Fatigue in neuromuscular disorders: focus on Guillain-Barré syndrome and Pompe disease

Non-motor symptoms in patients with amyotrophic lateral sclerosis: current state and future directions

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive degeneration of both upper and lower motor neurons. A defining histopathological feature in approximately 97% of all ALS cases is the accumulation of phosphorylated trans-activation response (TAR) DNA-binding protein 43 protein (pTDP-43) aggregates in the cytoplasm of neurons and glial cells within the central nervous system. Traditionally, it was believed that the accumulation of TDP-43 aggregates and subsequent neurodegeneration primarily occurs in motor neurons. However, contemporary evidence suggests that as the disease progresses, other systems and brain regions are also affected. Despite this, there has been a limited number of clinical studies assessing the non-motor symptoms in ALS patients. These studies often employ various outcome measures, resulting in a wide range of reported frequencies of non-motor symptoms in ALS patients. The importance of assessing the non-motor symptoms reflects in a fact that they have a significant impact on patients' quality of life, yet they frequently go underdiagnosed and unreported during clinical evaluations. This review aims to provide an up-to-date overview of the current knowledge concerning non-motor symptoms in ALS. Furthermore, we address their diagnosis and treatment in everyday clinical practice.

Improvement of fatigue in generalised myasthenia gravis with zilucoplan

BACKGROUND

Fatigue is a debilitating symptom of myasthenia gravis (MG). The impact of fatigue on MG can be assessed by Quality of Life in Neurological Disorders (Neuro-QoL) Short Form Fatigue scale. Transformation of raw Neuro-QoL fatigue scores to T-scores is a known approach for facilitating clinical interpretation of clinically meaningful and fatigue severity thresholds.

METHODS

In the Phase 3, double-blind, placebo-controlled RAISE study (NCT04115293), adults with acetylcholine receptor autoantibody-positive generalised MG (MG Foundation of America Disease Class II-IV) were randomised 1:1 to daily subcutaneous zilucoplan 0.3 mg/kg or placebo for 12 weeks. Patients completing RAISE could opt to receive zilucoplan 0.3 mg/kg in an ongoing, open-label extension study, RAISE-XT (NCT04225871). In this post-hoc analysis, we evaluated the long-term effect of zilucoplan on fatigue in RAISE patients who entered RAISE-XT. We report change in Neuro-QoL Short Form Fatigue T-scores and fatigue severity levels from RAISE baseline to Week 60.

RESULTS

Mean Neuro-QoL Short Form Fatigue T-scores improved from baseline to Week 12 in the zilucoplan group (n = 86) with a clinically meaningful difference versus placebo (n = 88; least squares mean difference: - 3.61 (nominal p-value = 0.0060]), and these improvements continued further to Week 60. At Week 12, more patients on zilucoplan (n = 34, 47.2%) experienced improvements in ≥ 1 fatigue severity level from baseline versus placebo (n = 23, 28.4%; p = 0.017). At Week 60, most (n = 55, 65.5%) patients had mild fatigue or none.

CONCLUSION

Treatment with zilucoplan demonstrated statistical and clinically meaningful improvements in fatigue scores and severity versus placebo during RAISE, which were sustained to Week 60 in RAISE-XT.

The influence of symptom severity and fatigue on sleep quality in patients with myasthenia gravis

INTRODUCTION

Myasthenia gravis is a rare and chronic autoimmune disease. The study aimed to evaluate the influence of symptom severity and fatigue on sleep quality in patients with myasthenia gravis.

METHODS

This was a cross-sectional study, and the population consisted of patients with MG throughout Turkey. The study was completed with 163 patients on 1 April and 31 July 2022.

RESULTS

 It was found that the mean Myasthenia Gravis-Activities of Daily Living Scale score was 6.32 ± 3.9, the Fatigue Severity Scale score was 37.01 ± 23.26, and the total Pittsburgh Sleep Quality Index score was 9.04 ± 2.69. The variables affecting the Pittsburgh Sleep Quality Index scores were age, Body Mass Index, Fatigue Severity Scale ≥ 4, Myasthenia Gravis-Activities of Daily Living Scale ≥ 5.5, duration of diagnosis, and income level; a multiple regression model was created with these variables, and the variables in the resulting model explained 26.4% of the Pittsburgh Sleep Quality Index scores. In addition, those with clinically significant symptom severity (MG-ADL ≥5.5) in daily living and those with severe fatigue (FSS ≥4) explained 17.2% of the PSQI scores, and the model was statistically significant (p < 0.001).

CONCLUSION

The study determined that the participants had clinically significant symptom severity in daily living, severe fatigue, and poor sleep quality. The participants with clinically significant severe symptoms in daily living and fatigue had higher sleep disturbances, daytime dysfunction, and poor sleep quality.

Characterization of neuromuscular performances in adults with late-onset Pompe disease: A control case cross-sectional study

Adults with late-onset Pompe disease (aLOPD) are characterized by muscular contractile tissue deterioration. However, their neuromuscular performances are poorly known. We aimed to compare maximal muscle strength, activation, explosive strength and neuromuscular fatigue between aLOPD and controls. We studied 20 aLOPD and 20 matched controls. Isometric maximum voluntary contraction (MVC) torque was obtained for the hip, knee and ankle muscles. The voluntary activation level (VAL) during knee extensor MVC was assessed using interpolated twitch technique. Explosive strength was evaluated for knee and ankle muscles through the rate of torque development (RTD) during fast contractions. Neuromuscular fatigue was measured during a 30-second contraction of knee flexors and extensors. All muscle MVC torques were significantly lower in aLOPD than controls (p <0.05). The weakest muscles were the hip extensors followed by hip abductors and abductors. Raw value of RTD was lower in aLOPD for the majority of muscles (p <0.05). No intergroup differences were reported for normalized RTD, VAL and neuromuscular fatigue (p-values> 0.05). Our study shows that maximal strength was the only neuromuscular characteristic affected in aLOPD with a proximal-distal intensity gradient. This suggests that the surviving muscle tissue of aLOPD is as functionally efficient as that of control individuals.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

Neural dysregulation in post-COVID fatigue

Following infection with SARS-CoV-2, a substantial minority of people develop lingering after-effects known as 'long COVID'. Fatigue is a common complaint with a substantial impact on daily life, but the neural mechanisms behind post-COVID fatigue remain unclear. We recruited 37 volunteers with self-reported fatigue after a mild COVID infection and carried out a battery of behavioural and neurophysiological tests assessing the central, peripheral and autonomic nervous systems. In comparison with age- and sex-matched volunteers without fatigue (n = 52), we show underactivity in specific cortical circuits, dysregulation of autonomic function and myopathic change in skeletal muscle. Cluster analysis revealed no subgroupings, suggesting post-COVID fatigue is a single entity with individual variation, rather than a small number of distinct syndromes. Based on our analysis, we were also able to exclude dysregulation in sensory feedback circuits and descending neuromodulatory control. These abnormalities on objective tests may aid in the development of novel approaches for disease monitoring.

Frequency, entity and determinants of fatigue in Charcot-Marie-Tooth disease

BACKGROUND AND PURPOSE

Fatigue, a disabling symptom in many neuromuscular disorders, has been reported also in Charcot-Marie-Tooth disease (CMT). The presence of fatigue and its correlations in CMT was investigated.

METHODS

The Modified Fatigue Impact Scale (MFIS) was administered to CMT patients from the Italian Registry and a control group. An MFIS score >38 indicated abnormal fatigue. The correlation with disease severity and clinical characteristics, the Hospital Anxiety and Depression Scale and Epworth Sleepiness Scale scores, and drug use was analysed.

RESULTS

Data were collected from 251 CMT patients (136 women) and 57 controls. MFIS total (mean ± standard deviation 32 ± 18.3, median 33), physical (18.9 ± 9.7, 20) and psychosocial (2.9 ± 2.4, 3) scores in CMT patients were significantly higher than controls. Abnormal fatigue occurred in 36% of the patients who, compared to patients with normal scores, had more severe disease (median CMT Examination Score 9 vs. 7), more frequent use of foot orthotics (22% vs. 11%), need of support for walking (21% vs. 8%), hand disability (70% vs. 52%) and positive sensory symptoms (56% vs. 36%). Patients with abnormal fatigue had significantly increased frequency of anxiety/depression/general distress (Hospital Anxiety and Depression Scale), somnolence (Epworth Sleepiness Scale), obesity (body mass index ≥ 30) and use of anxiolytic/antidepressant or anti-inflammatory/analgesic drugs.

CONCLUSIONS

Fatigue is a relevant symptom in CMT as 36% of our series had scores indicating abnormal fatigue. It correlated with disease severity but also with anxiety, depression, sleepiness and obesity, indicating different components in the generation of fatigue. CMT patients' management must include treatment of fatigue and of its different generators, including general distress, sleepiness and obesity.

Protocol for a hybrid II study exploring the feasibility of delivering, evaluating, and implementing a self-management programme for people with neuromuscular diseases at a specialist neuromuscular centre

BACKGROUND

Self-management support (SMS) forms a central pillar in the management of long-term conditions. It is firmly aligned with UK health policy but there is a paucity of evidence exploring how it is enacted in the context of neuromuscular diseases (NMDs). Bridges is a SMS programme originally developed in stroke. A new version of the programme (Neuromuscular Bridges) has recently been co-designed with people with lived experience of NMD and requires evaluation. The implementation of SMS is inherently complex with potential barriers at the level of the patient, provider, and wider organisation. The success of implementing programmes can be highly dependent on context, indicating a rationale for considering implementation determinants at an early stage. This study aims to explore the feasibility of (1) delivering, (2) evaluating, and (3) implementing Neuromuscular Bridges at a specialist neuromuscular centre.

METHODS

This study employs a hybrid II design underpinned by Normalisation Process Theory (NPT), which has been used prospectively to inform the implementation plan and will also inform the analysis. The feasibility of delivering, evaluating, and implementing Neuromuscular Bridges will be assessed using a single-arm pre-post design. In terms of delivery and evaluation, we will explore acceptability, demand within the service, performance of outcome measures, recruitment, and retention. Implementation strategies have been selected from a refined taxonomy of strategies, mapped to NPT, and targeted at known barriers and facilitators at the specialist centre that were identified from preliminary stakeholder engagement activities. The impact of the strategy bundle on fidelity, acceptability, appropriateness, and adoption will be evaluated using qualitative interviews, administrative data, surveys, and a notes audit.

CONCLUSIONS

This this study will provide valuable feasibility data on a co-designed SMS programme for people with NMDs that will be used to inform a larger implementation study, requirements for embedding it in a specialist centre, and rollout to other specialist centres. Using hybrid methodology at the feasibility stage is unusual and this study will provide important insights into the usefulness of taking this approach at this point in the research pipeline.

TRIAL REGISTRATION

ISRCTN Trial ID: ISRCTN14208138 . Date registered: 18/08/2021.

Motor Function Characteristics of Adults With Late-Onset Pompe Disease: A Systematic Scoping Review

BACKGROUND AND OBJECTIVES

Pompe disease is a rare neuromuscular disease caused by a deficiency of the lysosomal enzyme acid α-glucosidase. The late-onset Pompe disease (LOPD) in adults is characterized by weakness of ventilatory, axial, and proximal extremity muscles. These muscle impairments progressively impair various motor functions such as locomotion and postural control. Nearly 87% of adults with LOPD (aLOPD) report walking problems, and more than 80% report instability and falls. Knowledge of these motor functions is now sufficient to provide a clear and comprehensive overview of motor function in aLOPD. Therefore, this scoping review aimed to summarize current knowledge about motor function in aLOPD. It specifically targeted neuromuscular performance, locomotion, and postural control.

METHODS

A systematic search in MEDLINE (through PubMed), EMBASE, and Cochrane databases was conducted until May 2021. We included studies providing primary data on at least 4 participants, exploring neuromuscular performance, locomotion, and/or postural control in aLOPD. Risk of bias analysis was assessed using tools appropriate to the study designs; the risk of bias 2 (Cochrane tool) for randomized controlled trials, risk of bias in Nonrandomized Studies - of Interventions (Cochrane tool) for nonrandomized interventional trials, and the Newcastle-Ottawa Scale for cohort studies and case-control studies.

RESULTS

The search identified 2,885 articles. After screening, 58 articles were included in the analysis. In these studies, 88% explored locomotion, 83% neuromuscular performance, and 3% postural control. This review showed that aLOPD experience symmetrical weakness, concerning especially the hip and lumbar muscles. Locomotor activities are limited with a distance reduction, spatiotemporal gait parameter modification, and an increased pelvic drop and tilt. Balance disorders are also observed especially in the anteroposterior direction.

DISCUSSION

We performed the first review on motor function characteristics in aLOPD. Although a significant amount of knowledge was synthesized in this review, our study also highlighted the lack of current research on this topic. Maximal muscle strength was the only neuromuscular performance studied, and gait biomechanics and postural control were poorly explored in LOPD. Relationships between the degree of muscle weakness and motor function alterations also remain to be determined in aLOPD.

Early Approach Towards Atypical Guillain-Barré Syndrome: A Physiotherapy Perspective in a Case Report

Guillain-Barré syndrome (GBS) is acute, ascending, immune-mediated, monophasic polyneuropathy, which manifests itself as a lower motor neuron lesion, which occurs mostly after a prior infection. It is autoimmune in origin and has an impact on the peripheral nervous system. GBS is usually not linked to an autoimmune or other systemic condition and is most frequently a post-infectious disorder that affects healthy patients. The symptoms of GBS, an acute immune-mediated polyradiculoneuropathy, include symmetrical limb weakness that worsens quickly and hypo- or areflexia. There may also be sensory complaints, involvement of cranial and autonomic nerve fibres, and frequent pain that will appear before weakening. Weakness, sensory loss, weariness, and discomfort are the most typical remaining deficiencies in an atypical variant of GBS. This case also describes the variant of atypical GBS. A 10-year-old girl was referred to the hospital with complaints of difficulty in swallowing, drooling of saliva, weakness of left upper and bilateral lower limbs, and fever for 10 days. There was no past history of travelling or infection. At the time of admission, the patient was on oxygen support for breathing and she was transferred to ICU immediately. Investigations were done such as a nerve conduction velocity test and complete blood count. Neuro-physiotherapy of the patient was started after 35 days of hospitalisation. With proper rehabilitation, the patient was able to gain strength and the ability to swallow food. The patient was able to resume her academic career.

Supervised, individualised exercise reduces fatigue and improves strength and quality of life more than unsupervised home exercise in people with chronic Guillain-Barré syndrome: a randomised trial

QUESTION

In people in the chronic phase of Guillain-Barré syndrome (GBS), how much more does a supervised, individualised exercise program improve functional independence with activities of daily living than a home-based exercise program? How do the two exercise programs compare regarding their effects on muscle strength, fatigue, pain and quality of life?

DESIGN

Randomised controlled trial with concealed allocation, intention-to-treat analysis and blinding of outcome assessors.

PARTICIPANTS

Sixteen adults with stable residual disability ≥ 6 months after the onset of GBS.

INTERVENTION

Participants in the experimental group were allocated to 60-minute sessions of physiotherapist-supervised strengthening, endurance and breathing exercises, gait training and pain management, two to three sessions/week for 12 weeks. The control group was prescribed a home program of 30-minute sessions of maintenance exercises and education in self-management, two to three sessions/week for 12 weeks.

OUTCOME MEASURES

Functional independence in activities of daily living on the 100-point Barthel Index (primary outcome), muscle strength on the 60-point Medical Research Council scale, fatigue on the 0-to-63 Fatigue Severity Scale, a visual analogue scale of pain severity, and quality of life, measured at baseline and months 6 and 12.

RESULTS

At month 6, the median between-group difference was 5 (95% CI 0 to 20) for functional independence, 8 (95% CI 4 to 18) for strength, -13 (95% CI -28 to -1) for fatigue, and 12 (95% CI 3 to 13) for the environment domain of quality of life. Estimated effects at month 12 had a similar magnitude, but most of the CIs had greater uncertainty.

CONCLUSION

Supervised, individualised exercise reduced fatigue and improved strength and quality of life more than unsupervised home exercise in people with chronic Guillain-Barré syndrome.

REGISTRATION

CTRI/2016/08/007150.

Intellectual disability in paediatric patients with genetic muscle diseases

The differential diagnosis of genetic muscle disease has become increasingly difficult due to the rapid progress in genetic medicine in recent years. Where classifications based on the clinical picture were attributed to one gene only a few years ago, today we know that a variety of clinical presentations can result from the same mutation and, conversely, various genes are associated with a similar phenotype. A significant consideration in assessing a patient with muscle weakness is the presence or absence of intellectual disability, thus narrowing the differential diagnostic approach in any child with an as yet undiagnosed muscle disease. Intellectual disability in neuromuscular diseases is often associated with behavioural disorders and may be correlated with abnormal brain imaging. Conversely, brain involvement can sometimes be seen without intellectual disability, but may be associated with an epilepsy risk and is helpful for the differential diagnosis. This review focuses on the three most common causes of paediatric muscle diseases with intellectual disability, dystrophinopathies, myotonic dystrophy type 1 and dystroglycanopathies. It also summarises differential diagnostic considerations when assessing a child with a genetic muscle disease and intellectual disability. The recent scientific literature on this topic is reviewed, the frequency of intellectual disability assessed, and specific clinical features are described. Where available, data on disease onset, progression and serum creatine kinase levels are presented and the pattern of muscle involvement described in an algorithm. Central nervous involvement and brain imaging analysis was reviewed and included.

Influence of Mirror Therapy (Specular Face Software) on Electromyographic Behavior of the Facial Muscles for Facial Palsy

Introduction: Facial paralysis (FP) is a neuromuscular disorder caused by facial nerve injury. There are two main types of FP (which can be either primary or secondary): central and peripheral; Procedure of cases: This case series presents five patients with facial paralysis with different etiologies. In all cases, we assessed the facial disability index and a clinical test registering the electromyographic activity, with and without biofeedback generated by Specular Face, a new software program; Discussion: After performing the appropriate tests, we checked the patients’ ability to change certain expressions when the Specular Face program was added. We can confirm that the mirror visual feedback therapy changes the behavior of synkinesis and the muscle function in these patients; Conclusion: The use of mirror therapy using a computerized treatment system of facial images yields promising results in modulating the muscle activity of patients with FP.

Intensive Care and Treatment of Severe Guillain-Barré Syndrome

Guillain–Barré syndrome (GBS) is an acute polyneuropathy mostly characterized by acute flaccid paralysis with or without sensory/autonomous nerve dysfunction. Current immuno therapies including intravenous immunoglobulin (IVIg), plasma exchange (PE), and newly developed biological drugs benefit patients by alleviating hyperreactive immune responses. Up to 30% of patients develop respiratory failure during hospitalization and require mechanical ventilation and intensive care. Immunotherapies, mechanical ventilation, supportive care, and complication management during the intensive care unit (ICU) stay are equally emphasized. The most important aspect of intensive care and treatment of severe GBS, that is, mechanical ventilation, has been extensively reviewed elsewhere. In contrast to immunotherapies, care and treatment of GBS in the ICU setting are largely empirical. In this review, we intend to stress the importance of intensive care and treatment, other than mechanical ventilation in patients with severe GBS. We summarize the up-to-date knowledge of pharmacological therapies and ICU management of patients with severe GBS. We aim to answer some key clinical questions related to the management of severe GBS patients including but not limited to: Is IVIg better than PE or vice versa? Whether combinations of immune therapies benefit more? How about the emerging therapies promising for GBS? When to perform tracheal intubation or tracheostomy? How to provide multidisciplinary supportive care for severe cases? How to avert life-threatening complications in severe cases?

Prevalence and associated factors of fatigue in autoimmune myasthenia gravis

Fatigue is usually defined as a subjective perception of lacking energy, mentally or physically, with a difficulty sustaining voluntary activities. It is a common symptom of many diseases and most likely has a multifactorial cause. In myasthenia gravis (MG), fatigue has a high prevalence and is correlated with female sex and disease severity. However, no large scale studies have been performed. Therefore, we aimed to evaluate fatigue in the Dutch participants (n = 420) of the Dutch-Belgian Myasthenia Patient Registry using an online survey. Additional information was obtained on mood, sleep, coping, quality of life, disease severity, physical activities and medication. Severe fatigue was present in 62% with a mean score of 37.1 ± 13.2 points. Fatigue severity and prevalence increased significantly with disease severity. A positive correlation was found for female gender, BMI, disease severity and depressive symptoms. A negative correlation was found for strenuous physical activities and older age. The strong association with disease severity suggests that fatigue should be recognized as an element of the symptomatology of MG. The observed association between strenuous activity and fatigue and differences in coping style between fatigued and non-fatigued patients warrant future clinical trials on exercise and cognitive behavioral therapy.

Guillain-Barré Syndrome and Other Acute Polyneuropathies

Guillain-Barré syndrome (GBS) is an acute autoimmune neuropathy that can cause motor, sensory, and autonomic symptoms. Although GBS primarily is a neuropathic disorder, multiple organ systems can be affected during the disease course, and older patients may be more vulnerable to systemic complications. Close clinical monitoring and early interventions using pharmacologic and nonpharmacological treatments may lead to an improved long-term outcome.

Effects of Teleassistance on the Quality of Life of People With Rare Neuromuscular Diseases According to Their Degree of Disability

Rare neuromuscular diseases (RNMDs) are a group of pathologies characterized by a progressive loss of muscular strength, atrophy, fatigue, and other muscle-related symptoms, which affect quality of life (QoL) levels. The low prevalence, high geographical dispersion and disability of these individuals involve difficulties in accessing health and social care services. Teleassistance is presented as a useful tool to perform psychosocial interventions in these situations. The main aim of this research is to assess the effects of a teleassistance psychosocial program on the QoL levels of people with RNMDs who have different levels of disability. A sample of 73 participants was divided into an experimental group (n = 40), which participated in the intervention, and a control wait list group (n = 33). QoL was evaluated through the SIP and the SF-36, and disability through the WHO-DAS II. The participants with a moderate to severe level of disability were those who most benefited from the intervention. The results also revealed that the psychosocial teleassistance program was suitable to improve physical and psychosocial aspects of people suffering from a rare neuromuscular disease with a moderate level of disability, but just psychosocial aspects in those with a severe level of disability.

Role of immunoglobulin and antibodies in disease management

The immune system is a highly advanced and coordinated mechanism that allows a living organism to distinguish between "self" and "non-self". The host uses both innate and adaptive immune response mechanisms to identify and eliminate pathogenic microorganisms. Human immunoglobulin is the prominently used blood product in the clinical practice. Immunoglobulin applications have improved rapidly due to the exploration of its immunomodulatory and anti-inflammatory properties. This made this blood product into a precious and advanced tool in the treatment of numerous disease conditions which are linked with humoral immune deficiency or that cause immune system dysfunction. Human immunoglobulin (Ig) is used for Ig replacement therapy in both primary and secondary immunodeficiency conditions, for prevention and treatment of certain infections. It also acts as an immunomodulatory agent for autoimmune and inflammatory disorders. Therapeutic antibodies have been successfully used for the treatment of diverse pathological conditions. Drug development programs exclusively select highly specific antibodies that recognize a single disease-associated target. Hopefully this review will give an insight towards the immune system, the involvement of the specialized immune cells, their products and involvement in various immune disorders and pathological conditions.

Psychiatric Sequelae of Guillain-Barré Syndrome: Towards a Multidisciplinary Team Approach

Guillain-Barré syndrome (GBS) is a post-infectious autoimmune polyneuropathy. Recent research has highlighted that GBS is associated with the onset of psychiatric symptoms which represent a burden for patients and close relatives. However, acute psychiatric sequelae due to GBS may be misinterpreted as ‘intensive care unit (ICU) delirium’. This review outlines the existing evidence for the psychiatric symptoms associated with GBS with a view to improving psychoeducation of patients. The main psychiatric symptoms of GBS that have been reported in the literature include, stress, anxiety, depression, fatigue, sleep abnormalities, visual hallucinations, paranoid delusions, disorientation, terror and psychosis. These psychiatric symptoms, which occur during the acute phase of GBS, if not recognised and treated, may progress to long-term psychiatric problems that interfere with improvement of physical symptoms. A multidisciplinary team approach to the management of GBS may improve both physical and psychiatric recovery.

Perceived Fatigue in Spinal Muscular Atrophy: A Pilot Study

BACKGROUND

Fatigue is a common complaint in spinal muscular atrophy (SMA). Fatigability is well described in ambulatory SMA but the relationship to perceived fatigue has not been evaluated. Understanding this relationship has proven challenging for most disorders.

OBJECTIVE

To assess the relationship of perceived fatigue to fatigability, function, and quality of life in SMA.

METHODS

Thirty-two participants with SMA (21.9% type 2, 78.1% type 3) were recruited. Perceived fatigue and fatigability, function, and quality of life were assessed using standardized questionnaires and assessments. Associations were analyzed using Pearson correlation coefficients (p = 0.05). Also, the effects of age, type, and ambulatory status were determined on perceived fatigue.

RESULTS

All SMA participants reported fatigue. Perceived fatigue was not associated with function, quality of life, or fatigability in ambulatory SMA patients. Neither age, type, nor ambulatory status influenced perceived fatigue.

CONCLUSIONS

Perceived fatigue can be quantified in SMA. Interestingly, perceived fatigue did not correlate with fatigability or function, suggesting that cognitive, homeostatic, or psychologic factors may be more relevant as co-morbid factors. Clinical trials targeting perceived fatigue in SMA should focus on these patient-reported assessments. A multilevel approach is required to separate the various mechanisms involved in perceived fatigue.

Pompe disease: what are we missing?

Pompe disease is a multisystemic metabolic disorder caused by a deficiency of lysosomal acid alpha-glucosidase (GAA) leading to progressive accumulation of lysosomal glycogen, lysosomal swelling and rupture in all tissues of the human body. Furthermore, autophagic buildup, organelle abnormalities, and energy deficit are regularly observed. Enzyme replacement therapy has been available for patients living with Pompe disease for more than 15 years. Although our disease knowledge has grown enormously, we still have multiple challenges to overcome. Here, I will discuss unmet clinical needs, neglected or overlooked aspects of the pathophysiology, and issues related to future therapies.

Nutrition and exercise in Pompe disease

The current standard of care for Pompe disease (PD) is the administration of enzyme replacement therapy (ERT). Exercise and nutrition are often considered as complementary strategies rather than "treatments" per se. Nutritional assessment is important in patients with locomotor disability because the relative hypodynamia limits energy expenditure and thus the total amount of energy must be reduced to avoid obesity. A lower total energy intake often leads to lower protein and micronutrient intake. Consequently, ensuring that Pompe patients are tested for and replaced for deficiencies (protein, vitamin D, vitamin B12, etc.) is an important aspect of care. Furthermore, given the role of autophagy in the pathophysiology of PD and the fact that fasting induces autophagy, it is important that strategies such as nutritional timing and amino acid intake (L-arginine, L-leucine) be evaluated as therapies. Exercise interventions have been shown to improve six-minute walk testing distance by more than what was seen in the seminal ERT study in late-onset PD. Exercise therapy can also activate autophagy, and this is likely another component of its efficacy. The current review will evaluate the theoretical and practical aspects of nutrition and exercise as therapies for patients with PD.

Cancer-Related Fatigue: Perception of Effort or Task Failure?

CONTEXT

Patient's rating of perceived effort (RPE) is used to assess central fatigue. Cancer-related fatigue (CRF) is believed to be of central origin. The increased RPE with a motor task, such as the Finger-Tapping Test (FTT), can easily be measured in the clinical setting.

OBJECTIVES

To correlate the FTT, RPE and the Brief Fatigue Inventory (BFI) rated fatigue severity in patients with cancer.

METHODS

Subjective fatigue was assessed in adult patients with cancer by the BFI. Participants performed a modified FTT with the index finger of the dominant hand: 15 seconds × 2, 30 seconds × 2, and 60 seconds × 2 with 1 minute of rest between each time trial. Rating of perceived effort at the end of task was measured by the Borg 10 scale.

EXCLUSIONS

Brain metastasis, history of brain radiation, Parkinson disease, Huntington Chorea, multiple sclerosis, delirium, and depression. Pearson correlation coefficients were used to describe the relationships between BFI, FTT, and Borg 10 scale.

RESULTS

Thirty patients participated. Mean age was 56.2. Sixteen were females (53.3%). The mean BFI mean was 4.1, median 4.4. Tapping rate did not correlate with fatigue severity. The RPE correlated with the mean BFI: r _s 0.438, P = .0155. These correlations persisted after adjustment for age.

CONCLUSION

An increased RPE in the absence of task failure suggests that the origin of CRF is central. The performance of an FTT with RPE helps to improve our understanding of fatigue in the clinical setting.

Depressive Syndromes in Autoimmune Disorders of the Nervous System: Prevalence, Etiology, and Influence

Autoimmune diseases of the nervous system (ADNS) consist of a group of severely disabling disorders characterized by abnormal immune attack against protein components of the nervous system. This type of attack behavior may occur in the central or peripheral nervous system, and in the neuromuscular junction, resulting in neuronal damage, axonal injury, demyelination or destruction of the neuromuscular junction. While the neurological deficits of patients with ADNS have received significant research attention, the manifestation of depression tends to be ignored. In fact, depressive manifestation is common in ADNS and adds significant burden upon patients suffering from this disease. Here, we systematically reviewed the current literature to highlight the prevalence, etiology and influence of depressive manifestation in ADNS. Most autoimmune diseases of the nervous system are discussed in this paper, from multiple sclerosis, acute disseminated encephalomyelitis and autoimmune encephalitis to acute myelitis, neuromyelitis optica, Guillain-Barré syndrome and myasthenia gravis. Depressive symptoms usually develop as a comorbidity during the course of disease, but sometimes exist as a primary presentation of the disease. Psychosocial factors, long periods of disablement and chronic pain are the three most common causes of depressive symptoms in many chronic conditions, particularly in peripheral neuropathy. Furthermore, the higher prevalence of depressive symptoms in ADNS suggests that immunological dysregulation may contribute to the elevated morbidity of depression. Finally, structural lesions of the brain, and some medications for ADNS, are also thought to precipitate depressive states in ADNS.

6-minute walk test as a measure of disease progression and fatigability in a cohort of individuals with RYR1-related myopathies

Background

RYR1-related Myopathies (RYR1-RM) comprise a group of rare neuromuscular diseases (NMDs) occurring in approximately 1/90000 people in the US pediatric population. RYR1-RM result from pathogenic mutations in the ryanodine receptor isoform-1 (RYR1) gene where consequent RyR1 protein calcium dysregulation leads to impaired excitation-contraction coupling, oxidative and nitrosative stress, and mitochondrial depletion. These physiological deficits perpetuate RyR1 dysfunction causing further muscle injury, muscle weakness, and muscle fatigue. Muscle weakness and fatigue are two primary complaints in patients with RYR1-RM and are major symptoms that limit the ability of individuals to perform activities of daily living. The six-minute walk test (6MWT) is an endurance test with high reliability and validity used to measure walking capacity, disease progression, and more recently, fatigability in NMDs with limited results in RYR1-RM. Therefore, the purpose of our study is to objectively assess disease progression and fatigability in RYR1-RM affected individuals using the 6MWT. We hypothesized that 6MWT distance and fatigability would not change significantly between 0 and 6-month visits in RYR1-RM patients, given the clinically reported stable or slowly progressive nature of the disease. We also hypothesized participants would show fatigability during the 6MWT, given muscle weakness and fatigue are the two primary complaints of affected individuals.

Results

As expected, paired t-test analyses revealed no significant difference between total distance traveled (p = .608) or percent change in speed (p = .141) at 0-months compared with the 6-month visit. Fatigability was observed given the decline in speed between the first and last minute of the 6MWT at the 6-month time point (p ≤ .0005,). Although this decline was not significant at baseline, a significant decline in speed from the 1st minute did occur at minutes 2, 3, and 4 during the baseline visit.

Conclusion

In this RYR1-RM cohort, the 6MWT showed disease stability over a 6-month period but revealed fatigability during the test. Given these results, the 6MWT may be a promising endpoint for evaluating fatigability and therapeutic efficacy in the 6-month treatment phase of our current n-acetylcysteine trial in this population. Improvement post intervention could be attributed to the intervention rather than variability in disease progression.

Trial Registration

Clinical Trials.gov, NCT02362425, Registered 13 February 2015-Prospectively registered.

Three-Year Follow-Up Study in Patients with Guillain-Barré Syndrome

A majority of patients with Guillain-Barré syndrome (GBS) have tendency of a good recovery. Our aim was to evaluate the outcome of the disease 1 and 3 years after GBS symptom onset. Methods: During 2014, GBS was diagnosed in 82 patients in seven tertiary healthcare centers. Neurological follow-up was conducted in 57 (70%) patients after 1 year, and in 54 (66%) after 3 years. Functional disability was estimated according to the GBS disability scale (GDS), with a score of 0-3 indicating mild disability and a score of 4-6 indicating severe disability during acute phase, whereas a score >1 indicated poor recovery on follow-ups. Visual analog scale was used to assess sensory symptoms and musculoskelatal pain, and Krupp’s Fatigue Severity Scale was used to asses fatigue. Results: Poor functional outcome was found in 39% of GBS patients at year 1 and 30% at year 3. Paresthesias/dysesthesias were detected in 60% of patients after 1 year and 43% after 3 years. Musculoskeletal pain was present in 40% of patients at year 1 and 33% at year 3. Significant fatigue after 1 year was found in 21% of subjects and after 3 years in 7%. Parameters associated with poor functional outcome after 1 year were age >55 years (p=0.05), severe disability at admission (p<0.05), and on discharge (p<0.01). Poor functional outcome after 3 years was associated with male gender (p<0.05) and severe disability on discharge (p=0.06). Conclusion: One and even three years after GBS onset, a substantial number of patients had neurological sequelae, including functional disability, sensory symptoms, pain, and fatigue.

Fatigue, Pain, Anxiety and Depression in Guillain-Barré Syndrome and Chronic Inflammatory Demyelinating Polyradiculoneuropathy

BACKGROUND

In the clinical evaluation of patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), scant attention is paid to symptoms such as fatigue, pain and anxiety/depression. We aimed at addressing seminal studies that focused on the burden of these symptoms and their impact on quality of life (QoL) in these conditions.

SUMMARY

Fatigue, pain, and anxiety/depression are increasingly being recognized in patients with GBS and CIDP, although their pathophysiological provenance remains unknown. Fatigue and pain are significant in terms of prevalence and intensity, may be a presenting symptom, and can persist for years after apparent functional recovery, suggesting residual injury. Anxiety/depression has also been examined although studies are limited. Despite their negative impact on QoL, the long-term dynamics of these symptoms in patients with GBS and particularly CIDP receiving therapy in routine clinical practice have not been systematically evaluated. Such observations formed the basis for the ongoing (GAMEDIS) studies evaluating the effect of Gamunex on fatigue and depression in patients with CIDP, of which some preliminary data are presented.

KEY MESSAGES

Strength and sensory deficits are the main areas of focus in patients with GBS and CIDP, but they do not explain the total reduction in QoL, suggesting the possible role of other complaints. A more comprehensive approach to patient care demands that factors such as pain, fatigue and anxiety/depression receive greater attention. The non-interventional GAMEDIS studies are expected to provide valuable insight into the long-term effectiveness of Gamunex in everyday practice.

A conceptual disease model for adult Pompe disease

Background

Studies in orphan diseases are, by nature, confronted with small patient populations, meaning that randomized controlled trials will have limited statistical power. In order to estimate the effectiveness of treatments in orphan diseases and extrapolate effects into the future, alternative models might be needed. The purpose of this study is to develop a conceptual disease model for Pompe disease in adults (an orphan disease). This conceptual model describes the associations between the most important levels of health concepts for Pompe disease in adults, from biological parameters via physiological parameters, symptoms and functional indicators to health perceptions and final health outcomes as measured in terms of health-related quality of life.

Methods

The structure of the Wilson-Cleary health outcomes model was used as a blueprint, and filled with clinically relevant aspects for Pompe disease based on literature and expert opinion. Multiple observations per patient from a Dutch cohort study in untreated patients were used to quantify the relationships between the different levels of health concepts in the model by means of regression analyses.

Results

Enzyme activity, muscle strength, respiratory function, fatigue, level of handicap, general health perceptions, mental and physical component scales and utility described the different levels of health concepts in the Wilson-Cleary model for Pompe disease. Regression analyses showed that functional status was affected by fatigue, muscle strength and respiratory function. Health perceptions were affected by handicap. In turn, self-reported quality of life was affected by health perceptions.

Conclusions

We conceptualized a disease model that incorporated the mechanisms believed to be responsible for impaired quality of life in Pompe disease. The model provides a comprehensive overview of various aspects of Pompe disease in adults, which can be useful for both clinicians and policymakers to support their multi-faceted decision making.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-015-0334-6) contains supplementary material, which is available to authorized users.

The Intervention Effects of Acupuncture on Fatigue Induced by Exhaustive Physical Exercises: A Metabolomics Investigation

In this study, the antifatigue effects of acupuncture had been investigated at the metabolic level on the young male athletes with exhaustive physical exercises. After a series of exhaustive physical exercises and a short-term rest, the athletes either were treated with needling acupuncture on selected acupoints (TA group) or enjoyed an extended rest (TR group). NMR-based metabolomics analysis was then applied to depict the metabolic profiles of urine samples, which were collected from the athletes at three time points including the time before exercises, the time before and after the treatment of acupuncture, or taking the extended rest. The results from multivariate statistical analysis indicated that the recoveries of disturbed metabolites in the athletes treated with acupuncture were significantly faster than in those only taking rest. After the treatment with acupuncture, the levels of distinguished metabolites, 2-hydroxybutyrate, 3-hydroxyisovalerate, lactate, pyruvate, citrate, dimethylglycine, choline, glycine, hippurate, and hypoxanthine were recovered at an accelerated speed in the TA group in comparison with the TR group. The above-mentioned results indicated that the acupuncture treatment ameliorated fatigue by backregulating the perturbed energy metabolism, choline metabolism, and attenuating the ROS-induced stress at an accelerated speed, which demonstrated that acupuncture could serve as an alternative fatigue-relieving approach.

The checklist individual strength (CIS20-R) in patients with amyotrophic lateral sclerosis - a longitudinal study

OBJECTIVES

Fatigue may be underestimated symptom in amyotrophic lateral sclerosis (ALS). The self-administered checklist individual strength (CIS20-R) was used to measure both physical and mental fatigue in ALS.

MATERIALS AND METHODS

Fatigue was measured in 51 consecutive patients with ALS using the fatigue severity scale (FSS) and the CIS20-R (four dimensions: subjective fatigue experience, concentration, motivation, activity). The questionnaire scores were compared with disease and progression parameters [revised ALS functional rating scale (ALS-FRS-R), MRC sum score, slow vital capacity (slow VC)]. Patients had follow-ups at six and 12 months.

RESULTS

At baseline (mean age: 57.9 years ± 12.3, mean disease duration: 15.8 months ± 12.7) clinical relevant fatigue was seen in 49% in FSS and 40% in CIS20-R. FSS and CIS20-R (except the subscale for concentration) were steadily increasing in the course of the disease. CIS1 (subjective fatigue) but not FSS showed a correlation to the ALS-FRS-R and the progression of the ALS-FRS-R after 12 months. There was a moderate positive correlation between FSS and CIS20-R.

CONCLUSIONS

The CIS20-R is a sensitive tool to detect clinically relevant fatigue in early stages of ALS. Both physical and mental (motivation) dimensions of fatigue steadily increase during the course of the disease in ALS.

Abnormal Lactate Levels Affect Motor Performance in Myotonic Dystrophy Type 1

Myotonic Dystrophy type 1 (DM1) is a dominantly inherited disease comprehending multiple features. Fatigue and exhaustion during exercise often represent significant factors able to negatively influence their compliance to rehabilitation programs. Mitochondrial abnormalities and a significant increase in oxidative markers, previously reported, suggest the hypothesis of a mitochondrial functional impairment. The study aims at evaluating oxidative metabolism efficiency in 18 DM1 patients and in 15 healthy subjects, through analysis of lactate levels at rest and after an incremental exercise test. The exercise protocol consisted of a submaximal incremental exercise performed on an electronically calibrated treadmill, maintained in predominantly aerobic condition. Lactate levels were assessed at rest and at 5, 10 and 30 minutes after the end of the exercise. The results showed early exercise-related fatigue in DM1 patients, as they performed a mean number of 9 steps, while controls completed the whole exercise. Moreover, while resting values of lactate were comparable between the patients and the control group (p=0.69), after the exercise protocol, dystrophic subjects reached higher values of lactate, at any recovery time (p<0,05). These observations suggest an early activation of anaerobic metabolism, thus evidencing an alteration in oxidative metabolism of such dystrophic patients. As far as intense aerobic training could be performed in DM1 patients, in order to improve maximal muscle oxidative capacity and blood lactate removal ability, then, this safe and validate method could be used to evaluate muscle oxidative metabolism and provide an efficient help on rehabilitation programs to be prescribed in such patients.

Sleep-related symptoms and sleep-disordered breathing in adult Pompe disease

BACKGROUND AND PURPOSE

Respiratory muscle weakness is the major cause of early death in patients with adult Pompe disease. It first manifests as nocturnal hypercapnia, eventually leading to sleep disruption. Sleep-related symptoms along with motor performance, forced vital capacity (FVC) and respiratory symptoms were investigated in 65 adult patients with Pompe disease.

METHODS

Patients answered the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, the Fatigue Severity Scale, the Rotterdam Nine-item Handicap Scale, the SF-36 health-related quality of life questionnaire, and a respiratory symptom questionnaire. In all patients, the 6-min walk test was performed and FVC was obtained. Polysomnography and oxycapnometry results were available in 31 patients.

RESULTS

Sixty patients received enzyme replacement therapy, and 32 individuals were on home ventilatory support. Reduced sleep quality was highly prevalent (PSQI > 5; 43.1%) and correlated with both excessive daytime sleepiness (Epworth Sleepiness Scale > 10; 24.6%) and fatigue (Fatigue Severity Scale > 4; 72.3%). The SF-36 health-related quality of life questionnaire was reduced in the physical domains, and was inversely correlated with sleep quality, FVC and motor performance. In 11 out of 17 non-ventilated patients with polysomnography records, sleep-disordered breathing was present, and duration of nocturnal oxygen desaturation (SaO2 < 90%) was significantly correlated to the PSQI global score.

CONCLUSIONS

In adult Pompe disease, sleep disturbances are a common cause of excessive daytime sleepiness and fatigue. Sleep-related symptoms may be indicative of respiratory muscle weakness and should give rise to further work-up of sleep-disordered breathing.

Multiscale feature based analysis of surface EMG signals under fatigue and non-fatigue conditions

In this work, an attempt has been made to differentiate sEMG signals under muscle fatigue and non-fatigue conditions using multiscale features. Signals are recorded from biceps brachii muscle of 50 normal adults during repetitive dynamic contractions. After prescribed preprocessing, each signal is divided into six segments out of which first and last segments are considered in this analysis. Multiscale RMS (MSRMS) and Multiscale Permutation Entropy (MSPE) are computed for each subject in the time scales ranging from 1 to 50. The median values of the MSRMS and MSPE are calculated for further analysis. The results show an increase in amplitude for sEMG signals under fatigue condition. MSRMS values are found to be significantly higher in fatigue. An approximately constant difference in MSRMS value between fatigue and non-fatigue condition is observed over the entire time scale with a negative slope. Further, the median of MSRMS values for each subject is able to distinguish fatigue and non-fatigue conditions. Similar analysis on MSPE showed significant difference between fatigue and non-fatigue cases and lower values of MSPE is observed in fatigue. It is also observed that the median value of MSRMS and MSPE are able to distinguish these conditions. t-test for MSRMS, MSPE and their median value show high statistical significance. It appears that this method of analysis can be used for clinical evaluation of muscles.

Fatigue in patients with spinal muscular atrophy type II and congenital myopathies: evaluation of the fatigue severity scale

PURPOSE

The aim of this study was to evaluate whether the fatigue severity scale (FSS) is an appropriate instrument to assess fatigue in patients with spinal muscular atrophy type II (SMA II) and congenital myopathies (CM).

METHODS

FSS and visual analog scale (VAS) were administered to 33 SMA II- and 72 CM patients. The psychometric properties of the FSS were evaluated by means of classical test theories for each of the disease groups. If abnormal fatigue was present in the disease group, the construct of fatigue was evaluated by means of focus group interviews.

RESULTS

Fatigue was rare in SMA II patients, but very frequent in patients with CM. The cut-off score designating abnormal fatigue (FSS score ≥ 4) was exceeded by 10% of the SMA II patients in contrast to 76% of the CM patients, of whom 52% suffered from severe fatigue (FSS score ≥ 5). Focus group interviews demonstrated that fatigue had an adverse effect on motor function, level of energy, social relations, and identity, four themes that could be captured by the FSS. The FSS and VAS were strongly correlated in SMA II patients, but only moderately in CM patients. The psychometric properties indicated that the original FSS with nine items measures more than one construct of fatigue, eliminating the first two items improved scale properties.

CONCLUSION

This study demonstrates that fatigue is characteristic in patients with CM, but not in patients with SMA II, in whom fatigue does not seem to impact daily life. While fatigue in CM and SMA II can be captured by FSS, omitting the first two items of the scale will improve its properties and content validity, along with comprehension of the scale itself.

Enzyme replacement therapy and fatigue in adults with Pompe disease

BACKGROUND

Pompe disease is a hereditary metabolic myopathy, for which enzyme replacement therapy (ERT) has been available since 2006. We investigated whether ERT reduces fatigue in adult patients with Pompe disease.

METHODS

In this prospective international observational survey, we used the Fatigue Severity Scale (FSS) to measure fatigue. Repeated measures ANOVA was used to analyze the data over time. In a subgroup of patients, we also evaluated muscle strength using the Medical Research Council Scale, measured pulmonary function as Forced Vital Capacity, and assessed depression using the Hospital Anxiety and Depression Scale.

RESULTS

We followed 163 patients for a median period of 4 years before ERT and for 3 years during ERT. Before ERT, the mean FSS score remained stable at around 5.3 score points; during ERT, scores improved significantly by 0.13 score points per year (p < 0.001). Fatigue decreased mainly in women, in older patients and in those with shorter disease duration. Patients' improvements in fatigue were moderately correlated with the effect of ERT on depression (r 0.55; CI 95% 0.07 to 0.70) but not with the effect of ERT on muscle strength or pulmonary function.

CONCLUSIONS

Fatigue is a common and disabling problem in patients with early and advanced stages of Pompe disease. Our finding that ERT helps to reduce fatigue is therefore important for this patient population, irrespective of the mechanisms underlying this effect.

Severe fatigue and reduced quality of life in children with hereditary motor and sensory neuropathy 1A

Severe fatigue and low quality of life are reported by a majority of adult patients with hereditary motor and sensory neuropathy 1A. In children with hereditary motor and sensory neuropathy 1A, the prevalence and impact of fatigue have not been studied yet. In this questionnaire survey, 55 Dutch children (response rate 77%) with genetically confirmed hereditary motor and sensory neuropathy 1A participated (mean age 15 years [standard deviation 2.1]). Prevalence of severe fatigue (based on a cut-off score of the Checklist Individual Strength) was 24%, in contrast to 14% in a Dutch school-based population (P < .05). Almost all quality-of-life scores (measured with the Child Health Questionnaire-Child Form 87) were significantly worse than population norms (P < .05). Fatigue severity was associated significantly (P < .01) with all quality-of-life scores (-0.4 < r < -0.7). In conclusion, severe fatigue and diminished quality of life are more frequent among children with hereditary motor and sensory neuropathy 1A compared to healthy peers. The strong association between fatigue severity and quality of life suggests a negative impact of fatigue on quality of life in these children.

Fatigue in immune-mediated neuropathies

Fatigue, a highly debilitating symptom, is reported in most patients with immune-mediated neuropathies, particularly in Guillain-Barré syndrome, chronic immune-mediated demyelinating polyradiculoneuropathy, monoclonal gammopathy of undetermined significance related polyneuropathy, and multifocal motor neuropathy. Aspects like the degree of known fatigue in these disorders, its impact on daily functioning and quality of life, the suggested underlying mechanisms, and possible therapeutic interventions for fatigue will be addressed in this review.

Clinical applications of immunoglobulin: update

Human immunoglobulin is the most used blood product in the clinical practice. Immunoglobulin applications have increased quickly since the elucidation of its immunomodulatory and antiinflammatory properties which turned this blood product into a precious tool in the treatment of numerous diseases that present with humoral immune deficiency or that cause immune system dysfunction. Currently, the approved indications for Ig are: primary immunodeficiencies, secondary immunodeficiencies (multiple myeloma or chronic lymphoid leukemia), Kawasaki syndrome, immune thrombocytopenic purpura, Guillain Barré syndrome, graft-versus-host disease following bone marrow transplantation and repeat infections in HIV children. On the other hand, there are numerous "off-label" indications of immunoglobulin, which represent 20-60% of all clinical applications of this drug. It is important to study all these indications and, above all, the scientific evidence for its use, in order to provide patients with a new therapeutic option without burdening the health system. This review results from a wide selection of papers identified in the Pubmed and Lilacs scientific electronic databases. A group of descriptors were used from human immunoglobulin to the names of each disease that immunoglobulin is clinically applied. Our main objective is to list the numerous indications of immunoglobulin, both authorized and "off-label" and to analyze these indications in the light of the most recent scientific evidence.

Is it time to retire the A.V. Hill Model?: A rebuttal to the article by Professor Roy Shephard

Recent publications by Emeritus Professor Roy Shephard propose that a "small group of investigators who have argued repeatedly (over the past 13 years) for a 'Central Governor'," should now either "Put up or shut up." Failing this, their 'hypothesis' should be 'consigned to the bottom draw for future reference'; but Professor Shephard's arguments are contradictory. Thus, in different sections of his article, Professor Shephard explains: why there is no need for a brain to regulate exercise performance; why there is no proof that the brain regulates exercise performance; and why the brain's proven role in the regulation of exercise performance is already so well established that additional comment and research is unnecessary. Hence, "The higher centres of an endurance athlete … call forth an initial effort … at a level where a minimal accumulation of lactate in the peripheral muscles is sensed." Furthermore, "a variety of standard texts have illustrated the many mutually redundant feedback loops (to the nervous system) that limit exercise." Yet, the figure from Professor Shephard's 1982 textbook does not contain any links between the nervous system, "many mutually redundant feedback loops" and skeletal muscle. This disproves his contradictory claims that although there is neither any need for, nor any proof of, any role of the brain in the regulation of exercise performance, the physiological mechanisms for this (non-existent) control were already well established in 1982. In contrast, the Central Governor Model (CGM) developed by our "small group … in a single laboratory" after 1998, provides a simple and unique explanation of how 'redundant feedback loops' can assist in the regulation of exercise behaviour. In this rebuttal to his article, I identify (i) the numerous contradictions included in Professor Shephard's argument; (ii) the real meaning of the facts that he presents; (iii) the importance of the evidence that he ignores; and (iv) the different philosophies of how science should be conducted according to either the Kuhnian or the Popperian philosophies of scientific discovery. My conclusion is that the dominance of an authoritarian Kuhnian philosophy, which refuses to admit genuine error or "the need to alter one's course of belief or action," explains why there is little appetite in the exercise sciences for the acceptance of genuinely novel ideas such as the CGM. Furthermore, to advance the case for the CGM, I now include evidence from more than 30 studies, which, in my opinion, can only be interpreted according to a model of exercise regulation where the CNS, acting in an anticipatory manner, regulates the exercise behaviour by altering skeletal muscle recruitment, specifically to ensure that homeostasis is maintained during exercise. Since few, if any, of those studies can be explained by the 'brainless' A.V. Hill Cardiovascular Model on which Professor Shephard bases his arguments, I argue that it is now the appropriate time to retire that model. Perhaps this will bring to an end the charade that holds either (i) that the brain plays no part in the regulation of exercise performance; or, conversely, (ii) that the role of the brain is already so well defined that further research by other scientists is unnecessary. However, this cannot occur in a discipline that is dominated by an authoritarian Kuhnian philosophy.

Fatigue in spinocerebellar ataxia: patient self-assessment of an early and disabling symptom

OBJECTIVE

To identify the prevalence and severity of fatigue and predicting factors for severe fatigue in autosomal dominant spinocerebellar ataxia (SCA).

METHODS

We studied a cross-section of 123 patients with SCA. Six functional scales were used in a self-assessment: the Fatigue Severity Scale (FSS); the Beck Depression Inventory (BDI); the Rotterdam Handicap Scale (RHS); the Short Form-36 health survey, distinguishing a norm-based physical and mental component score (Nb-PCS and Nb-MCS); the Pittsburgh Sleep Quality Index (PSQI); and the Epworth Sleepiness Scale (ESS). A subset of 58 patients was clinically evaluated, measuring severity of ataxia with the Scale for the Assessment and Rating of Ataxia and cognitive functioning with the Mini-Mental State Examination.

RESULTS

Severe fatigue (FSS ≥5) was present in 69% of patients and FSS value correlated with the scores on RHS, Nb-PCS, Nb-MCS, BDI, PSQI, and ESS. There was no relation with disease duration, gender, or medication use. Multivariate analysis revealed that Nb-PCS and BDI were the best independent predictors for severe fatigue. Interestingly, the presence of visual symptoms was related to FSS value in the clinically evaluated subgroup.

CONCLUSION

Fatigue is a severe and disabling symptom in adult patients with SCA, even early in the course of disease. Physical functioning and depression are the strongest predictors of fatigue. In treatment strategies, all treatable factors for fatigue should be addressed, especially depression, visual symptoms, and sleeping disorders.

Recombinant human acid alpha-glucosidase (rhGAA) in adult patients with severe respiratory failure due to Pompe disease

Pompe disease is a rare metabolic myopathy caused by lysosomal α-glucosidase deficiency. Pompe disease ranges from a rapidly progressive course when symptoms present in infancy to a more slowly progressive rate when symptoms present in childhood or adulthood. This open-label prospective exploratory study investigated the effect of 12 months of recombinant enzyme replacement therapy in 5 adult patients who had already advanced to a very severe stage of Pompe disease. Muscular and respiratory function, quantitative muscle testing and spirometry were assessed. Four patients were tracheostomized. Respiratory parameters did not deteriorate. A moderate improvement in sitting/supine slow vital capacity in 2 patients (from 7% to 11% and 28% to 32% of predicted) and reductions of ventilation support in 2 patients was observed. Three patients, wheelchair bound at baseline, improved sitting and proximal motor function; 2 patients improved in their ability to stand and transfer. The treatment was well tolerated. Alglucosidase alfa may stabilize or even slightly improve muscle strength and respiratory function among patients with severe Pompe disease.