Pulmonary function and dysfunction in multiple sclerosis

Impaired lung function in multiple sclerosis: a single-center observational study in 371 persons

INTRODUCTION

Abnormal lung function in people with multiple sclerosis (PwMS) could be considered as the result of muscle weakness or MS-specific structural central nervous system (CNS) abnormalities as a precipitant factor for the worsening of motor impairment or cognitive symptoms.

METHODS

This is a cross-sectional observational study in PwMS. Forced spirometry was conducted, and normative metrics of forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the relation FEV1/FVC were calculated. Qualitative and quantitative brain magnetic resonance imaging (MRI) examinations were carried out.

RESULTS

A total of 371 PwMS were included in the study. Of those, 196 (53%) had RRMS, 92 (25%) SPMS, and 83 (22%) PPMS. Low FVC and FEV1 was present in 16 (8%), 16 (19%), and 23 (25%) of the patients in the RRMS, PPMS, and SPMS, respectively. PwMS with T2-FLAIR lesions involving the corpus callosum (CC) had a significantly higher frequency of abnormally low FVC and FEV1 (OR 3.62; 95% CI 1.33-9.83; p = 0.012) than patients without lesions in that region. This association remained significant in the RRMS group (OR 10.1; 95% CI 1.3-67.8; p 0.031) when the model excluded PPMS and SPMS. According to our study, for every increase of 1 z score of FVC, we observed an increase of 0.25 cm3 of hippocampal volume (β 0.25; 95% CI 0.03-0.47; p 0.023) and 0.43 cm3 of left hippocampus volume (β 0.43; 95% CI 0.16-0.71; p 0.002).

CONCLUSIONS

We observed an incremental prevalence of abnormally low pulmonary function tests that parallels a sequence from more early relapsing courses to long-standing progressive courses (RRMS to PPMS or SPMS).

Respiratory issues in patients with multiple sclerosis as a risk factor during SARS-CoV-2 infection: a potential role for exercise

Coronavirus disease-2019 (COVID-19) is associated with cytokine storm and is characterized by acute respiratory distress syndrome (ARDS) and pneumonia problems. The respiratory system is a place of inappropriate activation of the immune system in people with multiple sclerosis (MS), and this may cause damage to the lung and worsen both MS and infections.The concerns for patients with multiple sclerosis are because of an enhance risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The MS patients pose challenges in this pandemic situation, because of the regulatory defect of autoreactivity of the immune system and neurological and respiratory tract symptoms. In this review, we first indicate respiratory issues associated with both diseases. Then, the main mechanisms inducing lung damages and also impairing the respiratory muscles in individuals with both diseases is discussed. At the end, the leading role of physical exercise on mitigating respiratory issues inducing mechanisms is meticulously evaluated.

Effect of eight weeks respiratory muscle training on respiratory capacity, functional capacity and quality of life on subjects with mild to moderate relapsing-remitting multiple sclerosis: A single-blinded randomized controlled trial

BACKGROUND

Multiple Sclerosis (MS) is a chronic inflammatory disease of the nervous system leading to muscle weakness, including the respiratory muscles that cause pulmonary complications, impair functional capacity, increased fatigue, and as a result decreases the quality of life.

AIM

The purpose of the present study is to examine the influence of 8 weeks of respiratory muscle training (RMT) on pulmonary function and respiratory muscle strength in MS patients.

METHODS

The present study was a single-blind, randomized controlled trial that was conducted on 36 (27 Female, 9 Male) relapsing-remitting MS patients who were definitively diagnosed by a neurologist and randomly were divided into intervention and control groups. Both groups were educated on lifestyle modification with an emphasis on regular physical activity. In addition, the intervention group was prescribed eight weeks of respiratory muscle training with a threshold resistance device, daily, twice a day for three sets of 15 repetitions per set. Maximal expiratory pressure (PImax), maximal expiratory pressure (PEmax), spirometric indices, functional tests (six-minute walk test, timed up and go test), fatigue questionnaire, and questionnaire of quality of life were assessed before and after trials.

RESULTS

A total of 36 patients (75% female; mean age 38.00(8.86) years; BMI 26.56(2.64) kg/m²) were included in the study. The strength of inspiratory and expiratory muscles, respiratory function, fatigue, and quality of life were significantly improved in the intervention group (p<0.005). In addition, there was a significant improvement in the rate of fatigue and quality of life in all their dimensions (p<0.005). Only in the six-minute walk test, no significant improvement was seen in the intervention group compared to the control group (p = 0.262).

CONCLUSION

Findings could help therapists to provide MS patients with more effective respiratory muscle training protocols to maximize the benefits of rehabilitation.

Multiple Sclerosis and related disorders

Multiple Sclerosis (MS) is a common neuroinflammatory disorder which is associated with disabling clinical consequences. The MS disease process may involve neural centers implicated in the control of breathing, leading to ventilatory disturbances during both wakefulness and sleep. In this chapter, a brief overview of MS disease mechanisms and clinical sequelae including sleep disorders is provided. The chapter then focuses on obstructive sleep apnea-hypopnea (OSAH) which is the most prevalent respiratory control abnormality encountered in ambulatory MS patients. The diagnosis, prevalence, and clinical consequences as well as data on effects of OSAH treatment in MS patients are discussed, including the impact on the disabling symptom of fatigue and other clinical sequelae. We also review pathophysiologic mechanisms contributing to OSAH in MS, and in turn mechanisms by which OSAH may impact on the MS disease process, resulting in a bidirectional relationship between these two conditions. We then discuss central sleep apnea, other respiratory control disturbances, and the pathogenesis and management of respiratory muscle weakness and chronic hypoventilation in MS. We also provide a brief overview of Neuromyelitis Optica Spectrum Disorders and review current data on respiratory control disturbances and sleep-disordered breathing in that condition.

Pulmonary Function and Respiratory Muscle Strength in Patients with Multiple Sclerosis

Background

In patients with multiple sclerosis (MS), there is a decline in muscle strength and physical capacity due to demyelination and axonal loss in the central nervous system. In patients with advanced MS or in a later stage of the disease, also respiratory impairment may occur. The degree of pulmonary dysfunction in the earlier stages of MS has not been thoroughly described. Therefore, the primary aims of this study are to describe pulmonary function and respiratory muscle strength in patients with a moderate disease course and to identify associations between respiratory muscle strength and functional capacity.

Methods

A sample of 48 patients with a diagnosis of MS and mean age 56 ± 11 years was studied using a descriptive cross-sectional design. The patients had a disease duration of 24 ± 11 years and a median Expanded Disability Status Scale (EDSS) score of 4.5 (interquartile range 4.0-6.5). Pulmonary function assessed by spirometry, respiratory muscle strength, peak cough flow and peripheral oxygen saturation, subjective breathing and coughing ability, and physical capacity measured using the 6MWT were evaluated.

Results

The patients had normal pulmonary function with no significant abnormalities in dynamic spirometry (vital capacity 103 ± 16% predicted, forced expiratory volume in 1 second 95 ± 15% predicted). Peak expiratory flow rate 89 ± 17% predicted was in the lower limit of normal. Respiratory muscle strength, determined by maximal inspiratory (MIP) and expiratory (MEP) static pressures, was normal but with large differences between individuals. MIP ranged from 26 to 143 cmH₂O (98 ± 31% predicted); the MEP values ranged from 43 to 166 cmH₂O (104 ± 29% predicted), with two patients having values below the lower limit of normal. Significant positive associations between MIP as well as MEP were found in several pulmonary function variables. A significant negative association was found between EDSS score and MEP (r = −0.312, p = 0.031). Mean peak cough flow was 389 ± 70 L/min, which is comparable with the values reported for healthy adults. The patients did not experience a severely decreased ability to take deep breaths or cough. There was a moderate correlation between MEP and physical capacity, as assessed by the 6MWT (r = 0.399, p = 0.010) and between peak expiratory flow (PEF) and the 6MWT (r = 0.311, p = 0.048).

Conclusion

Respiratory muscle strength, pulmonary function assessed by spirometry, and peak cough flow were normal in patients with mild to moderate MS; however, there were large individual differences demonstrating low respiratory muscle strength in some patients. Significant associations between MEP and functional capacity and between MEP and disease severity were found, indicating that patients with impaired respiratory muscle strength have lower functional capacity and more severe disease.

Urinary incontinence and impaired physical function are associated with expiratory muscle weakness in patients with multiple sclerosis

PURPOSE

Patients with multiple sclerosis (MS) with respiratory muscle weakness could have physical function impairments, given the functional/biomechanical link of the trunk stabilising system. Thus, clinicians could employ new treatment strategies targeting respiratory muscles to improve their physical function. This study pretends to evaluate the relationship between respiratory muscle strength, pulmonary function and pelvic floor function, and also to correlate these variables with physical function (gait function, disability and quality of life) in patients with MS.

METHODS

41 patients participated in this descriptive cross-sectional study. Respiratory muscle strength [maximal respiratory pressures (MIP/MEP)], pulmonary function (forced spirometry), pelvic floor function [urinary incontinence (UI)], physical function [Timed Up & Go (TUG) test, Barthel index and health status questionnaire (SF-12)] were evaluated.

RESULTS

Respiratory muscle strength and pulmonary function were moderately related to UI (MIP: rho = -0.312; MEP: rho = -0.559). MEP was moderately related to physical function (TUG: rho = -0.508; Barthel index: rho = 0.418). Patients with and without expiratory muscle weakness showed differences in UI, pulmonary and physical function.

CONCLUSION

Patients with MS with greater deterioration in pulmonary function and respiratory muscle strength, especially expiratory muscles, showed greater deterioration in UI and physical function. Expiratory muscle weakness had a negative impact on urinary, physical and pulmonary function.Implications for rehabilitationPulmonary function is associated with urinary incontinence and gait functionality in patients with multiple sclerosis (MS).Expiratory muscle weakness is associated with impaired urinary and physical function in patients with MS.The inclusion of respiratory muscle training to the rehabilitation programs of patients with MS could improve their pelvic floor disorders and physical function.

Evolving relationship between respiratory functions & impairment in sleep and cognition in patients with multiple sclerosis

BACKGROUND

The most apparent source of disability in patients with multiple sclerosis (MS) is the physical and mental impact. The pathophysiological mechanisms of cognitive dysfunction are multifactorial although hypoventilation secondary to respiratory dysfunction may contribute to cognitive decline.

METHODS

This study was conducted on 146 MS patients with baseline clinical assessments including the Epworth sleepiness scale (ESS) and physical disability was assessed using the Expanded Disability Status Scale (EDSS). Cognitive testing was performed utilizing the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and the Perceived Deficits Questionnaire (PDQ). Respiratory functions were assessed by spirometry and the respiratory muscle functional assessment was done by maximal mouth pressure measurement.

RESULTS

The respiratory muscle function test had a significant negative correlation with the score of ESS and PDQ scale and a significant positive correlation with the BICAMS scale score (p < 0.001). The ESS and PDQ scores were significantly negatively correlated with forced expiratory volume in the first second (FEV1)/ forced vital capacity (FVC) (p = 0.03, 0.02), FVC supine (p = 0.03, 0.01), FVC upright- FVC supine (ΔFVC) (p < 0.001, <0.001) FEV1 (p < 0.001) and FVC (L) (p < 0.001), respectively. While the BICAMS showed a significant positive correlation with spirometry results except FVC upright. ESS scores were significantly correlated with the BICAMS and PDQ scale score (p < 0.001).

CONCLUSION

Among MS patients, impaired respiratory functions are significantly associated with sleep disturbance and cognitive impairment. Thus the spirometry and respiratory muscle strength assessment are necessary from the early phase of MS.

Effects of Intensive Voice Treatment (The Lee Silverman Voice Treatment [LSVT LOUD]) in Subjects With Multiple Sclerosis: A Pilot Study

AIM

The rehabilitation of voice disorders is an unmet need in multiple sclerosis (MS). The Lee Silverman Voice Treatment (LSVT LOUD) is a well-documented and effective speech treatment, developed to treat voice disorders in Parkinson Disease. The purpose of the present study was to examine the viability of applying the LSVT LOUD to individuals with MS and verify short- and long-term improvements in acoustic and perceptual voice parameters.

METHODS

A single subject design was performed in a consecutive sample of 8 subjects with MS. The subjects' voice was recorded with PRAAT software for 5 days at baseline during the 16  treatment sessions, and at follow-up (FU) 6/12 months later. PRAAT provided data on sustained /a/ (SPL/a/) voice intensity and maximum phonation time (MPT/a/) of sustained /a/, and on functional sentences voice intensity. In addition, self-assessment questionnaire Voice Handicap Index, the perceptual GIRBAS scale and intensity of monologue were collected at first day of baseline, post-treatment and at FU. In the treatment phase each subject received treatment according to LSVT LOUD protocol. Visual analysis calculated for daily acoustic variables was used to determine baseline stability and analyse changes following treatment. The Wilcoxon test was used to assess statistically significant differences between baseline and post treatment.

RESULTS

All participants completed the LSVT LOUD programme; one participant dropped out at FU. Improvements in acoustic analysis were found: SPL/a/ improved on average (± standard deviation) 11.64 ± 4.19 dB with 7 subjects showing statistically significant improvement (P < 0.05); MPT/a/ improved on average 1.2 ± 1.53seconds, while intensity of functional sentences improved on average 8.11 ± 3.46  dB with 4 and 5 subjects showed statistically significant improvement, respectively. Intensity of monologue improved 14.90 ± 3.33 dB. Acoustic values are maintained or increased at FU respect to baseline. All subjects improved perceptual ratings at Voice Handicap Index and results were maintained at FU. These changes were associated with improvements on five parameters on the GIRBAS scale at post-treatment, however no further improvement were observed at FU.

CONCLUSION

Intensive LSVT LOUD treatment is a viable approach to treat hypophonia in MS. LSVT LOUD improved both quantitative-instrumental and perceptive-subjective assessments. Randomised controlled trials are needed to provide a firm support on the effectiveness of LSVT LOUD in MS.

Self-Reported Changes in Cognition, Communication and Swallowing in Multiple Sclerosis: Data from the Swedish Multiple Sclerosis Registry and from a National Survey

PURPOSE

The aim of this study was to investigate self-reported cognition, speech, communication and swallowing changes in a large sample of individuals with multiple sclerosis (MS) in Sweden. A second aim was to update information about speech and language pathology (SLP) services received by people with MS (pwMS).

METHOD

Self-ratings of cognition, speech/communication and swallowing registered by pwMS between 2012 and 2018 were retrieved from the Swedish MS Registry. In addition, more detailed information about speech, communication, swallowing and provision of SLP services was collected using an online survey distributed via a national patient organization.

RESULTS

In total, entries from 5,289 pwMS were retrieved from the MS Registry. Nearly two thirds of the respondents reported that cognition was affected to some degree, whereas approximately one third perceived some difficulties with speech/communication. A smaller group reported swallowing problems. The majority of those who reported problems with speech/communication also reported problems with cognition. Among the 440 individuals who responded to the MS survey, word-finding difficulties were the most frequently self-reported problem related to communication, and the second most common problem was getting off topic. In all, close to four out of five respondents experienced at least one symptom related to speech and communication, such as speech-related fatigue or imprecise articulation. Swallowing difficulties were reported by one out of four respondents in the MS survey. As a result of their speech difficulties, up to one in three experienced changes in professional or social roles and participation. A limited number of respondents had received SLP services, the most common intervention being voice training.

CONCLUSIONS

In MS, changes associated with cognition as well as speech/communication are frequent, cognitive-linguistic symptoms being the most common. Swallowing difficulties are also relatively prevalent. Access to SLP services seems to be insufficient compared to prevalence of perceived symptoms. Considering that the majority of pwMS are part of the working-age population, access to SLP services must be more highly prioritized and must address cognitive-linguistic problems as well as voice, speech and swallowing dysfunction.

Respiratory repercussions of neurological diseases and how best to manage them

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

Exploring the feasibility of a mild and short 4-week combined upper limb and breathing exercise program as a possible home base program to decrease fatigue and improve quality of life in ambulatory and non-ambulatory multiple sclerosis individuals

PURPOSE

To evaluate the feasibility of a combined upper limb and breathing exercise for a home-based program and to explore its effect on primary fatigue and quality of life in ambulatory and non-ambulatory individuals with multiple sclerosis (MS) in a short time.

METHOD

Nineteen individuals with MS were assigned into semi-controlled pre-post feasibility study based on Expanded Disability Status Scale (EDSS) status and divided into two groups: exercise (five ambulatory, five non-ambulatory; EDSS 1.0-8.0) and related control with no exercise (four ambulatory, five non-ambulatory; EDSS 1.0-7.5). Exercise group performed combined upper limb and breathing exercise in a controlled group (2 days/week, 60 min/session) accompanied by independent home exercise (3 days/week, ≥ 20 min/session). Participants underwent measures of fatigue impact (Modified Fatigue Impact Scale (MFIS) and quality of life (RAND Medical outcomes study 36-item short-form health survey (SF-36)) before and after a 4-week period.

RESULTS

The MFIS (physical, psychosocial, total) showed statistically significant group-by-time interaction in ambulatory (p = 0.033, d = 1.60; p = 0.039, d = 1.59; p = 0.033, d = 1.62) and non-ambulatory individuals (p = 0.009, d = 2.42; p = 0.018, d = 1.96; p = 0.0008, d = 3.92). Physical functioning (SF-36) showed statistically significant group-by-time interaction in ambulatory (p = 0.014, d = 2.14) but no significance in non-ambulatory (p = 0.368, d = 0.68) individuals. Despite the absent statistical significance, there were large intervention effects on MFIS cognitive scores for ambulatory (d = 1.28) and non-ambulatory (d = 1.47), and on other SF-36 scores for ambulatory (general health: d = 1.76 and pain: d = 1.02) and non-ambulatory (physical limitation: d = 1.03 and emotional well-being: d = 0.94) individuals.

CONCLUSION

Our 4-week program reduced some aspects of fatigue and improved some aspects of quality of life in a small group of ambulatory and non-ambulatory individuals with MS. Good feasibility and significant positive changes from baseline warrant further exploratory work.

TRIAL REGISTRATION

Name of the registry: The Impact of Exercise Training on Living Quality in Multiple Sclerosis. Registration: The study was registered at www.clinicaltrial.gov on July 14, 2017. First participant enrollment: August 28, 2017. URL: 602-01/17-01-147; Trial registration ID: NTC03222596.

Respiratory muscle training for multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic disease of the central nervous system, affecting approximately 2.5 million people worldwide. People with MS may experience limitations in muscular strength and endurance - including the respiratory muscles, affecting functional performance and exercise capacity. Respiratory muscle weakness can also lead to diminished performance on coughing, which may result in (aspiration) pneumonia or even acute ventilatory failure, complications that frequently cause death in MS. Training of the respiratory muscles might improve respiratory function and cough efficacy.

OBJECTIVES

To assess the effects of respiratory muscle training versus any other type of training or no training for respiratory muscle function, pulmonary function and clinical outcomes in people with MS.

SEARCH METHODS

We searched the Trials Register of the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group (3 February 2017), which contains trials from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, LILACS and the trial registry databases ClinicalTrials.gov and WHO International Clinical Trials Registry Platform. Two authors independently screened records yielded by the search, handsearched reference lists of review articles and primary studies, checked trial registers for protocols, and contacted experts in the field to identify further published or unpublished trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that investigated the efficacy of respiratory muscle training versus any control in people with MS.

DATA COLLECTION AND ANALYSIS

One reviewer extracted study characteristics and study data from included RCTs, and two other reviewers independently cross-checked all extracted data. Two review authors independently assessed risk of bias with the Cochrane 'Risk of bias' assessment tool. When at least two RCTs provided data for the same type of outcome, we performed meta-analyses. We assessed the certainty of the evidence according to the GRADE approach.

MAIN RESULTS

We included six RCTs, comprising 195 participants with MS. Two RCTs investigated inspiratory muscle training with a threshold device; three RCTs, expiratory muscle training with a threshold device; and one RCT, regular breathing exercises. Eighteen participants (˜ 10%) dropped out; trials reported no serious adverse events.We pooled and analyzed data of 5 trials (N=137) for both inspiratory and expiratory muscle training, using a fixed-effect model for all but one outcome. Compared to no active control, meta-analysis showed that inspiratory muscle training resulted in no significant difference in maximal inspiratory pressure (mean difference (MD) 6.50 cmH₂O, 95% confidence interval (CI) -7.39 to 20.38, P = 0.36, I² = 0%) or maximal expiratory pressure (MD -8.22 cmH₂O, 95% CI -26.20 to 9.77, P = 0.37, I² = 0%), but there was a significant benefit on the predicted maximal inspiratory pressure (MD 20.92 cmH₂O, 95% CI 6.03 to 35.81, P = 0.006, I² = 18%). Meta-analysis with a random-effects model failed to show a significant difference in predicted maximal expiratory pressure (MD 5.86 cmH₂O, 95% CI -10.63 to 22.35, P = 0.49, I² = 55%). These studies did not report outcomes for health-related quality of life.Three RCTS compared expiratory muscle training versus no active control or sham training. Under a fixed-effect model, meta-analysis failed to show a significant difference between groups with regard to maximal expiratory pressure (MD 8.33 cmH₂O, 95% CI -0.93 to 17.59, P = 0.18, I² = 42%) or maximal inspiratory pressure (MD 3.54 cmH₂O, 95% CI -5.04 to 12.12, P = 0.42, I² = 41%). One trial assessed quality of life, finding no differences between groups.For all predetermined secondary outcomes, such as forced expiratory volume, forced vital capacity and peak flow pooling was not possible. However, two trials on inspiratory muscle training assessed fatigue using the Fatigue Severity Scale (range of scores 0-56 ), finding no difference between groups (MD, -0.28 points, 95% CI-0.95 to 0.39, P = 0.42, I² = 0%). Due to the low number of studies included, we could not perform cumulative meta-analysis or subgroup analyses. It was not possible to perform a meta-analysis for adverse events, no serious adverse were mentioned in any of the included trials.The quality of evidence was low for all outcomes because of limitations in design and implementation as well as imprecision of results.

AUTHORS' CONCLUSIONS

This review provides low-quality evidence that resistive inspiratory muscle training with a resistive threshold device is moderately effective postintervention for improving predicted maximal inspiratory pressure in people with mild to moderate MS, whereas expiratory muscle training showed no significant effects. The sustainability of the favourable effect of inspiratory muscle training is unclear, as is the impact of the observed effects on quality of life.

Maximum inspiratory pressure as a clinically meaningful trial endpoint for neuromuscular diseases: a comprehensive review of the literature

Respiratory muscle strength is a proven predictor of long-term outcome of neuromuscular disease (NMD), including amyotrophic lateral sclerosis, Duchenne muscular dystrophy, and spinal muscular atrophy. Maximal inspiratory pressure (MIP), a sensitive measure of respiratory muscle strength, one of several useful tests of respiratory muscle strength, is gaining interest as a therapeutic clinical trial endpoint for NMD. In this comprehensive review we investigate the use of MIP as a measure of respiratory muscle strength in clinical trials of therapeutics targeting respiratory muscle, examine the correlation of MIP with survival, quality of life, and other measures of pulmonary function, and outline the role of MIP as a clinically significantly meaningful outcome measure. Our analysis supports the utility of MIP for the early evaluation of respiratory muscle strength, especially of the diaphragm, in patients with NMD and as a surrogate endpoint in clinical trials of therapies for NMD.

Effects of multiple sclerosis on respiratory functions

Objectives: To measure respiratory functions of ambulatory patients with multiple sclerosis and compare the results with expected values from healthy general population data. Further, to study the correlation of respiratory function impairment with the multiple sclerosis-induced disability level.

Subjects: Thirty-eight patients with definite diagnosis of multiple sclerosis from the multiple sclerosis outpatient clinic.

Methods: The Expanded Disability Status Scale (EDSS) scores (mean 4.34±1.39) were evaluated to measure disability level. Respiratory functions tested in the laboratory included spirometric (FVC, FEV1, FEV1/FVC), maximal inspiratory (MIP) and expiratory (MEP) mouth pressure measurements. Patients were clinically assessed using a pulmonary dysfunction index (PDI) and dyspnoea index; various breathing features were also recorded.

Results: With respect to expected values from healthy general population, important decreases were found in mouth pressures with MIP (77%±23%, p ≃ 0) and MEP (60%±13%, p ≃ 0) while spirometric measures were significantly but less affected (FVC 94%±12%, p < 0.01, FEV191%±16%, p < 0.001). FEV1/FVC ratios were normal. Notable increases in PDI (5.58±0.68, p ≃ 0) and dyspnoea index (0.32±0.47, p ≃ 0) were observed. Significant relationships (p < 0.01) between respiratory function impairment and the multiple sclerosis disability level could be detected for FVC, MEP and PDI.

Conclusions: Multiple sclerosis clearly impairs respiratory functions; maximal mouth pressures are more severely reduced. This impairment increases with multiple sclerosis-induced disability level but is found to be independent from duration of disease.

Breathing-enhanced upper extremity exercises for patients with multiple sclerosis

Objective: To explore the effectiveness of breathing-enhanced upper extremity exercises on the respiratory function of patients with multiple sclerosis.

Design: Randomized controlled study of six-week duration.

Subjects: Forty patients with multiple sclerosis (age 39.2 ± 7 years; Kurtzke Expanded Disability Status Scale scores: 4.51 ± 1.55) randomly divided into two groups.

Methods: The training group followed a six-week home training programme designed to strengthen accessory respiratory muscles. Controls performed no exercises. All subjects submitted to baseline and post-training tests of spirometry, respiratory muscle strength and 6-minute walking. They were also assessed with pulmonary dysfunction and exertion fatigue indices.

Results: Spirometry revealed clear improvement in forced expiratory volume in 1 second (FEV1) (+13%, P = 0.003) resulting in higher FEV1/FVC (forced vital capacity) (+8.5%, P = 0.03). Maximal inspiratory pressure ( PImax) increased by +7.1% but not significantly. Maximal expiratory pressure ( PEmax) and FVC were significantly higher (by +7.1%, P = 0.0066 and +4.8%, P = 0.036 respectively) with respect to baseline measures. Pulmonary dysfunction was reduced (—9%, P = 0.002) while 6-minute walking distance was longer (+16%, P = 0.029) at equal exertion fatigue level.

Conclusions: The programme improved most pulmonary performance measures and had clinical significance. Its sustained application may prevent respiratory complications frequently observed in the later stages of multiple sclerosis.

Measures of respiratory function correlate with fatigue in ambulatory persons with multiple sclerosis

PURPOSE

This article examines the association between measures of respiratory muscle function and fatigue in individuals with mild-to-moderate disability multiple sclerosis (MS).

METHODS

This was a cross-sectional study of 37 ambulatory volunteers with MS (28 F/9 M, 52.7 ± 10.2 years, Expanded Disability Status Scale [EDSS] = 3.5 ± 1.9). No patients withdrew from the study. Primary outcome variables included measures of respiratory function: maximal inspiratory (MIP) and expiratory pressures (MEP), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), maximal voluntary ventilation (MVV₁₂); and a self-reported measure of fatigue: the Modified Fatigue Impact Scale (MFIS). Secondary measures included 6-min walking test (6MWT), a timed stair climb, the Short Form (SF)-36, the Epworth Sleepiness Scale and the Physical Activity and Disability Scale (PADS).

RESULTS

Significant correlations were shown between expiratory muscle strength (MEP) and the MFIS total (p < 0.03, r = -0.362) and between MEP and physical fatigue scores (p < 0.03, r = -0.360), as well as between MVV₁₂ percent predicted (respiratory muscle endurance) and both the 6MWT (p = 0.045, r = 0.346) and the Epworth Sleepiness Scale (p = 0.006, r = 0.447).

CONCLUSIONS

Respiratory muscle performance is correlated with perceived fatigue (MFIS), whereas respiratory endurance correlated to reductions in physical function and sleep quality among individuals with mild-to-moderate severity MS. Implications for Rehabilitation Multiple sclerosis (MS) results in peripheral and respiratory muscle weakness and affected individuals report fatigue as one of their most disabling symptoms. Expiratory muscle strength was correlated with self-reported physical fatigue, while respiratory muscle endurance was correlated with functional performance and sleepiness. Respiratory muscle strength was not correlated with lung spirometry testing. These findings highlight the importance of considering the effects of respiratory muscle weakness when evaluating causes of fatigue among individuals with mild-to-moderate MS.

Respiratory dysfunction in multiple sclerosis

Respiratory dysfunction frequently occurs in patients with advanced multiple sclerosis (MS), and may manifest as acute or chronic respiratory failure, disordered control of breathing, respiratory muscle weakness, sleep disordered breathing, or neurogenic pulmonary edema. The underlying pathophysiology is related to demyelinating plaques involving the brain stem or spinal cord. Respiratory complications such as aspiration, lung infections and respiratory failure are typically seen in patients with long-standing MS. Acute respiratory failure is uncommon and due to newly appearing demyelinating plaques extensively involving areas of the brain stem or spinal cord. Early recognition of MS patients at risk for respiratory complications allows for the timely implementation of care and measures to decrease disease associated morbidity and mortality.

Patients with neuromuscular disorder

This article describes the preoperative preparation of patients with neuromuscular disorders. These entities are a relatively rare and diverse group of diseases that can affect various organ systems in addition to the central nervous system. The anesthetic implications for the various comorbidities are varied and can be profound. These patients should be optimized before surgery, with the involvement of a multidisciplinary team of specialists.

Pulmonary issues in patients with chronic neuromuscular disease

Patients with chronic neuromuscular diseases such as spinal cord injury, amyotrophic lateral sclerosis, and muscular dystrophies experience respiratory complications that are cared for by the respiratory practitioner. An organized anatomical approach for evaluation and treatment is helpful to provide appropriate clinical care. Effective noninvasive strategies for management of hypoventilation, sleep-disordered breathing, and cough insufficiency are available for these patients.

Lung volume recruitment in multiple sclerosis

Introduction

Pulmonary function abnormalities have been described in multiple sclerosis including reductions in forced vital capacity (FVC) and cough but the time course of this impairment is unknown. Peak cough flow (PCF) is an important parameter for patients with respiratory muscle weakness and a reduced PCF has a direct impact on airway clearance and may therefore increase the risk of respiratory tract infections. Lung volume recruitment is a technique that improves PCF by inflating the lungs to their maximal insufflation capacity.

Objectives

Our goals were to describe the rate of decline of pulmonary function and PCF in patients with multiple sclerosis and describe the use of lung volume recruitment in this population.

Methods

We reviewed all patients with multiple sclerosis referred to a respiratory neuromuscular rehabilitation clinic from February 1999 until December 2010. Lung volume recruitment was attempted in patients with FVC <80% predicted. Regular twice daily lung volume recruitment was prescribed if it resulted in a significant improvement in the laboratory.

Results

There were 79 patients included, 35 of whom were seen more than once. A baseline FVC <80% predicted was present in 82% of patients and 80% of patients had a PCF insufficient for airway clearance. There was a significant decline in FVC (122.6 mL/y, 95% CI 54.9–190.3) and PCF (192 mL/s/y, 95% 72–311) over a median follow-up time of 13.4 months. Lung volume recruitment was associated with a slower decline in FVC (p<0.0001) and PCF (p = 0.042).

Conclusion

Pulmonary function and cough decline significantly over time in selected patients with multiple sclerosis and lung volume recruitment is associated with a slower rate of decline in lung function and peak cough flow. Given design limitations, additional studies are needed to assess the role of lung volume recruitment in patients with multiple sclerosis.

Lower motor neuron loss in multiple sclerosis and experimental autoimmune encephalomyelitis

OBJECTIVE

Multiple sclerosis (MS) is considered a chronic inflammatory and demyelinating disease of the central nervous system. Evidence that axonal and neuronal pathology contributes to the disease is accumulating, however, the distribution of neuronal injury as well as the underlying mechanisms have not yet been fully clarified. Here, we investigated the role of neuronal cell loss in MS and its animal model, experimental autoimmune encephalomyelitis (EAE).

METHODS

We performed electrophysiological investigations in MS patients, including assessment of compound muscle action potentials and motor unit numbers and quantified neuronal cell loss in human MS samples and different EAE models by high-precision stereology.

RESULTS

Both electrophysiological and morphological analyses indicated a massive loss of lower motor neurons in MS patients. We regularly found dying spinal motor neurons surrounded by CD3+ (CD4+ as well as CD8+) T cells expressing tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We observed a similar degree of damage and immune attack in different variants of EAE; the lower motor neurons were preserved in adoptive transfer EAE induced with TRAIL-deficient T lymphocytes.

INTERPRETATION

Our study indicates that damage to lower motor neurons and TRAIL-mediated inflammatory neurodegeneration in the spinal cord contribute to MS pathology.

Abnormalities of respiratory control and the respiratory motor unit

BACKGROUND

Control of ventilation depends on a brainstem neuronal network that controls activity of the motor neurons innervating the respiratory muscles. This network includes the pontine respiratory group and the dorsal and ventral respiratory groups in the medulla. Neurologic disorders affecting these areas or the respiratory motor unit may lead to abnormal breathing.

REVIEW SUMMARY

The brainstem respiratory network contains neurons critical for respiratory rhythmogenesis; this network receives inputs from peripheral and central chemoreceptors sensitive to levels of carbon dioxide (PaCO2) and oxygen (PaO2) and from forebrain structures that control respiration as part of integrated behaviors such as speech or exercise. Manifestations associated with disorders of this network include sleep apnea and dysrhythmic breathing frequently associated with disturbances of cardiovagal and sympathetic vasomotor control. Common disorders associated with impaired cardiorespiratory control include brainstem stroke or compression, syringobulbia, Chiari malformation, high cervical spinal cord injuries, and multiple system atrophy. By far, neuromuscular disorders are the more common neurologic conditions leading to respiratory failure.

CONCLUSIONS

Respiratory dysfunction constitute an early and relatively major manifestation of several neurologic disorders and may be due to an abnormal breathing pattern generation due to involvement of the cardiorespiratory network or more frequently to respiratory muscle weakness.

Randomized control trial of effects of a 10-week inspiratory muscle training program on measures of pulmonary function in persons with multiple sclerosis

Pulmonary impairments have long been recognized as major causes of morbidity and mortality in individuals with advanced multiple sclerosis (MS). This study was designed to determine if a 10-week home exercise inspiratory training program in community-dwelling persons with MS improves pulmonary muscle strength and endurance. Forty-six ambulatory individuals with clinically diagnosed MS [Expanded Disability Status Scale (EDSS) 2.0-6.5, intervention group mean = 3.96 and control group mean = 3.36] were randomly assigned to an intervention group that received 10 weeks of inspiratory muscle strength training (IMT) or a nontreatment control group. Twenty-one subjects in the control group and 20 subjects in the intervention group completed the study. The intervention group demonstrated significantly greater improvement than the control group in maximal inspiratory pressure (P < 0.001). When compared to the control group, no significant differences were noted for maximal expiratory pressure or maximal ventilation volume after training in the intervention group. Baseline and postexercise training comparison of secondary pulmonary expiratory outcomes were significant in the intervention group for forced expiratory volume at one second (FEV1) (P = 0.014), forced vital capacity (FVC) (P = 0.041), and midexpiratory flow rate(FEF(25-75%)) (P = 0.011). No significant changes were noted for the control group. Thus, IMT significantly increased inspiratory muscle strength and resulted in generalized improvements in expiratory pulmonary function in persons with MS who have minimal to moderate disability. Future studies are needed that focus on the long-term effects of IMT with increased resistance and the impact it has on increasing pulmonary function and functional performance.

Rééducation fonctionnelle et sclérose en plaques : une vue d’ensemble

Multiple sclerosis (MS) is a chronic progressive disease which is the leading cause, after road traffic accidents, of handicap in young subjects. The large range of symptoms associated with MS lead to continuing decline in mood and quality of life. Despite therapeutic advances, functional impairments have significant consequences. Neurorehabilitation can be highly contributive in this disease with the goals of increasing independence and quality-of-life and improving functional capacities. Individualized programs elaborated by a multidisciplinary team of experts are the key to success of rehabilitation. Assessment is difficult because of the underlying conflict between the philosophies of rehabilitation and evidence-based medicine. The aim of this paper is to provide an overview of MS rehabilitation. Physical exercise is safe and should be encouraged for people with MS. Some studies have shown that supervised exercises have a beneficial effect on MS disability and quality of life. Inpatient rehabilitation for MS yields short-term benefits in function, mobility and quality of life; periodic hospitalization may be needed. In the future, rehabilitation professionals will have to learn how to anticipate patient needs and lay the groundwork for services and equipment in advance. Rehabilitation is one of the treatments of MS patients and should be viewed as an ongoing process to maintain and restore maximum function and quality of life.

Cardiopulmonary and metabolic functions, aerobic capacity, fatigue and quality of life in patients with multiple sclerosis

OBJECTIVES

The objectives of this study were to evaluate cardiopulmonary and metabolic functions in patients with multiple sclerosis (MS) and to clarify the relationship between these functions and neurological deficits, respiratory involvement, fatigue and quality of life.

MATERIALS AND METHODS

Twenty-five patients with MS and 15 healthy controls were included in the study. Cardiopulmonary and metabolic responses to maximum exercise were investigated with an electronically braked arm crank ergometer. A computerized gas analysis system collected and analysed expired gases during exercise.

RESULTS

In the present study, significant respiratory muscle weakness, and decreased aerobic performance and cardiopulmonary and metabolic responses to maximum exercise were determined in patients with MS.

CONCLUSIONS

As respiratory muscle function plays a strong role in aerobic capacity and in most of the cardiopulmonary and metabolic responses to exercise, measurement of respiratory muscle strength and endurance should also be carried out in the MS population.

Comparison of the influence of different rehabilitation programmes on clinical, spirometric and spiroergometric parameters in patients with multiple sclerosis

PURPOSE

The aim of this study was to compare the effect of four different programmes on spiroergometric, spirometric and clinical parameters in multiple sclerosis (MS) patients.

METHODS

One hundred and twelve MS patients were divided into four groups. The first group underwent neurophysiologically based physiotherapy, the second aerobic training, the third combined therapy (neurophysiologically based physiotherapy and aerobic training) and the fourth did not change any habits. Seventeen patients did not finish the study. Patients were examined on impairment (Expanded Disability Status Scale), disability (Barthel Index), handicap (Environment Status Scale), quality of life (Multiple Sclerosis Quality of Life), fatigue (Modified Fatigue Impact Scale), depression (Beck Depression Inventory Score), respiratory function (spirometric parameters on spirometry) and physical fitness (spiroergometric parameters on a bicycle ergometer).

RESULTS

The patients who participated in one of our training programmes showed a significant improvement of the examined parameters in comparison to those who did not change their present habits. Each of the four training programmes had a different impact on the parameters, which means that each of them had a different effect. The neurophysiologically based physiotherapy had the greatest impact on impairment, and the aerobic training on spirometric and spiroergometric parameters. All methods (the neurophysiologically based physiotherapy, the aerobic training and the combined programme) had an impact on fatigue.

Expiratory muscle strength training in persons with multiple sclerosis having mild to moderate disability: effect on maximal expiratory pressure, pulmonary function, and maximal voluntary cough

OBJECTIVE

To determine the effect of expiratory muscle strength training (EMST) on maximal expiratory strength, pulmonary function, and maximal voluntary cough in persons with multiple sclerosis (MS) having mild to moderate disability.

DESIGN

Before-after trial.

SETTING

Assessments were completed in the privacy of the subject's home or exercise physiology laboratory.

PARTICIPANTS

Seventeen persons with MS were age- and sex-matched to 14 healthy controls.

INTERVENTION

Eight weeks of EMST and 4 weeks of detraining.

MAIN OUTCOME MEASURES

Maximal respiratory pressures, pulmonary function, and maximal voluntary cough were assessed 3 times (pretraining, posttraining, detraining). Maximal expiratory pressure (MEP) was assessed weekly and training intensity adjusted based on the new measurement.

RESULTS

Subjects with MS had lower MEP, decreased pulmonary function, and weaker maximal voluntary cough at each assessment. EMST increased MEP and peak expiratory flow. However, improvement in maximal voluntary cough only occurred in subjects with a moderate level of disability when the MS group was subdivided into mild and moderate disability levels based on the Expanded Disability Status Scale.

CONCLUSIONS

EMST is a viable tool to enhance the strength of the respiratory muscles. However, further work is needed to determine the best parameters to assess change in cough following EMST.

Six-minute walk distance as a measure of functional exercise capacity in multiple sclerosis

PURPOSE

We hypothesised that six-minute walk (6MWT) distance of patients with ambulatory multiple sclerosis (MS)would differ from age-matched healthy control subjects. We also investigated the contribution of demographic, physical and physiological factors to impaired functional capacity in MS.

METHOD

Thirty MS patients and 30 healthy subjects participated in this study. Respiratory muscle strength was measured. Pulmonary function test and 6MWT were performed. The Barthel Index (BI) was used to assess activities of daily living, and the Modified Ashworth Scale was used to determine spasticity. Symptomatic fatigue was measured using the Fatigue Severity Scale (FSS).

RESULTS

Pulmonary function and respiratory muscle strength of ambulatory MS patients were significantly lower, and baseline heart rate and fatigue perception were significantly higher than were healthy controls (p < 0.05). MS patients reached a significantly higher exercise heart rate, and walked significantly shorter distance than did healthy subjects (p < 0.05). The BI score, baseline heart rate and FSS score together accounted for 81 percent variance in 6MWT distance of MS patients (p < 0.05).

CONCLUSION

The shorter distance covered during a 6MWT is determined by the limitations in activities of daily living,resting heart rate and subjective symptomatic fatigue in ambulatory patients with MS. Respiratory muscle weakness, lung function and level of neurological impairment do not contribute to impaired functional exercise capacity in these patients.

Spiroergometric and spirometric parameters in patients with multiple sclerosis: are there any links between these parameters and fatigue, depression, neurological impairment, disability, handicap and quality of life in multiple sclerosis?

One-hundred and twelve patients with multiple sclerosis were selected as population-based sample and examined on impairment (Expanded Disability Status Scale), disability (Barthel Index), handicap (Environment Status Scale), the quality of life (Multiple Sclerosis Quality of Life), fatigue (Modified Fatigue Impact Scale), depression (Beck Depression Inventory Score), respiratory function (spirometric parameters on spirometry) and physical fitness (spiroergometric parameters on a bicycle ergometer). The aim of the study was to examine and analyse (descriptive statistics) spiroergometric and spirometric parameters in patients with multiple sclerosis. Firstly, we tested the hypothesis whether spiroergometric and spirometric parameters are decreased and whether there are any correlations between these parameters and measures of impairment, depression, disability, handicap and quality of life. Secondly, we tested the hypothesis whether there is any correlation between a possible deconditioning and fatigue, and between a possible respiratory dysfunction and fatigue in multiple sclerosis. It results from this study that many spiroergometric parameters in patients with multiple sclerosis are significantly lowered in comparison to the population norm. A link can be found between some spiroergometric parameters and neurological impairment, disability, handicap and quality of life. It is not possible to prove any correlation between spiroergometric parameters and depression. From the spirometric parameters, these are expiratory flows that are significantly lowered in MS patients. It is not possible to prove any correlation between spirometric parameters and fatigue, depression, neurological impairment, duration of the disease, disability, handicap and quality of life in multiple sclerosis.

Cardiorespiratory response to walk in multiple sclerosis patients

To ascertain whether fatigue perception is linked to exertion dyspnea and/or to an impaired cardiorespiratory response during walk, 11 patients (8 females, age range 21-46 years) with multiple sclerosis (MS) and mild disability underwent the 6-min walk test. Ten healthy subjects (7 females, age range 25-49 years) were studied, as a control group. Patients did not differ from controls in spirometry, lung volumes and respiratory muscle strength. There was a significant difference in walk distance between patients and controls (P<0.001), but not in dyspnea perception. In patients, the walk distance significantly related to disability score (P<0.01), but not to fatigue. Compared to controls, patients had a significant decrease in oxygen pulse during walk (P<0.05) and a significant increase in the ventilatory equivalent of CO2 both at baseline and during walk (P<0.05). The relative contribution of both the tidal volume and of the ratio of inspiratory to total breathing cycle duration to the increase in minute ventilation during walk was significantly less in patients, as compared to controls (P<0.05). We conclude that in MS patients with mild disability, fatigue and exertion dyspnea are different sensations without any link and a peripheral limitation during walk can occur.

Effect of inspiratory muscle training in patients with multiple sclerosis

OBJECTIVE

To evaluate whether inspiratory muscle training (IMT) improves inspiratory muscle strength, respiratory capacity, fatigue, and subjective perception of physical endurance in patients with advanced multiple sclerosis (MS).

DESIGN

Randomized controlled trial.

SETTING

Outpatient clinic in Sweden.

PARTICIPANTS

Fifteen severely disabled patients with MS, randomized to a training or control group.

INTERVENTION

Seven patients trained with a Threshold inspiratory muscle trainer, twice every other day, with 3 sets of 10 loaded inspirations (40%-60% of patients' maximal inspiratory pressure [Pimax]) over a 10-week period.

MAIN OUTCOME MEASURES

Spirometry, Pimax, maximal expiratory pressure (Pemax), clinical assessments, and questionnaires on the patients' fatigue severity and physical endurance were evaluated.

RESULTS

After training, the Pimax (P<.008) and Pemax (P<.02) increased in the training group. The improvement in Pimax after 10 weeks of training was higher than the improvement in the control group (P<.01) and was maintained 1 month after the training period ended. The training affected neither respiratory function nor the patients' symptoms.

CONCLUSIONS

IMT had a beneficial effect on inspiratory muscle strength in patients with MS and is recommended as a complement to ordinary physical training.

Are the neurophysiological techniques useful for the diagnosis of diaphragmatic impairment in multiple sclerosis (MS)?

OBJECTIVE

To characterize cortico-diaphragmatic pathway involvement in multiple sclerosis (MS) by means of transcranial magnetic stimulation (TMS), and verify its clinical impact.

METHODS

TMS from diaphragm (Dia), and abductor digiti minimi (AbdV degrees ) was performed in 26 MS patients. Phrenic nerve (PN) conduction study was also performed. Expanded disability status scale (EDSS) and fatigue descriptive scale (FDS) were measured. Forced vital capacity (FVC), forced expiratory volume at the first second (FEV1), peak expiratory flow (PEF) were tested: the predicted percentage value (% pred) was considered.

RESULTS

Cortical motor evoked potential (Cx-MEP) latency and central motor conduction time (CMCT) were prolonged, respectively, in 31 and 23% of patients from Dia, in 76 and 79% from AbdV degrees. PN-compound motor action potential (CMAP) was normal. EDSS correlated to Cx-MEP from AbdV degrees (P<0.01), and PN-CMAP amplitude (P<0.05), FEV1 % pred (P<0.01), PEF % pred (P<0.01). PN-CMAP amplitude correlated to FVC % pred P=0.05, FEV1 % pred P<0.01, PEF % pred P<0.01. Fatigue was related to AbdV degrees Cx-MEP and CMCT (P<0.05 and P<0.01).

CONCLUSIONS

Cortico-diaphragmatic pathway is impaired only in a minority of MS patients. Lack of correlation between TMS findings from Dia and respiratory tests argues against its routinary use to detect subclinical respiratory alterations. Fatigue seems to be related to the motor impairment rather than to respiratory distress.

Rapid weaning from mechanical ventilator in acute cervical cord multiple sclerosis lesion after steroids

IMPLICATIONS

We report a patient with multiple sclerosis (MS), who developed neuromuscular respiratory failure requiring ventilation because of a cervical cord relapse. Serial pulmonary function tests documented improvement after steroid treatment. Cervical cord or brainstem relapses should be suspected in MS patients with respiratory failure. Identification and management of this critical condition are discussed.

Pulmonary function testing in neuromuscular disease

Pulmonary function testing is useful in the diagnosis and management of patients with neuromuscular disease. It is important, however, to keep in mind that certain tests commonly used to assess these patients, such as MIPs and MEPs, although useful, are fraught with potential error and rigorous attention should be paid to technical details when performing them. In addition, many studies have shown that pulmonary impairment does not always parallel generalized muscle impairment and thorough testing therefore should be done in any patient with neuromuscular disease to assess the level of respiratory compromise accurately. In addition, the clinician should be aware that the pattern of involvement-bulbar versus inspiratory, versus expiratory muscle weakness-may vary markedly among patients, even with the same diagnosis, so testing should be tailored to detect these patterns. Furthermore, serial follow-up examinations should be performed to track the rate of deterioration so that therapeutic interventions can be initiated before respiratory crises occur.

Respiratory muscle weakness and respiratory muscle training in severely disabled multiple sclerosis patients

OBJECTIVE

To evaluate the contribution of respiratory muscle weakness (part 1) and respiratory muscle training (part 2) to pulmonary function, cough efficacy, and functional status in patients with advanced multiple sclerosis (MS).

DESIGN

Survey (part 1) and randomized controlled trial (part 2).

SETTING

Rehabilitation center for MS.

PATIENTS

Twenty-eight bedridden or wheelchair-bound MS patients (part 1); 18 patients were randomly assigned to a training group (n = 9) or a control group (n = 9) (part 2).

INTERVENTION

The training group (part 2) performed three series of 15 contractions against an expiratory resistance (60% maximum expiratory pressure [PEmax]) two times a day, whereas the control group performed breathing exercises to enhance maximal inspirations.

MAIN OUTCOME MEASURES

Forced vital capacity (FVC), inspiratory, and expiratory muscle strength (PImax and PEmax), neck flexion force (NFF), cough efficacy by means of the Pulmonary Index (PI), and functional status by means of the Extended Disability Status Scale (EDSS).

RESULTS

Part 1 revealed a significantly reduced FVC (43% +/- 26% predicted), PEmax (18% +/- 8% predicted), and PImax (27% +/- 11% predicted), whereas NFF was only mildly reduced (93% +/- 26% predicted). The PI (median score, 10) and EDSS (median score, 8.5) were severely reduced. PEmax was significantly correlated to FVC, EDSS, and PI (r = .77, -.79, and -.47, respectively). In stepwise multiple regression analysis. PEmax was the only factor contributing to the explained variance in FVC (R2 = .60), whereas body weight (R2 = .41) was the only factor for the PI. In part 2, changes in PImax and PEmax tended to be higher in the training group (p = .06 and p = .07, respectively). The PI was significantly improved after 3 months of training compared with the control group (p < .05). After 6 months, the PI remained significantly better in the training group.

CONCLUSIONS

Expiratory muscle strength was significantly reduced and related to FVC, cough efficacy, and functional status. Expiratory muscle training tended to enhance inspiratory and expiratory muscle strength. In addition, subjectively and objectively rated cough efficacy improved significantly and lasted for 3 months after training cessation.

Micturitional disturbances are associated with impaired breathing control in multiple sclerosis

STUDY OBJECTIVES

To investigate whether the localization of multiple sclerosis (MS), the duration of the disease, and the level of neurologic functioning in patients with MS predispose them to disturbed breathing control.

DESIGN

Case-control study.

SETTING

Outpatient pneumology department of a university hospital.

PATIENTS

Twenty-three MS patients and 51 healthy control subjects.

MEASUREMENTS AND RESULTS

Resting mouth occlusion pressure at 0.1 s after onset of inspiratory effort (P0.1) was measured during the hypercapnic response (HCR) and the hypoxic response (HR) in all subjects. The Kurtzke expanded disability status scale and the functional system score were used to describe the level of neurologic functioning of the MS patients. Predictors of HCR and HR were assessed by multiple regression analysis. Low maximal inspiratory pressure (MIP) values correlated with low resting P0.1 values (r = 0.44; p = 0.05), although in neuromuscular diseases, high resting P0.1 values are usually found to compensate for low MIPs. Detrusor-sphincter dyssynergia (DSD) was the only predictor for lower ventilatory HCR (p = 0.006; r2 = 0.52), lower P0.1 HCR (p = 0.004; r2 = 0.47), lower ventilatory HR (p = 0.04; r2 = 0.28), and lower P0.1 HR (p = 0.04; r2 = 0.10); low MIPs and pyramidal tract involvement had no role.

CONCLUSIONS

(1) Impaired control of breathing in some MS patients is related mainly to central defects. (2) DSD is the most important predictor of disturbed ventilatory control, presumably because the micturition and pneumotaxic center are closely related and located in the rostral pons. (3) No relationship with the duration of the MS disease could be demonstrated, which can be explained by the variable course of MS itself.

Reliability of maximal respiratory pressures in multiple sclerosis

OBJECTIVE

To assess the reliability of maximal inspiratory pressure (P(I)max) and maximal expiratory pressure (P(E)max) in subjects with multiple sclerosis (MS) and healthy control subjects by identifying the number of testing sessions and the number of measurements needed in a single testing session to obtain consistent, reproducible results.

DESIGN

A descriptive, comparative design with repeated measures was used.

SETTING

Four sets of 10 P(I)max and 10 P(E)max measurements were obtained over a 4-week period from MS subjects in their homes. The same measurements were obtained from healthy control subjects in a private setting.

SUBJECTS

Seventy-two MS patients and 61 healthy control subjects participated in the study.

MEASUREMENT

P(I)max and P(E)max values were obtained by using previously published methods.

RESULTS

Mean P(E)max and P(I)max values for MS patients differed over the first three of the four testing sessions. By contrast, mean P(E)max and P(I)max values for healthy control subjects differed only when the first session values were compared with values from the last three sessions. For MS patients, P(E)max and P(I)max increased between the first and 10th trial during the first testing session, but not during the subsequent three sessions.

CONCLUSIONS

The results of this study suggest that several practice sessions should be provided in order to obtain reliable P(E)max and P(I)max values in persons with MS. At least one practice session should be provided for healthy control subjects before identifying a baseline.

Music therapy as a treatment method for improving respiratory muscle strength in patients with advanced multiple sclerosis: a pilot study

Respiratory muscle weakness, predominantly of the expiratory muscles, is characteristic of individuals with advanced multiple sclerosis and can result in difficulty in clearing secretions and repeated episodes of pneumonia. This pilot study evaluated the effectiveness of music therapy in strengthening respiratory muscles through an emphasis on diaphragmatic breathing and coordination of breath and speech. Twenty patients were randomly assigned to one of two groups: one that received music therapy or one that attended music appreciation sessions. Participants' inspiratory and expiratory muscle strength was measured by testing mouth pressure before and after the intervention. The experimental group showed some improvement in terms of expiratory muscle strength, in contrast to the control group, which showed deterioration. The results were not statistically significant, however. Patients in both groups exhibited considerable weakness in their expiratory muscles, and results for 79% of the participants were below 30% of the predicted values. Variability, a major confounding factor that resulted in reduced statistical power, led the investigators to suggest an intercenter collaboration to amass sufficient numbers of patients for a future study. Early manifestation of respiratory muscle weakness warrants inclusion of respiratory muscle testing in examination protocols and early intervention efforts.

Expiratory training in multiple sclerosis

OBJECTIVE

To compare the effects of expiratory muscle training and sham training on respiratory muscle strength in patients with multiple sclerosis (MS).

DESIGN

A randomized control trial; subjects were randomly assigned to either expiratory muscle training or sham training.

SETTING

Training and measurement of respiratory muscle pressures were conducted in patients' homes. Weekly home visits were conducted to assure compliance with the training protocols and to obtain measurements.

PATIENTS

Twenty subjects with clinically definite MS and decreased expiratory muscle strength entered the study; 10 subjects completed 3 months of expiratory training using a threshold training device and 5 subjects completed 3 months of sham training using the same device but without an expiratory training threshold load.

MEASUREMENT

Respiratory muscle strength was assessed at baseline and after 1, 2, and 3 months of training; maximal inspiratory and expiratory pressures were used as measures of respiratory muscle strength.

RESULTS

There was a significant increase in expiratory muscle strength after 3 months of training when the expiratory training group was compared to the sham group (p = .003); no significant change in inspiratory muscle strength was observed.

CONCLUSIONS

The results of this pilot study suggest that the strength of the expiratory muscles of persons with MS can be increased through respiratory muscle training targeted to the expiratory muscles. Further research is indicated to determine if increasing the strength of the expiratory muscles in MS has an effect on clinical outcomes in this patient population.

Control of breathing and respiratory muscle strength in patients with multiple sclerosis

In 11 patients with moderately severe multiple sclerosis, lasting 11.2 +/- 7.3 years, in stable condition, and in 10 age- and sex-matched control subjects, we investigated lung function, respiratory muscle strength, and ventilatory control system. Respiratory muscle strength was assessed by measuring maximal inspiratory and expiratory mouth pressures (Pimax and Pemax, respectively). Respiratory central drive was evaluated in terms of neuromuscular (P0.1) and ventilatory (Ve) output, breathing room air and during CO2 rebreathing. In the absence of any significant impairment of lung function, patients showed a reduction of Pimax and Pemax amounting to about 40 percent and 60 percent of the predicted value at functional residual capacity (FRC), respectively; a significant, inverse correlation was found between both Pimax and Pemax at FRC and the severity score of the disease. While at rest Ve was similar to that of control subjects, baseline P0.1 was significantly higher in patients (1.97 +/- 0.79 vs 0.97 +/- 0.20 cm H2O, p < 0.005). Compared with the control group, during CO2 rebreathing P0.1/PetCO2 slope, although less steep, was not dissimilar in patients (0.34 +/- 0.13 vs 0.46 +/- 0.19 cm H2O/mm Hg, NS); on the other hand, Ve/PetCO2 slope was much lower in the patient group (1.93 +/- 0.91 vs 3.27 +/- 1.11 L/min/mm Hg, p < 0.01) and was significantly related to the functional stage of disease and to Pimax and Pemax values at FRC. These results indicate that in patients with clinically stable, moderately severe multiple sclerosis, the respiratory muscle function is abnormal. Moreover, the inspiratory drive at rest is increased and the drive response to CO2 appears normal, while the ventilatory response to CO2 is significantly impaired. Respiratory muscle weakness (and/or lack of coordination) could explain, at least in part, the lower ventilatory response in these patients, whereas the mechanism of increased rate of the initial inspiratory force generation remains unclear.

Hypoxemia during oral feedings in adults with dysphagia and severe neurological disabilities

Signs of respiratory distress including coughing, choking, and gagging are not uncommon during oral feedings in patients with severe dysphagia. Aspiration pneumonia and chronic lung disease are recognized complications. Pulse oximetry, respiratory inductance plethysmography, and nasal airflow measurement by thermistors are accurate noninvasive methods of monitoring cardiopulmonary adaptation during oral feedings in patients with severe dysphagia. We report significant, previously unrecognized, acquired hypoxemia during oral feedings in two patients with severe cerebral palsy and one with multiple sclerosis. The episodes of hypoxemia occurred only while swallowing specific food textures. Periods of hypoxemia most probably resulted from aspiration during oral feedings. Cardiopulmonary adaptation may prove to be an important consideration in decisions regarding the method and advisability of continued oral feedings in patients with severe dysphagia.

Respiratory function in multiple sclerosis. Utility of clinical assessment of respiratory muscle function

PURPOSE

The aim of this study was to assess the utility of clinical assessment of respiratory muscle weakness in MS.

PATIENTS AND METHODS

We studied 40 MS patients who performed pulmonary function tests using standard procedures and measures of respiratory muscle strength. Descriptive clinical indices included a history of detailed neurologic findings, including upper and lower extremity weakness, cerebellar signs, and evidence of cerebral lesions and other clinical signs including dependence in activities of daily living, shortness of breath, weak voice, dysarthria and dysphagia. We devised an index comprised of four clinical signs: the patient's report of difficulty in clearing pulmonary secretions and his report of a weakened cough, the examiner's observation of the patient's cough, and ability to count on a single exhalation.

RESULTS

Mean values of TLC (95 percent +/- 14) VC (91 percent +/- 19), and RV (106 percent +/- 34) were normal. By contrast, MVV (68 percent +/- 20), PImax (74 percent +/- 27) and PEmax (51 percent +/- 22) were decreased. Stepwise multiple regression indicated that the best single predictor of expiratory muscle weakness was the index score; the combination of index score, upper extremity weakness, and maximal voluntary ventilation accounted for 60 percent of the variance in PEmax.

CONCLUSION

We conclude that clinical assessment is a better predictor of respiratory muscle weakness than spirometry and that a systematic clinical assessment supplemented by respiratory muscle assessment and MVV can uncover subtle respiratory muscle weakness in patients with MS.

Diaphragmatic paralysis without bulbar or limb paralysis in multiple sclerosis

A patient is presented in whom disabling pulmonary symptoms in the absence of other significant disability complicated a long-standing course of MS. Clinical presentation and fluoroscopy confirmed the diagnosis of bilateral diaphragmatic paralysis. Magnetic resonance imaging revealed atrophy and extensive white matter changes within the cervical cord. This case is unique in that significant respiratory compromise due to cervical spinal cord involvement by MS was dissociated from bulbar dysfunction or profound limb paresis.

Helping patients live with multiple sclerosis. What primary care physicians can do

Patients with multiple sclerosis (MS) may experience progressive problems of many kinds, often over decades. Ambulation, muscle strength and coordination, bladder function, vision, behavior, and cognition may eventually be affected. The diagnosis is based on clinical features and laboratory studies, but no definitive test exists. The rate of misdiagnosis may be as high as 30%. Treatment consists of pharmacotherapy for symptoms, therapy for the disease itself, and experimental therapies. Long-term management of MS can be a worthwhile challenge for primary care physicians. Helpful resources include neurologists with an interest in the disease, regional treatment and rehabilitation centers, and local MS societies.