeutic follow-up. The respiratory alterations associated with this syndrome are the main cause of mortality in PD. They can be classified as peripheral when caused by disorders of the upper airways or muscles involved in breathing and as central when triggered by functional deficits of important neurons located in the brainstem involved in respiratory control. Currently, there is little research describing these disorders, and therefore, there is no well-established knowledge about the subject, making the treatment of patients with respiratory symptoms difficult. In this review, the history of the pathology and data about the respiratory changes in PD obtained thus far will be addressed.

[Respiratory dysfunction in Parkinson's disease]

For a long time it was believed that respiratory disorders (RD) in Parkinson's disease (PD) are rare. However, the situation has changed dramatically over the past 10 years. Thus, special studies have revealed RD in almost half of patients with PD. The paper presents: a literature review, classification of RD in PD, various mechanisms of their development and general approaches to their treatment. Classification of RD in PD is presented.

Changes to Ventilation, Vocalization, and Thermal Nociception in the Pink1-/- Rat Model of Parkinson's Disease

BACKGROUND

Individuals with Parkinson's disease (PD) experience significant vocal communication deficits. Findings in the Pink1-/- rat model of early-onset PD suggest that ultrasonic vocal communication is impaired early, progressively worsens prior to nigrostriatal dopamine depletion, and is associated with loss of locus coeruleus neurons, brainstem α-synuclein, and larynx pathology. Individuals with PD also demonstrate ventilatory deficits and altered sensory processing, which may contribute to vocal deficits.

OBJECTIVE

The central hypothesis is that ventilatory and sensory deficits are present in the early disease stages when limb and vocal motor deficits also present.

METHODS

Pink1-/- rats were compared to wildtype (WT) controls at longitudinal timepoints. Whole-body flow through plethysmography was used to measure ventilation in the following conditions: baseline, hypoxia, and maximal chemoreceptor stimulation. Plantar thermal nociception, and as a follow up to previous work, limb gait and vocalization were analyzed. Serotonin density (5-HT) in the dorsal raphe was quantified post-mortem.

RESULTS

Baseline breathing frequencies were consistently higher in Pink1-/- rats at all time points. In hypoxic conditions, there were no significant changes between genotypes. With hypercapnia, Pink1-/- rats had decreased breathing frequencies with age. Thermal withdrawal latencies were significantly faster in Pink1-/- compared with WT rats across time. No differences in 5-HT were found between genotypes. Vocal peak frequency was negatively correlated to tidal volume and minute ventilation in Pink1-/- rats.

CONCLUSION

This work suggests that abnormal nociceptive responses in Pink1-/- rats and ventilatory abnormalities may be associated with abnormal sensorimotor processing to chemosensory stimuli during disease manifestation.

Genetic polymorphisms are associated with alterations in anxiety levels and vital signs in patients undergoing third molar extractions

OBJECTIVE

The objective of this study was to evaluate the association between SLC6A4 (rs1042173 and rs3813034), DRD2 (rs6275 and rs6276), ANKK1 (rs1800497), and COMT (rs174675) genetic polymorphisms and alterations in anxiety levels and vital signs in individuals undergoing third molar extractions.

STUDY DESIGN

One hundred sixty-eight individuals were evaluated at the pre-, trans-, and postoperative periods by checking systolic blood pressure, diastolic blood pressure, heart rate, respiratory rate, and body temperature. Anxiety levels were assessed using the State-Trait Anxiety Inventory (STAI). Buccal mucosa cells were collected for genetic evaluation using real-time polymerase chain reaction. Statistical analysis was performed at a significance level of 5%.

RESULTS

The level of anxiety was associated with rs1800497 for STAI-Trait (P = .031) and rs174675 for STAI-State (P = .007). Considering the vital signs, there was a significant difference between the values of respiratory rate and rs1042173 (P = .029), rs3813034 (P = .024), and rs6275 (P = .025). The diastolic blood pressure values differed significantly for rs1042173 (P = .042), and the body temperature values differed significantly for rs174675 (P = .016).

CONCLUSIONS

Polymorphisms in SLC6A4, DRD2, ANKK1, and COMT genes could be associated with alterations in anxiety levels and vital signs in individuals undergoing third molar extractions.

Na+ leak-current channel (NALCN) at the junction of motor and neuropsychiatric symptoms in Parkinson's disease

Parkinson's disease (PD) is a debilitating movement disorder often accompanied by neuropsychiatric symptoms that stem from the loss of dopaminergic function in the basal ganglia and altered neurotransmission more generally. Akinesia, postural instability, tremors and frozen gait constitute the major motor disturbances, whereas neuropsychiatric symptoms include altered circadian rhythms, disordered sleep, depression, psychosis and cognitive impairment. Evidence is emerging that the motor and neuropsychiatric symptoms may share etiologic factors. Calcium/ion channels (CACNA1C, NALCN), synaptic proteins (SYNJ1) and neuronal RNA-binding proteins (RBFOX1) are among the risk genes that are common to PD and various psychiatric disorders. The Na⁺ leak-current channel (NALCN) is the focus of this review because it has been implicated in dystonia, regulation of movement, cognitive impairment, sleep and circadian rhythms. It regulates the resting membrane potential in neurons, mediates pace-making activity, participates in synaptic vesicle recycling and is functionally co-localized to the endoplasmic reticulum (ER)-several of the major processes adversely affected in PD. Here, we summarize the literature on mechanisms and pathways that connect the motor and neuropsychiatric symptoms of PD with a focus on recurring relationships to the NALCN. It is hoped that the various connections outlined here will stimulate further discussion, suggest additional areas for exploration and ultimately inspire novel treatment strategies.

A machine learning perspective on the emotional content of Parkinsonian speech

Patients with Parkinson's disease (PD) have distinctive voice patterns, often perceived as expressing sad emotion. While this characteristic of Parkinsonian speech has been supported through the perspective of listeners, where both PD and healthy control (HC) subjects repeat the same speaking tasks, it has never been explored through a machine learning modelling approach. Our work provides an objective evaluation of this characteristic of the PD speech, by building a transfer learning system to assess how the PD pathology affects the sadness perception. To do so we introduce a Mixture-of-Experts (MoE) architecture for speech emotion recognition designed to be transferable across datasets. Firstly, by relying on publicly available emotional speech corpora, we train the MoE model and then we use it to quantify perceived sadness in never seen before PD and matched HC speech recordings. To build our models (experts), we extracted spectral features of the voicing parts of speech and we trained a gradient boosting decision trees model in each corpus to predict happiness vs. sadness. MoE predictions are created by weighting each expert's prediction according to the distance between the new sample and the expert-specific training samples. The MoE approach systematically infers more negative emotional characteristics in PD speech than in HC. Crucially, these judgments are related to the disease severity and the severity of speech impairment in the PD patients: the more impairment, the more likely the speech is to be judged as sad. Our findings pave the way towards a better understanding of the characteristics of PD speech and show how publicly available datasets can be used to train models that provide interesting insights on clinical data.

Vigorous Aerobic Exercise in the Management of Parkinson Disease: A Systematic Review

OBJECTIVE

To summarize the findings from studies examining the effects of vigorous-intensity aerobic exercise in the management of Parkinson disease. TYPE: Systematic review.

LITERATURE SURVEY

PubMed/MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library, SPORTDiscus, and ScienceDirect databases were searched up to May 2020. Reference lists of the included articles were also searched for additional studies. Searches were restricted to English language.

METHODOLOGY

Seven papers, including six studies, five randomized controlled trials and one controlled trial, were identified. The studies examined the effects of vigorous-intensity aerobic exercise in participants with Parkinson disease. Studies in which the minimal intensity required was ≥77% of maximum heart rate, 60% of heart rate reserve or 64% of maximal oxygen uptake met the inclusion criteria. Method appraisal showed a mean score of 5.3 in the Physiotherapy Evidence Database (PEDro) scale.

SYNTHESIS

No statistically significant differences were found between vigorous-intensity aerobic exercise and moderate/low-intensity aerobic exercise for the main outcomes (disease severity and motor function). Only one study concluded a significant higher aerobic fitness in favor of the group that exercised at vigorous intensity compared to the moderate intensity group.

CONCLUSIONS

Vigorous-intensity aerobic exercise has not shown statistically significant improvements in motor and nonmotor impairments in individuals with Parkinson disease as compared to moderate/low-intensity aerobic exercise. Hence, the current evidence is too limited to allow recommendations for clinical practice.

Speaking dyspnea in Parkinson's disease: Preliminary findings

PURPOSE

To determine if people with Parkinson's disease (PD) experience dyspnea (breathing discomfort) during speaking.

METHOD

The participants were 11 adults with PD and 22 healthy adults (11 young, 11 old). Participants were asked to recall experiences of breathing discomfort across different speaking contexts and provide ratings of those experiences (Retrospective ratings); then they rated the breathing discomfort experienced while performing speaking tasks that were designed to differ in respiratory demands (immediate Post-Speaking ratings).

RESULTS

Participants with PD reported experiencing breathing discomfort during speaking significantly more frequently (approximately 60 % of the time) than did healthy participants (less than 20 % of the time). Retrospective ratings did not differ significantly from Post-Speaking ratings. Breathing discomfort was experienced by the fewest number of participants with PD for Conversation (two) and Extemporaneous Speaking (three) and by the greatest number for Extended Reading (ten) and Long Counting (nine), although the magnitude of the ratings generally reflected only "Slight" discomfort. Breathing discomfort was most frequently described as air hunger and breathing work, less frequently as mental effort, and very rarely as lung tightness. A few participants with PD reported experiencing emotions associated with their breathing discomfort and most reported using strategies to avoid breathing discomfort in their daily lives.

CONCLUSIONS

Individuals with PD are more apt to experience speaking dyspnea than healthy individuals, especially when speaking for extended periods or when using long breath groups. Such dyspnea may contribute to a tendency to avoid speaking situations and thereby impair quality of life.

The Effects of Respiratory Training in Parkinson's Disease: A Systematic Review

BACKGROUND

Signs of respiratory dysfunction can be present already early in the course of Parkinson's disease (PD). Respiratory training could alleviate this, but its effectiveness is not well understood.

OBJECTIVE

The purpose of this systematic review is to review the efficacy of different respiratory training interventions in PD.

METHODS

A search strategy was performed in four databases: PubMed, Physiotherapy Evidence Database (PEDro), Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). Methodological quality of original full-text articles was assessed using the Cochrane Risk of Bias tool for randomized controlled trials (RCTs) and the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool for the controlled trials (CTs). Levels of evidence were rated by the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Six papers reporting on four randomized controlled trials and another four controlled trials were included. Positive effects were reported for inspiratory muscle strength training (IMST), expiratory muscle strength training (EMST), air stacking, breath-stacking, incentive spirometry and postural training on respiratory muscle strength, swallowing safety, phonatory aspects and chest wall volumes. Best methodological quality was found for breath-stacking and incentive spirometry. Best levels of evidence were found for EMST, IMST and EMST plus air stacking.

CONCLUSION

Respiratory training shows positive effects and should be considered when people with PD experience respiratory dysfunction. Future studies should focus on standardizing both training devices, instruments to measure outcomes and intervention protocols to further increase the level of evidence.

COVID-19 and possible links with Parkinson's disease and parkinsonism: from bench to bedside

This Viewpoint discusses insights from basic science and clinical perspectives on coronavirus disease 2019 (COVID-19)/severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection in the brain, with a particular focus on Parkinson's disease. Major points include that neuropathology studies have not answered the central issue of whether the virus enters central nervous system neurons, astrocytes or microglia, and the brain vascular cell types that express virus have not yet been identified. Currently, there is no clear evidence for human neuronal or astrocyte expression of angiotensin-converting enzyme 2 (ACE2), the major receptor for viral entry, but ACE2 expression may be activated by inflammation, and a comparison of healthy and infected brains is important. In contrast to the 1918 influenza pandemic and avian flu, reports of encephalopathy in COVID-19 have been slow to emerge, and there are so far no documented reports of parkinsonism apart from a single case report. We recommend consensus guidelines for the clinical treatment of Parkinson's patients with COVID-19. While a role for the virus in causing or exacerbating Parkinson's disease appears unlikely at this time, aggravation of specific motor and non-motor symptoms has been reported, and it will be important to monitor subjects after recovery, particularly for those with persisting hyposmia.

Upper airway obstruction during extubation after general anesthesia, in a patient with Parkinson disease: A case report

RATIONALE

Parkinson disease (PD) is a chronic neurodegenerative condition often suffered by the elderly. Upper airway obstruction, though rare in patients with PD, can be life threatening and is associated with vocal cord paralysis, laryngeal spasm, and dystonia of jaw and neck muscles.

PATIENT CONCERNS

We describe a life-threatening upper airway obstruction caused by bilateral vocal cord paralysis, in an elderly man with PD, during extubation after general anesthesia.

DIAGNOSES

Based on clinical presentation and visual laryngoscopy, the patient was diagnosed with laryngeal spasm and bilateral vocal cord paralysis after extubation.

INTERVENTIONS

Re-intubation was carried out and dopamine hydrazine tablets were administered via a nasal feeding tube.

OUTCOMES

After re-intubation and further treatment, the endotracheal tube was successfully removed and no symptoms of respiratory distress were observed.

LESSONS

Patients with PD may be at a risk of life-threatening upper airway obstruction after extubation, which should be prevented systematically.

Dyspnea in Parkinson's disease: an approach to diagnosis and management

INTRODUCTION

Dyspnea is a complex and debilitating non-motor symptom experienced by a significant proportion of PD patients which results in limitations to physical ability and a reduction in quality of life.

AREAS COVERED

The authors highlight the underlying pathophysiological mechanisms that can contribute to dyspnea in PD patients, and provide the clinician with a practical working algorithm for the management of such patients. The authors further highlight important clinical red flags that should be heeded in dyspneic PD patients and discuss therapeutic strategies for managing dyspnea.

EXPERT OPINION

Although awareness of dyspnea in PD is increasing, further studies of its prevalence and natural history at different stages of the disease are needed. In particular, it is important to determine whether dyspnea could be an early or prodromal disease manifestation. Although peripheral mechanisms are likely to play a major role in the pathophysiology of dyspnea, the possibility that central changes in brainstem ventilatory control may also play a part warrants further investigation.

Parkinson's disease and patient related outcomes in stroke: A matched cohort study

OBJECTIVE

To evaluate post-stroke outcomes in patients with Parkinson's disease (PD).

METHODS

A matched cohort study was performed. Stroke patients with PD and non-PD controls were extracted from the Thailand Universal Insurance Database. Logistic regressions were used to evaluate the association between PD and in-hospital outcomes (mortality and complications). The PD-associated long-term mortality was evaluated using Royston-Parmar models.

RESULTS

A total of 1967 patients with PD were identified between 2003 and 2015 and matched to controls (1:4) by age, sex, admission year, and stroke type. PD patients had decreased odds of in-hospital death: OR (95% CI) 0.66 (0.52 - 0.84) and 0.61 (0.43 - 0.85) after ischaemic and haemorrhagic strokes, respectively. PD was associated with a length-of-stay greater than median (4 days) after both stroke types: 1.37 (1.21 - 1.56) and 1.45 (1.05 - 2.00), respectively. Ischaemic stroke patients with PD also had increased odds of developing pneumonia, sepsis and AKI: 1.52 (1.2 - 1.83), 1.54 (1.16 - 2.05), and 1.33 (1.02 - 1.73). In haemorrhagic stroke patients, PD was associated with pneumonia: 1.89 (1.31 - 2.72). Survival analyses showed that PD was protective against death in the short term (HR=0.66; 95% CI 0.53-0.83 ischaemic, and HR=0.50; 95% CI 0.37 - 0.68 haemorrhagic stroke), but leads to an increased mortality risk approximately 1 and 3 months after ischaemic and haemorrhagic stroke, respectively.

CONCLUSION

PD is associated with a reduced mortality risk during the first 2-4 weeks post-admission but an increased risk thereafter, in addition to increased odds of in-hospital complications and prolonged hospitalisation.

Respiratory Function and Dysfunction in Parkinson-Type Neurodegeneration

Parkinson's disease (PD) is most commonly manifested by the presence of motor symptoms. However, non-motor symptoms occur several years before the onset of motor symptoms themselves. Hallmarks of dysfunction of the respiratory system are still outside the main focus of interest, whether by clinicians or scientists, despite their indisputable contribution to the morbidity and mortality of patients suffering from PD. In addition, many of the respiratory symptoms are already present in the early stages of the disease and efforts to utilize these parameters in the early diagnosis of PD are now intensifying. Mechanisms that lead to the development and progression of respiratory symptoms are only partially understood. This review focuses mainly on the comparison of respiratory problems observed in clinical studies with available findings obtained from experimental animal models. It also explains pathological changes observed in non-neuronal tissues in subjects with PD.

Practical approach to respiratory emergencies in neurological diseases

Many neurological diseases may cause acute respiratory failure (ARF) due to involvement of bulbar respiratory center, spinal cord, motoneurons, peripheral nerves, neuromuscular junction, or skeletal muscles. In this context, respiratory emergencies are often a challenge at home, in a neurology ward, or even in an intensive care unit, influencing morbidity and mortality. More commonly, patients develop primarily ventilatory impairment causing hypercapnia. Moreover, inadequate bulbar and expiratory muscle function may cause retained secretions, frequently complicated by pneumonia, atelectasis, and, ultimately, hypoxemic ARF. On the basis of the clinical onset, two main categories of ARF can be identified: (i) acute exacerbation of chronic respiratory failure, which is common in slowly progressive neurological diseases, such as movement disorders and most neuromuscular diseases, and (ii) sudden-onset respiratory failure which may develop in rapidly progressive neurological disorders including stroke, convulsive status epilepticus, traumatic brain injury, spinal cord injury, phrenic neuropathy, myasthenia gravis, and Guillain-Barré syndrome. A tailored assistance may include manual and mechanical cough assistance, noninvasive ventilation, endotracheal intubation, invasive mechanical ventilation, or tracheotomy. This review provides practical recommendations for prevention, recognition, management, and treatment of respiratory emergencies in neurological diseases, mostly in teenagers and adults, according to type and severity of baseline disease.

Assessment of ventilatory function in patients with spinocerebellar ataxia type 2

BACKGROUND

Subclinical ventilatory dysfunction is observed in individuals with spinocerebellar ataxias (SCA). No studies have correlated ventilatory dysfunction to clinical and functional decline in SCA2.

OBJECTIVE

To evaluate the relationship between the values of peak expiratory flow (PEF), maximum inspiratory pressure (MIP), and presence of respiratory complaints with age, disease duration, age at onset of symptoms, balance scores, independence in basic (ADL) and instrumental (IADL) Activities of Daily Living (ADLs), and severity of ataxia (SARA) in individuals with SCA2.

METHODS

Cross-sectional study evaluating age, disease duration, age at onset of symptoms, scores in the Berg Balance Scale and in the SARA, Functional Independence Measure and Lawton's scale, values of PEF and MIP, and the presence of respiratory complaints.

RESULTS

The study included 36 individuals with SCA2, with a mean age of 42.5±2.4 years, disease duration of 7.6±8.2 years, age 33.7±11.5 years at onset of symptoms, and 9.9±10.3 points in the SARA scale. The lowest PEF values correlated with the longer disease duration (p=0.021). The lowest values of PEF and MIP correlated with greater balance impairment (p=0.019 and p=0.045, respectively), increased degree of dependence in the ADL (p=0.006 and p=0.050, respectively) and IADL (p=0.003 and p=0.001, respectively) scales, and highest severity of ataxia (p=0.00 and p=0.017, respectively). Respiratory complaints were observed in 12 (33.3%) individuals and were not related to age, disease duration, age at onset of symptoms, balance, independence, ataxia severity, or PEF and MIP values.

CONCLUSION

Ventilatory dysfunction, even when asymptomatic, is related to balance impairment, independence, and ataxia severity in individuals with SCA2.

Voice changes in Parkinson's disease: What are they telling us?

Emerging evidence suggests voice dysfunction is the earliest sign of motor impairment in Parkinson's disease (PD). The complexity and fine motor control involved in vocalization may result in dysfunction here before the limbs. The voice in PD demonstrates characteristic changes on perceptual and acoustic analyses. The physiological and anatomical correlates of these have been investigated through laryngoscopy, stroboscopy, photoglottography, laryngeal electromyography, computed-tomography, pulmonary function testing and aerodynamic assessments. These have revealed numerous abnormalities including incomplete glottic closure and vocal fold hypoadduction/bowing to account for these voice changes. Many of these phenomena are likely related to rigidity or bradykinesia of the laryngeal muscles. The early onset of voice changes is resonant with the pathophysiological insights offered by Braak's hypothesis and murine models of the disease. These physiological abnormalities and pathological models largely stand to support dopaminergic and non-dopaminergic mechanisms being implicated in the pathogenesis of voice dysfunction. This review focuses on characterizing the voice changes in PD. These stand as a promising area of enquiry to further our understanding of the pathophysiology of the disease and offer potential to be utilized as an early diagnostic biomarker or marker of disease progression.

Bilateral vocal cord paralysis during emergence from general anesthesia in a patient with Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that affects the extrapyramidal system, and respiratory dysfunction has also been noted in patients with PD. However, acute upper airway obstruction due to bilateral vocal cord paralysis is a very rare finding in PD. Here, we describe a rare life-threatening respiratory failure caused by bilateral vocal cord paralysis in an elderly woman with PD during emergence from general anesthesia. The tracheostomy was performed on the postoperative period because the condition persisted. The general anesthesia in PD may have aggravated vocal cord impairment. We recommend when a patient with PD is scheduled for general anesthesia that the anesthesiologist performs careful preoperative examinations, strictly monitors respiratory function, and rapidly manages acute upper airway obstruction.

Should respiratory muscle training be part of the treatment of Parkinson’s disease? A systematic review of randomized controlled trials

Objective:

To determine the effectiveness of respiratory muscle training in persons with Parkinson’s disease.

Data sources:

PubMed/MEDLINE, EMBASE, Web of Science, Scopus and PEDro electronic databases were searched until 15 November 2019. Reference lists of included studies were hand-searched.

Methods:

Randomized controlled trials assessing the effects of respiratory muscle training programmes (both inspiratory and expiratory) in patients with Parkinson’s disease were included. Two reviewers independently identified eligible studies and extracted data. Method quality was appraised with the PEDro scale.

Results:

Five papers including three randomized controlled trials with a total of 111 patients were identified. Method appraisal showed a mean score of 5 in the PEDro scale. One study analysed inspiratory muscle training, one expiratory muscle training and two established a comparison between both of them. Statistically positive results were found in maximal inspiratory pressure ( P < 0.05 and d = 0.76), maximal expiratory pressure ( P < 0.01 and d = 1.40), perception of dyspnoea ( P < 0.01), swallowing function ( d = 0.55) and phonatory measures, without significant differences in spirometric indices.

Conclusions:

Respiratory muscle training may be an effective alternative for improving respiratory muscle strength, swallowing function and phonatory parameters in subjects with Parkinson’s disease. Nevertheless, the lack of primary studies about this type of training prevents obtaining robust evidence.

Dysregulation of Respiratory Center Drive (P0.1) and Muscle Strength in Patients With Early Stage Idiopathic Parkinson's Disease

Objective: The goal of this study is to evaluate pulmonary function and respiratory center drive in patients with early-stage idiopathic Parkinson's disease (IPD) to facilitate early diagnosis of Parkinson's Disease (PD).

Methods: 43 IPD patients (Hoehn and Yahr scale of 1) and 41 matched healthy individuals (e.g., age, sex, height, weight, BMI) were enrolled in this study. Motor status was evaluated using the Movement Disorders Society-Unified PD Rating Scale (MDS-UPDRS). Pulmonary function and respiratory center drive were measured using pulmonary function tests (PFT). All IPD patients were also subjected to a series of neuropsychological tests, including Non-Motor Symptoms Questionnaire (NMSQ), REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), Beck Depression Inventory (BDI) and Mini Mental State Examination (MMSE).

Results: IPD patients and healthy individuals have similar forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), forced expiratory volume in 1s/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and carbon monoxide diffusion capacity (DLCOcSB). Reduced respiratory muscle strength, maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) was seen in IPD patients (p = 0.000 and p = 0.002, respectively). Importantly, the airway occlusion pressure after 0.1 s (P0.1) and respiratory center output were notably higher in IPD patients (p = 0.000) with a remarkable separation of measured values compared to healthy controls.

Conclusion: Our findings suggest that abnormal pulmonary function is present in early stage IPD patients as evidenced by significant changes in PImax, PEmax, and P0.1. Most importantly, P0.1 may have the potential to assist with the identification of IPD in the early stage.

Aquatic exercise improves motor impairments in people with Parkinson's disease, with similar or greater benefits than land-based exercise: a systematic review

QUESTIONS

What are the effects of aquatic exercise on disease severity, (non-)motor impairments, activity performance, fear of falling, and quality of life in people with Parkinson's disease (PD)? Does aquatic exercise have greater effects on these outcomes than other forms of exercise in people with PD?

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

PARTICIPANTS

People with idiopathic PD.

INTERVENTION

Supervised aquatic exercise programs ≥ 2 weeks.

OUTCOMES MEASURES

The primary outcomes were disease severity, motor impairments, activity performance, and fear of falling. The secondary outcomes were non-motor impairments and quality of life.

RESULTS

Of the 129 identified records, seven trials met the inclusion criteria and six were meta-analysed (159 participants). One trial assessed the effect of aquatic exercise compared with control and found a significant improvement in the Unified Parkinson's Disease Rating Scale Part III (MD -4.6, 95% CI -7.5 to -1.7) in favour of aquatic exercise. Six studies compared aquatic exercise with land-based exercise after intervention (mean 7.2 weeks of training (SD 2.2); 159 participants). The effect of aquatic exercise was superior to land-based exercise on the Berg Balance Scale (MD 2.7, 95% CI 1.6 to 3.9), the Falls Efficacy Scale (MD -4.0, 95% CI -6.1 to -1.8) and the 39-item Parkinson's Disease Questionnaire (MD -6.0, 95% CI -11.3 to -0.6), with no other significant effects identified. The significant benefit on the Berg Balance Scale was maintained at the follow-up assessment (MD 6.3, 95% CI 2.1 to 10.5, 54 participants).

CONCLUSION

Aquatic exercise improves motor impairments in people with PD significantly more than no intervention. It also has slightly to moderately greater benefits than land-based exercise on balance capacity, fear of falling, and health-related quality of life. On other outcomes, the benefits of aquatic exercise are similar to those of land-based exercise.

TRIAL REGISTRATION

PROSPERO CRD42017077370.

Respiratory disturbances in a mouse model of Parkinson's disease

NEW FINDINGS

What is the central question of this study? Clinical reports have described and suggested central and peripheral respiratory abnormalities in Parkinson's disease (PD) patients; however, these reports have never addressed the occurrence of these abnormalities in an animal model. What is the main finding and its importance? A mouse model of PD has reduced neurokinin-1 receptor immunoreactivity in the pre-Bӧtzinger complex and Phox2b-expressing neurons in the retrotrapezoid nucleus. The PD mouse has impairments of respiratory frequency and the hypercapnic ventilatory response. Lung collagen deposition and ribcage stiffness appear in PD mice.

ABSTRACT

Parkinson's disease (PD) is a neurodegenerative motor disorder characterized by dopaminergic deficits in the brain. Parkinson's disease patients may experience shortness of breath, dyspnoea, breathing difficulties and pneumonia, which can be linked as a cause of morbidity and mortality of those patients. The aim of the present study was to clarify whether a mouse model of PD could develop central brainstem and lung respiratory abnormalities. Adult male C57BL/6 mice received bilateral injections of 6-hydroxydopamine (10 μg μl^-1 ; 0.5 μl) or vehicle into the striatum. Ventilatory parameters were assessed in the 40 days after induction of PD, by whole-body plethysmography. In addition, measurements of respiratory input impedance (closed and opened thorax) were performed. 6-Hydroxydopamine reduced the number of tyrosine hydroxylase neurons in the substantia nigra pars compacta, the density of neurokinin-1 receptor immunoreactivity in the pre-Bӧtzinger complex and the number of Phox2b neurons in the retrotrapezoid nucleus. Physiological experiments revealed a reduction in resting respiratory frequency in PD animals, owing to an increase in expiratory time and a blunted hypercapnic ventilatory response. Measurements of respiratory input impedance showed that only PD animals with the thorax preserved had increased viscance, indicating that the ribcage could be stiff in this animal model of PD. Consistent with stiffened ribcage mechanics, abnormal collagen deposits in alveolar septa and airways were observed in PD animals. Our data showed that our mouse model of PD presented with neurodegeneration in respiratory brainstem centres and disruption of lung mechanical properties, suggesting that both central and peripheral deficiencies contribute to PD-related respiratory pathologies.

Principles of Urgent Management of Acute Airway Obstruction

Recognizing and acting early on airway compromise reduces morbidity and mortality in patients with airway obstruction. Causes include foreign bodies, toxic/hot fumes, difficult intubation, laryngeal spasm, and tumors. Before definitive control of the airway is possible, provide 100% oxygen with a tightly fitting mask to optimize body oxygen stores. Pulse oximetry is a poor indicator of airway compromise; a decreasing arterial hemoglobin oxygen saturation is a late sign of impending hypoxemia. Basic airway maneuvers improve the patency of an obstructed airway. Getting help from an anesthetist early is a priority.

Levodopa-induced respiratory dysfunction confirmed by levodopa challenge test: A case report

INTRODUCTION

Parkinson disease is associated with various nonmotor symptoms, including rare respiratory dysfunction events. However, patients with Parkinson disease often have comorbid medical problems, such as respiratory distress, and differentiating nonmotor symptoms can be difficult.

CASE PRESENTATION

A 78-year-old male presented with repetitive shortness of breath. He was diagnosed with Parkinson disease and chronic obstructive pulmonary disease (COPD) several years prior. His symptoms were ambiguous between acute COPD exacerbation and levodopa-related nonmotor symptoms of Parkinson disease. To clarify the underlying cause, we performed the levodopa challenge test. After the patient complained of dyspnea following levodopa administration, levodopa-induced respiratory dysfunction was diagnosed. After adjusting antiparkinson medication, the patient's respiratory symptoms gradually improved.

CONCLUSION

Respiratory dysfunction as a nonmotor symptom of Parkinson disease can be caused by levodopa medication. To determine whether the symptoms are induced by levodopa, the levodopa challenge test may be useful in clarifying symptoms related to antiparkinson medication.