Pulmonary complications of chronic neuromuscular diseases and their management

Management of neurological problems in children on home invasive mechanical ventilation

INTRODUCTION

Home invasive mechanical ventilation (HIMV) has become a crucial long-term respiratory support for children with neurological disorders, but requires advanced technological skills and 24-h care. The increasing global population of children on HIMV is attributed to advancements in intensive care and improved survival rates.

METHOD

The manuscript will review the most common neurological problems encountered in children on HIMV.

CONCLUSION

The manuscript emphasizes the multidisciplinary nature of managing these patients, involving pediatric pulmonologists, pediatric neurologists, pediatric intensivists, nurses, therapists, dietitians, psychologists, and caregivers. The manuscript outlines the challenges posed by neurological disorders, such as spinal muscular atrophy, muscular dystrophy, cerebral palsy, spinal cord injuries, and neurodegenerative disorders, which may result in respiratory muscle weakness and impaired ventilation. The importance of individualized assessments, appropriate ventilator mode and equipment selection, training of caregivers, airway clearance techniques, nutritional support, regular follow-up visits, psychological and educational support, and addressing specific neurological issues such as involuntary movement disorders, prolonged seizures, sleep disorders, pain, sialorrhea, and immobilization-related complications are discussed. The treatment options for these specific challenges are outlined. This review highlights the complex nature of managing children with neurological disorders on HIMV and the importance of a collaborative approach among healthcare professionals and caregivers to optimize care and improve the quality of life for these children.

Respiratory comorbidities and treatments in Duchenne muscular dystrophy: impact on life expectancy and causes of death

BACKGROUND

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder with progressive decline of pulmonary function increasing the risk of early mortality. The aim of this study was to explore the respiratory-related comorbidities, and the effect of these comorbidities and treatments on life expectancy and causes of death.

METHODS

All male patients living in Sweden with DMD, born and deceased 1970-2019, were included. Data regarding causes of death were collected from the Cause of Death Registry and cross-checked with the medical records along with diagnostics and relevant clinical features.

RESULTS

Hundred and twenty nine patients were included with a median lifespan of 24.3 years. Acute respiratory failure accounted for 63.3% of respiratory-related causes of death. 70.1% suffered at least one pneumonia, with first episode at a median age of 17.8 years. Hypoventilation was found in 73.0% with onset at 18.1 years. 60.5% had their first pneumonia before established hypoventilation. Age at onset of hypoventilation showed a strong correlation with age at first pneumonia. First pneumonia and scoliosis non-treated with scoliosis surgery increased the risk of dying of respiratory-related causes. In 10% of the patients, first pneumonia resulted in acute tracheostomy or early death. Patients treated with assisted ventilation had higher life expectancy compared to untreated patients.

CONCLUSIONS

Our results highlight the importance of identifying subclinical hypoventilation in a timely manner and the importance of an active treatment regime upon clinical signs of pneumonia.

Introducing Mechanically Assisted Cough for Patients With Progressive Neurological Disease: Patient-Physical Therapist Interaction and Physical Therapist Perspective

OBJECTIVE

The goal of this study was to explore the patient-physical therapist interaction and the physical therapist's experience of the introductory session for mechanical insufflation-exsufflation (MI-E) device treatment for patients with progressive neurological disease.

METHODS

Qualitative content analysis of participant's observation of interaction between patients and physical therapists during 9 MI-E introduction sessions in different clinical care settings and 10 follow-up interviews with 6 physical therapists.

RESULTS

The introduction of MI-E emerged as a process of instilling a sense of security in the patient. The process can be described in 4 steps: (1) gain understanding by being responsive to the person's whole life situation; (2) share knowledge and expectations in a respectful and permissive way; (3) introduce the device in a gentle and reciprocal interactivity; and (4) adapt to home use in an inclusive dialog with the patient and their significant others. Physical therapists described a need for assurance to instill a sense of security in the patient, implying a need for confidence, competent peers, guiding yet flexible routines, and emotional support.

CONCLUSION

Physical therapists have a need to foster assurance in employing a person-centered approach to make a patient feel secure in the process of introducing MI-E treatment. Multiple modes of professional knowledge were used together with action-based and relational-based ethics to facilitate a person-centered care approach. This seems to be a promising approach for providing good care when introducing MI-E to patients. Further research is needed to explore this from the patient's perspective.

IMPACT

This study added to the body of knowledge regarding MI-E treatment in relation to patients. This has direct implication, particularly for inexperienced physical therapists, for informed care for the patient during introduction. Our study also supports that person-centered care should be implemented at all levels of health care to make it possible for physical therapists to practice person-centered care.

Chemogenetic stimulation of phrenic motor output and diaphragm activity

Impaired diaphragm activation contributes to morbidity and mortality in many neurodegenerative diseases and neurologic injuries. We conducted experiments to determine if expression of an excitatory DREADD (designer receptors exclusively activation by designer drugs) in the mid-cervical spinal cord would enable respiratory-related activation of phrenic motoneurons to increase diaphragm activation. Wild type (C57/bl6) and ChAT-Cre mice received bilateral intraspinal (C4) injections of an adeno-associated virus (AAV) encoding the hM3D(Gq) excitatory DREADD. In wild type mice, this produced non-specific DREADD expression throughout the mid-cervical ventral horn. In ChAT-Cre mice, a Cre-dependent viral construct was used to drive DREADD expression in C4 ventral horn motoneurons, targeting the phrenic motoneuron pool. Diaphragm EMG was recorded during spontaneous breathing at 6-8 weeks post-AAV delivery. The selective DREADD ligand JHU37160 (J60) caused a bilateral, sustained (>1 hr) increase in inspiratory EMG bursting in both groups; the relative increase was greater in ChAT-Cre mice. Additional experiments in a ChAT-Cre rat model were conducted to determine if spinal DREADD activation could increase inspiratory tidal volume (VT) during spontaneous breathing without anesthesia. Three to four months after intraspinal (C4) injection of AAV driving Cre-dependent hM3D(Gq) expression, intravenous J60 resulted in a sustained (>30 min) increase in VT assessed using whole-body plethysmography. Subsequently, direct nerve recordings confirmed that J60 evoked a >50% increase in inspiratory phrenic output. The data show that mid-cervical spinal DREADD expression targeting the phrenic motoneuron pool enables ligand-induced, sustained increases in the neural drive to the diaphragm. Further development of this technology may enable application to clinical conditions associated with impaired diaphragm activation and hypoventilation.

Clinical phenotypes of nontuberculous mycobacterial disease by cluster analysis based on pulmonary function

BACKGROUND

Nontuberculous mycobacterial pulmonary disease (NTM-PD) often exhibits pulmonary function impairment, such as obstructive or restrictive pattern, with variation among patients according to the damaged lesions in the lung.

METHODS

Patients with NTM-PD were consecutively enrolled between September 2019 and December 2020 at the Respiratory Infection Clinic of our hospital. Patients' data were comprehensively collected through laboratory examinations, PFT, chest computed tomography, and questionnaires for the assessment of subjective symptoms and health-related quality of life (HRQOL). Hierarchical cluster analysis was performed using PFT parameters to compare the clinical findings among clusters.

RESULTS

Data of 104 patients were analyzed and classified into four clusters. The restrictive pattern with decreased forced expiratory volume in 1 s (FEV1) group showed high serum C-reactive protein and low albumin levels, severe radiological findings, and low HRQOL. In the restrictive pattern with preserved FEV1 group, HRQOL was as low as that in the restrictive pattern with decreased FEV1 group, and bacterial exacerbation was observed relatively frequently. HRQOL in the obstructive impairment group was maintained in comparison with that in the normal group.

CONCLUSION

NTM-PD phenotypes were identified using cluster analysis based on PFT. Two different severe phenotypes were also observed. In the early stages of NTM-PD, PFT may be useful in recognizing disease progression.

Can postural changes in spirometry in children with Duchenne muscular dystrophy predict sleep hypoventilation?

AIM

To explore the relationship between postural changes in lung function and polysomnography (PSG) in children with Duchenne muscular dystrophy (DMD).

METHODS

In this prospective cross-sectional study, children with DMD performed spirometry in sitting and supine positions. A control group of age and gender matched healthy children also underwent postural lung function testing. PSG was performed within six months of spirometry.

RESULTS

Seventeen children with DMD, aged 12.3 ± 3 years performed sitting spirometry. 14 (84%) performed acceptable spirometry in the supine position. Mean FEV1sit and FVCsit were 77% (SD ± 22) and 74% (SD ± 20.4) respectively, with mean% ΔFVC(sit-sup) 9% (SD ± 11) (range 2% to 20%), and was significantly greater than healthy controls 4% (n = 30, SD ± 3, P < 0.001). PSG data on the 14 DMD children with acceptable supine spirometry showed total AHI 6.9 ± 5.9/hour (0.3 to 29), obstructive AHI 5.2 ± 4.0/hour (0.2 to 10), and REM AHI 14.1 ± -5.3/hour (0.1 to 34.7). ΔFVC(sit-sup) had poor correlation with hypoventilation on polysomnography.

CONCLUSION

Children with DMD and mild restrictive lung disease showed greater postural changes in spirometry than healthy controls but lower supine spirometry was not predictive of sleep hypoventilation.

Detection of episodic nocturnal hypercapnia in patients with neurodegenerative disorders

PURPOSE

Episodic nocturnal hypercapnia (eNH) in transcutaneous carbon dioxide pressure (PtcCO2) corresponding to rapid eye movement sleep hypoventilation is a useful biomarker for detecting nocturnal hypoventilation. However, the relationship between eNH and neurodegenerative diseases with sleep-related breathing disorders (SRBDs) is unknown. The aim of this study was to evaluate the relationship between eNH and nocturnal hypoventilation in neurodegenerative diseases.

METHODS

Patients with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), multiple system atrophy (MSA), Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome, and idiopathic normal pressure hydrocephalus, were enrolled and received overnight PtcCO2 monitoring. The patients were divided into groups for eNH and sleep-associated hypoventilation (SH) prevalence analysis: A (ALS), B (MSA), and C (others).

RESULTS

Among 110 patients, twenty-three (21%) and 10 (9%) of the patients met eNH and SH criteria, respectively. eNH and SH were significantly more frequent in groups A and B than in C. The prevalence of SH in the patients with eNH was 39% whereas most of patients with SH (90%) presented with eNH. Among patients with daytime carbon dioxide pressure in arterial blood ≤ 45 mmHg, eNH frequency was 13%, whereas none of the patients met SH criteria. The frequency of noninvasive positive pressure ventilation after PtcCO2 monitoring was significantly higher in those with than without eNH.

CONCLUSIONS

eNH is common in patients with MSA and ALS who present with SRBD. eNH with overnight PtcCO2 monitoring is a useful biomarker to detect hypoventilation among neurodegenerative diseases with different SRBD mechanisms.

Diaphragm Ultrasonography: Reference Values and Influencing Factors for Thickness, Thickening Fraction, and Excursion in the Seated Position

INTRODUCTION

Measurements of diaphragm function by ultrasonography are affected by body position, but reference values in the seated position have not been established for an Asian population. This study aimed to determine reference values for diaphragm thickness, thickening fraction, and dome excursion by ultrasonography and to investigate the effects of sex, height, and body mass index.

METHODS

Diaphragm ultrasonography was performed on 109 seated Japanese volunteers with normal respiratory function who were enrolled between March 2022 and January 2023. Thickness, thickening fraction, and excursion were measured. Reference values and the measurement success rate were calculated. Multivariate analysis adjusted for sex, height, and body mass index was performed.

RESULTS

The measurement success rate was better for thickness than for excursion. The mean (lower limit of normal) values on the right/left sides were as follows. During quiet breathing, thickness at end expiration(mm) was 1.7 (0.9)/1.6 (0.80), thickening fraction(%) was 50 (0.0)/52 (0.0), and excursion(cm) was 1.7 (0.5)/1.9 (0.5). During deep breathing, the thickening fraction was 111 (24)/107 (22), and the excursion was 4.4 (1.7)/4.1 (2.0). In multivariate analysis, body mass index was positively associated with thickness but not with the thickening fraction.

CONCLUSION

The reference values in this study were smaller than those in previous reports from Europe. Considering that thickness is influenced by body mass index, using Western reference values in Asia, where the average body mass index is lower, might not be appropriate. The thickening fraction in deep breathing is unaffected by other items and can be used more universally.

Sleep Disordered Breathing in Children with Neuromuscular Disease

Sleep disordered breathing (SDB) in children with neuromuscular disease (NMD) is more prevalent compared to the general population, and often manifests as sleep-related hypoventilation, sleep-related hypoxemia, obstructive sleep apnea, central sleep apnea, and/or disordered control of breathing. Other sleep problems include, sleep fragmentation, abnormal sleep architecture, and nocturnal seizures in certain neuromuscular diseases. The manifestation of sleep disordered breathing in children depends on the extent, type, and progression of neuromuscular weakness, and in some instances, may be the first sign of a neuromuscular weakness leading to diagnosis of an NMD. In-lab diagnostic polysomnography (PSG) remains the gold standard for the diagnosis of sleep disordered breathing in children, but poses several challenges, including access to many children with neuromuscular disease who are non-ambulatory. If SDB is untreated, it can result in significant morbidity and mortality. Hence, we aimed to perform a comprehensive review of the literature of SDB in children with NMD. This review includes pathophysiological changes during sleep, clinical evaluation, diagnosis, challenges in interpreting PSG data using American Academy of Sleep (AASM) diagnostic criteria, management of SDB, and suggests areas for future research.

Effect of Dynamic Neuromuscular Stabilization and Vojta Therapy on Respiratory Complications in Neuromuscular Diseases: A Literature Review

Objective

The purpose of this study was to review the literature on the effect of dynamic neuromuscular stabilization (DNS)/Vojta on respiratory complications of neuromuscular diseases.

Methods

The search strategy was conducted, based on the population, intervention, comparison, and outcome method, in the PubMed, Embase, ISI Web of Knowledge, ProQuest, and Scopus databases from inception to August 2021. The quality assessment of included papers was performed through the Physiotherapy Evidence Database scale. A narrative analysis was performed since a meta-analysis could not be conducted.

Results

A total of 7 papers were chosen for the final assessment. All studies, except 1, evaluated individuals with neurological disease. Three studies evaluated Vojta therapy effects, and 4 studies evaluated DNS effects on respiratory parameters. Although the studies had limitations in their methodology according to the Physiotherapy Evidence Database scale, 4 were identified as level 1 evidence. None of the studies reported any adverse effects of Vojta therapy or DNS on respiratory parameters. However, not enough clinical trials were found to examine the effect of DNS on respiratory disease.

Conclusion

Although the studies were weak in internal and external validity, this review suggests that Vojta therapy and DNS may influence respiratory parameters, such as blood gases, diaphragm movements, and functional respiratory parameters, in patients with neuromuscular diseases.

ATS Core Curriculum 2022. Pediatric Pulmonary Medicine: Updates in pediatric neuromuscular disease

The American Thoracic Society Core Curriculum updates clinicians annually in pediatric pulmonary disease. This is a concise review of the Pediatric Pulmonary Medicine Core Curriculum presented at the 2022 American Thoracic Society International Conference. Neuromuscular diseases (NMD) comprise a variety of conditions that commonly affect the respiratory system and cause significant morbidity including dysphagia, chronic respiratory failure, and sleep disordered breathing. Respiratory failure is the most common cause of mortality in this population. Substantial progress has been made in diagnosis, monitoring and treatment for NMD over the last decade. Pulmonary function testing (PFT) is utilized to objectively measure respiratory pump function and PFT milestones are utilized in NMD-specific pulmonary care guidelines. New disease modifying therapies are approved for the treatment of patients with Duchenne muscular dystrophy and spinal muscular atrophy (SMA), including the first ever approved systemic gene therapy, in the case of SMA. Despite extraordinary progress in the medical management of NMD, little is known regarding the respiratory implications and long-term outcomes for patients in the era of advanced therapeutics and precision medicine. The combination of technological and biomedical advancements has increased the complexity of the medical decision-making process for patients and families, thus emphasizing the importance of balancing respect for autonomy with the other foundational principles of medical ethics. This review features an overview of PFT, noninvasive ventilation strategies, novel and developing therapies, as well as the ethical considerations specific to the management of patients with pediatric NMD.

Tracheostomy, Feeding-Tube, and In-Hospital Postoperative Mortality in Children: A Retrospective Cohort Study

BACKGROUND

Neuromuscular/neurologic disease confers increased risk of perioperative mortality in children. Some patients require tracheostomy and/or feeding tubes to ameliorate upper airway obstruction or respiratory failure and reduce aspiration risk. Empiric differences between patients with and without these devices and their association with postoperative mortality have not been previously assessed.

METHODS

This retrospective cohort study using the Pediatric Health Information System measured 3- and 30-day in-hospital postsurgical mortality among children 1 month to 18 years of age with neuromuscular/neurologic disease at 44 US children's hospitals, from April 2016 to October 2018. We summarized differences between patients presenting for surgery with and without these devices using standardized differences. Then, we calculated 3- and 30-day mortality among patients with tracheostomy, feeding tube, both, and neither device, overall and stratified by important exposures, using Fisher exact test to test whether differences were significant.

RESULTS

There were 43,193 eligible patients. Unadjusted 3-day mortality was 1.3% (549/43,193); 30-day mortality was 2.7% (1168/43,193). Most (79.1%) used neither a feeding tube or tracheostomy, 1.2% had tracheostomy only, 15.5% had feeding tube only, and 4.2% used both devices. Compared to children with neither device, children using either or both devices were more likely to have multiple CCCs, dysphagia, chronic pulmonary disease, cerebral palsy, obstructive sleep apnea, or malnutrition, and a prolonged intensive care unit (ICU) stay within the previous year. They were less likely to present for high-risk surgeries (33% vs 57%). Having a feeding tube was associated with decreased 3-day mortality overall compared to having neither device (0.9% vs 1.3%, P = .003), and among children having low-risk surgery, and surgery during urgent or emergent hospitalizations. Having both devices was associated with decreased 3-day mortality among children having low-risk surgery (0.8% vs 1.9%; P = .013), and during urgent or emergent hospitalizations (1.6% vs 2.9%; P = .023). For 30-day mortality, having a feeding tube or both devices was associated with lower mortality when the data were stratified by the number of CCCs.

CONCLUSIONS

Patients requiring tracheostomy, feeding tube, or both are generally sicker than patients without these devices. Despite this, having a feeding tube was associated with lower 3-day mortality overall and lower 30-day mortality when the data were stratified by the number of CCCs. Having both devices was associated with lower 3-day mortality in patients presenting for low-risk surgery, and surgery during urgent or emergent hospitalizations.

Health System Factors Affecting the Experience of Non-Invasive Ventilation Provision of People with Neuromuscular Disorders in New Zealand

Non-invasive ventilation (NIV) is a critical therapy for many patients with neuromuscular disorders (NMD), supporting those with respiratory failure to achieve adequate respiration and improve their quality of life. The aim of this study was to explore the experiences of access to, consent, uptake, maintenance and safe use of non-invasive ventilation by people with NMD. Semi-structured individual interviews were conducted with 11 people with NMD, each using NIV for more than 12 months. A critical realism ontological paradigm with contextualism epistemology guided the Reflexive Thematic Analysis. An Equity of Health Care Framework underpinned the analysis. Three themes were interpreted: Uptake and informed consent for NIV therapy; Practicalities of NIV; and Patient-clinician relationships. We identified issues at the system, organization and health professional levels. Conclusions: We recommend the development of national service specifications with clear standards and dedicated funding for patients with NMD and call on the New Zealand Ministry of Health to proactively investigate and monitor the variations in service delivery identified. The specific areas of concern for patients with NMD suggest the need for NMD-related NIV research and service provision responsive to the distinct needs of this population.

Post-operative steroids in patients with patients with severe cerebral palsy undergoing posterior spinal fusion

INTRODUCTION

Posterior spinal fusion (PSF) represents a large physiologic challenge for children with neuromuscular scoliosis (NMS). Perioperative complications are numerous with many occurring in the post-operative period due to pain and relative immobilization. This study assessed the impact of steroids on patients undergoing PSF for NMS.

METHODS

A retrospective review of consecutive patients managed at a single center with PSF for NMS was reviewed. Clinical and radiographic analysis was used to evaluate baseline demographics, curve characteristics, and post-operative course.

RESULTS

Eighty-nine patients who underwent PSF for NMS were included. Fifty-seven of these patients did not receive post-operative steroids (NS) while 32 patients were treated with post-operative steroids (dexamethasone, WS) for a median of 3 doses (median 6.0 mg/dose every 8 h after surgery). The demographic variables of the cohorts were similar with no difference in curve magnitude, number of vertebrae fused, number of osteotomies, or EBL between groups. A 70% decrease in the median post-operative morphine equivalents was observed in the steroid cohort (0.50 mg/kg WS vs 1.65 mg/kg NS, p value < 0.001). There was an association between post-operative morphine equivalents and length of stay (Spearman's rho = 0.22, p value = 0.04). There was no difference in wound healing, infection, and pulmonary or gastrointestinal complications between groups. No difference was found in pain at discharge, 30-day ED returns, or 30-day OR returns between groups.

CONCLUSIONS

Post-operative dexamethasone resulted in a 70% decrease in morphine equivalent use after PSF for NMS without any increase in perioperative wound infections.

LEVEL OF EVIDENCE

Level 3: case-control series.

Characteristics and Outcomes of Young Adult Patients with Severe Sepsis Admitted to Pediatric Intensive Care Units Versus Medical/Surgical Intensive Care Units

Purpose: Young adults receive severe sepsis treatment across pediatric and adult care settings. However, little is known about young adult sepsis outcome differences in pediatric versus adult hospital settings. Material and Methods: Using Truven MarketScan database from 2010-2015, we compared in-hospital mortality and hospital length of stay in young adults ages 18-26 treated for severe sepsis in Pediatric Intensive Care Units (PICUs) versus Medical ICUs (MICUs)/Surgical ICUs (SICUs) using logistic regression models and accelerated time failure models, respectively. Comorbidities were identified using Complex Chronic Conditions (CCC) and Charlson Comorbidity Index (CCI). Results: Of the 18 900 young adults hospitalized with severe sepsis, 163 (0.9%) were treated in the PICU and 952 (5.0%) in the MICU/SICU. PICU patients were more likely to have a comorbid condition compared to MICU/SICU patients. Compared to PICU patients, MICU/SICU patients had a lower odds of in-hospital mortality after adjusting for age, sex, Medicaid status, and comorbidities (adjusting for CCC, odds ratio [OR]: 0.50, 95% CI 0.29-0.89; adjusting for CCI, OR: 0.51, 95% CI 0.29-0.94). There was no difference in adjusted length of stay for young adults with severe sepsis (adjusting for CCC, Event Time Ratio [ETR]: 1.14, 95% CI 0.94-1.38; adjusting for CCI, ETR: 1.09, 95% CI 0.90-1.33). Conclusions: Young adults with severe sepsis experience higher adjusted odds of mortality when treated in PICUs versus MICU/SICUs. However, there was no difference in length of stay. Variation in mortality is likely due to significant differences in the patient populations, including comorbidity status.

Risk assessment of postoperative pneumonia in children with neurologic disorders and obesity

INTRODUCTION

Postoperative pneumonia increases the risk of postsurgical mortality, making it a serious healthcare-associated complication. Children with preoperative neuromuscular impairments have a higher risk of postoperative pneumonia. Obesity is also a risk factor for postoperative pulmonary complications, including pneumonia. Moreover, obesity is increasingly prevalent among children living with a neurological diagnosis. Whether obesity increases the risk of postoperative pneumonia among children with neurologic diseases remains largely unknown. Therefore, we assessed the risk of postoperative pneumonia among children with neurologic diagnoses based on their obesity status.

METHODS

We analyzed a retrospective cohort of children ≤18 years from the National Surgical Quality Improvement Program (2012-2019) database who underwent inpatient orthopedic surgery. We used Cox proportional regression model to estimate the hazard ratio for the association between neurologic disorders and postoperative pneumonia. In addition, we included an interaction term between body mass index and neurologic disorders to evaluate the moderating effect of obesity status and then performed stratified analyses to compare the magnitude of hazard ratios across body mass index subgroups.

RESULTS

A total of 60 745 children underwent inpatient orthopedic surgery during the study period, of whom 43.6% were healthy weight and 30.8% overweight/obese. The median age was 13 years (Interquartile range: 8-15). The incidence of postoperative pneumonia was higher among healthy weight patients with neurologic disorders than healthy weight patients without any neurologic disorders [Hazard ratio: 3.55 vs. 0.34]. Furthermore, the association between neurologic disorders and postoperative pneumonia was strongest among overweight patients than healthy weight or obese patients [Hazard ratio:11.88 vs. 9.45 vs. 4.40]. This observation was consistent across the various neurologic disorders analyzed.

CONCLUSION

Childhood obesity buffered the association between neurologic disorders and postoperative pneumonia, consistent with an 'obesity paradox'. Further research exploring the underlying mechanisms for the obesity paradox in children with neurologic disorders is warranted.

Chronic Neuromuscular Respiratory Failure and Home Assisted Ventilation

Chronic respiratory failure is a common, important complication of many types of neuromuscular and chest wall disorders. While the pathophysiology of each disease may be different, these disorders can variably affect all muscles involved in breathing, including inspiratory, expiratory, and bulbar muscles, ultimately leading to chronic respiratory failure and hypoventilation. The use of home assisted ventilation through noninvasive interfaces aims to improve the symptoms of hypoventilation, improve sleep quality, and, when possible, improve mortality. An increasing variety of interfaces has allowed for improved comfort and compliance. In a minority of scenarios, noninvasive ventilation is either not appropriate or no longer effective due to disease progression, and a transition to tracheal ventilation should be considered.

Respiratory Insufficiency in Neuromuscular Disease (RIND): A Delphi Study to Establish Consensus Criteria to Define and Diagnose Hypoventilation in Pediatric Neuromuscular Disease

Chronic respiratory failure is a common endpoint in the loss of respiratory muscle function in patients with progressive neuromuscular disease (NMD). Identifying the onset of hypoventilation is critical to allow for the timely introduction of ventilator support and effectively manage respiratory failure [1-3]. While there are accepted criteria governing the diagnosis of hypoventilation during polysomnography (PSG) [4], there is concern that criteria are insufficient for identifying hypoventilation in the earlier stages of respiratory insufficiency related to NMD. The purpose of this project was to identify more sensitive criteria for identifying hypoventilation.

METHODS

Fifteen pediatric pulmonologists with broad experience in managing patients with NMD, 10 of whom were board certified in and practice sleep medicine, were assembled and performed a review of the pertinent literature and a two-round Delphi process with 6 domains (Table 1).

RESULTS

Within the 6 domains there were three pertinent items per domain (Table 2). There was clear agreement on findings on history (morning headaches) and pulmonary function testing (FVC < 50% or awake TcCO2 > 45 mmHg) indicating a high concern for nocturnal hypoventilation. There was close agreement on the definitions for nocturnal hypercapnia and hypoxemia. PSG criteria were identified that indicate a patient is likely in the transitional phase from adequate ventilation to hypoventilation.

DISCUSSION

We identified a set of clinical criteria that may allow for more sensitive diagnosis of hypoventilation in NMD and earlier initiation of non-invasive ventilation leading to a reduction in the respiratory morbidity in progressive NMD. These criteria need to be further and more broadly validated prospectively to confirm their utility.

Do handgrip strength and dexterity predict respiratory function in neuromuscular disease?

BACKGROUND

Neuromuscular diseases are acquired or inherited diseases that affect the function of the muscles in our body, including respiratory muscles.

OBJECTIVE

We aimed to discover more cost-effective and practical tools to predict respiratory function status, which causes serious problems with patients with neuromuscular disease.

METHODS

The Vignos and Brooke Upper Extremity Functional Scales were used to evaluate functional status for patient recruitment. The handgrip strength and dexterity of patients were measured using a dynamometer and nine-hole peg test. Respiratory function parameters: forced vital capacity, forced expiratory volume in one second, and peak expiratory flow were evaluated using spirometry.

RESULTS

The mean age of the 30 patients was 11.5 ± 3.79 years old. Significant relationships were found between nine-hole-peg-test scores and respiratory function parameters on both sides. Significant correlations were found between both handgrip strength and respiratory function parameters (p < 0.05). In the linear regression analysis, it was seen that the forced expiratory volume in 1 second, and peak expiratory flow values could be explained in different percentages (p < 0.05).

CONCLUSIONS

Handgrip strength and dexterity measurements can be used as indicators for estimating respiratory function parameters in terms of cost and accessibility, although it is known that they will not replace respiratory function tests.

Pulmonological issues

Pediatric leukodystrophies are rare neurodegenerative diseases involving multiple systems. Each form has unique neurologic features but are characterized by encephalopathy with accompanying impairments evidenced in reflexes, muscle tone and movement control. Weakness of expiratory, inspiratory, and upper airway muscles may lead to impaired airway secretion clearance resulting in recurrent respiratory infections, dysphagia, sleep-disordered breathing, restrictive lung disease, and ultimately chronic respiratory insufficiency.

Physical therapy for the management of motor symptoms in amyotrophic lateral sclerosis: protocol for a systematic review

INTRODUCTION

The prescription of an intervention plan can be challenging for the physical therapist, considering clinical phenotypes, individual prognosis and the rapid, progressive and deteriorating nature of amyotrophic lateral sclerosis (ALS). In this context, therapeutic exercises (eg, resistance and aerobic exercises) for patients with ALS remain controversial and may influence the treatment plan. Therefore, this review aims to critically assess whether physical therapy interventions are effective for improving functional capacity, quality of life and fatigue of individuals with ALS.

METHODS AND ANALYSIS

Studies will be selected according to eligibility criteria, and language, geographical area or publication date will not be restricted. Four databases will be used: MEDLINE, EMBASE, Cochrane Library (CENTRAL) and Physiotherapy Evidence Database (PEDro). Searches will also be conducted on ClinicalTrials.gov and references from included studies. We plan to conduct the searches between October and December 2022. Two independent authors will examine titles and abstracts and exclude irrelevant studies and duplicates. We will assess the quality of studies and quality of evidence, and disagreements will be resolved with a third researcher. The findings will be presented in the text and tables; if possible, we will perform meta-analyses.

ETHICS AND DISSEMINATION

No ethical approval is required because this study does not involve human beings. We will publish our findings in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42021251350.

Chronic moderate hypercapnia suppresses ventilatory responses to acute CO&lt;sub&gt;2&lt;/sub&gt; challenges

Chronic hypercapnia (CH) is a hallmark of chronic lung disease, and CH increases the risk for acute-on-chronic exacerbations leading to greater hypoxemia/hypercapnia and poor health outcomes. However, the role of hypercapnia per se (duration and severity) in determining an individual's ability to tolerate further hypercapnic exacerbations is unknown. Our primary objective herein was to test the hypothesis that mild-to-moderate CH (arterial [Formula: see text] ∼50-70 mmHg) increases susceptibility to pathophysiological responses to severe acute CO₂ challenges. Three groups (GR) of adult female goats were studied during 14 days of exposure to room air (<i>GR 1</i>; control) or 6% inspired CO₂ (<i>GR 2</i>; mild CH), or 7 days of 6% inspired CO₂ followed by 7 days of 8% inspired CO₂ (<i>GR 3</i>; moderate CH). Consistent with previous reports, there were no changes in physiological parameters in <i>GR 1</i> (RA control), but mild CH (<i>GR 2</i>) increased steady-state ventilation and transiently suppressed CO₂/[H⁺] chemosensitivity. Further increasing InCO₂ from 6% to 8% (<i>GR 3</i>) transiently increased ventilation and arterial [H⁺]. Similar to mild CH, moderate CH increased ventilation to levels greater than predicted. However, in contrast to mild CH, acute ventilatory chemosensitivity was suppressed throughout the duration of moderate CH, and the arterial - mixed expired CO₂ gradient became negative. These data suggest that moderate CH limits physiological responses to acute severe exacerbations and provide evidence of recruitment of extrapulmonary systems (i.e., gastric CO₂ elimination) during times of moderate-severe hypercapnia.<b>NEW &amp; NOTEWORTHY</b> Moderate levels of chronic hypercapnia (CH; ∼70 mmHg) in healthy adult female goats elicited similar steady-state physiological adaptations compared with mild CH (∼55 mmHg). However, unlike mild CH, moderate CH chronically suppressed acute CO₂/[H⁺] chemosensitivity and reversed the arterial to mixed expired CO₂ gradient. These findings suggest that moderate CH suppresses vital mechanisms of ventilatory control and recruits additional physiological systems (i.e., gastric CO₂ release) to help buffer excess CO₂.

Clinical Characteristics and Outcome of MDR/XDR Bacterial Infections in a Neuromuscular Semi-Intensive/Sub-Intensive Care Unit

(1) Background: The aim of this study was to assess the clinical and microbiological characteristics of multidrug-resistant infections in a neuromuscular semi-intensive/sub-intensive care unit; (2) Methods: Retrospective analysis on data from 18 patients with NMD with proven MDRO/XDRO colonisation/infection from August 2021 to March 2022 was carried out; (3) Results: Ten patients were males (55.6%), with a median age of 54 years, and there were fourteen patients (77.8%) with amyotrophic lateral sclerosis. All patients had at least one invasive device. Ten (55.6%) patients developed MDRO/XDRO infection (with a median time of 24 days) while six (33.3%) were colonised. The Charlson comorbidity index was >2 in both groups but higher in the infected compared with the colonised (4.5 vs. 3). Infected patients were mostly females (seven patients) with a median age of 62 years. The most common pathogens were Acinetobacter baumannii and Pseudomonas aeruginosa, infecting four (28.6%) patients each. Of eighteen infectious episodes, nine were pneumonia (hospital-acquired in seven cases). Colistin was the most commonly active antibiotic while carbapenems were largely inactive. Eradication of infection occurred in seven infectious episodes (38.9%). None of those with infection died; (4) Conclusions: MDRO/XDRO infections are common in patients with neuromuscular diseases, with carbapenem-resistant non-fermenting Gram-negative bacilli prevailing. These infections were numerically associated with the female sex, greater age, and comorbidities. Both eradication and infection-related mortality appeared low. We highlight the importance of infection prevention in this vulnerable population.

Outcomes Following Total Hip Arthroplasty in Patients With Postpolio Syndrome: A Matched Cohort Analysis

BACKGROUND

Patients with postpolio syndrome (PPS) may be afflicted by hip arthritis in either the paralytic or contralateral limb. Total hip arthroplasty (THA) may be considered in these patients. However, short-term and long-term outcomes following THA in PPS patients remain poorly characterized.

METHODS

The PearlDiver MHip administrative database was queried for patients undergoing THA. Patients with a diagnosis of PPS were matched 1:4 with control patients on the basis of age, gender, and comorbidity burden. Incidence of postoperative adverse events and readmission in the 90 days following surgery and occurrence of revision arthroplasty in the five-year postoperative period were assessed between the two cohorts.

RESULTS

In total, 1,519 PPS patients were matched to 6,076 control patients without PPS. After controlling for patient demographics and comorbidities, PPS patients demonstrated higher 90-day odds of urinary tract infection (odds ratio [OR] = 1.34, P = .016), pneumonia (OR = 2.07, P < .001), prosthetic dislocation (OR = 1.63, P = .018), and readmission (OR = 1.49, P = .002). Five years following surgery, 94.7% of the PPS cohort remained revision-free, compared to 96.7% of the control cohort (P = .001).

CONCLUSION

Compared to patients without PPS, patients with PPS demonstrated a higher incidence of urinary tract infection, pneumonia, prosthetic dislocation, and hospital readmission. In addition, five-year incidence of revision arthroplasty was significantly higher among the PPS cohort. In light of these increased risks, special considerations should be made in both preoperative planning and postoperative surveillance of PPS patients undergoing THA.

LEVEL OF EVIDENCE

Level III.

Weakness in the intensive care unit

When asked to assess patients in an intensive care unit (ICU) who have respiratory muscle weakness, oropharyngeal weakness and a vulnerable airway, our immediate thought may be of Guillain-Barré syndrome or myasthenia gravis, but there are many other possible causes. For example, previously unrecognised chronic neurological conditions may decompensate and require ICU admission. Clinicians can use various clinical clues to help recognise them and need to understand how patterns of weakness reflect differing causes of reduced consciousness on ICU. Additionally, patients admitted to ICU for any reason may develop weakness during their stay, the most likely cause being ICU-acquired weakness. Assessing patients in ICU is challenging, hampered by physical barriers (machines, tubes), medication barriers (sedatives) and cognitive barriers (delirium, difficulty communicating). Nonetheless, we need to reach a clinical diagnosis, organise appropriate tests and communicate clearly with both patients and ICU colleagues.

The clinical use of impulse oscillometry in neuromuscular diseases

BACKGROUND

The patients with neuromuscular diseases (NMD) are very fragile and it is hard to evaluate respiratory involvement of the primary disease in this group. Therefore, our study aimed to reveal the relationship between pulmonary function tests (PFT) and impulse oscillometry (IOS) and their correlation with respiratory clinical findings in NMD.

MATERIAL AND METHODS

A total of 86 consecutive patients with NMD were included. The clinical findings of respiratory involvement, PFT, and IOS results of the patients were analyzed.

RESULTS

Forty patients out of 86 were female. There were 29 patients with amyotrophic lateral sclerosis, four patients with myasthenia gravis, and 53 patients with muscular dystrophies/myopathies. According to the PFT results, 47 patients had restrictive PFT. However, there was no difference in IOS parameters when we compared the patients according to restrictions in PFT. A positive correlation was found with FVC %pred and X₅. PEF %pred values were positively correlated with X₁₀, X₁₅, and X₂₀, and negatively correlated with A_X and R_5-20. The patients with worse swallowing capability had increased R_rs levels, and more negative X_rs levels. The shortness of breath led to lower FEV₁ %pred., higher R₅, A_X and R_5-20, and also more negative X₁₀, X₁₅, and X₃₅.

CONCLUSION

Clinically reported dysphagia, a decreased capability of coughing, and shortness of breath in patients with NMD make R_rs increase in general, but X_rs parameters, which mainly express rib cage elasticity, turn more negative. In patients with NMD, IOS monitoring may help in evaluating the regression in respiratory functions, however, future studies are needed to understand more.

Atypical Causes of Dyspnea: A Review of Neuromuscular and Chest Wall Disorders that Compromise Ventilation

Dyspnea is a common presenting symptom among patients with cardiopulmonary diseases. However, several neuromuscular and chest wall conditions are often overlooked and under-recognized causes of dyspnea. These disorders frequently adversely affect the structure and function of the ventilatory pump (diaphragm, accessory muscles of ventilation) and can precipitate respiratory failure despite normal lung parenchyma. Weakened musculature impairs clearance of airway secretions leading to aspiration and pneumonia, further compromising respiratory function. Radiologists should be aware of the pathophysiology and imaging manifestations of these conditions and might suggest them to be causes of dyspnea which otherwise may not have been considered by referring clinicians.

A Multidisciplinary Perspective Addressing the Diagnostic Challenges of Late-Onset Pompe Disease in the Arabian Peninsula Region Developed From an Expert Group Meeting

Pompe disease is a rare, metabolic, autosomal recessive disorder. Early diagnosis is critical for progressive Pompe disease as delays can significantly alter the clinical course of the disease. Diagnostic modalities, including dried blood spot testing and genetic testing, are available and are effective for diagnosing patients with late-onset Pompe disease (LOPD). However, clinicians face numerous clinical challenges related to the diagnosis of the disease. Two expert group committee meetings, involving 11 experts from the United Arab Emirates, Kuwait, the Kingdom of Saudi Arabia, and Oman, were convened in October 2019 and November 2020 respectively to develop a uniform diagnostic algorithm for the diagnosis of pediatric and adult LOPD in the Arabian Peninsula region. During the first meeting, the specialty-specific clinical presentation of LOPD was defined. During the second meeting, a diagnostic algorithm was developed after a thorough validation of clinical presentation or symptoms, which was performed with the aid of existing literature and expert judgement. A consensus was reached on the diagnostic algorithm for field specialists, such as neurologists, rheumatologists, general practitioners/internal medicine specialists, orthopedic specialists, and pulmonologists. This specialty-specific diagnostic referral algorithm for pediatric and adult LOPD will guide clinicians in the differential diagnosis of LOPD.

Methods and Applications in Respiratory Physiology: Respiratory Mechanics, Drive and Muscle Function in Neuromuscular and Chest Wall Disorders

Individuals with neuromuscular and chest wall disorders experience respiratory muscle weakness, reduced lung volume and increases in respiratory elastance and resistance which lead to increase in work of breathing, impaired gas exchange and respiratory pump failure. Recently developed methods to assess respiratory muscle weakness, mechanics and movement supplement traditionally employed spirometry and methods to evaluate gas exchange. These include recording postural change in vital capacity, respiratory pressures (mouth and sniff), electromyography and ultrasound evaluation of diaphragmatic thickness and excursions. In this review, we highlight key aspects of the pathophysiology of these conditions as they impact the patient and describe measures to evaluate respiratory dysfunction. We discuss potential areas of physiologic investigation in the evaluation of respiratory aspects of these disorders.

The effects of inspiratory muscle training in adults with muscular dystrophy

Background/Aims Patients with muscular dystrophy usually have impaired lung function and respiratory muscle strength, leading to pneumonia and respiratory failure, which are significant causes of morbidity and mortality. Inspiratory muscle training might be a safe adjunct treatment to increase the strength and endurance of weakened respiratory muscles. The researchers have developed a new protocol for inspiratory muscle training and evaluated its effect on inspiratory muscle strength and coughing capacity.

Methods A total of 12 participants diagnosed with muscle dystrophy and decreased maximal inspiratory pressure (<60 cmH2O) participated in this prospective study. Training was individually tailored, starting with low resistance levels and progressing according to tolerance and symptoms. The primary outcome measure was maximal inspiratory pressure. Secondary outcomes were maximal expiratory pressure, peak cough flow and the feasibility of the intervention.

Results There were two participants who did not complete the study, and three were lost to follow-up; therefore, only seven patients finished the intervention. In these patients, the authors found a statistically significant improvement in the maximal inspiratory pressure (P=0.018) and peak cough flow (P=0.046) after 3 months of training. There was also an improvement in the maximal expiratory pressure, although this was not statistically significant (P=0.176). Median compliance to training was 99% (94.5–100).

Conclusions This intervention led to statistically significant improvements in inspiratory muscles strength and coughing capacity in patients with muscular dystrophy. The results were significantly positive and contribute to the evidence in support of this underused, yet possibly beneficial, treatment, although larger randomised controlled trials are required to verify this.

Remote versus face-to-face home-based exercise programme in people with amyotrophic lateral sclerosis: protocol for a randomised clinical trial

INTRODUCTION

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease with variable and complex clinical manifestations that requires a multidisciplinary approach. However, face-to-face treatment in this population may experience barriers, such as difficulty accessing physical therapists or other professionals. As a result, strategies (eg, telerehabilitation) emerged to facilitate treatment and physical therapy monitoring. This study aims to evaluate the effects of remote versus face-to-face home-based exercise programmes on clinical outcomes and treatment adherence of people with ALS.

METHODS AND ANALYSIS

This is a single-blind randomised clinical trial protocol that will include 44 people with clinical diagnosis of ALS at any clinical stage and aged between 18 and 80 years. Participants will be randomised into two groups after face-to-face evaluation and perform a home-based exercise programme three times a week for 6 months. A physical therapist will monitor the exercise programme once a week remotely (phone calls-experimental group) or face-to-face (home visits-control group). The primary outcome measure will be functional capacity (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised). Secondary outcomes will include disease severity (Amyotrophic Lateral Sclerosis Severity Scale), fatigue (Fatigue Severity Scale), pain (Visual Analogue Scale and body pain diagram), adverse events and adherence rate. Outcomes will be initially evaluated face-to-face and revaluated remotely every 2 months and 1 month after interventions. Linear mixed models will compare outcome measures between groups and evaluations (α=5%).

ETHICS AND DISSEMINATION

This study was approved by the research ethics committee of Hospital Universitário Onofre Lopes/Universidade Federal do Rio Grande do Norte (no. 3735479). We expect to identify the effects of an exercise programme developed according to ALS stages and associated with remote or face-to-face monitoring on clinical outcomes using revaluations and follow-up after interventions.

TRIAL REGISTRATION NUMBER

Brazilian Registry Clinical Trials (RBR-10z9pgfv).

Long-term follow-up of respiratory function in facioscapulohumeral muscular dystrophy

Objective

To evaluate the 5-year change in respiratory function in patients with facioscapulohumeral muscular dystrophy (FSHD).

Methods

Genetically confirmed patients with FSHD aged ≥ 18 years were examined twice over five years. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were measured using hand-held spirometry with a face mask. Several clinical outcome measures were correlated to respiratory function.

Results

Ninety-two patients were included (57% male, age 18–75 years). At baseline, the spirometry outcomes of 41 patients showed a restrictive ventilatory pattern (FVC < 80% and FEV1/FVC ≥ 70% of predicted) and of 48 patients at follow-up. The mean FVC decreased from baseline to follow-up from 79.0 to 76.7% predicted (p = 0.021). This decrease was driven by a subgroup of 15 patients who had a deterioration of FVC of > 10% predicted. The subgroup of 15 patients was more severely affected at baseline (p = 0.002 for FSHD clinical score and 0.007 for Ricci score). They developed more frequently spinal and thorax deformities (p < 0.001 for kyphoscoliosis and 0.012 for pectus excavatum) and had a larger decline in axial muscle function (p = 0.020). Only weak correlations were found between the change in FVC% predicted and the change in clinical scores between baseline and follow-up.

Interpretation

Respiratory function remained stable in most patients with FSHD, but a subgroup of patients showed a pronounced deterioration. They showed more severe muscle weakness including the leg muscles at baseline (Ricci score ≥ 6), had spinal and thorax deformities and a relatively fast decline in axial muscle function at follow-up.

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.

Experience in neuromuscular diseases in children and adolescents and their comorbidities in a tertiary hospital

Introduction

Neuromuscular diseases include a large group of heterogeneous and rare pathologies that affect different components of the motor unit. It is essential to optimize resources to know the prevalence of comorbidities in the most frequent groups to establish an early multidisciplinary approach in a specialized setting.

Patients and methods

Retrospective descriptive study of pediatric and adolescent patients with neuromuscular diseases (NMDs). The Inclusion criteria were NMDs patients with motor neuron involvement divided into three groups, depending on the affected component of the motor unit. Group I: involvement of the motor neuron; Group II: peripheral neuropathies; Group III: myopathies. Demographic variables, association with comorbidities, need for respiratory support, and rehabilitative treatment were collected in each group.

Results

Ninety-six patients who met the inclusion criteria were studied. In group I, when compared to the other two groups, a higher incidence of scoliosis (68.3%, p = 0.011), deformity of the rib cage (31.3%, p = 0.0001), chronic respiratory insufficiency (62.5%, p = 0.001) and bronchial aspiration (12.5%, p = 0.03) was detected. In this group, 50%of the patients required non-invasive mechanical ventilation (p = 0.0001). The in-hospital requirement for respiratory physiotherapy was higher in group I (75%, p = 0.001). We observed a higher incidence of scoliosis in Group III compared to Group II.

Conclusions

Neuromuscular diseases with motor neuron involvement present more comorbidities and require an early approach after diagnosis to improve prognosis.

Diagnosis and treatment of pneumonia, a common cause of respiratory failure in patients with neuromuscular disorders

Patients with neuromuscular diseases, during their illness are more susceptible to respiratory infections due to predisposing factors. Ineffective cough and the presence of atelectasis and hypoventilation, dysphagia and drooling can represent risk factors for the development of respiratory infection and fatal respiratory failure.

Infections of respiratory tract with acute respiratory failure are the most common reason for hospitalizations, and pneumonia is among the leading causes of morbidity and mortality worldwide. The setting in which pneumonia is acquired heavily influences diagnostic and therapeutic choices. We will focus on aetiopathogenesis, diagnosis and treatment of pneumonia in these subjects, particularly considering the disease severity, rates of antibiotic resistance and the possible complications. In this case consultations with specialized physicians are strongly recommended.

The relationship between ventilatory function and cognitive and behavioral impairment in ALS

Objective: To study the association between ventilatory function and cognitive and behavioral impairment in ALS patients accounting for the effects of pertinent covariates. Methods: Four hundred and eighty-one patients were identified from the Mayo Clinic Florida ALS registry who had concurrent forced vital capacity (FVC) and cognitive and behavioral testing using the ALS Cognitive Behavioral Screen (ALS-CBS). Multiple linear regression analysis was used to study the effects of FVC and relevant covariates on the ALS-CBS cognition score, subscores, and caregiver behavioral inventory. Results: FVC was positively correlated to the cognitive and behavioral subscores on the ALS-CBS (p < 0.001), and the correlation was independent of the effects of site of ALS onset, age, and years of education. Conclusion: Cognitive and behavioral function may be adversely affected by ventilatory impairment in ALS. The presence of cognitive and behavioral impairment warrants a detailed assessment of ventilatory function.

Validation of home portable monitoring for the diagnosis of sleep-disordered breathing in adolescents and adults with neuromuscular disorders

STUDY OBJECTIVES

Sleep-disordered breathing (SDB) is common in patients with neuromuscular disorders (NMD), developing before chronic hypercapnia appears. Polysomnography (PSG) is the diagnostic gold standard but is often impractical and poorly accessible for individuals with NMD. We sought to determine the diagnostic accuracy, feasibility, and patient preference of home sleep apnea testing (HSAT) compared with PSG for the detection of SDB in NMD.

METHODS

Participants with NMD at risk for SDB aged ≥ 13 years underwent HSAT followed by overnight PSG with concomitant laboratory sleep apnea testing (same device as HSAT). Sensitivity and specificity were calculated for standard apnea-hypopnea index cutoffs for mild (≥ 5 events/h), moderate (≥ 15 events/h), and severe SDB (≥ 30 events/h) and for an oxygen desaturation index ≥ 5 events/h. Receiver operating characteristic curves were built. A questionnaire assessed patient preference.

RESULTS

Of 38 participants, 73% had moderate to severe SDB and 79% had technically acceptable HSAT. For an apnea-hypopnea index ≥ 15 events/h, HSAT sensitivity and specificity were 50% and 88%, respectively. For an oxygen desaturation index ≥ 5 events/h, HSAT sensitivity and specificity were 95% and 78%, respectively. The area under the receiver operating characteristic curve for an apnea-hypopnea index ≥ 15 events/h was 0.88 (95% confidence interval, 0.69-1.00) for HSAT. The HSAT underestimated the apnea-hypopnea index from PSG (bias, -10.7 ± 15.9 events/h). HSAT was preferred to PSG by 61% of participants.

CONCLUSIONS

HSAT is feasible, preferred by patients, and reliable for detecting SDB in most patients, although it cannot definitively rule out SDB. Therefore, HSAT is a viable diagnostic approach for SDB in NMD when PSG is not feasible, recognizing that it does not accurately distinguish between upper-airway obstruction and hypoventilation. Additional work is needed to further optimize home sleep testing in NMD.

CITATION

Westenberg JN, Petrof BJ, Noel F, et al. Validation of home portable monitoring for the diagnosis of sleep-disordered breathing in adolescents and adults with neuromuscular disorders. J Clin Sleep Med. 2021;17(8):1579-1590.

Optimal Noninvasive Medicare Access Promotion: Patients with Thoracic Restrictive Diseases A Technical Expert Panel Report from the American College of Chest Physicians, the American Association for Respiratory Care, the American Academy of Sleep Medicine, and the American Thoracic Society

The existing coverage criteria for Non-Invasive Ventilation (NIV) do not recognize the benefits of early initiation of NIV for those with Thoracic Restrictive Disease (TRD) and do not address the unique needs for daytime support as the patient's progress to ventilator dependence. This document summarizes the work of the Thoracic Restrictive Disease Technical Expert Panel working group. The most pressing current coverage barriers identified were: 1) Delays in implementing NIV treatment 2) Lack of coverage for many non-progressive Neuro-Muscular Disease (NMD) and 3) Lack of clear policy indications for Home -Mechanical Ventilation (HMV) Support in TRD. To best address these issues we make the following key recommendations: 1) Given the need to encourage early initiation of NIV with Bi-level Positive Airway Pressure (BPAP) devices, we recommend that symptoms be considered as a reason to initiate therapy even at mildly reduced FVC's.; 2) Broaden CO2 measurements to include surrogates such as transcutaneous, end-tidal or Venous Blood Gas (VBG); 3) Expand the diagnostic category to include Phrenic Nerve injuries and Disorders of Central Drive; 4) Allow a BPAP device to be advanced to an HMV when the VC is <30% or to address severe daytime respiratory symptoms; 5) Provide an additional HMV when the patient is ventilator dependent with use >18 hours/ day. Adoption of these proposed recommendations would result in the right device, at the right time, for the right type of patients with hypoventilation syndromes.

Hypoxia and Hypoxia-Inducible Factor Signaling in Muscular Dystrophies: Cause and Consequences

Muscular dystrophies (MDs) are a group of inherited degenerative muscle disorders characterized by a progressive skeletal muscle wasting. Respiratory impairments and subsequent hypoxemia are encountered in a significant subgroup of patients in almost all MD forms. In response to hypoxic stress, compensatory mechanisms are activated especially through Hypoxia-Inducible Factor 1 α (HIF-1α). In healthy muscle, hypoxia and HIF-1α activation are known to affect oxidative stress balance and metabolism. Recent evidence has also highlighted HIF-1α as a regulator of myogenesis and satellite cell function. However, the impact of HIF-1α pathway modifications in MDs remains to be investigated. Multifactorial pathological mechanisms could lead to HIF-1α activation in patient skeletal muscles. In addition to the genetic defect per se, respiratory failure or blood vessel alterations could modify hypoxia response pathways. Here, we will discuss the current knowledge about the hypoxia response pathway alterations in MDs and address whether such changes could influence MD pathophysiology.

Effects of an optimised approach to home-based respiratory care in individuals with amyotrophic lateral sclerosis: a study protocol for a randomised controlled trial

INTRODUCTION

This study aims to investigate the effects of an optimal home-based respiratory care protocol in individuals with amyotrophic lateral sclerosis (ALS).

METHODS AND ANALYSIS

This is a randomised, blinded controlled trial involving patients diagnosed with ALS, both sexes, age between 18 and 80 years. Patients will be randomly allocated into the conventional respiratory care (CRC) group and the optimised respiratory care home-based (ORC) group. Primary outcomes will be peak cough flow, the number of exacerbations and ALS Functional Rating Scale Revised. Secondary outcomes will include chest wall volumes, maximal respiratory pressures, sniff nasal inspiratory pressure, nasal expiratory pressure and forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV1) and FEV1/FVC. The CRC group will receive educational information about respiratory care at the clinic. The ORC group will receive conventional care and home-based care. The clinical status of all individuals will be monitored weekly through telephone calls. A 6-month intervention is planned, the outcomes will be assessed every 3 months and 3 and 6 months follow-up after final evaluation. The primary and secondary results will be described as average or median for continuous variables and absolute and relative frequencies for qualitative variables. Treatment effects or differences between the outcomes (baseline, 3 months and 6 months) of the study groups will be analysed using an analysis of variance. The level of significance will be set as p≤0.05.

ETHICS AND DISSEMINATION

The research ethics committee approved the study. It is expected to evaluate respiratory function in patients with ALS in the short, medium and long terms with home-based care protocol applied. The disease's rapid progression is a limitation for performing a long-term clinical study.

TRIAL REGISTRATION NUMBER

RBR-3z23ts; Pre-results.

Predictive value of positional change in vital capacity to identify diaphragm dysfunction

RATIONALE

Sitting-to-supine fall in vital capacity (ΔVC) can be used to help identify diaphragm dysfunction (DD), but its optimal predictive threshold value is uncertain. Our aim was to evaluate the diagnostic performance of ΔVC in identifying the presence of unilateral or bilateral DD.

METHODS

Patients referred to the diaphragm dysfunction clinic of our center (2017-2018) were included. All subjects had lung function testing (including measurement of ΔVC) and an ultrasound assessment of diaphragm thickening fraction (TFdi). Unilateral DD was defined as a single hemidiaphragm with TFdi ≤30 % and bilateral DD as a mean TFdi value of both hemidiaphragms ≤30 %. Clinical and physiological characteristics were compared across groups, and sensitivity/specificity analyses of ΔVC to identify DD were performed.

RESULTS

84 patients were included (31 unilateral DD, 17 bilateral DD and 36 without significant DD). DD groups had similar age, gender and BMI (all p > 0.05), but patients with bilateral DD had lower FVC, FEV1, MIP, TLC, ΔVC and more frequent orthopnea than patients with unilateral DD (all p < 0.05). There was a significant correlation between TFdi and ΔVC (rho=-0.56, p < 0.001). The optimal ΔVC value to identify bilateral DD was ≤-15 % [AUC 0.97 (95 %CI 0.89-1.00), p < 0.001, with sensitivity and specificity of 100 % and 89 %, respectively]. No single threshold of ΔVC could accurately predict unilateral DD [AUC 0.58 (95 %CI 0.45-0.72), p = 0.24].

CONCLUSION

ΔVC performs poorly in identifying patients with unilateral DD. However, a ΔVC value ≤-15 % is strongly associated with the presence of bilateral DD. These findings should be taken into account when using ΔVC in the evaluation of patients with suspected DD.

Sleep disordered breathing: Assessment and therapy in the age of emerging neuromuscular therapies

The term neuromuscular disease (NMD) encompasses a large variety of disorders that result in abnormal muscle function. Although it may be conventional to relate the use of this term to the most common muscular diseases (Duchenne muscular dystrophy [DMD], spinal muscular atrophy [SMA], and amyotrophic lateral sclerosis, etc), it is important to extend the term to pathologies manifested by severe neurologic (brain and spinal cord) malformations and injuries. In many of these scenarios, there are common mechanisms that contribute to sleep disordered breathing (SDB) and respiratory insufficiency although comorbidities may be somewhat different. Advances in the understanding of these diseases and their natural history, and increasing availability of mechanical ventilation to these patients have improved survival. The development of novel genetic and molecular therapies (as in the cases of DMD, SMA, and X-linked myotubular myopathy) provides an opportunity to use SDB as a reasonable outcome measure while also allowing the use of polysomnography as a validation tool in the assessments of effectiveness of therapies. We seek to provide an understanding of SDB in NMDs, and in the same light, would like to begin the conversation of thinking about weaning respiratory support when possible.

The relationship between pulmonary and swallowing functions in patients with neuromuscular diseases followed up by a tertiary referral center: a cross-sectional study

INTRODUCTION

Respiratory muscle weakness is common in patients with neuromuscular diseases (NMD). This puts them at risk for dysphagia and other pulmonary complications.

OBJECTIVES

To investigate the relationship between pulmonary function and swallowing in NMD.

MATERIALS AND METHODS

In this cross-sectional study, medical records of patients undergoing treatment at the Tertiary Referral Center for Neuromuscular Diseases of Hospital de Apoio de Brasília, Brazil, were reviewed. Respiratory function was assessed through spirometry (FVC and FEV1 measured) and swallowing assessed by the Dysphagia Risk Evaluation Protocol and the Functional Oral Intake Scale.

RESULTS

Two hundred and twenty-two patients were included. Dysphagia was present in 46.8% of patients and impairment of pulmonary function in 64.0%. The mean FVC observed was 66.9% and FEV1 was 66.0%, indicating restrictive lung disease. A correlation between the decline of pulmonary and swallowing functions was observed in patients with NMDs (FVC vs. DREP, R = 0.46; FVC vs. FOIS, R = 0.42; FEV1 vs. DREP, R = 0.42; FEV1 vs. FOIS, R = 0.40, p<.01). FVC and FEV1 values tend to be lower in patients with dysphagia in the context of NMD.

CONCLUSIONS

A positive correlation between pulmonary function and swallowing outcomes was observed in patients with NMD. Despite respiratory and swallowing impairment being widely present in the population with NMD, they require different treatments according to the disease's pathophysiology. Future studies should be conducted to explore the disease-specific relationship between pulmonary function and swallowing in patients with NMD.

Respiratory Complications of Pediatric Neuromuscular Diseases

Respiration is an event of oxygen consumption and carbon dioxide production. Respiratory failure is common in pediatric neuromuscular diseases and the main cause of morbidity and mortality. It is a consequence of lung failure, ventilatory pump failure, or their combination. Lung failure often is due to chronic aspiration either from above or from below. It may lead to end-stage lung disease. Ventilatory pump failure is caused by increased respiratory load and progressive respiratory muscles weakness. This article reviews the normal function of the respiratory pump, general pathophysiology issues, abnormalities in the more common neuromuscular conditions and noninvasive interventions.

Management of Rare Causes of Pediatric Chronic Respiratory Failure

The need for long-term noninvasive positive pressure ventilation (NiPPV) in children with chronic respiratory failure is rapidly growing. This article reviews pediatric-specific considerations of NiPPV therapy. Indications for NiPPV therapy can be categorized by the cause of the respiratory failure: (1) upper airway obstruction, (2) musculoskeletal and/or neuromuscular disease, (3) lower respiratory tract diseases, and (4) control of breathing abnormalities. The role of NiPPV therapy in select rare conditions (spinal muscular atrophy, congenital central hypoventilation syndrome, cerebral palsy, scoliosis, and Chiari malformations) is also reviewed.

Inspiratory Muscle Training in Rehabilitation of Low Back Pain: A Randomized Controlled Trial

CONTEXT

People with chronic low back pain (CLBP) suffer from weaknesses in their core muscle activity and dysfunctional breathing. Inspiratory muscle training (IMT) was recently developed to treat this condition.

OBJECTIVES

The present study was conducted to investigate the effect of IMT on core muscle activity, pulmonary parameters, and pain intensity in athletes with CLBP.

DESIGN

This study was designed as a single-blind, randomized, controlled trial.

SETTING

Clinical rehabilitation laboratory.

PARTICIPANTS

A total of 23 male and 24 female athletes with CLBP were randomly divided into the experimental and control groups.

MAIN OUTCOME MEASURES

The experimental group performed IMT for 8 weeks, 7 days per week and twice daily, using POWERbreathe KH1, beginning at 50% of maximum inspiratory pressure with a progressively increasing training load. The surface electromyography muscle activity of the erector spinae, multifidus, transverse abdominis and rectus abdominis, respiratory function and Visual Analogue Scale score were also measured before and after the intervention in both groups. The repeated-measures analysis of variance and 1-way analysis of covariance were further used to compare the intragroup and intergroup results following the intervention.

RESULTS

The findings of the study revealed that multifidus and transverse abdominis activity, as well as respiratory function, increased significantly in the IMT group (P < .05). Moreover, a descending trend was observed in the Visual Analogue Scale score in the experimental group (P < .05).

CONCLUSION

The results showed that IMT can improve respiratory function, increase core muscle activity, and, consequently, reduce pain intensity in athletes with CLBP.

Sleep-Disordered Breathing in Adult Patients With Mitochondrial Diseases: A Cohort Study

OBJECTIVE

To describe the prevalence and characteristics of sleep-disordered breathing (SDB) in a large cohort of patients with genetically confirmed mitochondrial diseases.

METHODS

This is a prospective observational study performed at the Neurophysiopatology Unit of Fondazione Policlinico Universitario A. Gemelli IRCCS. All participants had a defined mitochondrial disease and were investigated by full-night polysomnography.

RESULTS

One hundred three consecutive patients were enrolled. SDB was demonstrated in 49 patients (47.6%). Regarding phenotypes, we found differences in distribution between the groups: patients affected by progressive external ophthalmoplegia with single or multiple mtDNA deletions frequently had obstructive apneas (50% and 43.8%) or REM-related hypoventilation when associated with m.3243A>G mutations (75%). Furthermore, a high percentage of participants with maternally inherited diabetes and deafness and myoclonic epilepsy with ragged-red fibers syndromes were characterized by obstructive sleep apnea and REM-related hypoventilation, respectively. In contrast to what has been described in previous studies, central sleep apnea was rarely reported in our cohort.

CONCLUSIONS

SDB has a higher prevalence in mitochondrial diseases compared to general population-based data. Overall, these results suggest that patients characterized by a specific phenotype-genotype combination are most at risk of developing a specific subgroup of SDB. The early identification of this disorder is crucial in the management of these fragile patients.

Bi-allelic mutations in EGR2 cause autosomal recessive demyelinating neuropathy by disrupting the EGR2-NAB complex

BACKGROUND AND PURPOSE

Mutations in the early growth response 2 gene (EGR2) cause demyelinating, but also axonal, neuropathies differing in severity and age of onset. Except for one family, all reported cases have autosomal dominant inheritance and mutations are localized within the three zinc finger (ZNF) DNA-binding domain. The aim of this study was to provide a clinical and molecular analysis of a novel recessive mutation in EGR2.

METHODS

Clinical and electrophysiological assessments of three affected patients, from a consanguineous family, were performed. Genetic analyses of EGR2 were carried out by Sanger sequencing. Functional effects of clinical recessive mutations were assessed using a mammalian two-hybrid assay.

RESULTS

A novel missense mutation (c.791C>T; p.P264L) in the homozygous state was detected outside the ZNF domains of the EGR2 gene. Three affected siblings presented with distal demyelinating polyneuropathy with severe sensory loss, progressive thoracolumbar scoliosis and trigeminal neuralgia. Respiratory compromise and cranial nerve dysfunction were also found. Our data indicate that the p.P264L mutation prevents interaction of EGR2 transcription factor with NAB corepressors, suggesting that a disruption of the NAB-EGR2 protein interactions can result in dramatic neuropathy.

CONCLUSION

Mutations in, or next to, the R1 domain of EGR2 should be considered with extreme caution for genetic counseling, since these could cause a severe neuropathy with an autosomal recessive manner of transmission.