Dyspnea: An underestimated symptom in Parkinson's disease

Dyspnea and dystussia in Parkinson's disease: patient-reported prevalence and determinants

BACKGROUND

The prevalence of respiratory dysfunction in PD is unknown and a better understanding of determinants contributing to respiratory dysfunction is important to facilitate early recognition and treatment.

OBJECTIVE

To examine the prevalence and determinants of self-reported symptoms of respiratory dysfunction among people with PD.

METHODS

In a cross-sectional study, we administered a self-completed questionnaire among a sample of 939 persons with PD. Respiratory dysfunction was defined as experiencing at least one of the following symptoms: breathing difficulties, breathlessness/shortness of breath, tightening of the chest, frequent throat clearing, frequent coughing, or coughing difficulties. A principal component analysis (PCA) was used to define composite constructs of respiratory dysfunction. The association with participant-reported determinants was assessed using multivariable logistic regression models (with adjustment for pulmonary diseases and COVID-19 symptoms).

RESULTS

The overall prevalence rate of respiratory dysfunction was 44% in persons with PD (42% after excluding pulmonary diseases or COVID-19). The PCA resulted in two constructs of respiratory dysfunction: 'dyspnea' and 'dystussia' (an impaired cough response), which together explained 68% of the total variance. Female sex (OR = 1.39), higher BMI kg/m2 (OR = 1.04), longer disease duration (OR = 1.35), greater self-reported rigidity (OR = 1.16), previous pulmonary disease(s) (OR = 7.12), and anxiety (OR = 1.04) were independently associated with 'dyspnea'. Pulmonary disease(s) (OR = 1.81), COVID-19 symptoms (OR = 2.20), swallowing complaints (OR = 1.48), and speech complaints (OR = 1.02) were independently associated with 'dystussia'.

CONCLUSIONS

Dyspnea and dystussia are common manifestations of respiratory dysfunction among people with PD and deserves more awareness in clinical practice. A proactive screening for the determinants of dyspnea and dystussia may contribute to earlier recognition and treatment of respiratory dysfunction.

Therapeutic singing and expiratory muscle strength training in Parkinson's disease: a mixed methods comparison

Introduction

The purpose of this study was to understand how two respiratory strengthening protocols, therapeutic singing (TS) and expiratory muscle strength training (EMST), compare on measures of quality of life (QOL), depression and anxiety for persons with Parkinson's disease. An equally important aim was to understand participants' perceptions of both treatments.

Methods

Quantitative and qualitative datasets were integrated in a convergent mixed methods design within a randomized crossover intervention trial. Thirteen persons with mild-moderate PD (Hoehn and Yahr stage 1-3) completed both interventions, in random order, for 4 weeks, 5 days per week, for approximately 20 min per day. Participants completed self-report questionnaires (Geriatric Depression Scale, Parkinson's Anxiety Scale, Parkinson's Disease Questionnaire-39, and a Survey after Treatment) after each intervention, and twelve participants' qualitative data were analyzed.

Results

Quantitative data did not reveal significant differences between the interventions in depression on the Geriatric Depression Scale or anxiety on the Parkinson's Anxiety Scale and the qualitative data support those findings. There were no significant differences between interventions in QOL as measured by the Parkinson's Disease Questionnaire-39, but there was a main effect of time, with a significant decline (p = 0.01) in perceived QOL between baseline and the final visit. The quantitative data diverged from the qualitative data as there were no themes that emerged to corroborate a decrease in QOL. Five qualitative themes were derived from thematic analysis: Benefits, Accessibility, Acceptability, Advice/Feedback, and Preference. Participants' perceptions of the interventions were closely aligned to individual differences and preferences, with an equal split of participants preferring TS and EMST.

Conclusions

Findings from this mixed methods comparison of two respiratory interventions will help to improve the acceptability and accessibility of the interventions to better facilitate adherence to the interventions and promote continued engagement, thereby delaying respiratory decline in those with PD.

Dyspnea in Parkinson's disease

BACKGROUND

Dyspnea is an important non-motor symptom in Parkinson's disease (PD) that impacts quality of life. The mechanisms underlying dyspnea have been difficult to determine due to challenges separating central respiratory control abnormalities from peripheral respiratory muscle dysfunction and chest wall rigidity.

METHODS

A comprehensive literature review was conducted, searching the PubMed database for observational studies on respiratory dysfunction and dyspnea in PD. Inclusion criteria were studies with PD patients without other neurological disorders. Case studies were excluded. Data on study size, disease duration, control groups, and respiratory defects were extracted.

RESULTS

The search yielded 23 unique publications on pulmonary function in PD. Key findings were: 1) restrictive defects are common, with prevalence up to 85 % in some studies; 2) effects of levodopa on pulmonary function are variable across studies; 3) there is limited research on the role of central respiratory centers in dyspnea pathophysiology in PD. Proposed mechanisms include direct involvement of brainstem respiratory structures, loss of dopamine input to these regions, and astrocyte dysfunction affecting respiratory rhythm generation.

CONCLUSION

This review outlines potential mechanisms underlying dyspnea in PD, including central respiratory dysfunction, peripheral muscle/chest wall abnormalities, impaired respiratory sensation, and medication effects. More research is needed investigating specific brainstem regions involved, chemoreceptor pathology, correlations between respiratory load and perceived dyspnea, and medication effects on pulmonary function.

Effects of three physical exercise modalities on respiratory function of older adults with Parkinson's disease: A randomized clinical trial

INTRODUCTION

Deficits in respiratory function of patients with Parkinson's disease contribute to aspiration pneumonia, one of the main causes of mortality in this population. The aim of this study was to evaluate the effects of functional training, bicycle exercise, and exergaming on respiratory function of elderly with Parkinson's disease.

METHODS

A randomized clinical trial with single blinding was conducted in a public reference outpatient clinic for the elderly. The participants were randomly assigned to three groups. Group 1 was submitted to functional training (n = 18); group 2 performed bicycle exercise (n = 20), and group 3 trained with Kinect Adventures exergames (n = 20). The sessions performed lasted 8 weeks with a frequency of three 50-min sessions per week. The primary outcome was the forced expiratory volume in the first second; and the secondary outcomes were forced vital capacity, peak expiratory flow, and maximum inspiratory and expiratory pressures.

RESULTS

The interventions performed did not improve the forced expiratory volume in the first second, forced vital capacity, and peak expiratory flow. However, group 2 improved (p = 0.03) maximum expiratory pressure (from 65.5cmH2O to 73.1cmH2O) (effect size 0.47), and group 3 increased (p = 0.03) maximum inspiratory pressure (from -61.3cmH2O to -71.6cmH2O) (effect size 0.53).

CONCLUSIONS

No effect was found on lung volume, forced respiratory flow and capacity of the participants with Parkinson's disease submitted to three different modalities of motor training. However, bicycle exercise and exergaming have improved expiratory and inspiratory muscle strength, respectively. NCT02622737.

Effects of high-intensity respiratory muscle training on respiratory muscle strength in individuals with Parkinson's disease: Protocol of a randomized clinical trial

OBJECTIVE

To investigate the efficacy of high-intensity respiratory muscle training (combined inspiratory and expiratory muscle training) in improving inspiratory and expiratory muscle strength, inspiratory muscle endurance, peak cough flow, dyspnea, fatigue, exercise capacity, and quality of life in this population.

METHODS

A randomized controlled trial, concealed allocation, blinded assessments, and intention-to-treat analysis will be carried out. Altogether, 34 individuals with PD (age ≥ 50 years old, with maximum inspiratory pressure (MIP) <80cmH2O or maximum expiratory pressure (MEP) <90cmH2O) will be recruited. Patients will be randomly assigned to either (1) high-intensity respiratory muscle training (experimental group, 60% of MIP and MEP) or (2) sham training (control group, 0cmH2O). Individuals will perform a home-based intervention, with indirect home supervision, consisting of two daily 20-min sessions (morning and afternoon), seven times a week, during eight weeks. Primary outcomes are MIP and MEP. Secondary outcomes are inspiratory muscle endurance, peak cough flow, dyspnea, fatigue, exercise capacity, and quality of life. The effects of the training will be analyzed from the collected data using intention-to-treat. Between-group differences will be measured using a two-way ANOVA with repeated measures (2*3), considering baseline, post-intervention, and 12-week follow-up.

IMPACT

The results of this trial will provide valuable new information on the efficacy of high-intensity respiratory muscle training in improving muscle strength, functional outcomes, and quality of life in individuals with PD. Performing combined inspiratory and expiratory muscle training using a single equipment is cheaper and feasible, takes less time and is easy to use. In addition, this intervention will be carried out in the home environment that increases accessibility, reduces time, and costs of transport, which increases the feasibility to reproduce their findings in clinical practice.

TRIAL REGISTRATION

NCT05608941. Registered on November 8, 2022.

Characteristics and outcomes of elderly patients with Parkinson's disease hospitalized due to COVID‑19‑associated pneumonia

Patients with Parkinson's disease (PD) and coronavirus disease 2019 (COVID-19)-associated pneumonia present, according to the literature, high mortality rates due to the nature of the disease, advanced age, and underlying diseases. Most available studies, however, refer to the first waves of the pandemic. The aim of the present study was to investigate the clinical characteristics and outcomes of elderly patients (≥65 years old) with PD hospitalized with COVID-19-associated pneumonia during the period of prevalence of various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, as well as to determine possible prognostic factors for poor outcomes. During the period from February 15, 2021, to July 15, 2022, 1,144 elderly patients with COVID-19 pneumonia were hospitalized. Age, sex, Charlson comorbidity index, vaccination status against SARS-CoV-2, and admission laboratory parameters were recorded for all patients. A total of 36 (3.1%) patients with PD were hospitalized due to COVID-19-associated pneumonia (18 males, 50%). The mean age of the patients was 82.72±8.18 years. In total, 8 patients (22.2%) were hospitalized during the period of alpha variant predominance, 3 patients (8.3%) during the period of delta variant predominance, and 25 patients (69.4%) during the omicron variant predominance period. Of note, 16 patients (44.4%) were vaccinated with at least two doses. In addition, 17 (47.2%) patients succumbed to the disease. Between the patients who survived and those who succumbed, a statistically significant difference was only found in the mean value of albumin (37.48±6.02 vs. 31.97±5.34 g/l, P=0.019). In particular, as shown by receiver operating characteristic curve analysis, albumin exhibited a satisfactory predictive ability for mortality (area under the curve, 0.780; P=0.013) with an albumin value ≤37.7 g/l being able to predict mortality with 85.7% sensitivity and 54.8% specificity. Overall, the findings of the present study indicate that mortality among elderly patients with PD hospitalized with COVID-19-associated pneumonia was high in all phases of the pandemic. A low albumin value, not only as an indicator of the immune status, but also of the nutritional status, is a predictor of adverse outcomes.

The impact of emotional context on neural substrates of respiratory sensory gating

Psychological challenges have been found to impact respiratory symptom perception in healthy individuals as well as in patients with various neurological disorders. Human respiratory sensory gating is an objective measure to examine respiratory sensory information processing of repetitive respiratory mechanical stimuli in the central nervous system. With this electrophysiological method, patients with higher anxiety levels showed reduced respiratory sensory gating function in the cortex, and increased symptom perception. In addition, positive emotional contexts were found to increase the respiratory sensory gating function using RREPs. However, neural substrates related to emotional impacts on respiratory sensory gating remain still unclear. In the present study, we examined the emotion processing of respiratory sensory gating using functional magnetic resonance imaging. We hypothesized that positive compared with neutral stimuli would result in reduced brain activations in cortical areas with the paired occlusion paradigm. Thirty-five healthy adults participated in this event-designed fMRI experiment. Paired inspiratory occlusions (two transient occlusions with a 500 ms inter-stimulus-interval are delivered during one inspiration) were provided using an external trigger outside of the scanner. At least 40 paired inspiratory occlusions were collected for each trial. The experiment contained three runs during which participants underwent 12 min for the paired inspiratory occlusion paradigm while watching a fixation cross (the control condition), neutral and positive emotional picture series. The order of emotional picture series was randomized across the participants. Our results revealed an overall trend of reduction of brain activity from the neutral (minus fixation) condition, to the pleasant (minus fixation) condition. For bilateral thalamus and primary visual cortices, there was no significant difference in neural activation between the two contrasts of pleasant (Contrast_P–F) and neutral condition (Contrast_N–F). The activation of the mid-cingulate and the orbitofrontal cortex was lower in Contrast_P–F compared to Contrast_N–F. In conclusion, our results suggest that emotional context, especially positive valence, modulates neural correlates in middle cingulate cortex and orbitofrontal cortex in terms of respiratory sensory gating. Future studies are recommended to test emotional impacts on respiratory sensations in patients with neurological disorders.

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.

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.

Experienced Respiratory Symptoms and the Impact on Daily Life from the Perspective of People with Parkinson's Disease: A Grounded Theory

BACKGROUND

Abnormal respiratory function tests can be observed early in the course of Parkinson's disease (PD). A better understanding of the impact of respiratory dysfunction on daily life in PD is needed to prevent later occurring complications as a (aspiration) pneumonia.

OBJECTIVE

To explain which respiratory symptoms people with PD or a form of atypical parkinsonism experience and how these symptoms impact on their daily lives.

METHODS

This qualitative study used a grounded theory approach. A purposeful sample strategy was used to capture information-rich cases. Data were collected in semi-structured interviews with participants diagnosed with either PD (n = 11) or atypical parkinsonism (n = 3), all of whom had confirmed respiratory symptoms. Data were analyzed using grounded theory analysis by creating codes, categories, theoretical themes, and, ultimately, a conceptual model.

RESULTS

Four respiratory profiles emerged, describing different types of respiratory dysfunction, with various positive and negative influencing factors. First, a loss of breathing automatism was experienced. Second, episodes of breathlessness or a rapid, shallow breathing pattern were triggered by either physical exertion, fatigue, or postural deformities. Third, stress and anxiety also triggered episodes of breathlessness. Fourth, a decreased cough strength and frequent coughing. Based on these findings, we constructed a conceptual model that visualizes the relations between these four types of respiratory dysfunction and their impact on daily life, with 'discomfort' and 'avoidance of social activities' as crucial elements.

CONCLUSION

A tailored approach for each profile of respiratory dysfunction is recommended to improve respiratory dysfunction and to reduce its social impact in people with PD.

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.

Covid-19: pharmacotherapeutic insights on various curative approaches in terms of vulnerability, comorbidities, and vaccination

A novel coronavirus disease (COVID-19), caused by a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was discovered in Wuhan, China, in December 2019, and the world has suffered from a pandemic. As of 22nd March 2020, at least 185 countries worldwide had been affected by COVID-19. SARS-CoV-2, leading to COVID-19 pneumonia, infects cells through ACE-2 receptors. The disease has different clinical signs and symptoms, including chills, high fever, dyspnea, and cough. Other symptoms including haemoptysis, myalgia, diarrhoea, expectoration, and fatigue may also occur. The rapid rise in confirmation cases is severe in preventing and controlling COVID-19. In this review, the article will explore and evaluate the insights into how COVID influences patients with other comorbid conditions such as cardiovascular disease, diabetes, Parkinson's, and how conditions Urolithiasis, anosmia, and anuria may develop after infection. The virus mutates and the variants are now prevalent in the present scenario where the world stands in eradicating the pandemic by looking into the development of vaccines by several countries and how the vaccination can temporarily help prevent COVID spread.

Walking training augments the effects of expiratory muscle training in Parkinson's disease

OBJECTIVES

To investigate the effects of walking training combined with respiratory muscle training (RMT) on pulmonary function, respiratory muscle strength, and functional exercise capacity in patients with Parkinson's disease.

MATERIALS & METHODS

Thirty patients with Parkinson's disease were included in the study. Patients were randomly divided into two groups: the walking and RMT group (W + RMT, n = 15) and the RMT (n = 15) group. Spirometry, respiratory muscle strength, and a 6-min walking test were measured before and after the eighth week of the study. RMT was performed using inspiratory and expiratory threshold loading methods. Walking training intensity was adjusted according to the 6-min walking test. Patients performed 15 min of inspiratory muscle training and 15 min of expiratory muscle training in both groups, and 15 min of walking training in the W + RMT group in addition to RMT, twice per day, 5 days/week, for a total of 8 weeks at home. Training intensity was adjusted once per week for the groups at the hospital.

RESULTS

Respiratory muscle strength and 6-min walking distance were significantly increased (p = .001), and UPDRS-III scores were significantly improved (W + RMT: p = .008 and RMT: p = .01) in the two groups. The increase in maximal expiratory pressure was significantly higher in the W + RMT group than in the RMT group (p = .007).

CONCLUSION

Walking training increases the effect of expiratory muscle training in patients with Parkinson's disease.

Impact of the COVID-19 Pandemic on Chronic Neurological Disorders: Focus on Patients with Dementia

The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) represents a public health problem worldwide. COVID-19 triggers a maladaptive cytokine release commonly referred to as cytokine storm syndrome with increased production of proinflammatory cytokines, which also appears to contribute to chronic neuroinflammation and neurodegenerative disorders' appearance, including multiple sclerosis, Parkinson's disease, and Alzheimer's disease. In this context, SARS-CoV-2 might enter the central nervous system through binding with the angiotensin converting enzyme 2 receptors which are highly expressed in glial cells and neurons. For this reason, an association between COVID-19, its dependent cytokine storm, and the development and/or progression of neurodegenerative disorders might be evaluated. Therefore, the aim of this review was to assess the impact of COVID-19 on neurodegenerative disorders, focusing on the possible increased mortality risk and/or deterioration of the clinical course of pre-existing chronic neurological diseases in patients with dementia.

Treatment paradigms in Parkinson's Disease and Covid-19

People with Parkinson's Disease (PwP) may be at higher risk for complications from the Coronavirus Disease 2019 (Covid-19) due to older age and to the multi-faceted nature of Parkinson's Disease (PD) per se, presenting with a variety of motor and non-motor symptoms. Those on advanced therapies may be particularly vulnerable. Taking the above into consideration, along with the potential multi-systemic impact of Covid-19 on affected patients and the complications of hospitalization, we are providing an evidence-based guidance to ensure a high standard of care for PwP affected by Covid-19 with varying severity of the condition. Adherence to the dopaminergic medication of PwP, without abrupt modifications in dosage and frequency, is of utmost importance, while potential interactions with newly introduced drugs should always be considered. Treating physicians should be cautious to acknowledge and timely address any potential complications, while consultation by a neurologist, preferably with special knowledge on movement disorders, is advised for patients admitted in non-neurological wards. Non-pharmacological approaches, including the patient's mobilization, falls prevention, good sleep hygiene, emotional support, and adequate nutritional and fluid intake, are essential and the role of telemedicine services should be strengthened and encouraged.

Breathing disorders in neurodegenerative diseases

Neurodegenerative disorders are a diverse group of conditions caused by progressive degeneration of neurons resulting in cognitive, motor, sensory, and autonomic dysfunction, leading to severe disability and death. Pulmonary dysfunction is relatively common in these conditions, may be present early in the disease, and is less well recognized and treated than other symptoms. There are variable disorders of upper and lower airways, central control of ventilation, strength of respiratory muscles, and breathing during sleep which further impact daily activities and quality of life and have the potential to injure vulnerable neurons. Laryngopharyngeal dysfunction affects speech, swallowing, and clearance of secretions, increases the risk of aspiration pneumonia, and can cause stridor and sudden death. In Parkinson's disease, L-Dopa benefits some pulmonary symptoms but there are limited pharmacological treatment options for pulmonary dysfunction. Targeted treatments include strengthening of respiratory muscles, positive airway pressure in sleep and techniques to improve cough efficacy. Well-designed clinical trials are needed to evaluate the long-term benefits of these interventions. Challenges for the future include earlier identification of pulmonary dysfunction in the clinic, institution of the most effective treatments (based on clinical trials that measure long-term meaningful outcomes) and the development of neuroprotective treatment.

Recommendations for traveling to altitude with neurological disorders

BACKGROUND

Several neurological conditions might worsen with the exposure to high altitude (HA). The aim of this review was to summarize the available knowledge on the neurological HA illnesses and the risk for people with neurological disorders to attend HA locations.

METHODS

A search of literature was conducted for several neurological disorders in PubMed and other databases since 1970. The neurological conditions searched were migraine, different cerebrovascular disease, intracranial space occupying mass, multiple sclerosis, peripheral neuropathies, neuromuscular disorders, epileptic seizures, delirium, dementia, and Parkinson's disease (PD).

RESULTS

Attempts were made to classify the risk posed by each condition and to provide recommendations regarding medical evaluation and advice for or against traveling to altitude. Individual cases should be advised after careful examination and risk evaluation performed either in an outpatient mountain medicine service or by a physician with knowledge of HA risks. Preliminary diagnostic methods and anticipation of neurological complications are needed.

CONCLUSIONS

Our recommendations suggest absolute contraindications to HA exposure for the following neurological conditions: (1) Unstable conditions-such as recent strokes, (2) Diabetic neuropathy, (3) Transient ischemic attack in the last month, (4) Brain tumors, and 5. Neuromuscular disorders with a decrease of forced vital capacity >60%. We consider the following relative contraindications where decision has to be made case by case: (1) Epilepsy based on recurrence of seizure and stabilization with the therapy, (2) PD (± obstructive sleep apnea syndrome-OSAS), (3) Mild Cognitive Impairment (± OSAS), and (4) Patent foramen ovale and migraine have to be considered risk factors for acute mountain sickness.

Inhibition of anandamide hydrolysis does not rescue respiratory abnormalities observed in an animal model of Parkinson's disease

NEW FINDINGS

What is the central question of this study? The respiratory frequency to hypercapnia is attenuated in an animal model of Parkinson's disease (PD): what is the therapeutic potential of inhibition of anandamide hydrolysis for this respiratory deficit? What is the main finding and its importance? In an animal model of PD there is an increased variability in resting respiratory frequency and an impaired tachypnoeic response to hypercapnia, which is accompanied by diminished expression of Phox2b immunoreactivity in the retrotrapezoid nucleus (RTN). Inhibition of anandamide hydrolysis also impaired the response to hypercapnia and decreased the number of Phox2b immunoreactive cells in the RTN. This strategy does not reverse the respiratory deficits observed in an animal model of PD.

ABSTRACT

Parkinson's disease (PD) is characterized by severe classic motor symptoms along with various non-classic symptoms. Among the non-classic symptoms, respiratory dysfunctions are increasingly recognized as contributory factors to complications in PD. The endocannabinoid system has been proposed as a target to treat PD and other neurodegenerative disorders. Since symptom management of PD is mainly focused on the classic motor symptoms, in this work we aimed to test the hypothesis that increasing the actions of the endocannabinoid anandamide by inhibiting its hydrolysis with URB597 reverses the respiratory deficits observed in an animal model of PD. Results show that bilateral injection of 6-hydroxydopamine hydrochloride (6-OHDA) in the dorsal striatum leads to neurodegeneration of the substantia nigra, accompanied by reduced expression of Phox2b in the retrotrapezoid nucleus (RTN), an increase in resting respiratory frequency variability and an impaired tachypnoeic response to hypercapnia. URB597 treatment in control animals was associated with an impaired tachypnoeic response to hypercapnia and a reduced expression of Phox2b in the RTN, whereas treatment of 6-OHDA-lesioned animals with URB597 was not able to reverse the deficits observed. These results suggest that targeting anandamide may not be a suitable strategy to treat PD since this treatment mimics the respiratory deficits observed in the 6-OHDA model of PD.

[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.

Paroxysmal dyspnea in Parkinson's disease: Respiratory dyskinesias and autonomic hyperventilation are not the same

Respiratory complaints are not uncommon in patients with Parkinson's disease (PD). While many are explained by pulmonary and cardiovascular problems unrelated to PD, secondary effects of PD, such as kyphoscoliosis, respiratory muscle rigidity, repeated pneumonias, or side effects of medication such as dyskinesias, there is a small group of patients with paroxysmal dyspnea for whom neither anxiety or other explanation has been found. This Point of View was written to call attention to this neglected, uncommon, but very distressing symptom.

The impact of SARS-COV2 infection on people in residential care with Parkinson Disease or parkinsonisms: Clinical case series study

On March 2019 the World Health Organization declared Coronavirus disease (COVID-19) pandemic. Several recent reports disclose that the outcome of the infection is related to age, sex and can be influenced by underlying clinical conditions. Parkinson's disease (PD) and other parkinsonisms are the most common chronic disease which can cause, directly or indirectly, the patient to be more exposed to other diseases, mostly respiratory system's ones. Our primary outcome is to evaluate if PD patients are more susceptible than non-PD to take COVID-19 infection. Second, to detect if the infection course is worse in PD-COVID+ patients versus non-PD. This is a retrospective observational study on a cohort of 18 patients (13 PD- 5 non-PD), hospitalized in a Rehabilitative Unit during the occurrence of SARS-CoV2 epidemic outbreak. All patients performed laboratory tests, lung Computed Tomography (CT) and have been tested for COVID-19 thorough pharyngeal swab. PD and non-PD groups were comparable for age, gender and Hoehn and Yahr stage. Seventy-seven (77)% of PD and 60% of non-PD resulted positive for COVID-19. PD-COVID+ and PD-COVID- did not differ for age, disease duration and L-dopa daily dose. PD COVID-19+ subjects were mainly asymptomatic (50%) while non-PD ones were all symptomatic, mostly with respiratory difficulties. PD doesn't seem to be a risk factor to take SARS-COV2 infection, even if our study is related to a limited sample size. Our results, together with those of other recent studies, highlight the need to evaluate the actual susceptibility of patients with Parkinson's disease to develop COVID-19 disease, and how the infection may influence the risk of clinical worsening and increase of mortality.

Respiratory Dysfunctions in Parkinson's Disease Patients

Respiratory dysfunctions have been associated with Parkinson's disease since the first observations of the disease in 1817. Patients with Parkinson's disease frequently present respiratory disorders with obstructive ventilatory patterns and restrictive modifications, as well as limitations in respiratory volumes. In addition, respiratory impairments are observed due to the rigidity and kyphosis that Parkinson's disease patients experience. Subsidiary pulmonary complications can also appear as side effects of medication. Silent aspiration can be the cause of pneumonia in Parkinson's disease. Pulmonary dysfunction is one of the main factors that leads to the morbidity and mortality of patients with Parkinson's disease. Here, we performed a narrative review of the literature and reviewed studies on dyspnea, lung volumes, respiratory muscle function, sleep breathing disorders, and subsidiary speech and swallow impairments related to pulmonary dysfunction in patients with Parkinson's disease.

Alzheimer's and Parkinson's Diseases Predict Different COVID-19 Outcomes: A UK Biobank Study

In December 2019, a coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began infecting humans, causing a novel disease, coronavirus disease 19 (COVID-19). This was first described in the Wuhan province of the People's Republic of China. SARS-CoV-2 has spread throughout the world, causing a global pandemic. To date, thousands of cases of COVID-19 have been reported in the United Kingdom, and over 45,000 patients have died. Some progress has been achieved in managing this disease, but the biological determinants of health, in addition to age, that affect SARS-CoV-2 infectivity and mortality are under scrutiny. Recent studies show that several medical conditions, including diabetes and hypertension, increase the risk of COVID-19 and death. The increased vulnerability of elderly individuals and those with comorbidities, together with the prevalence of neurodegenerative diseases with advanced age, led us to investigate the links between neurodegeneration and COVID-19. We analysed the primary health records of 13,338 UK individuals tested for COVID-19 between March and July 2020. We show that a pre-existing diagnosis of Alzheimer's disease predicts the highest risk of COVID-19 and mortality among elderly individuals. In contrast, Parkinson's disease patients were found to have a higher risk of SARS-CoV-2 infection but not mortality from COVID-19. We conclude that there are disease-specific differences in COVID-19 susceptibility among patients affected by neurodegenerative disorders.

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.

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.

Dyspnea Is a Specific Symptom in Parkinson's Disease

BACKGROUND

Dyspnea is a multidimensional sensation that is reported in Parkinson's disease (PD). The multidimensional dyspnea profile (MDP) questionnaire can help to distinguish the perceptive dimension and the emotion response.

OBJECTIVE

The aim was to assess the clinical features associated with dyspnea using the MDP questionnaire in order to determine which aspects of the symptom was linked with anxiety, depression or motor severity of the disease.

METHODS

Non-demented patients were asked whether they experienced shortness of breath in the last month. In case of positive answer, dyspnea was assessed by the MDP. MDS-UPDRS, global cognitive performance, non-motor symptoms and quality of life were assessed.

RESULTS

60/163 patients were dyspneic since 4.6±2.4 years. The most frequent best sensory quality (SQ) described were: hyperpnoea (35%), physical breathing effort (25%) and air hunger (20%). Hyperpnoea and air hunger had the highest SQ intensity. Anxiety had the highest intensity in the emotional domain.

CONCLUSION

Dyspnea is a frequent symptom in PD, with specific presentations and two main aspects: one related with anxiety and another with ventilation control impairment.

COVID-19 in Parkinson's Disease Patients Living in Lombardy, Italy

BACKGROUND

It is unknown whether patients with PD are at greater risk of COVID-19, what their risk factors are, and whether their clinical manifestations differ from the general population.

OBJECTIVES

The study aimed to address all these issues.

METHODS

In a case-controlled survey, we interviewed 1,486 PD patients attending a single tertiary center in Lombardy, Italy and 1,207 family members (controls).

RESULTS

One hundred five (7.1%) and 92 controls (7.6%) were identified as COVID-19 cases. COVID-19 patients were younger, more likely to suffer from chronic obstructive pulmonary disease, to be obese, and vitamin D nonsupplemented than unaffected patients. Six patients (5.7%) and 7 family members (7.6%) died from COVID-19. Patients were less likely to report shortness of breath and require hospitalization.

CONCLUSIONS

In an unselected large cohort of nonadvanced PD patients, COVID-19 risk and mortality did not differ from the general population, but symptoms appeared to be milder. The possible protective role of vitamin D supplementation warrants future studies. © 2020 International Parkinson and Movement Disorder Society.

Dyspnea after subthalamic deep brain stimulation in Parkinson's disease: a case-control study

OBJECTIVE

Dyspnea can be present as non-motor symptom in patients with Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor and non-motor symptoms in PD. However, new-onset dyspnea has been reported after DBS surgery. We have studied respiratory characteristics of PD patients with bilateral STN-DBS to assess the impact of DBS on pulmonary function.

METHODS

STN-DBS PD patients with dyspnea after surgery (cases) were matched with STN-DBS PD patients without dyspnea (controls). Motor and pulmonary function were assessed with stimulation and without medication (on stim/off med), and without stimulation and medication (off stim/off med). Pulmonary function was investigated with spirometry and dyspnea with the Medical Research Council Dyspnea Scale (MRCDS) and the Borg Scale (BS).

RESULTS

Seven cases (five men, 58.30 ± 6.70 years of age) and seven controls (six men, 61.10 ± 6.30 years of age) were enrolled. MRCDS and BS revealed the presence of dyspnea in both groups. No significant changes in pulmonary function were found in both cases and controls in on stim/off med vs. off stim/off med condition (p < 0.05), and in cases vs. controls in on stim/ off med condition (p < 0.05).

CONCLUSIONS

No impact of STN-DBS on pulmonary function was found in cases. Impaired perception of dyspnea and spread of stimulation surrounding the STN might account for new-onset dyspnea after DBS surgery. Dyspnea was detected also in controls using ad hoc questionnaires. Our findings suggest further investigation of this non-motor symptom in PD patients.

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.

COVID-19: An Early Review of Its Global Impact and Considerations for Parkinson's Disease Patient Care

While many infectious disorders are unknown to most neurologists, COVID-19 is very different. It has impacted neurologists and other health care workers, not only in our professional lives but also through the fear and panic within our own families, colleagues, patients and their families, and even in the wider public. COVID-19 affects all sorts of individuals, but the elderly with underlying chronic conditions are particularly at risk of severe disease, or even death. Parkinson's disease (PD) shares a common profile as an age-dependent degenerative disorder, frequently associated with comorbidities, particularly cardiovascular diseases, so PD patients will almost certainly fall into the high-risk group. Therefore, the aim of this review is to explore the risk of COVID-19 in PD based on the susceptibility to severe disease, its impact on PD disease severity, potential long-term sequelae, and difficulties of PD management during this outbreak, where neurologists face various challenges on how we can maintain effective care for PD patients without exposing them, or ourselves, to the risk of infection. It is less than six months since the identification of the original COVID-19 case on New Year's Eve 2019, so it is still too early to fully understand the natural history of COVID-19 and the evidence on COVID-19-related PD is scant. Though the possibilities presented are speculative, they are theory-based, and supported by prior evidence from other neurotrophic viruses closely related to SARS-CoV-2. Neurologists should be on high alert and vigilant for potential acute and chronic complications when encountering PD patients who are suspected of having COVID-19.

The Challenge of Managing Parkinson's Disease Patients during the COVID-19 Pandemic

The 2019 novel coronavirus (nCoV) pandemic is rapidly developing across the globe and new information is emerging expeditiously and constantly, particularly in relation to neurological illnesses. Both central and peripheral nervous system involvement has been reported including headache, dizziness, hyposmia/anosmia, taste disturbances, seizures, stroke, alteration of the sensorium, and even acute hemorrhagic necrotizing leukoencephalopathy. Varying degrees of olfactory disturbances may pre-empt the diagnosis of COVID-19. Although no direct effect of 2019 nCoV has been reported yet on Parkinson's disease, there are enormous possible indirect effects and implications. We examine the potential effects and challenges posed by this pandemic to individuals with Parkinson's disease, particularly in the Indian context where telecommunication access or support group access may be lacking for these patients. Additionally, lockdown and social distancing may pose hurdles in the provision of optimum medical therapy, particularly if patients experience motor and non-motor deteriorations due to diverse reasons.