Abnormal pulmonary function and respiratory muscle strength findings in Chinese patients with Parkinson's disease and multiple system atrophy--comparison with normal elderly

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.

Effect of expiratory muscle strength training on voice and speech: An exploratory study in persons with Parkinson's disease or multiple sclerosis

PURPOSE

This study explored how respiration, voice, and speech were affected following expiratory muscle strength training (EMST) and maintenance training in persons with Parkinson's disease (PD) or multiple sclerosis (MS).

METHOD

Nine participants with PD and six with MS participated in a randomised study, where the effects of EMST, sham, and maintenance treatment were investigated. Outcome measures included maximum expiratory pressure (MEP); maximum phonation time (MPT); intelligibility; verbal diadochokinesis (DDK); speech rate; a self-report form on voice, speech, and communication; and open questions about how the participants experienced the intervention. Group comparisons were performed within and between groups.

RESULT

The PD and the MS groups both improved significantly in MEP, and this improvement remained after 3 months of maintenance EMST. An improvement was also seen in DDK. Post-EMST, 33% of the PD group and 80% of the MS group reported a positive effect on communication.

CONCLUSION

The results of this study support previous evidence that EMST has positive effects on expiratory pressure in persons with PD or MS, but its effect on voice and speech remains unclear. Since subjective reports of the intervention and effects on communication were predominantly positive, further research is needed on larger groups to explore appropriate outcome measures.

Assessment of Pulmonary Functions in Parkinson's Disease and Unveiling the Role of Levodopa Therapy: A Cross-Sectional Study

INTRODUCTION

This investigation aimed to thoroughly characterize the range of pulmonary function abnormalities present in individuals with Parkinson's disease (PD) and to evaluate the effects of levodopa therapy on these respiratory dysfunctions.

METHODS

 Ninety-five PD patients diagnosed via the UK Parkinson's Disease Society Brain Bank Diagnostic Criteria were recruited, excluding those with a smoking history or unable to perform pulmonary function tests (PFTs). Severity was assessed using the Hoehn and Yahr Scale. Spirometry-measured PFT parameters (forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow rate (PEFR)) were compared against matched predicted values. The changes in PFT parameters post-levodopa challenge were assessed.

RESULTS

Most of the PD patients were aged between 51-60 years, with a mean age of 55.89 ± 8.37 years. Of these, 65.3% were male. A significant proportion of the cohort exhibited restrictive pulmonary patterns (73.7%), while a smaller fraction displayed obstructive (7.4%) or normal (18.9%) pulmonary function patterns. Notably, levodopa treatment correlated with marked improvements in all measured PFT parameters, especially evident in the enhancements from the "off" medication stage to the "on" stage for FVC and FEV1 (P=0.0001). A weak positive correlation between the severity of respiratory restriction and the duration of PD (r = 0.139, P = 0.021) was found, suggesting that PD's progression exerts an increasingly adverse effect on respiratory function over time.

CONCLUSION

 The findings of this study illustrate that restrictive pulmonary abnormalities are more prevalent than obstructive patterns in PD patients and that these patients respond favorably to levodopa therapy.

Effects of Rehabilitative Intervention for Augmenting Cough Function in Patients with Multiple System Atrophy

Objectives

One of the causes of death in patients with multiple system atrophy (MSA) is aspiration pneumonia caused by cough dysfunction. This study aimed to identify an effective approach to improve coughing and to explore the establishment of criteria for the use of gastrostomy based on cough and respiratory dysfunctions.

Methods

Eighteen probable MSA patients participated in the study. They were categorized into air stacking and non-air stacking groups. First, we investigated how the inspiration volume changes by applying maximum insufflation capacity (MIC). Second, peak cough flow (PCF) was measured by different cough augmentation methods: 1) spontaneous coughing (SpC); 2) SpC with MIC (SpC + MIC); 3) SpC with manually assisted cough (MAC) (SpC + MAC); and 4) SpC with MIC and MAC (SpC + MIC + MAC). Among these four conditions, PCF values were compared to determine the most effective approach for cough augmentation. Receiver operating characteristic analysis was performed on percent forced vital capacity (%FVC) to determine an index for discriminating PCF below160 L/min, which indicates a high risk of suffocation, involving SpC and SpC + MIC.

Results

Inspiration volume increased significantly with MIC in both groups (P < 0.05), and PCF increased significantly with MIC in the air stacking group (P < 0.01). PCF could not be maintained at 160 L/min when %FVC fell below 59%, even when MIC was applied.

Conclusions

PCF increases with MIC in patients with MSA. It may be meaningful to consider the timing of gastrostomy introduction based on the severity of cough and respiratory dysfunction.

Deterioration of Cough, Respiratory, and Vocal Cord Functions in Patients with Multiple System Atrophy

The purpose of this study was to clarify changes in cough function in patients with multiple system atrophy (MSA). Seventeen probable patients with MSA were studied. Peak cough flow (PCF), respiratory function (percentage of vital capacity, percentage of forced vital capacity, and percentage of predicted forced expiratory volume in one second), respiratory muscle strength (percentage of maximal inspiratory mouth pressure and percentage of maximal expiratory mouth pressure), and maximum phonation time (MPT) were assessed. Walking ability, disease duration, possibility of air stacking, Unified MSA Rating Scale (UMSARS), and Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III were also assessed. Data were separately analyzed for ambulatory and non-ambulatory groups categorized by Functional Ambulation Categories. PCF, respiratory function, respiratory muscle strength, and MPT were significantly lower in the non-ambulatory group than in the ambulatory group. On the other hand, no correlation between PCF and disease duration was observed. A significant number of patients in the non-ambulatory group were unable to hold their breath. The UMSARS and MDS-UPDRS Part III in the non-ambulatory group were significantly higher than in the ambulatory group. It was concluded that ambulatory dysfunction is associated with the decline of cough function and respiratory-related function in patients with MSA.

Impaired skeletal muscle health in Parkinsonian syndromes: clinical implications, mechanisms and potential treatments

There is increasing evidence that neurodegenerative disorders including the Parkinsonian syndromes are associated with impaired skeletal muscle health, manifesting as wasting and weakness. Many of the movement problems, lack of muscle strength and reduction in quality of life that are characteristic of these syndromes can be attributed to impairments in skeletal muscle health, but this concept has been grossly understudied and represents an important area of unmet clinical need. This review describes the changes in skeletal muscle health in idiopathic Parkinson's disease and in two atypical Parkinsonian syndromes, the most aggressive synucleinopathy multiple system atrophy, and the tauopathy progressive supranuclear palsy. The pathogenesis of the skeletal muscle changes is described, including the contribution of impairments to the central and peripheral nervous system and intrinsic alterations. Pharmacological interventions targeting the underlying molecular mechanisms with therapeutic potential to improve skeletal muscle health in affected patients are also discussed. Although little is known about the mechanisms underlying these conditions, current evidence implicates multiple pathways and processes, highlighting the likely need for combination therapies to protect muscle health and emphasizing the merit of personalized interventions for patients with different physical capacities at different stages of their disease. As muscle fatigue is often experienced by patients prior to diagnosis, the identification and measurement of this symptom and related biomarkers to identify early signs of disease require careful interrogation, especially for multiple system atrophy and progressive supranuclear palsy where diagnosis is often made several years after onset of symptoms and only confirmed post-mortem. We propose a multidisciplinary approach for early diagnosis and implementation of personalized interventions to preserve muscle health and improve quality of life for patients with typical and atypical Parkinsonian syndromes.

Expiratory Muscle Strength Training in Multiple System Atrophy: A Pilot Study

Background

The effects of expiratory muscle strength training (EMST) has not yet been investigated in MSA patients.

Objective

The primary objective was to test the effects of EMST on expiratory muscle strength and voluntary peak cough flow (vPCF) in patients with multiple system atrophy (MSA). The secondary objective was to assess the suitability of the pulmonary dysfunction index as a tool for identifying MSA patients with expiratory muscle weakness and reduced voluntary peak cough flow.

Methods

This was an open label, non-controlled study, with an 8-week intensive home-based EMST protocol. The outcome measures included: maximal expiratory pressure (MEP) and vPCF. The sensitivity and specificity of the index of pulmonary dysfunction in the respiratory diagnostic process were assessed using receiver operating characteristic (ROC) analysis.

Results

Fifteen MSA patients were enrolled in the study. Twelve MSA patients completed the training period. After the training period, MEP significantly increased (P = 0.006). Differences in vPCF were not significant (P = 0.845). ROC analysis indicated that the overall respiratory diagnostic accuracy of the index of pulmonary dysfunction had an outstanding capability to detect patients at risk of less effective coughing and an acceptable capability of detecting patients with decreased expiratory muscle strength.

Conclusions

These findings indicate non-significant differences in vPCF after 8 weeks of EMST. The index of pulmonary dysfunction appears to be a promising prognostic screening tool for identifying altered cough efficacy in MSA patients. Test cut-offs may be used to select an appropriate respiratory physiotherapy technique.

A systematic review and meta-analysis of respiratory dysfunction in Parkinson's disease

INTRODUCTION

Respiratory dysfunction in Parkinson's disease (PD) is common and associated with increased hospital admission and mortality rates. Central and peripheral mechanisms have been proposed in PD. To date no systematic review identifies the extent and type of respiratory impairments in PD compared with healthy controls.

METHODS

PubMed, EMBASE, CINAHL, Web of Science, Pedro, MEDLINE, Cochrane Library and OpenGrey were searched from inception to December 2021 to identify case-control studies reporting respiratory measures in PD and matched controls.

RESULTS

Thirty-nine studies met inclusion criteria, the majority with low risk of bias across Risk of Bias Assessment tool for Non-randomized Studies (RoBANS) domains. Data permitted pooled analysis for 26 distinct respiratory measures. High-to-moderate certainty evidence of impairment in PD was identified for vital capacity (standardised mean difference [SMD] 0.75; 95% CI 0.45-1.05; p < 0.00001; I2  = 10%), total chest wall volume (SMD 0.38; 95% CI 0.09-0.68; p = 0.01; I2  = 0%), maximum inspiratory pressure (SMD 0.91; 95% CI 0.64-1.19; p < 0.00001; I2  = 43%) and sniff nasal inspiratory pressure (SMD 0.58; 95% CI 0.30-0.87; p < 0.00001; I2  = 0%). Sensitivity analysis provided high-moderate certainty evidence of impairment for forced vital capacity and forced expiratory volume in 1 s during medication ON phases and increased respiratory rate during OFF phases. Lower certainty evidence identified impairments in PD for maximum expiratory pressure, tidal volume, maximum voluntary ventilation and peak cough flow.

CONCLUSIONS

Strong evidence supports a restrictive pattern with inspiratory muscle weakness in PD compared with healthy controls. Limited data for central impairment were identified with inconclusive findings.

Association between Respiratory Function and Motor Function in Different Stages of Parkinson's Disease

INTRODUCTION

Respiratory dysfunction in patients with Parkinson's disease (PD) could present in the early stage and worsen in the late stages. These changes could be a factor affecting the ability of daily living and quality of life of patients with PD. The primary objective of this study was to assess the respiratory function and its association with motor function in patients with different stages of PD.

METHODS

This was a cross-sectional study conducted at the Huashan Hospital of Fudan University in Shanghai, China. The study included 65 patients diagnosed with PD (the Hoehn and Yahr scale between 1 and 4) and 20 healthy individuals of similar age, gender, weight, and height. The ventilatory function was assessed using the spirometry. Motor function was evaluated using subscale III of the United Parkinson's disease rating scale (UPDRS-III). After confirming the normality of data distribution, we performed one-way ANOVA with a Tukey's post hoc test.

RESULTS

Compared with the healthy individuals, there was no statistical significance in forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) in the H&Y 1 group and H&Y 2 group (p > 0.05) but reduced peak expiratory flow (PEF) in the H&Y 2 group (p = 0.002). Reduced FVC, FEV1, and PEF was seen in the H&Y 3 group (p = 0.002, p = 0.001, and p = 0.0001, respectively). Reduced FVC, FEV1, PEF, and FEF25-75% was seen in the H&Y 4 group (p = 0.001, p = 0.0001, p = 0.0001, and p = 0.025, respectively). The correlation analysis revealed that there was a significant negative correlation between FVC and UPDRS-III scores (r = -0.248, p = 0.046), disease duration (r = -0.276, p = 0.026), H&Y scale (r = -0.415, p = 0.001). FEV1 was negatively correlated with UPDRS-III scores (r = -0.277, p = 0.025), disease duration (r = -0.291, p = 0.019), H&Y scale (r = -0.434, p = 0.0001). FEF25-75% was negatively correlated with disease duration (r = -0.247, p = 0.047), H&Y scale (r = -0.278, p = 0.025).

CONCLUSION

Our findings revealed that respiratory impairment is present in moderate and advanced PD patients, and directly related to the severity of the disease. It is important to conduct respiratory function test in the clinical practice.

Sleep-related hypoventilation and hypercapnia in multiple system atrophy detected by polysomnography with transcutaneous carbon dioxide monitoring

PURPOSE

We aimed to evaluate sleep-related hypoventilation in multiple system atrophy (MSA) using polysomnography (PSG) with transcutaneous partial pressure of carbon dioxide (PtcCO2) monitoring.

METHODS

This prospective study included 34 patients with MSA. Motor and autonomic function, neuropsychological tests, PSG with PtcCO2 monitoring, and pulmonary function tests were performed. Sleep-related hypoventilation disorder (SRHD) was defined according to the International Classification of Sleep Disorders, third edition.

RESULTS

Nine (27%) of the 34 patients met the diagnostic criteria of SRHD. Twenty-nine (85%) patients had sleep-related breathing disorders based on an Apnea-Hypopnea Index of ≥ 5/h. The patients with MSA and SRHD had a higher arousal index (p = 0.017) and obstructive apnea index (p = 0.041) than those without SRHD. There was no difference in the daytime partial pressure of carbon dioxide in arterial blood or respiratory function between MSA patients with and without SRHD.

CONCLUSION

Sleep-related hypoventilation may occur in patients with MSA even with a normal daytime partial pressure of carbon dioxide. This can be noninvasively detected by PSG with PtcCO2 monitoring. SRBD and sleep-related hypoventilation are common among patients with MSA, and clinicians should take this into consideration while evaluating and treating this population.

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.

Risk of SARS-CoV-2 infection, hospitalization and death for COVID-19 in people with Parkinson's disease or parkinsonism over a 15-month period: a cohort study

BACKGROUND

The patterns of long term risk of SARS-CoV-2 infection, hospitalization for COVID-19 and related death are uncertain in people with Parkinson's disease (PD) or parkinsonism (PS). The aim of the study was to quantify these risks compared to a control population cohort, during the period March 2020-May 2021, in Bologna, northern Italy.

METHOD

ParkLink Bologna cohort (759 PD; 192 PS) and controls (9,226) anonymously matched (ratio 1:10) for sex, age, district, comorbidity were included. Data were analysed in the whole period and in the two different pandemic waves (March-May 2020 and October 2020-May 2021).

RESULTS

Adjusted hazard ratio of SARS-CoV-2 infection was 1.3 (95% CI 1.04-1.7) in PD and 1.9 (1.3-2.8) in PS compared to the controls. The trend was detected in both the pandemic waves. Adjusted hazard ratio of hospitalization for COVID-19 was 1.1 (95% CI 0.8-1.7) in PD and 1.8 (95% CI 0.97-3.1) in PS. A higher risk of hospital admission was detected in PS only in the first wave. The 30-day mortality risk after hospitalization was higher (p=0.048) in PS (58%) than in PD (19%) and controls (26%).

CONCLUSIONS

Compared with controls, after adjustment for key covariates, people with PD and PS showed a higher risk of SARS-CoV-2 infection throughout the first 15 months of the pandemic. COVID-19 hospitalization risk was increased only in people with PS and only during the first wave. This group of patients was burdened by a very high risk of death after infection and hospitalization.

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.

Task-related trunk training on balance, trunk control, pulmonary function and quality of life in patients with Parkinson's disease. A randomised controlled trial

Background/Aims

Stooped posture and ‘en-bloc’ movement of the trunk in people with Parkinson's disease are related to balance issues, pulmonary dysfunction and difficulty in daily tasks. The primary objective of this study was to examine the effects of task-related trunk training on balance in people with Parkinson's disease. The secondary objective was to observe whether trunk control, thoracic rotation range, pulmonary function and quality of life would change for patients with Parkinson's disease after trunk training.

Methods

A total of 32 individuals participated in this randomised controlled trial. They had a mean age of 70.8 years, with a modified Hoehn and Yahr Scale grade of 1.5–3, could take more than six steps in the 360° turn test, were scored as grade I or II on the retropulsion test and had an absence of severe cognitive deficits. Task-related trunk training emphasised the thoracic spine's extension and rotation in prone position on elbows, hands and knees and in kneeling, sitting and standing positions. Standard physiotherapy included breathing exercises, stretching of shoulder and neck muscles, balance and walking training. Both groups practised for 1 hour a day, 3 days a week over 6 weeks. The primary outcome measure was the Mini-Balance Evaluation Systems Test. The secondary outcome measures were the Trunk Control Test, thoracic rotation range of movement, Pulmonary Function Test and Parkinson's Disease Questionnaire-39.

Results

Repeated measure analysis of variance revealed significant group by time interaction for the Mini-Balance Evaluation Systems Test and thoracic rotation range (P<0.05), but not for the pulmonary function test and quality of life measures.

Conclusions

Task-related trunk training appears to be more beneficial in the balance capacity of individuals with Parkinson's disease than standard physiotherapy, but does not have any significant effects for pulmonary function and health-related quality of life.

Pulmonary function testing in neuromuscular disease

Neuromuscular disorders frequently compromize pulmonary function and effective ventilation, and a thorough respiratory evaluation often can assist in diagnosis, risk assessment, and prognostication. Since many of these disorders can be progressive, serial assessments may be necessary to best define a trajectory of impairment or improvement with therapy. Patients with neuromuscular diseases may have few respiratory symptoms and limited signs of skeletal muscle weakness, but can have significant respiratory muscle weakness. A single testing modality may fail to elucidate true respiratory compromise, and often a combination of tests is recommended to fully evaluate these patients. Common tests performed in this population include measurement of flow rates, lung volumes, maximal pressures, and airways resistance. This review covers the major respiratory testing modalities available in the evaluation of these patients, emphasizing both the benefits and shortcomings of each approach. The majority of parameters are available in a standard pulmonary laboratory (flows, volumes, static pressures), although referral to a specialized center may be necessary to conclusively evaluate a given patient.

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.

[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.

Detraining Effect on Pulmonary and Cardiovascular Autonomic Function and Functional Outcomes in Patients With Parkinson's Disease After Respiratory Muscle Training: An 18-Month Follow-Up Study

Background: The effect of 3-month respiratory muscle training (RMT) on pulmonary and autonomic function and functional outcomes has been demonstrated in patients with Parkinson's disease (PD); however, there is a paucity of information on the durability of the training effect. In this study, we monitored the pulmonary and cardiovascular autonomic function and clinical severity scales until 18 months after the cessation of RMT to elucidate the detraining effect after RMT.

Methods: All patients with PD receiving RMT were assessed with clinical severity scales as well as pulmonary and autonomic function tests at four different stages (baseline on enrollment, immediately after 3 months of RMT, and 6 and 18 months after cessation of RMT). A control group of PD patients who did not receive RMT was also recruited for comparison. Pulmonary function parameters, including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP), were assessed. Cardiovascular autonomic function was assessed using measures including heart rate response to deep breathing (HRDB), Valsalva ratio, and baroreflex sensitivity. Clinical severity scores were also measured using the Hoehn and Yahr staging and the Unified Parkinson's Disease Rating Scale (UPDRS).

Results: The results showed significant improvements in MIP, MEP, HRDB, and UPDRS immediately after RMT. Despite some decay, the improvements in pulmonary function (MIP and MEP) and functional outcomes (UPDRS) remained significant until 6 months of detraining (9 months after enrollment). However, the improvement in cardiovascular autonomic function (HRDB) was reversed after 6 months of detraining.

Conclusions: Based on these findings, we recommend that RMT may be repeated after at least 6 months after previous session (9 months after enrollment) for patients with PD to maintain optimal therapeutic effects.

Ventilatory Impairments Associated with Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The peripheral and central repercussions of Parkinson's disease (PD) affect the neuromuscular system producing a loss of muscle strength that can influence the respiratory system. Although several studies have examined various respiratory aspects of PD, to the best of our knowledge no study to date has systematically reviewed the existing data.

OBJECTIVES

To examine the available literature related to the respiratory impairment in PD patients.

METHODS

We used PRISMA guidelines when reporting this review. We searched Pubmed, Cinhal, SciELO, and Cochrane Library, from inception until August 2018. Main variables assessed were forced vital capacity percent predicted (FVC%) and forced expiratory volume in 1 s percent predicted (FEV1%) for PD patients.

RESULTS

Six studies were included in this systematic review and meta-analysis. The obtained results concluded that PD patients present poorer pulmonary function when compared to healthy controls. When PD patients were compared between ON and OFF states, the results reviewed are in favour of the ON state. In the meta-analysis performed for FVC% and FEV1%, the results fail to find significant differences between PD patients and controls (p = 0.336 and p = 0.281, respectively), and between PD ON and OFF states (p = 0.109 and p = 0.059, respectively).

CONCLUSIONS

We conclude that PD patients have impaired respiratory capacities that are related to the PD severity, time since diagnosis, and OFF state. Adequate follow-up of the respiratory function and studies focused on PD phenotypes have to be considered in future studies.

Effect of Disease Severity on Respiratory Impedance in Parkinson's Disease

Background:

Parkinson’s disease (PD) is a progressive neurodegenerative disorder. PD has been traditionally perceived as a motor disorder. However, it is frequently associated with pulmonary dysfunction which has been assessed by Spirometry, an effort-dependent technique.

Purpose:

To evaluate in patients with PD the effect of disease severity on respiratory impedance using Impulse Oscillometry (IOS) and to correlate with Spirometry.

Methods:

The study was conducted on 30 patients diagnosed with PD. Pulmonary function was assessed by IOS and spirometer. IOS is an effort-independent technique that uses sound waves of different frequencies to measure airway resistance. Spirometer measures the lung volume and generates flow–volume and volume–time relationship.

Results:

The mean age of patients was 60.1±9.45. Resistance at 5 Hz (R5) was found to be negatively correlated with forced expiratory volume in the first second of the FVC manoeuver (FEV₁) (r = –0.628, P = .002), FEV₁/FVC (forced vital capacity) (r = –0.487, P = .025), and PEF (r = –0.599, P = .004), and resistance at 20 Hz (R20) with FEV₁ (r = –0.474,

P = .029) and PEF (r = –0.522, P = .015). There was significant increase in R5 (0.32(0.36–0.28) vs 0.47(0.60–0.36); P = .04) and R20 (0.25(0.28–0.20) vs 0.30(0.40–0.25); P = .04) in stage II as compared to stage I of Hoehn–Yahr scale.

Conclusion:

IOS might be a promising tool for diagnosis of respiratory dysfunction in addition to Spirometry, especially in cases where patients are not able to perform forced manoeuvers.

Nonpharmacological interventions for respiratory health in Parkinson's disease: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Respiratory dysfunction in Parkinson's disease (PD) is often an underdiagnosed and untreated impairment associated with the disease. Clinically, a reactive approach to respiratory morbidity is taken, rather than preventative approaches that address underlying impairment/s. This systematic review identifies the current evidence to support nonpharmacological interventions to improve respiratory impairments in individuals with PD.

METHODS

The relevant literature was searched using a customised and systematic strategy. Randomised and nonrandomised control trials of nonpharmacological interventions targeting respiratory outcome measures in PD were included. Outcomes of interest were respiratory morbidity and mortality, respiratory muscle strength, spirometry measures, lung volumes, peak cough flow, and perception of dyspnoea.

RESULTS

Nonpharmacological interventions included: functional training, generalised strength training, respiratory muscle strength training, aerobic exercise, qigong, yoga, breath stacking, incentive spirometry and singing. Methodological quality of included studies varied. Meta-analyses of nonpharmacological interventions demonstrated significant effects for inspiratory muscle strength (mean difference [MD] 19.68; confidence interval [CI] 8.49, 30.87; z = 3.45; p = 0.0006; I²  = 2%), expiratory muscle strength (MD 18.97; CI 7.79, 30.14; z = 3.33; p = 0.0009; I²  = 23%) and peak expiratory flow (MD 72.21; CI 31.19, 113.24; z = 3.45; p = 0.0006; I²  = 0%). Best-evidence synthesis identified level 1 evidence supporting nonpharmacological interventions for improving peak cough flow and perceived dyspnoea. No studies were identified reporting outcomes of respiratory rate, inspiration:expiration ratio or respiratory morbidity or mortality in PD.

CONCLUSIONS

Nonpharmacological interventions improved respiratory muscle strength and peak expiratory flow in PD. Additional trials targeting respiratory dysfunction and longitudinal studies examining the relationship between respiratory dysfunction and morbidity and mortality rates in PD are required.

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.

Cough reflex sensitivity and urge-to-cough deterioration in dementia with Lewy bodies

Cough, an important respiratory symptom, predominantly involves the brainstem and the urge-to-cough (UTC) is modulated by the cerebral cortex. Lewy body disease is associated with decreased cough reflex sensitivity and central respiratory chemosensitivity. Additionally, the insula, associated with the UTC, shows decreased activation and atrophy in dementia with Lewy bodies (DLB). We investigated the relationships between cognition and cough reflex and the UTC and compared the differences in responses of patients with DLB and other dementia subtypes.

We conducted a cross-sectional study within a geriatric ward of a university hospital involving elderly patients diagnosed with Alzheimer's disease (AD), DLB, or non-dementia (controls). The cough reflex sensitivities were estimated based on the lowest concentrations of inhaled citric acid that could induce ≥2 coughs (C₂) or ≥5 coughs (C₅). Subjects were asked to rate the UTC based on the threshold concentrations (C_u) using the modified Borg scale.

C₂, C₅ and C_u were negatively correlated with cognitive function in female participants but not in males (p<0.01). The cough reflex sensitivities expressed as C₂ and C₅ were significantly higher in the DLB group than in the AD and control groups (p<0.01 adjusted for gender). The UTC threshold expressed as C_u was also significantly higher in the DLB group, while the UTC log–log slope was less responsive in the DLB group than in the other groups.

The cough reflex sensitivity and perceived UTC deteriorated in the DLB group more than in the other groups. This result might be valuable in treating patients with DLB.

Morbidity and mortality of aspiration pneumonia (AP) in people with dementia are increasing. The cough reflex sensitivity and the urge to cough, which are important responsible factors for AP, are deteriorated in dementia with Lewy bodies.http://bit.ly/2Yyax9w

Simultaneously Improved Pulmonary and Cardiovascular Autonomic Function and Short-Term Functional Outcomes in Patients with Parkinson's Disease after Respiratory Muscle Training

Both pulmonary function and autonomic function are impaired in patients with Parkinson’s diseases (PD). This study tested the hypothesis that respiratory muscle training (RMT) can not only improve pulmonary function, but also simultaneously improve cardiovascular autonomic function and short-term functional outcomes in patients with PD. Pulmonary function was measured by the forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum inspiratory pressures (MIP), and maximum expiratory pressures (MEP). Cardiovascular autonomic function was measured by the heart rate response to deep breathing (HRDB), Valsalva ratio, baroreflex sensitivity, and spectral analysis. The functional and severity scores were measured by the Hoehn and Yahr stage and Unified Parkinson’s Disease Rating Scale (UPDRS). These measures were evaluated in patients with PD before and after 3 months of RMT, compared with a control group of PD patients without RMT. The results showed significant improvement of clinical scores (total UPDRS and UPDRS I, II and III) after RMT (p < 0.0001). Concerning pulmonary function, the parameters of MIP and MEP improved significantly. The parameters of cardiovascular function also improved after RMT, although only HRDB reached statistical significance. Based on the results of our study, RMT can not only improve both pulmonary and cardiovascular autonomic function, but can also improve short-term functional outcomes in patients with PD.

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.

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.

Respiratory repercussions of neurological diseases and how best to manage them

Introduction: The high incidence of respiratory impairments in patients with neurological diseases is recognized, but the design, dosage, and effectiveness of interventions to manage them are seen as an ongoing challenge.Areas covered: This article summarizes the evidence regarding the respiratory impairments in major neurological diseases, and how to best manage them.Expert opinion: On the balance of available evidence, respiratory impairments are part of the clinical profile of neurological diseases including Multiple Sclerosis, Stroke, and Parkinson's Disease, acquiring more importance as the pathologies progress. It is recognized that knowledge gaps remain in some areas of relevance related to respiratory function and further research is required. When considering the therapeutic options, the respiratory training emerges as the approach with most evidence. However, important questions remain unsolved: what kind, how much, and how to best include respiratory interventions is uncertain. At present, respiratory programs also fail to include clinically relevant factors such as ambulation and trunk stability.

Respiratory muscle strength and lung function in the stages of Parkinson's disease

Objective:

To investigate parameters of lung function and respiratory muscle strength in different stages of Parkinson’s disease (PD), as well as to determine their correlation with motor function and quality of life.

Methods:

This was a cross-sectional study conducted at a referral center for PD in the city of Recife, Brazil. Respiratory muscle strength and lung function, as well as their relationship with motor function and quality of life, were evaluated in patients with PD, stratified by the level of severity, and were compared with the data obtained for a control group. After confirming the normality of data distribution, we performed one-way ANOVA with a post hoc t-test.

Results:

The sample comprised 66 individuals, in two groups: PD (n = 49) and control (n = 17). All of the parameters investigated showed inverse correlations with PD severity, and there were significant differences among the levels of severity, as well as between the PD and control groups, in terms of the MIP, MEP, FVC, FEV₁, and FEF_25-75%. The lung function parameters also showed moderate to weak inverse correlations with bradykinesia and rigidity. On a quality of life questionnaire, the total score and mobility domain score both presented a moderate inverse correlation with FVC, FEV₁, PEF, and MEP.

Conclusions:

Respiratory muscle strength and some lung function parameters are impaired from the early stages of PD onward, bradykinesia and rigidity being the cardinal signs that correlate most strongly with impairment of those parameters. Such alterations negatively affect the quality of life of patients with PD.

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.

Association between neurodegenerative diseases and pneumonia: a retrospective population-based study

PURPOSE

The association between pneumonia and neurodegenerative diseases (NDs) has never been reported in detail. We address this relationship with reference to the general population.

METHODS

Using Taiwan's National Health Insurance Research Database to identify a pneumonia cohort (including the typical and atypical), we established an ND cohort of 19,062 patients and a non-ND cohort of 76,227 people. In both cohorts, the risk of pneumonia was measured using multivariable Cox proportional hazards models.

RESULTS

The adjusted hazard ratio (aHR) (95% confidence interval [CI]) for the pneumonia cohort was 2.10 (1.96-2.24), regardless of age, sex, comorbidities or drug use in the ND cohort. The aHR (95% CI) for adults aged 20-49 years was 2.08 (1.58-2.75), men 2.20 (2.01-2.40). However, older subjects were at greatest risk of pneumonia, (3.41 [2.99-3.88]) if the 20-49 years age group is used as the reference. For the ND and non-ND cohorts, those with comorbidities (with the exception of hyperlipidemia) had higher risk; aHR (95% CI) 2.35 (2.30-2.52). The aHR (95% CI) for those without comorbidities is 3.28 (2.52-4.26). No significant difference was observed in incidence of pneumonia between those who were and were not using statin medications; the aHR (95% CI) was 1.03 (0.93-1.14).

CONCLUSION

The ND cohort had a higher risk of pneumonia, regardless of age, sex, comorbidities or statin use. The risk of pneumonia was higher in elderly and male patients in the ND cohort.

Effects of inspiratory muscle training on respiratory muscle strength, lung function, functional capacity and cardiac autonomic function in Parkinson's disease: Randomized controlled clinical trial protocol

BACKGROUND

Individuals with Parkinson's disease (PD), in addition to motor impairment, may evolve with respiratory and autonomic nervous system disorders. Currently, there are few studies with emphasis on muscle and pulmonary dysfunction and that verify the benefits of inspiratory muscle training (IMT) in this population.

AIM

The aim of this study was to evaluate whether IMT is effective for the improvement of respiratory muscle strength, lung function, thoracic mobility, functional capacity and cardiac autonomic function in PD.

METHODS

A randomized and controlled trial will be conducted with 26 participants with idiopathic PD, with aged between 50 and 65 years, in the Stages I to III by the Modified Hoehn and Yahr Scale. Respiratory muscle strength will be performed by manovacuometry and lung function by spirometry. Functional capacity will be evaluated by the 6-min walk test and autonomic cardiac function by heart rate variability. In addition, thoracic mobility measurement will also be performed. After the evaluations, these participants will be randomly assigned to two groups: the IMT group with Powerbreathe^® , which will perform the eight series of 2 min each, with 1 min of rest between them, totaling 30 min, at 60% of the maximum inspiratory pressure and the control group, who will perform the same training protocol but with the load maintained at 9 cmH₂ O. All participants will be submitted to the same motor training protocol.

CONCLUSION

It is expected that IMT increases the inspiratory muscle strength, contributing to the improved expiratory muscle strength, lung function, thoracic mobility, functional capacity and cardiac autonomic function in individuals with mild to moderate PD.

Pulmonary Function Testing in Neuromuscular and Chest Wall Disorders

Neuromuscular and chest wall disorders frequently compromise pulmonary function, and thorough respiratory evaluation often can assist in diagnosis, risk assessment, and prognosis. Because many of these disorders can be progressive, serial assessments are necessary to best define a trajectory of impairment (or improvement with therapy). This article covers the major respiratory testing modalities available in the evaluation of these patients, emphasizing both the benefits and shortcomings of each approach. Most parameters are available in a standard pulmonary laboratory (flows, volumes, static pressures), although referral to a specialized center may be necessary to conclusively evaluate a given patient.

Pneumonia-associated death in patients with dementia: A systematic review and meta-analysis

BACKGROUND

Pneumonia is a serious disease associated with mortality among patients with dementia. However, the reported frequency of pneumonia as a cause of death in patients with dementia varies, the reason for which has not been fully elucidated.

METHODS

We conducted a systematic search in PubMed and the Cochrane Database of Systematic Reviews (inception to December 2016). Two authors independently determined the suitability of studies and potential bias and extracted the data. The primary outcome was frequency of pneumonia-associated death in patients with dementia. Stratified subgroup analysis was conducted among studies grouped according to type of mortality cause (immediate or underlying), information source of mortality cause (autopsy or death certificate), and study setting (clinic, hospital, or nursing home).

RESULTS

We included 7 studies reporting the cause of death among patients with dementia and 12 studies comparing the cause of death among patients with and without dementia. The frequency of pneumonia-associated death among 19 eligible studies was 29.69% (95% confidence interval [CI], 25.86-33.53). Those frequencies differed according to whether the source for information about cause of death was an autopsy confirmation (49.98%; 95% CI, 43.75-56.71) or death certificate (19.65%; 95% CI, 15.48-23.83) and according to whether the type of mortality cause was an indirect cause of death (13.96%; 95% CI, 9.42-18.51) or direct cause of death (44.45%; 95% CI, 29.81-50.10). The risk of pneumonia-associated death in patients with dementia was twice as high as among those without dementia (odds ratio, 2.15; 95% CI, 1.63-2.83; p < 0.001).

CONCLUSION

The various frequencies of pneumonia-associated death in patients with dementia were associated with the information source, type of mortality cause, and study setting. Patients with dementia in the terminal stages urgently require careful clinical management of pneumonia, to maximize patient life expectancy and quality.

A cross-sectional analysis of clinical evaluation in 35 individuals with mutations of the valosin-containing protein gene

Inclusion body myopathy (IBM) associated with Paget disease of the bone and frontotemporal dementia or IBMPFD is an autosomal dominant degenerative disorder caused by mutations in the valosin-containing protein (VCP) gene. We aim to establish a detailed clinical phenotype of VCP disease amongst 35 (28 affected individuals, 7 presymptomatic gene carriers) individuals versus 14 unaffected first-degree relatives in 14 families to establish useful biomarkers for IBMPFD and identify the most meaningful tests for monitoring disease progression in future clinical trials. Comprehensive studies included the Inclusion Body Myositis Functional Rating Scale (IBMFRS) and fatigue severity scale questionairres, strength measurements using the Manual Muscle Test with Medical Research Council (MRC) scales, hand-held dynamometry using the microFET and Biodex dynamometers, 6 minute walk test (6MWT), and pulmonary function studies. Strong correlation was observed between the IBMFRS and measurements of muscle strength with dynamometry and the other functional tests, indicating that it may be utilized in long-term follow-up assessments due to its relative simplicity. This cross-section study represents the most comprehensive evaluation of individuals with VCP disease to date and provides a useful guide for evaluating and possible monitoring of muscle weakness and pulmonary function progression in this unique cohort of individuals.

Mortality and quality of death certification in a cohort of patients with Parkinson's disease and matched controls in North Wales, UK at 18 years: a community-based cohort study

OBJECTIVE

This investigation reports the cause and the quality of death certification in a community cohort of patients with Parkinson's disease (PD) and controls at 18 years.

SETTING

Denbighshire North Wales, UK.

PARTICIPANTS

The community-based cohorts consisted of 166 patients with PD and 102 matched controls.

PRIMARY OUTCOMES

All-cause mortality was ascertained at 18 years by review of hospitals' primary care records and examination of death certificates obtained from the UK General Register Office. Mortality HRs were estimated using Cox proportional regression, controlling for covariates including age at study entry, age at death, gender, motor function, mood, health-related quality of life (HRQoL) and cognitive function.

RESULTS

After 18 years, 158 (95%) of patients in the PD cohort and 34 (33%) in the control cohort had died. Compared with the general UK population, the PD cohort had a higher risk of mortality (standard mortality rate, 1.82, 95% CI 1.55 to 2.13). As the primary or underlying cause of death, PD was not reported in 75/158 (47%) of the death certificates. In addition, although 144/158 (91%) of the PD cohort had a diagnosis of dementia, this was reported in less than 10% of death certificates. The main cause of death reported in the PD cohort was pneumonia (53%), followed by cardiac-related deaths (21%). Compared with controls, patients with PD had a greater risk of pneumonia (2.03, 95% CI 1.34 to 3.6), poorer HRQoL and more likely to reside in institutional care at death (P<0.01).

CONCLUSION

This investigation found that PD was associated with an excess risk of mortality compared with the general population. However, PD as a primary or underlying cause of death recorded on certificates was found to be suboptimal. This suggests that the quality of mortality statistics drawn from death certificates alone is not a valid or reliable source of data.

Ventilatory Dysfunction in Parkinson's Disease

In contrast to some other neurodegenerative diseases, little is known about ventilatory dysfunction in Parkinson’s disease (PD). To assess the spectrum of ventilation disorders in PD, we searched for and reviewed studies of dyspnea, lung volumes, respiratory muscle function, sleep breathing disorders and the response to hypoxemia in PD. Among the studies, we identified some limitations: (i) small study populations (mainly composed of patients with advanced PD), (ii) the absence of long-term follow-up and (iii) the absence of functional evaluations under “off-drug” conditions. Although there are many reports of abnormal spirometry data in PD (mainly related to impairment of the inspiratory muscles), little is known about hypoventilation in PD. We conclude that ventilatory dysfunction in PD has been poorly studied and little is known about its frequency and clinical relevance. Hence, there is a need to characterize the different phenotypes of ventilation disorders in PD, study their relationships with disease progression and assess their prognostic value.

Electromyographic activities of the abdominal muscles during 30% and 75% of maximum expiratory pressure

The aim of this study was to quantify the activities of the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles during 30% and 75% of maximum expiratory pressure (PE max). Fifteen healthy male university students participated in this study. Electromyographic (EMG) activities of the RA, EO, and IO muscles were measured during 30% and 75% of PE max and then normalized relative to maximum voluntary contractions (%MVC). All muscles during 75% of PE max showed significantly higher %MVC compared to that during 30% of PE max (P < 0.01). The EO and IO muscles showed significantly higher %MVC compared to the RA muscle during 30% and 75% of PE max (P < 0.05). Muscle endurance and strength induced by expiratory muscle strength training might be different in each abdominal muscle.

Multiple System Atrophy - State of the Art

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disorder that is characterized by a variable combination of parkinsonism, cerebellar impairment, and autonomic dysfunction. Some symptomatic treatments are available while neuroprotection or disease-modification remain unmet treatment needs. The pathologic hallmark is the accumulation of aggregated alpha-synuclein (α-syn) in oligodendrocytes forming glial cytoplasmic inclusions, which qualifies MSA as synucleinopathy together with Parkinson's disease and dementia with Lewy bodies. Despite progress in our understanding of the pathogenesis of MSA, the origin of α-syn aggregates in oligodendrocytes is still a matter of an ongoing debate. We critically review here studies published in the field over the past 5 years dealing with pathogenesis, genetics, clinical signs, biomarker for improving diagnostic accuracy, and treatment development.

Oleic Derivatives of Dopamine and Respiration

Ventilatory inhibition is considered an undesirable pharmacological side effect of pharmacotherapy in neurodegenerative conditions underlain by brain dopamine deficiency. In this context, oleic derivatives of dopamine or N-acyl-dopamines are novel substances that may be of high therapeutic interest as having the ability to cross the blood-brain barrier and acting in dopamine-like manner. In the present study we seek to define the influence of N-acyl-dopamines on lung ventilation and its hypoxic responses in the rat. We found that N-oleoyl-dopamine decreased both normoxic and peak hypoxic ventilation in response to 8% acute hypoxia, on average, by 31% and 41%, respectively. Its metabolite, 3'-O-methyl-N-oleoyl-dopamine, caused a 15% ventilatory decrease each, whereas an oleic ester derivative, 3'-O-oleoyl-N-oleoyl-dopamine, caused 11% and 19% ventilatory decreases, respectively. All three N-acyl-dopamines investigated displayed an inhibitory effect on ventilation. The findings indicate that 3'-O-methyl-N-oleoyl-dopamine and 3'-O-oleoyl-N-oleoyl-dopamine performed better than N-oleoyl-dopamine in term of less ventilatory suppression, albeit the differences among the three compounds were modest. We conclude that N-acyl-dopamines are worthy of intensified explorations as potential carriers of dopamine molecule in view of the lack of clinically effective methods of dopamine delivery into the brain in neurodegenerative conditions.

Measurement of Voluntary Cough Production and Airway Protection in Parkinson Disease

OBJECTIVE

To examine relations between peak expiratory (cough) airflow rate and swallowing symptom severity in participants with Parkinson disease (PD).

DESIGN

Cross-sectional study.

SETTING

Outpatient radiology clinic at an acute care hospital.

PARTICIPANTS

Men and women with PD (N=68).

INTERVENTIONS

Participants were cued to cough into an analog peak flow meter then swallowed three 20-mL thin liquid barium boluses. Analyses were directed at detecting potential relations among disease severity, swallowing symptom severity, and peak expiratory (cough) airflow rate.

MAIN OUTCOME MEASURES

Peak expiratory (cough) airflow rate and swallow symptom severity.

RESULTS

Peak expiratory (cough) airflow rate varied significantly across swallowing severity classifications. Participants with more severe disease displayed a significant, linear decrease in peak expiratory (cough) airflow rate than those participants with earlier stage, less severe disease. Swallowing symptom severity varied significantly across groups when comparing participants with less severe PD with those with more severe PD. Participants with early stage PD demonstrated little to no swallowing symptoms and had the highest measures of peak expiratory (cough) airflow rate. In contrast, participants with the most severe swallowing symptoms also displayed the lowest measures of peak expiratory (cough) airflow rate.

CONCLUSIONS

Relations existed among PD severity, swallowing symptom severity, and peak expiratory (cough) airflow rate in participants with PD. Peak expiratory (cough) airflow rate may eventually stand as a noninvasive predictor of aspiration risk in those with PD, particularly those with later stage disease. Inclusion of peak expiratory (cough) airflow rates into existing clinical swallowing assessments may increase the sensitivity and predictive validity of these assessments.

Post-mortem brain pathology is related to declining respiratory function in community-dwelling older adults

Damage to brain structures which constitute the distributed neural network that integrates respiratory muscle and pulmonary functions, can impair adequate ventilation and its volitional control. We tested the hypothesis that the level of brain pathology in older adults is associated with declining respiratory function measured during life. 1,409 older adults had annual testing with spirometry (SPI) and respiratory muscle strength (RMS) based on maximal inspiratory and maximal expiratory pressures (MEPs). Those who died underwent structured brain autopsy. On average, during 5 years of follow-up, SPI and RMS showed progressive decline which was moderately correlated (ρ = 0.57, p < 0.001). Among decedents (N = 447), indices of brain neuropathologies showed differential associations with declining SPI and RMS. Nigral neuronal loss was associated with the person-specific decline in SPI (Estimate, −0.016 unit/year, S.E. 0.006, p = 0.009) and reduction of the slope variance was equal to 4%. By contrast, Alzheimer’s disease (AD) pathology (Estimate, −0.030 unit/year, S.E. 0.009, p < 0.001) and macroscopic infarcts (−0.033 unit/year, S.E., 0.011, p = 0.003) were associated with the person-specific decline in RMS and reduction of the slope variance was equal to 7%. These results suggest that brain pathology is associated with the rate of declining respiratory function in older adults.

Design, synthesis and biological evaluation of praziquantel and endoperoxide conjugates as antischistosomal agents

Background: The widespread use of praziquantel for the treatment of schistosomiasis has led to concerns over the potential development of drug resistance. Therefore, the discovery of novel antischistosomal agents is imperative. In this study, a series of praziquantel and endoperoxide conjugates were synthesized and evaluated as potential antischistosomal agents. Results: Some compounds exhibited high efficacy against both adult and juvenile Schistosoma, in in vitro studies. Structure-activity relationship (SAR) analysis revealed that compounds with amide bond linker and cyclopentyl adjacent to the 1,2,4,5-tetraxane pharmacophore displayed the highest efficacy. Overall, compounds showed consistent activity against Schistosoma japonicum and Schistosoma mansoni. In vivo study resulted in moderate but statistically significant activity. Conclusion: Important preliminary results were obtained from thorough activity evaluation of praziquantel-endoperoxide conjugates. Further pharmacokinetic property investigation is necessary to improve in vivo efficacy.