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

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.

A Pilot Study of the Effect of a Non-Contact Boxing Exercise Intervention on Respiratory Pressure and Phonation Aerodynamics in People with Parkinson's Disease

This study investigated the effects of a non-contact boxing exercise program on maximum expiratory pressure and aerodynamic voice measurements.

METHODS

Eight adult males diagnosed with Parkinson's disease participated in the study. Individuals participated in twice-weekly exercise classes lasting one hour across 12-months. Dependent variables were measured on three baseline days and then at six additional time points. A pressure meter acquired maximum expiratory pressure, and a pneumotachograph system acquired transglottal airflow and subglottal air pressure.

RESULTS

Measures of average maximum expiratory pressure significantly increased after 9- and 12- months of exercise when compared to baseline. There was an increasing trend for these measures in all participants, with a corresponding large effect size. Measures of transglottal airflow and subglottal pressure did not change over the course of 9- or 12-months, although their stability may indicate that the exercise program influenced maintenance of respiratory-phonatory coordination during voicing.

CONCLUSIONS

A non-contact boxing exercise program had a significant effect on maximum expiratory pressure in people with Parkinson's disease. The aerobic nature of the program and challenges to the respiratory muscles potentially explain the "ingredient" causing this effect. The small sample size of this pilot study necessitates future research incorporating larger and more diverse participants.

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.

Perceptual and qualitative voice alterations detected by GIRBAS in patients with Parkinson's disease: is there a relation with lung function and oxygenation?

BACKGROUND

Impairments in respiration, voice and speech are common in people with Parkinson's disease (PD).

AIMS

To evaluate the prevalence of dysphonia, assessed by a specific acoustic evaluation and description of the voice by the speech therapist (GIRBAS), and its relation with lung function and oxygenation, in particular cough ability and during the night or exercise desaturation.

METHODS

This is a posthoc analysis of a prospective cross-sectional observational study on PD patients collecting anthropometric and clinical data, comorbidities, PD severity, motor function and balance, respiratory function at rest, during exercise and at night, voice function with acoustic analysis and presence of speech disorders, in addition to the GIRBAS scale. Based on GIRBAS Global dysphonia ('G') score, we divided patients into dysphonic (moderate-to-severe deviance from the euphonic condition) vs. no/mild dysphonic and analyzed the relations with respiratory impairments.

RESULTS

We analyzed 55 patients and found significant impairments in both respiratory and voice/speech functions. Most patients (85.5%) presented mild-to-severe deviance from the euphonic condition in at least one GIRBAS perceptual element (80% of cases for Global dysphonia) and only 14.5% did not show deviance in all elements simultaneously. At Odds Ratio analysis, the risk of presenting nocturnal desaturation and reduced peak cough expiratory flow was approximately 24 and 8 times higher, respectively, in dysphonic patients vs. those with no/mild dysphonia.

CONCLUSION

Perceptual and qualitative evaluation of the voice with GIRBAS showed that mild-to-severe dysphonia was highly prevalent in PD patients, and associated with nocturnal oxygen desaturation and poor cough ability.

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.

Abnormal Pulmonary Function in Early Parkinson's Disease: A Preliminary Prospective Observational Study

Early Parkinson’s disease (PD) may cause respiratory dysfunction; however the findings vary among studies. The aim of the preliminary prospective observational study was to explore the deterioration of pulmonary function at various stages in patients with early PD. A total of 237 patients with PD were screened. Fifty-six patients were included (modified Hoehn and Yahr stage ≤ 2.5). In addition, 56 age-matched healthy controls were also included in the study. Significant differences between the PD and control groups were found in all the investigated lung-function parameters. The maximal voluntary ventilation (MVV) percent predicted was the only parameter that distinguished PD stages (101.1 ± 14.9% vs. 82.8 ± 19.2% vs. 71.4 ± 12.9%, Hoehn and Yahr stages 1.5 vs. 2 vs. 2.5, respectively; p < 0.005). MVV could be the most sensitive parameter for distinguishing the severity of early-stage 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.

The Role of the Diaphragm in Postural Stability and Visceral Function in Parkinson's Disease

Background: In normal subjects, the diaphragm plays a key functional role in postural stability, articulation, respiration, defecation, and urination.

Objectives: The aim of this study was to investigate the role of the diaphragm in postural stability and visceral function in patients with Parkinson’s disease (PD) and to compare the diaphragm function by gender, Hoehn and Yahr (H&Y) staging, and motor subtypes.

Methods: In total, 79 patients were enrolled in this cross-sectional study. The severity of the disease was assessed by the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale III and by H&Y staging. Postural stability was quantitatively recorded, and respiratory function was evaluated by spirometry. Several scales were used to evaluate visceral function in patients with PD. In addition, diaphragm ultrasound was used to measure the excursion, contraction velocity, and thickness of the diaphragm during quiet breathing, deep breathing, and the sniff test. Significant features were selected by the least absolute shrinkage and selection operator (LASSO) regression and fitted in the multivariate linear regression and Pearson’s correlation analysis.

Results: Diaphragm thickness and excursion during quiet breathing were significantly different between men and women and between H&Y stage 1–2 and stage 2.5–3, whereas the diaphragm function was not influenced by motor subtypes. It was shown that the diaphragmatic function was significantly correlated with postural stability, voice function, respiratory function, constipation, and urological function to varying degrees in patients with PD.

Conclusion: The diaphragmatic function is associated with dysfunction in PD although it remains unclear as to whether the observed changes in the diaphragm are primary or secondary.

Management of Sleep Disturbances in Parkinson's Disease

Parkinson's disease (PD) is defined by its motor symptoms rigidity, tremor, and akinesia. However, non-motor symptoms, particularly autonomic disorders and sleep disturbances, occur frequently in PD causing equivalent or even greater discomfort than motor symptoms effectively decreasing quality of life in patients and caregivers. Most common sleep disturbances in PD are insomnia, sleep disordered breathing, excessive daytime sleepiness, REM sleep behavior disorder, and sleep-related movement disorders such as restless legs syndrome. Despite their high prevalence, therapeutic options in the in- and outpatient setting are limited, partly due to lack of scientific evidence. The importance of sleep disturbances in neurodegenerative diseases has been further emphasized by recent evidence indicating a bidirectional relationship between neurodegeneration and sleep. A more profound insight into the underlying pathophysiological mechanisms intertwining sleep and neurodegeneration might lead to unique and individually tailored disease modifying or even neuroprotective therapeutic options in the long run. Therefore, current evidence concerning the management of sleep disturbances in PD will be discussed with the aim of providing a substantiated scaffolding for clinical decisions in long-term PD therapy.

Exercise Intolerance and Oxygen Desaturation in Patients with Parkinson's Disease: Triggers for Respiratory Rehabilitation?

The role that oxygen desaturation plays in exercise tolerance and its rehabilitative implications in patients with Parkinson's disease (PD) are unclear. We aimed to test exercise tolerance and oxygen saturation levels both during exercise and at night in PD patients to better define their rehabilitative needs. In clinically stable PD patients, undergoing inpatient rehabilitation, and in "ON" phase, we prospectively assessed clinical data, sleepiness, comorbidities, PD severity (Hoehn&Yahr, HY), motor function (ADLs, UPDRSII and UPDRSIII, Barthel Index, Functional Independence Measure), balance, spirometry, respiratory muscles (MIP/MEP), peak cough expiratory flow (PCEF), continuous night oxygen monitoring, and meters at 6MWT. Of 55 patients analyzed (28 with moderate-severe PD, HY ≥ 2.5), 37% and 23% showed moderate-severe impairment on UPDRSII and UPDRSIII, respectively; 96% had reduced exercise tolerance and severe respiratory muscles impairment (MIP/MEP < 45% pred.); 21.8% showed desaturations during exercise; and 12.7% showed nocturnal desaturations. At multiple regression, low exercise tolerance and low mean nocturnal and exercise-induced saturation correlated with several respiratory and motor function and disability indices (all p < 0.03). Exercise tolerance, exercise-induced desaturations, and nocturnal desaturations were extremely frequent in PD patients and were worse in more severe PD patients. This suggests considering a combined role for motor and respiratory rehabilitation in these patients.

Respiratory Disorders in Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) non motor symptoms may present early in the disease course and worsen with advancing disease. Respiratory changes can affect individuals to remain physically active, contributing to a reduction of functionality and quality of life.

OBJECTIVE

The aim of this systematic review is to synthesize evidence of respiratory disorders in patients with PD.

METHODS

An electronic search was performed up to November 2020 on PubMed-MEDLINE, Embase, Web of Science, Lilacs, Cinahl, and Cochrane using the following keyword combination: [("Parkinson disease") AND ("respiratory function tests" OR "evaluation") AND ("respiratory system" OR "respiration disorders" OR "respiratory muscles")].

RESULTS

The electronic search resulted in 601 references in English or Portuguese. The selection process and data extraction were made by two independent reviewers. We selected 19 studies including cross-sectional studies that investigated the respiratory disorders in patients with PD through pulmonary function, respiratory muscle strength, or physical capacity evaluation. We excluded studies that considered patients with other diseases. Eighteen studies evaluated the pulmonary function in patients with PD, eleven studies verified the influence of PD on respiratory muscle strength, and three studies assessed the physical capacity through functional tests.

CONCLUSION

The evidence showed that PD patients have higher chances to present a pulmonary dysfunction, either obstructive or restrictive, when compared to healthy subjects. In addition, these patients present lower respiratory muscle strength and a consequent decrease in physical capacity in endurance exercises. The respiratory impairment in PD seems to be directly related to the progression of the disease.

Compensatory metabolic and central respiratory drive mechanisms in ALS

Introduction: Airway pressure in the first 100 ms of an occluded inspiration (P0.1) evaluates respiratory center activity. Its increase compensates for respiratory muscle weakness in amyotrophic lateral sclerosis (ALS). We aimed to evaluate if an exhaustion over disease progression emerges. Methods: Consecutive ALS patients with P0.1 at baseline (T0) above 90th percentile for the whole population were included. There were two patient categories within this population: G1 patients had respiratory function tests (RFT) at T0 and 6 months later (T1); G2 patients were immediately adapted to noninvasive ventilation at T0. Functional ALS rating scale (ALSFRS) and its subscores, RFT including maximal inspiratory pressure (MIP), P0.1 percentage (%P0.1), P0.1/MIP, blood gas analyses, phrenic nerve motor amplitude and nocturnal pulsed oximetry (NPO) were compared at T0 between groups (Mann-Whitney U test) and longitudinal progression in G1 was assessed (Wilcoxon test). p < 0.05 was taken as significant. Results: Forty-nine patients were studied: 13 men, mean disease duration 17.1 ± 19.5 months, 21 with spinal-onset; 27 bulbar-onset; one with respiratory presentation. In G1, there was a progressive deterioration in all variables but P0.1/MIP did not significantly change (p = 0.394). PCO₂ (p = 0.045) and bicarbonate ion (HCO₃^-p = 0.054) increased. In G2, the ALSFRS (p = 0.049) scores were lower, PCO₂ (p = 0.057) and HCO₃^- (p = 0.016) higher, and reduced arterial oxygen saturation (SpO₂<90%) at NPO (p = 0.007). Discussion: Patients with high central respiratory drive responses did not develop a short-term "exhaustion phenomenon". Both metabolic and central respiratory mechanisms interact to compensate for respiratory muscle weakness. The role of spasticity and the respiratory-metabolic-renal buffering system deserves further studies.

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.

Mouth occlusion pressure at 100ms (P0.1) as a respiratory biomarker in amyotrophic lateral sclerosis

INTRODUCTION

Airway pressure in the first 100ms of an occluded inspiration (P0.1) evaluates the respiratory center activity, increasing in the presence of respiratory muscle weakness. It is uncertain if its activity can compensate for respiratory muscles weakness in amyotrophic lateral sclerosis (ALS). Methods: Consecutive ALS patients with P0.1 evaluated at first visit were included. Depending on P0.1 percentile, patients were divided in three groups: G1 (<25th percentile); G2 (25th-74th percentiles); G3 (≥75th percentile); two subgroups were further considered: SG0 (<10th percentile); SG1 (>90th percentile). Body mass index (BMI), functional ALS rating scale and its subscores, respiratory function tests, including forced vital capacity, maximal inspiratory (MIP) and expiratory pressures, percentage of P0.1 (%P0.1), blood gas analyses, phrenic nerve motor amplitude (MeanPhrenAmpl) were compared. P0.1/MIP and %P0.1 predictors were explored by linear and multinomial logistic regression analyses. p < 0.05 was considered as significant. Results: From the 497 patients included, 124 were in G1 and G3 each, 249 in G2, 49 in SG0 and SG1 each. G1 included more men, with higher BMI (p < 0.001). G3 had older women, with predominant bulbar phenotype (p < 0.001). Lower respiratory function (p < 0.05) was present in both groups. SG0 (%P0.1 < 51.73%, P0.1/MIP = 1.48 ± 1.02) had more spinal-onset men (p < 0.001) with lower MeanPhrenAmpl (p < 0.004). SG1 (P0.1 > 147.12, P0.1/MIP = 7.92 ± 4.62) predominantly included older patients (p = 0.033), women (p = 0.012), with lower MeanPhrenAmpl (p = 0.039). Discussion: ALS patients with respiratory failure can show high or low P01 values, related to phenotype. Possible central drive reactivity and exhaustion, and the role of respiratory-metabolic-renal buffering system should be further addressed.

Alleviating toxic α-Synuclein accumulation by membrane depolarization: evidence from an in vitro model of Parkinson's disease

Parkinson's disease (PD) is characterized by the formation of toxic, fibrillar form alpha-synuclein (α-Syn) protein aggregates in dopaminergic neurons. Accumulating evidence has shown a multifactorial interplay between the intracellular calcium elevation and α-Syn dynamics. However, whether membrane depolarization regulates toxic α-Syn aggregates remains unclear. To understand this better, we used an in vitro α-Syn preformed fibrils (PFF) model of PD in human neural cells. We demonstrated functional membrane depolarization in differentiated SH-SY5Y cells induced by two independent treatments: high extracellular K⁺ and the GABA_A receptor blocker picrotoxin. We then observed that these treatments significantly alleviated toxic α-Syn aggregation in PFF-treated SH-SY5Y cells. Moreover, clinically relevant direct current stimulation (DCS) also remarkably decreased toxic α-Syn aggregation in PFF-treated SH-SY5Y cells. Taken together, our findings suggest that membrane depolarization plays an important role in alleviating PFF-induced toxic α-Syn aggregates, and that it may represent a novel therapeutic mechanism for PD.

Impact of Age-related Diseases on Pulmonary Function Tests in Older Japanese Adults: A Cross-sectional Pilot Study

Introduction:

A widely used reference range for pulmonary function testing was derived from middle-aged, healthy, non-smoking adults in Japan. This study examined the effect of age-related diseases on pulmonary function tests for older Japanese adults.

Methods:

All patients aged ≥65 years who underwent spirometry before general and orthopedic surgeries in Itoigawa General Hospital (Niigata, Japan) from January 2014 to June 2019 were identified, and their charts were reviewed.

Results:

This study included 1050 Japanese patients (median age: 75 years). The median spirometric values of vital capacity, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and FEV1/FVC in all patients were 2.66 L [interquartile range; 2.24, 3.25], 2.57 L [2.13, 3.13], 1.98 L [1.66, 2.37], and 77.5% [72.2, 81.9], respectively. Multiple regression analyses revealed that spirometric values were significantly affected by age, body height, sex, smoking status, social dependency, dyslipidemia, diabetes, history of heart failure, peripheral artery disease, end-stage renal disease, neuromuscular disease, and psychiatric disorders. Male sex and height were positively correlated with FVC and FEV1. Other factors, such as a history of heart failure, neuromuscular disease, and independent physical activity, were negatively correlated with FVC and FEV1 to almost the same extent as that of age.

Conclusions:

These data will provide clinically useful information to accurately interpret pulmonary function test results in older Japanese adults.

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.

Adipose Stem Cell-Based Clinical Strategy for Neural Regeneration: A Review of Current Opinion

Nerve injury is a critical problem in the clinic. Nerve injury causes serious clinic issues including pain and dysfunctions for patients. The disconnection between damaged neural fibers and muscles will result in muscle atrophy in a few weeks if no treatment is applied. Moreover, scientists have discovered that nerve injury can affect the osteogenic differentiation of skeletal stem cells (SSCs) and the fracture repairing. In plastic surgery, muscle atrophy and bone fracture after nerve injury have plagued clinicians for many years. How to promote neural regeneration is the core issue of research in the recent years. Without obvious effects of traditional neurosurgical treatments, research on stem cells in the past 10 years has provided a new therapeutic strategy for us to address this problem. Adipose stem cells (ASCs) are a kind of mesenchymal stem cells that have differentiation potential in adipose tissue. In the recent years, ASCs have become the focus of regenerative medicine. They play a pivotal role in tissue regeneration engineering. As a type of stem cell, ASCs are becoming popular for neuroregenerative medicine due to their advantages and characteristics. In the various diseases of the nervous system, ASCs are gradually applied to treat the related diseases. This review article focuses on the mechanism and clinical application of ASCs in nerve regeneration as well as the related research on ASCs over the past decades.