Pain in amyotrophic lateral sclerosis: a population-based controlled study

Non-Pharmacological Interventions on Pain in Amyotrophic Lateral Sclerosis Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting upper and lower motor neurons. Some ALS patients exhibit concomitant nonmotor signs; thus, ALS is considered a multisystemic disorder. Pain is an important nonmotor symptom. Observational and case-control studies report high frequency of pain in ALS patients and it has been correlated with depression and quality of life. There are no specific scales for the assessment of pain and no randomized controlled trials (RCTs) regarding the drug management of pain in ALS.

AIM

To systematically review the evidence for the nonpharmacological interventions (NPIs) in relieving pain in ALS, on March 2024, we searched the following databases: Pubmed, Scopus, Web of Science, and Cochrane. We also checked the bibliographies of trials identified to include further published or unpublished trials.

MAIN RESULTS

A total of 1003 records were identified. Finally, five RCTs including 131 patients (64 in the intervention group and 67 in the control group) were included for meta-analysis. The interventions of the included RCTs consisted of muscle exercise, combined aerobics-strength intervention, and osteopathic manual treatment. The meta-analysis did not find a statistically significant difference in favor of NPIs for alleviating pain in ALS patients.

CONCLUSIONS

ALS has a fulminant course and irreversibly leads to death. Pain in ALS patients, although a common nonmotor symptom, is often unrecognized and undertreated, and this is underlined by the lack of any RCTs on drug therapy for pain. Albeit NPIs are considered safe, as adverse effects are rarely reported, this systematic review did not provide sufficient evidence for a beneficial effect on pain. The scarceness of relevant literature highlights the need for future studies, with larger samples, more homogeneous in terms of interventions and population characteristics (stage of disease), and better choice of measurement scales to further investigate the efficacy, if any, of various pain interventions in ALS patients.

Amyotrophic Lateral Sclerosis and Pain: A Narrative Review from Pain Assessment to Therapy

Amyotrophic lateral sclerosis (ALS) is the most frequent neurodegenerative disease of the motor system that affects upper and lower motor neurons, leading to progressive muscle weakness, spasticity, atrophy, and respiratory failure, with a life expectancy of 2-5 years after symptom onset. In addition to motor symptoms, patients with ALS have a multitude of nonmotor symptoms; in fact, it is currently considered a multisystem disease. The purpose of our narrative review is to evaluate the different types of pain, the correlation between pain and the disease's stages, the pain assessment tools in ALS patients, and the available therapies focusing above all on the benefits of cannabis use. Pain is an underestimated and undertreated symptom that, in the last few years, has received more attention from research because it has a strong impact on the quality of life of these patients. The prevalence of pain is between 15% and 85% of ALS patients, and the studies on the type and intensity of pain are controversial. The absence of pain assessment tools validated in the ALS population and the dissimilar study designs influence the knowledge of ALS pain and consequently the pharmacological therapy. Several studies suggest that ALS is associated with changes in the endocannabinoid system, and the use of cannabis could slow the disease progression due to its neuroprotective action and act on pain, spasticity, cramps, sialorrhea, and depression. Our research has shown high patients' satisfaction with the use of cannabis for the treatment of spasticity and related pain. However, especially due to the ethical problems and the lack of interest of pharmaceutical companies, further studies are needed to ensure the most appropriate care for ALS patients.

Non-motor symptoms in motor neuron disease: prevalence, assessment and impact

People with motor neuron disease often experience non-motor symptoms that may occur secondary to, or distinct from, motor degeneration and that may significantly reduce quality of life, despite being under-recognized and evaluated in clinical practice. Non-motor symptoms explored in this population-based study include pain, fatigue, gastrointestinal issues, poor sleep, low mood, anxiety, problematic saliva, apathy, emotional lability, cognitive complaints and sexual dysfunction. People registered on the Clinical Audit Research and Evaluation of motor neuron disease platform, the Scottish Motor Neuron Disease Register, were invited to complete a questionnaire on non-motor symptoms and a self-reported Amyotrophic Lateral Sclerosis Functional Rating Scale. The questionnaire comprised a pre-defined list of 11 potential non-motor symptoms, with the opportunity to list additional symptoms. A total of 120 individuals participated in this cross-sectional study, a 39% response rate of those sent questionnaires (n = 311); 99% of participants recruited (n = 120) experienced at least one non-motor symptom, with 72% (n = 120) reporting five or more. The symptoms most often reported were pain and fatigue (reported by 76% of participants, respectively). The symptoms reported to be most impactful were gastrointestinal issues (reported as 'severe' by 54% of participants who experienced them), followed by pain and problematic saliva (51%, respectively). Lower Amyotrophic Lateral Sclerosis Functional Rating Scale scores, indicating more advanced disease and being a long survivor [diagnosed over 8 years ago; Black et al. (Genetic epidemiology of motor neuron disease-associated variants in the Scottish population. Neurobiol Aging. 2017;51:178.e11-178.e20.)], were significantly associated with reporting more symptoms; 73% of respondents were satisfied with the frequency that non-motor symptoms were discussed in clinical care; 80% of participants indicated they believe evaluation of non-motor symptom is important to include as outcomes in trials, independent of their personal experience of these symptoms. The preferred method of assessment was completing questionnaires, at home. The overwhelming majority of people with motor neuron disease report non-motor symptoms and these frequently co-occur. Pain, fatigue, gastrointestinal issues, sleep, mood, anxiety, problematic saliva, apathy, emotional lability, cognitive complaints and sexual dysfunction are prevalent. People with motor neuron disease who had worse physical function and those who were long survivors were more likely to report more symptoms. Where reported, these symptoms are frequent, impactful and a priority for people with motor neuron disease in clinical care and trial design.

Pain in patients with motor neuron disease: Variation of pain and association with disease severity, health-related quality of life and depression - A longitudinal study

OBJECTIVES

To describe levels of pain over time during disease progression in individual patients and for a total sample of patients with motor neuron disease (MND), respectively, and to examine associations between pain, disease severity, health-related quality of life (HRQOL), and depression.

METHODS

A prospective cohort study was conducted on 68 patients with MND, including data collected on five occasions over a period of 2 years. Pain was assessed using the Brief Pain Inventory - Short Form. Depression was assessed using the Amyotrophic Lateral Sclerosis (ALS)-Depression-Inventory (ADI-12). Disability progression was measured using the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised Version (ALSFRS-R). HRQOL was assessed using the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5).

RESULTS

Participants reported great individual variation over time. The median level of pain was 4 (min 0 and max 10). Higher levels of pain during the last 24 h were associated with higher depression scores (ADI-12), poorer quality of life (ALSAQ-5), and lower reporting of fine and gross motor skills (ALSFRS-R). Baseline pain levels did not predict future values of depression and function. Individuals reporting average pain >3 experienced more hopelessness toward the future and reported higher depression scores compared with participants reporting average pain <3.

SIGNIFICANCE OF RESULTS

Great within-individual variation of pain intensity was reported. Pain intensity was associated with depression, function and HRQOL cross-sectionally, but it did not have a strong prognostic value for future depression, function, or HRQOL. Patients with MND should be offered frequent assessment of pain and depressive symptoms in person-centered care, allowing for individualization of treatment.

Palliative Care in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease of the motor neurons. Given the evolutive characteristics of this disease, palliative care principles should be a foundation of ALS care. A multidisciplinary medical intervention is of paramount importance in the different phases of disease. The involvement of the palliative care team improves quality of life and symptoms, and prognosis. Early initiation is of paramount importance to ensuring patient-centered care, when the patient has still the capability to communicate effectively and participate in his medical care. Advance care planning supports patients and family members in understanding and sharing their preferences according to their personal values and life goals regarding future medical treatment. The principal problems which require intensive supportive care include cognitive disturbances, psychological distress, pain, sialorrhrea, nutrition, and ventilatory support. Communication skills of health-care professionals are mandatory to manage the inevitability of death. Palliative sedation has peculiar aspects in this population, particularly with the decision of withdrawing ventilatory support.

Ultrasound-guided glenohumeral joint injections for shoulder pain in ALS: A case series

Introduction

Shoulder pain is a common secondary impairment for people living with ALS (PALS). Decreased range of motion (ROM) from weakness can lead to shoulder pathology, which can result in debilitating pain. Shoulder pain may limit PALS from participating in activities of daily living and may have a negative impact on their quality of life. This case series explores the efficacy of glenohumeral joint injections for the management of shoulder pain due to adhesive capsulitis in PALS.

Methods

People living with ALS and shoulder pain were referred to sports medicine-certified physiatrists for diagnostic evaluation and management. They completed the Revised ALS Functional Rating Scale and a questionnaire asking about their pain levels and how it impacts sleep, function, and quality of life at baseline pre-injection, 1-week post-injection, 1 month post-injection, and 3 months post-injection.

Results

We present five cases of PALS who were diagnosed with adhesive capsulitis and underwent glenohumeral joint injections. Though only one PALS reported complete symptom resolution, all had at least partial symptomatic improvement during the observation period. No complications were observed.

Conclusions

People living with ALS require a comprehensive plan to manage shoulder pain. Glenohumeral joint injections are safe and effective for adhesive capsulitis in PALS, but alone may not completely resolve shoulder pain. Additional therapies to improve ROM and reduce pain should be considered.

SOMAscan Proteomics Identifies Novel Plasma Proteins in Amyotrophic Lateral Sclerosis Patients

Amyotrophic lateral sclerosis (ALS) is a complex disease characterized by the interplay of genetic and environmental factors for which, despite decades of intense research, diagnosis remains rather delayed, and most therapeutic options fail. Therefore, unravelling other potential pathogenetic mechanisms and searching for reliable markers are high priorities. In the present study, we employ the SOMAscan assay, an aptamer-based proteomic technology, to determine the circulating proteomic profile of ALS patients. The expression levels of ~1300 proteins were assessed in plasma, and 42 proteins with statistically significant differential expression between ALS patients and healthy controls were identified. Among these, four were upregulated proteins, Thymus- and activation-regulated chemokine, metalloproteinase inhibitor 3 and nidogen 1 and 2 were selected and validated by enzyme-linked immunosorbent assays in an overlapping cohort of patients. Following statistical analyses, different expression patterns of these proteins were observed in the familial and sporadic ALS patients. The proteins identified in this study might provide insight into ALS pathogenesis and represent potential candidates to develop novel targeted therapies.

Sensory Involvement in Amyotrophic Lateral Sclerosis

Although amyotrophic lateral sclerosis (ALS) is pre-eminently a motor disease, the existence of non-motor manifestations, including sensory involvement, has been described in the last few years. Although from a clinical perspective, sensory symptoms are overshadowed by their motor manifestations, this does not mean that their pathological significance is not relevant. In this review, we have made an extensive description of the involvement of sensory and autonomic systems described to date in ALS, from clinical, neurophysiological, neuroimaging, neuropathological, functional, and molecular perspectives.

Amyotrophic Lateral Sclerosis-The Complex Phenotype-From an Epidemiological Perspective: A Focus on Extrapyramidal and Non-Motor Features

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease (MND) and has emerged, among the disorders, with the largest increase in incidence in Western countries. Although the typical clinical phenotype of ALS involves simultaneous upper and lower motor neurons, there is growing evidence that the neurodegeneration during the course of the disease can also involve other motor and non-motor regions. In this review, we analyzed and discussed available data from epidemiological population-based studies on extrapyramidal and non-motor features during the course of ALS.

Pain-Related Factors and Their Impact on Quality of Life in Chinese Patients With Amyotrophic Lateral Sclerosis

Objectives

Pain is considered a common symptom in amyotrophic lateral sclerosis (ALS). However, the results of studies on pain in ALS are limited and inconsistent. The aim of our study was to comprehensively evaluate the potential factors of pain and effects on quality of life (QoL) in patients with ALS from China.

Participants and Methods

Patients were eligible if they fulfilled the criteria of probable and definitive ALS according to the revised El Escorial criteria. Pain was assessed by the Brief Pain Inventory (BPI). Disease severity, sleep quality, fatigue, anxiety, depression, and quality of life (QoL) were evaluated in ALS patients by the ALS Functional Rating Scale-revised (ALSFRS-R) and ALS severity scale (ALSSS), Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale (FSS), Hamilton Anxiety Rating Scale (HARS), Hamilton Depression Rating Scale (HDRS) and McGill Quality of Life Questionnaire (MQOL). Then, the clinical characteristics of ALS patients with pain were compared with those without pain. Last, associated factors of pain, as well as impact on QoL in Chinese ALS patients, were assessed.

Results

A total of 86 ALS patients were included. ALS patients with pain tended to have higher FSS scores and poorer QoL. The FSS score and ALSSS [lower extremity (LE) + upper extremity (UE)] were associated with pain in ALS patients. The ALS Functional Rating Scale-revised (ALSFRS-R), Pain Severity Index (PSI), HARS and HDRS scores were significantly associated with both the physical and psychological domains of QoL.

Conclusion

Our study was the first to comprehensively evaluate factors associated with pain in Chinese ALS patients, finding that fatigue can be a risk factor for pain and ALSSS (LE + UE) score was related with pain intensity. Additionally, we identified the adverse effects of ALSSS (LE + UE), HARS and HDRS scores on QoL in Chinese ALS patients.

Pain in amyotrophic lateral sclerosis: a narrative review

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative condition characterized by loss of motor neurons, resulting in motor weakness of the limbs and/or bulbar muscles. Pain is a prevalent but neglected symptom of ALS, and it has a significant negative impact on the quality of life of patients and their caregivers. This review outlines the epidemiology, clinical characteristics, underlying mechanisms, and management strategies of pain in ALS to improve clinical practice and patient outcomes related to pain. Pain is a prevalent symptom among patients with ALS, with a variable reported prevalence. It may occur at any stage of the disease and can involve any part of the body without a specific pattern. Primary pain includes neuropathic pain and pain from spasticity or cramps, while secondary pain is mainly nociceptive, occurring with the progression of muscle weakness and atrophy, prolonged immobility causing degenerative changes in joints and connective tissue, and long-term home mechanical ventilation. Prior to treatment, the exact patterns and causes of pain must first be identified, and the treatment should be tailored to each patient. Treatment options can be classified into pharmacological treatments, including nonsteroidal anti-inflammatory drugs, antiepileptic drugs, drugs for cramps or spasticity, and opioid; and nonpharmacological treatments, including positioning, splints, joint injections, and physical therapy. The development of standardized and specific assessment tools for pain-specific to ALS is required, as are further studies on treatments to reduce pain, diminish suffering, and improve the quality of life of patients with ALS.

Review of disease-modifying drug trials in amyotrophic lateral sclerosis

We analysed clinical trials of pharmacological interventions on patients with amyotrophic lateral sclerosis (ALS), and compared study quality and design features. The systematic review included articles published in PubMed and trials registered in ClinicalTrials.gov. Included studies were randomised double-blind placebo-controlled clinical trials assessing a disease-modifying pharmacological intervention. Studies were excluded if primary end points were safety or dose finding. A total of 28 735 articles and 721 current trials were identified. 76 published articles and 23 ongoing trials met inclusion criteria; they referred to distinct populations comprising 22 817 participants with ALS. Most articles and all current trials had parallel group design; few articles had cross-over design. A run-in observation period was included in about 20% of published studies and ongoing trials. Primary end points included functional assessment, survival, muscle strength, respiratory function, biomarkers and composite measures. Most recent trials had only functional assessment and survival. Risk of bias was high in 23 articles, moderate in 35, low in 18. A disease modification effect was observed for 10 interventions in phase II studies, two of which were confirmed in phase III. Three confirmatory phase III studies are currently underway. The present review provides cues for the design of future trials. Functional decline and survival, as single or composite measures, stand as the reference end points. Post hoc analyses should not be performed, particularly in studies using composite end points. There is a general agreement on diagnostic criteria; but eligibility criteria must be improved. Run-in observations may be used for censoring patients but are discouraged for refining participants' eligibility. The ALS Functional Rating Scale-Revised needs improvement for use as an ordinal measure of functional decline.

Pain-Related Coping Behavior in ALS: The Interplay between Maladaptive Coping, the Patient’s Affective State and Pain

Background: Pain is a common symptom in patients with amyotrophic lateral sclerosis (ALS). Coping plays a central role in adjustment to pain. Objective: This study evaluates the use of different pain coping strategies in patients with ALS and investigates the interplay of maladaptive coping, and the patient’s affective state and pain. Methods: One hundred and fifty ALS patients from three German outpatient clinics completed the Brief Pain Inventory (BPI), the ALS-Functional Rating Scale-Extension (ALSFRS-EX), the ALS Depression Inventory (ADI-12), the subscale “emotional functioning” of the ALS Assessment Questionnaire (ALSAQ-40) and the Coping Strategies Questionnaire (CSQ). Based upon the results of correlational analyses, multiple regression analyses were performed to identify predictors of pain severity and to explore factors contributing to maladaptive coping. Results: Pain was prevalent in 56% (n = 84) of the patients. Patients applied different adaptive coping strategies as well as the maladaptive strategy “catastrophizing”. Regression analysis indicated that the CSQ-subscale “catastrophizing” significantly predicted pain intensity, explaining 34.0% of the variance (p < 0.001). Pain-related catastrophizing was associated with higher pain-related functional impairments and worse emotional functioning. The ADI-12 sum score as an indicator for depressive symptoms contributed significantly to the maladaptive coping strategy “catastrophizing” (p < 0.001) and explained 40.8% of the variance. Conclusion: Patients with ALS apply different strategies to cope with pain. Catastrophizing is an important determinant of higher pain intensity ratings and is associated with higher pain interferences and decreased emotional well-being. Pain-related catastrophizing is promoted by depressive symptoms. Catastrophizing and depressive symptoms thus represent important targets of individualized pain-management strategies.

A systematic review of non-motor symptom evaluation in clinical trials for amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is increasingly recognised as a multi-system disorder, presenting with common and impactful non-motor symptoms, such as neuropsychiatric symtpoms, cognitive and behavioural changes, pain, disordered sleep, fatigue and problematic saliva.

AIM/HYPOTHESIS

We aimed to systematically review 25 years of ALS clinical trials data to identify if non-motor features were evaluated, in addition to the traditional measures of motor functioning and survival, and where evaluated to describe the instruments used to assess. We hypothesised that assessment of non-motor symptoms has been largely neglected in trial design and not evaluated with ALS-suitable instruments.

METHODS

We reviewed clinical trials of investigative medicinal products in ALS, since the licensing of riluzole in 1994. Trial registry databases including WHO International Trials Registry, European Clinical Trials Register, clinicaltrials.gov, and PubMed were systematically searched for Phase II, III or IV trials registered, completed or published between 01/01/1994 and 16/09/2020. No language restrictions were applied.

RESULTS

237 clinical trials, including over 29,222 participants, were investigated for their use of non-motor outcome measures. These trials evaluated neuropsychiatric symptoms (75, 32%), cognitive impairment (16, 6.8%), behavioural change (34, 14%), pain (55, 23%), sleep disturbances (12, 5%) and fatigue (18, 8%). Problematic saliva was assessed as part of composite ALS-FRS(R) scores in 184 trials (78%) but with no focus on this as an isolated symptom. 31 (13%) trials including 3585 participants did not include any assessment of non-motor symptoms.

CONCLUSIONS

Non-motor symptoms such as neuropsychiatric, cognitive and behavioural changes, pain, disordered sleep, fatigue, and problematic saliva have not been consistently evaluated in trials for people with ALS. Where evaluated, non-symptoms were primarily assessed using instruments and impairment thresholds that are not adapted for people with ALS. Future trials should include non-motor symptom assessments to evaluate the additional potential therapeutic benefit of candidate drugs.

PROPSERO REGISTRATION

CRD42020223648.

Pain, disease severity and associations with individual quality of life in patients with motor neuron diseases

Background

Up to 85% of people with motor neuron disease (MND) report pain, but whether pain has negative impact on quality of life is unclear. The aim was to study associations between pain, disease severity and individual quality of life (IQOL) in patients with MND.

Methods

In this cross sectional study, 61 patients were recruited from four multidisciplinary teams in Sweden, whereof 55 responded to the pain measure (The Brief Pain Inventory – Short form) and were included in the main analyses. Disease severity was measured with the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised Version, and individual quality of life was measured with a study-specific version of the Schedule for the Evaluation of Individual Quality of Life - Direct Weighting.

Results

Forty-one (74%) of the participants who answered BPI-SF (n = 55) reported pain. Thirty-nine (71%) of those reported pain during the past 24 h. The severity of pain was on average moderate, with eight participants (14%) reporting severe pain (PSI ≥ 7).

Satisfaction with IQOL for the entire sample was good (scale 1-7, where 1 equals poor quality of life): median 5, interquartile range (IQR) 2.75 and there was no difference in satisfaction with IQOL between those reporting pain/not reporting pain (median 5, IQR 2/median 5, IQR 3.5, Mann-Whitney U = 249, p = 0.452). There was neither any correlation between pain severity and satisfaction with IQOL, nor between disease severity and satisfaction with IQOL.

Conclusions

The results add to the hypothesis that associations between non-motor symptoms such as pain prevalence and pain severity and IQOL in MND are weak. Pain prevalence was high and the results pointed to that some participants experienced high pain severity, which indicate that pain assessments and pain treatments tailored to the specific needs of the MND population should be developed and scientifically evaluated.

A Multi-Center Cohort Study on Characteristics of Pain, Its Impact and Pharmacotherapeutic Management in Patients with ALS

Background: Although pain is common in amyotrophic lateral sclerosis (ALS) and an effectively treatable symptom, it is widely under-recognized and undertreated. This study investigates epidemiological and clinical characteristics of pain, its impact and pharmacological treatment in ALS patients. In addition, opportunities for further optimization of pain therapy need to be identified. Methods: Patients from three German ALS outpatient clinics were asked to complete the Brief Pain Inventory and the ALS Functional Rating Scale—Extension and to participate in semi-structured telephone interviews. Results: Of the 150 study participants, 84 patients reported pain. Pain occurred across all disease stages, predominantly in the neck, back and lower extremities. It was described with a broad spectrum of pain descriptors and mostly interfered with activity-related functions. Of the 84 pain patients, 53.8% reported an average pain intensity ≥4 on the numerical rating scale (NRS), indicating pain of at least moderate intensity, and 64.3% used pain medication. Irrespective of the medication type, 20.4% of them had no sufficient pain relief. Thirteen out of 30 patients without pain medication reported an average NRS value ≥4. Eleven of them—mainly in the context of high pain interference with daily functions—were supposed to benefit from adequate pain therapy. However, many patients had relevant concerns and misconceptions about pain therapy. Conclusion: Given the frequency, extent and multi-faceted impact of pain, it is necessary to systematically assess pain throughout the disease course. Potentials to optimize pain therapy were seen in the subset of patients with insufficient pain relief despite medication and in those patients without pain medication but high pain interference. However, there is a need to respond to patients’ barriers to pain therapy.

Developments in the assessment of non-motor disease progression in amyotrophic lateral sclerosis

INTRODUCTION

The burden of non-motor symptoms is a major determinant of quality of life and outcome in amyotrophic lateral sclerosis (ALS) and has profound negative effect also on caregivers.

AREAS COVERED

Non-motor symptoms in ALS include cognitive impairment, neurobehavioral symptoms, depression and anxiety, suicidal ideation, pain, disordered sleep, fatigue, weight loss and reduced appetite, and autonomic dysfunctions. This review summarizes the measures used for the assessment of non-motor symptoms and their properties and recaps the frequency and progression of these symptoms along the course of ALS.

EXPERT OPINION

Non-motor symptoms in ALS represent a major component of the disease and span over several domains. These symptoms require a high level of medical attention and should be checked at each visit using ad hoc questionnaires and proactively treated. Several instruments assessing non-motor symptoms have been used in ALS. Specific screening questionnaires for non-motor symptoms can be used for monitoring patients during telehealth visits and for remote surveillance through sensors and apps installed on smartphones. Novel trials for non-motor symptoms treatment specifically designed for ALS are necessary to increase and refine the therapeutic armamentarium. Finally, scales assessing the most frequent and burdensome non-motor symptoms should be included in clinical trials.

Exploring Molecular Approaches in Amyotrophic Lateral Sclerosis: Drug Targets from Clinical and Pre-Clinical Findings

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease (MND) characterized by the death of upper and lower motor neurons (corticospinal tract) in the motor cortex, basal ganglia, brain stem, and spinal cord. The patient experiences the sign and symptoms between 55 to 75 years of age, which include impaired motor movement, difficulty in speaking and swallowing, grip loss, muscle atrophy, spasticity, and sometimes associated with memory and cognitive impairments. Median survival is 3 to 5 years after diagnosis and 5 to 10% of the patients live for more than 10 years. The limited intervention of pharmacologically active compounds, that are used clinically, is majorly associated with the narrow therapeutic index. Pre-clinically established experimental models, where neurotoxin methyl mercury mimics the ALS like behavioural and neurochemical alterations in rodents associated with neuronal mitochondrial dysfunctions and downregulation of adenyl cyclase mediated cAMP/CREB, is the main pathological hallmark for the progression of ALS in central as well in the peripheral nervous system. Despite the considerable investigation into neuroprotection, it still constrains treatment choices to strong care and organization of ALS complications. Therefore, this current review specially targeted the investigation of clinical and pre-clinical features available for ALS to understand the pathogenic mechanisms and to explore the pharmacological interventions associated with the up-regulation of intracellular adenyl cyclase/cAMP/ CREB and activation of mitochondrial-ETC coenzyme-Q10 as a future drug target in the amelioration of ALS mediated motor neuronal dysfunctions.

Characteristics of pain and the burden it causes in patients with amyotrophic lateral sclerosis - a longitudinal study

OBJECTIVE

Pain currently plays a subordinate role in the clinical care of patients with ALS. We aim to examine epidemiological and clinical characteristics of pain as well as its impact throughout the disease course.

METHODS

During a longitudinal follow-up at three time points, 151 ALS patients from three German outpatient clinics completed the Brief Pain Inventory, ALS-Functional Rating Scale-Extension and ALS Depression Inventory. Analysis of variance and covariance with repeated measures were performed.

RESULTS

Pain was prevalent in 56% of the 151 patients at baseline and in 70% of the remaining 40 patients at the third survey. Of the 28 patients with pain who participated in all three surveys, about two thirds suffered from an average pain intensity corresponding to at least moderate pain on the numerical rating scale (NRS ≥ 4). Patients reported different pain qualities and localized the pain most frequently in the extremities, back and neck. Pain moderately impaired the functions of daily living. Pain intensity, pain quality and pain-related impairment did not significantly change over time. One third of the patients suffered from clinically relevant depressive symptoms. However, there was no conclusive evidence of a link between pain intensity and depressive symptoms.

CONCLUSION

Pain is frequent and constitutes an additional strain on ALS patients who have to endure a rapidly progressive and severely debilitating disease. This study contributes to better understanding of the characteristics of pain and its impact on ALS patients throughout the disease course and may thus help to more effectively address this symptom.

The Evaluation of Pain with Nociceptive and Neuropathic Characteristics from Three Different Perspectives in Amyotrophic Lateral Sclerosis Patients: A Case Controlled Observational Study in Southwestern China

Background

Pain was considered a common and neglected symptom in amyotrophic lateral sclerosis (ALS) and had a substantial impact on the quality of life of ALS patients and their caregivers. However, pain in ALS was mainly evaluated from the perspective of nociceptive pain; only three studies referred to neuropathic pain in ALS, and there has been yet no study considering the neuropathic pain characteristics in ALS patients from China. Therefore, the purpose of our study was to determine characteristics of pain (nociceptive pain and neuropathic pain) by three different types of questionnaires. The correlation between pain and clinical parameters in ALS patients was also evaluated.

Methods

Patients were eligible if they fulfilled the criteria of probable and definitive ALS according to the revised El Escorial criteria. Healthy normal controls, matched to ALS patients by age and gender, were recruited. Pain was evaluated by numerical pain rating scale (NRS), Brief Pain Inventory (BPI), and Douleur Neuropathique-4 (DN4) in ALS patients and controls. Physical status of ALS patients was evaluated with ALS Functional Rating Scale-revised (ALSFRS-R).

Results

65 patients with sporadic ALS and 100 healthy normal controls in Southwestern China were included. Pain in the preceding week was more frequently reported by patients with ALS (30, 46.2%) than controls (36, 36%) (p = 0.193). DN4 score⩾4 was found in three ALS patients and one control (p = 0.480). Ten ALS patients (33.3%) and twenty-eight controls (77.8%) (p < 0.001) received therapy for pain. ALS patients with a DN4 score ≥ 4 had a longer disease duration and a higher PSI and PII score than ALS cases reporting nociceptive pain (p = 0.041, 0.048, and 0.027, respectively). Pain mainly interfered with ALS patients' mood, enjoyment of life, and the Pain Interference Index (PII) score.

Conclusions

Our findings indicated that pain in our ALS cohorts was insufficiently treated and interfered with patients' mood and enjoyment of life. Most notably, we found that ALS patients with a DN4 score⩾4 may have a longer disease duration and a higher PSI and PII score than ALS patients reporting nociceptive pain, which has never been reported, strongly deserving further validation.

Non-Motor Symptoms of Amyotrophic Lateral Sclerosis: A Multi-Faceted Disorder

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motor pathways. A growing body of evidence from recent years suggests that ALS results in a wide range of non-motor symptoms as well, which can have a significant impact on patients' quality of life. These symptoms could also, in turn, provide useful information as biomarkers for disease progression, and can shed insight on ALS mechanisms. Here we aim to review a wide range of non-motor symptoms of ALS, with emphasis on their importance to research and clinical treatment of patients.

Prevalence of pain in amyotrophic lateral sclerosis: a systematic review and meta-analysis

Objectives: Physical pain is a known symptom in amyotrophic lateral sclerosis (ALS), but no systematically derived prevalence estimate is available. The aim of this study was to determine the pooled prevalence of pain in ALS, relative to its method of measurement and pain characteristics. Methods: A systematic search across multiple databases was conducted on January 16, 2020. Random-effects meta-analyses of single proportions were performed on prevalence data. Heterogeneity was determined using the I² statistic. Where available, pain location, intensity, and type or source were compared. Results: 2552 articles were identified. Twenty-one eligible studies were included. All studies used observational designs (14 cross-sectional, 6 cohort, 1 case-control). Pooled prevalence of pain in ALS across all studies was 60% (95% CI = 50-69%), with a high degree of heterogeneity (I² = 94%, p < .001). Studies that used only validated measures had lower heterogeneity (I² = 82%, p = 0.002), compared to those that used tailored measures, or tailored supplemented with validated measures (I² = 90%, p < 0.001 and I² = 83%, p < 0.001, respectively). In a subset of studies (N = 9), the most commonly reported pain location was the upper limbs including shoulders/extremities (41.5%). A further study subset (N = 7) showed moderate-severe intensity pain was most frequently reported. Type of pain was commonly related to cramp or spasm. Conclusions: Experiencing physical pain in ALS occurs with high prevalence. Deriving consensus on which specific tools should be used to assess, monitor and compare symptoms of pain in this population will reduce current heterogeneity in approaches and increase the likelihood of ameliorating distressing experiences more effectively.

Pain Phenotypes in Rare Musculoskeletal and Neuromuscular Diseases

For patients diagnosed with a rare musculoskeletal or neuromuscular disease, pain may transition from acute to chronic; the latter yielding additional challenges for both patients and care providers. We assessed the present understanding of pain across a set of ten rare, noninfectious, noncancerous disorders; Osteogenesis Imperfecta, Ehlers-Danlos Syndrome, Achondroplasia, Fibrodysplasia Ossificans Progressiva, Fibrous Dysplasia/McCune-Albright Syndrome, Complex Regional Pain Syndrome, Duchenne Muscular Dystrophy, Infantile- and Late-Onset Pompe disease, Charcot-Marie-Tooth Disease, and Amyotrophic Lateral Sclerosis. Through the integration of natural history, cross-sectional, retrospective, clinical trials, & case studies we described pathologic and genetic factors, pain sources, phenotypes, and lastly, existing therapeutic approaches. We highlight that while rare diseases possess distinct core pathologic features, there are a number of shared pain phenotypes and mechanisms that may be prospectively examined and therapeutically targeted in a parallel manner. Finally, we describe clinical and research approaches that may facilitate more accurate diagnosis, monitoring, and treatment of pain as well as elucidation of the evolving nature of pain phenotypes in rare musculoskeletal or neuromuscular illnesses.

Do pain, anxiety and depression influence quality of life for people with amyotrophic lateral sclerosis/motor neuron disease? A national study reconciling previous conflicting literature

INTRODUCTION

The importance of elucidating the relationships between pain, mood and quality of life (QoL) amongst people with amyotrophic lateral sclerosis/motor neuron disease is evident to clinicians, yet the literature is limited and inconsistent. We explored the relationships between pain, depression, anxiety and QoL to reconcile the previous contrasting findings and inform future research and clinical practice.

METHODS

Patient-reported outcomes were obtained as part of the Trajectories of Outcomes in Neurological Conditions study. Mood and QoL scales underwent Rasch analysis. Correlation coefficients examined the strength of association between variables of interest. A bivariate regression model was developed to examine the effects of pain, depression and anxiety on joint psychological and physical QoL domains.

RESULTS

Of 636 people with ALS, 69% reported pain, of these most had mild pain. Seven percent (7%) of participants exceeded published cutoffs for probable depression and 14% had probable anxiety. Pain, depression and anxiety all influence quality of life; depression has a significant effect on both physical and psychological domains of QoL, whereas pain affects physical QoL and anxiety psychological QoL.

CONCLUSIONS

These results show the importance of expressing quality of life in a conceptually appropriate way, as failing to take account of the multidimensional nature of QoL can result in important nuances being overlooked. Clinicians must be aware that pain, depression and anxiety all worsen QoL across their ranges, and not just when pain is severe or when anxiety or depression reach case level.

Small fiber neuropathy in unexpected clinical settings: a review

Small fiber neuropathy (SFN) is being recognized with increasing frequency in neuromuscular practice due to improved diagnostic techniques. Although there are some common etiologies, up to one-third of cases are considered idiopathic. In recent years, several disorders have unexpectedly been reported in association with SFN, on clinical grounds and complementary investigations, including quantitative sensory testing, intraepidermal nerve fiber density and confocal corneal microscopy. Knowledge of these disorders is important in clinical practice as increased awareness enables prompt diagnosis of SFN in these settings and early optimal therapeutic management of affected patients. Furthermore, these new developments may lead to a better understanding of the pathophysiologic mechanisms underlying SFN in these different disorders as well as, in some cases, an expanded spectrum of affected organs and systems. This article reviews these reported associations, their possible pathophysiologic bases, and the potential resulting management implications.

Pain at the onset of Amyotrophic Lateral Sclerosis: a cross-sectional study

OBJECTIVE

We evaluated ALS patients reporting pain, either generalized or localized, at disease onset and determined whether this feature defined a specific ALS phenotype.

PATIENTS AND METHODS

We considered all consecutive ALS patients referred to our Motor Neuron Diseases Center between 2006 and 2016 and included only patients who fulfilled the El Escorial revised criteria for probable and definite ALS diagnosis. We then identified those cases who reported pain at disease onset and compared them to all remaining cases. Secondary causes of pain have been excluded.

RESULTS

Our initial sample consisted of 108 patients (55 men and 53 women). We identified 5 cases with generalized pain and 16 cases with localized pain at disease onset, corresponding to 4.6% and 14.8% of the initial sample, respectively. Cases with generalized pain were all female and had an earlier disease onset (49.6 ± 1.5 vs 66.6 ± 10.2 yrs, p = 0.002). Cases with localized pain showed a preponderance of upper motor neuron symptoms/signs at disease onset. Patients with pain, either localized or generalized, had a significantly higher involvement of the limbs (82.6% vs 100%, p = 0.022), while the bulbar district was spared at disease onset (17.4% vs 0%, p = 0.008). More specifically, the proximal upper and distal lower limbs were more frequently affected by ALS in patients with pain at disease onset. In two cases, the clinical presentation was notable for the resemblance with complex regional pain syndrome.

CONCLUSION

The presence of pain at disease onset seems to relate to peculiar clinical features of ALS and may be pathophysiologically associated with neurodegeneration.

Pain in amyotrophic lateral sclerosis

In this review, we discuss different aspects of pain syndrome in patients with amyotrophic lateral sclerosis: etiology, incidence, pathophysiology and main clinical features. Also we review the modern approaches to the treatment of pain in amyotrophic lateral sclerosis. Pain is actually not rare in this condition: it appears in 80% of patients, affecting their quality of life and functional activity, leading to the development of depressive and anxiety disorders. Pain in amyotrophic lateral sclerosis is often overlooked by clinicians, since their attention may focus on the motor symptoms of the disease. Thus, a more careful approach is needed to diagnose and treat pain in amyotrophic lateral sclerosis.

The multiple faces of pain in motor neuron disease: a qualitative study to inform pain assessment and pain management

Purpose: The aim was to explore personal experiences of pain in people with motor neuron disease.Materials and methods: Sixteen participants were individually interviewed on one occasion concerning their experiences of presentation, consequences, and management of pain. Qualitative content analysis with researcher triangulation was used to synthesize and interpret data.Results: Four themes emerged as the result of the analysis: (1) The multiple faces of pain, (2) The thin line between experience of pain and no pain, (3) The negative effects of pain on role functioning (4) Successful coping with pain requiring personal effort and competent engagement. The important findings were the experiences of unpredictability of pain breakthroughs, the efforts required to manage pain, consequences for activity and quality of life, and the suffering induced by diminishment and neglect of pain from both patients and staff.Conclusions: Pain in motor neuron disease seems to have certain and multiple characteristics, which is why there is a need to develop and implement pain assessment methods adapted to this population. Such methods may help make pain more predictable, and increase the possibilities to provide effective and individually tailored pain treatment.IMPLICATIONS FOR REHABILITATIONPain is a common, but often neglected, ailment in motor neuro disease, which deserves more attention from health care.Staff should provide information about the pain being possible to treat successfully with medication, by contrast to the possibility of curing the disease itself.Pain assessments should be implemented during the entire course of the disease, covering a time frame long enough to cover characteristic fluctuations of pain.Whenever possible, facilitate the performance of painful activities of daily living as much as possible to make room for engagement in other personally valued activities of importance for individual quality of life.

Disability and Contextual Factors in Patients with Amyotrophic Lateral Sclerosis - A Three-Year Observational Study

Background:

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by muscle weakness and wasting. Observational natural history studies can give information on body function/structure impairments, activity limitations and participation restrictions, i.e. disability. Information needed to plan and develop care and support.

Objective:

To describe and explore disease severity and impairments, activity limitations, participation restrictions and contextual factors over time. In specific, to explore concurrent presence of cognitive impairment, fatigue, anxiety, depression and pain, and whether these impairments were related to disease severity.

Methods:

In this three-year observational study, 60 patients with ALS were included at baseline. Follow-ups were performed every 6 months unless participants had deceased or declined participation. Data was collected from medical records, and by study-specific and standardized questionnaires administrated during home visits.

Results:

Regardless of disease severity; fatigue, anxiety, depression and pain were present in patients with ALS at each data collection. Approximately one-third experienced two or more of these impairments concurrently, i.e. at the same time point. Cognitive impairment could not be assessed in many patients due to their physical impairments. Disease severity was not associated with fatigue, anxiety, depression or pain.

Conclusions:

Patients with ALS need, throughout the course of the disease, to be regularly screened for commonly present impairments, activity limitations and participation restrictions so that person-centered interventions can be applied at the right time.

Motor neurone disease-associated neck pain misdiagnosed as cervical spondylosis: A case report and literature review

BACKGROUND

Motor neurone disease (MND) is a chronic, progressive and currently incurable neurodegenerative disorder. Although pain as a symptom appears in many patients with MND, it is often misdiagnosed as other diseases when occurs before the onset of weakness. Patients are often assigned to non-neurological departments due to the atypical symptoms, which can lead to diagnostic delay and inappropriate treatment.

OBJECTIVE

To analyze the causes of misdiagnosis and improve the clinician's understanding of neck pain in patients with MND.

METHODS

We reviewed relevant literature and retrospectively reported a misdiagnosis case of MND-associated neck pain.

RESULTS

A case of MND presenting prominently as neck pain was suspected of suffering from cervical spondylosis and wrongly assigned to orthopedic clinic. When eventually being diagnosed as MND, his neck pain was found to be caused by intracranial hypertension (ICH) resulting from hypoxia via insidious respiratory failure through ventilator insufficiency.

CONCLUSION

Careful evaluation of the clinical progression of the symptoms, extensive EMG and nerve conduction study, as well as the establishment of better clinical approach to the diagnosis and higher public awareness allow a reduction of misdiagnosis.

Clinical features of pain in amyotrophic lateral sclerosis: A clinical challenge

Pain in amyotrophic lateral sclerosis (ALS) is paradoxical in this disease of the upper and lower motor neurons. As such, it remains an underestimated and neglected clinical problem because it is poorly identified by physicians, its mechanisms are numerous and its treatments are generally not effective. Pain may be primary in the form of cramps, spasticity and neuropathy, or secondary as nociceptive pain, and may arise before the first motor symptoms. It may also lead to depression and, in all cases, affect patients' daily activities and quality of life. Given the high frequency of pain in ALS, the use of analgesic or sedative drugs is necessary and should reduce the course of the disease. Nevertheless, it is important to understand the pathophysiological mechanisms of pain in ALS, and to train physicians how to detect ALS pain early on and provide dedicated treatments. In France, the implementation of ALS centers is a positive response to the public-health problem resulting from this disorder.

Cutaneous somatic and autonomic nerve TDP-43 deposition in amyotrophic lateral sclerosis

OBJECTIVE

To evaluate the involvement of the sensory and autonomic nervous system in amyotrophic lateral sclerosis (ALS) and to determine whether TDP-43/pTDP-43 deposits in skin nerve fibers signify a valuable biomarker for ALS.

METHODS

Eighteen patients with ALS and 18 age- and sex-matched control subjects underwent physical examinations, in addition to donating skin biopsies from the distal leg. The density of epidermal, Meissner's corpuscle (MC), sudomotor, and pilomotor nerve fibers were measured. Confocal microscopy was used to determine the cutaneous somatic and autonomic nerve fiber density and TDP-43/pTDP-43 deposition.

RESULTS

Intraepidermal nerve fiber density (IENFD) was reduced in individuals with ALS (P < 0.001). MC density (MCD) (P = 0.001), sweat gland nerve fiber density (SGNFD) (P < 0.001), and pilomotor nerve fiber density (PNFD) (P < 0.001) were all reduced in ALS patients. The SGNFD correlated with the small-fiber neuropathy Symptoms Inventory Questionnaire (SFN-SIQ), VAS and age. The SFN-SIQ was higher in ALS with sensory symptoms than without sensory symptoms (P = 0.000). Furthermore, the SFN-SIQ was higher in ALS with autonomic symptoms than without autonomic symptoms (P = 0.002). SFN-SIQ was higher in ALS patients that were pTDP-43 positive than pTDP-43 negative (P = 0.04), respectively.

CONCLUSIONS

We established in the peripheral nervous system that higher SFN-SIQ and VAS was involved in ALS, indicating the loss of SGNF. The deposition of TDP-43/pTDP-43 in ALS nerve fibers may indicate an important role in the underlying pathogenesis of ALS. This observation might be used as a potential biomarker for diagnosing ALS.

Relationship between Pain and Functional Status in Patients with Amyotrophic Lateral Sclerosis: A Multicenter Cross-Sectional Study

BACKGROUND

Pain is a widely neglected symptom in patients with amyotrophic lateral sclerosis (ALS), even though it may be common and have a significant impact on the quality of life.

OBJECTIVE

The aim of this study was to determine the frequency and characteristics of pain and its treatment in ALS patients.

DESIGN

A multicenter cross-sectional study.

SETTING/SUBJECTS

Eighty patients with ALS from eight hospitals.

MEASUREMENTS

Data on demographics, functional status, and pharmacological treatment were collected. The Barthel Index (BI) was used to assess functional status. Pain was measured using the 0-5-point Wong-Baker FACES Pain Rating Scale.

RESULTS

Pain was reported by 53.8% of ALS patients, and 36.3% reported receiving pain medication. Opioids were the drugs most commonly used to treat pain. The differences in pain frequency according to functional status were not statistically significant (p = 0.38). The pain intensity in patients whose functional status was total dependence (BI 0-20, 2.5 ± 1.2) was significantly worse than that in those with better functional status (BI 21-60, 1.4 ± 0.7; BI 61-99, 1.4 ± 0.5; p < 0.01).

CONCLUSIONS

Our study indicates that all patients with ALS have the potential to suffer from pain, the intensity of which increases with decreased functional status.

Beyond weakness: Characterization of pain, sensory profile and conditioned pain modulation in patients with motor neuron disease: A controlled study

BACKGROUND

Motor neuron diseases (MND) represent a group of disorders that evolve with inexorable muscle weakness and medical management is based on symptom control. However, deeper characterization of non-motor symptoms in these patients have been rarely reported.

METHODS

This cross-sectional study aimed to describe non-motor symptoms in MND and their impact on quality of life and functional status, with a focus on pain and sensory changes. Eighty patients (31 females, 55.7 ± 12.9 years old) with MND underwent a neurological examination, pain, mood, catastrophizing and psychophysics assessments [quantitative sensory testing (QST) and conditioned pain modulation (CPM)], and were compared to sex- and age-matched healthy controls (HC).

RESULTS

Chronic pain was present in 46% of patients (VAS =5.18 ± 2.0). Pain of musculoskeletal origin occurred in 40.5% and was mainly located in the head/neck (51%) and lower back (35%). Neuropathic pain was not present in this sample. Compared to HC, MND patients had a lower cold detection threshold (p < 0.002), and significantly lower CPM scores (4.9 ± 0.2% vs. 22.1 ± 0.2%, p = 0.012). QST/CPM results did not differ between MND patients with and without pain. Pain intensity was statistically correlated with anxiety, depression and catastrophism, and spasticity scores were inversely correlated with CPM (ρ = -0.30, p = 0.026).

CONCLUSIONS

Pain is frequently reported by patients with MNDs. Somatosensory and CPM changes exist in MNDs and may be related to the neurodegenerative nature of the disease. Further studies should investigate the most appropriate treatment strategies for these patients.

SIGNIFICANCE

We report a comprehensive evaluation of pain and sensory abnormalities in motor neuron disease (MND) patients. We assessed the different pain syndromes present in MND with validated tools, and described the QST and conditioned pain modulation profiles in a controlled design.

Improving symptom management for people with amyotrophic lateral sclerosis

INTRODUCTION

Symptomatic management is the main focus of ALS clinical care. We aim to report the prevalence of ALS-related symptoms and characterize self-reported symptomatic management.

METHODS

A symptom management survey developed by the Muscular Dystrophy Association Clinical Research Network was completed by ALS registrants. Logistic regression identified potential predictors of symptom prevalence, severity, and treatment.

RESULTS

A total of 567 ALS participants reported fatigue (90%), muscle stiffness (84%), and muscle cramps (74%) as most prevalent symptoms. Fatigue (18%), muscle stiffness (14%), and shortness of breath (12%) were most bothersome. Although fatigue was the most prevalent symptom, it was also least treated (10%). Neither location of care nor disease duration was associated with symptom prevalence, severity, or probability of receiving treatment.

DISCUSSION

This large patient-reported symptom survey suggests that fatigue is the most prevalent, bothersome, and undertreated ALS symptom. Improving ALS symptom management is an unmet medical need and clinical trials of symptomatic treatments are needed. Muscle Nerve 57: 20-24, 2018.

Nonmotor Symptoms in Amyotrophic Lateral Sclerosis: A Systematic Review

BACKGROUND

ALS is a progressive neurodegenerative disease with no curative treatment. Nonmotor symptoms presenting in ALS may cause significant distress, worsen prognosis, and affect survival.

OBJECTIVE

To systematically review evidence for the prevalence of nonmotor ALS symptoms, and treatment options.

METHODS

Multiple medical literature databases were searched and studies screened using predefined inclusion criteria. Of 4580 studies, 44 were eligible for inclusion with 25 relating to treatment and 19 to the prevalence of nonmotor symptoms in ALS.

RESULTS

Nonmotor symptoms involve neuropsychiatric, autonomic, gastrointestinal, and vascular systems, and affect between 5% and 80% of people with ALS. Screening tools for individual nonmotor symptoms are useful in classifying symptom severity and to compare between treatment options. Several methods to relieve nonmotor symptoms have been trialed with varying success rates.

CONCLUSIONS

Many of the current studies of nonmotor symptoms in ALS have small sample sizes, requiring more evidence to increase precision in prevalence estimates. Further research is needed to assess the efficacy of current treatments and to find new therapies. Symptom relief or treatment of these nonmotor symptoms should therefore be considered during the clinical management of ALS.

Extra-motor abnormalities in amyotrophic lateral sclerosis: another layer of heterogeneity

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease defined by the presence of muscle weakness. The motor features of disease are heterogeneous in site of onset and progression. There are also extra-motor features in some patients. The genetic basis for extra-motor features is uncertain. The heterogeneity of ALS is an issue for clinical trials. Areas covered: This paper reviews the range and prevalence of extra-motor features associated with ALS, and highlights the current information about genetic associations with extra-motor features. Expert commentary: There are extra-motor features of ALS, but these are not found in all patients. The most common is cognitive abnormality. More data is required to ascertain whether extra-motor features arise with progression of disease. Extra-motor features are reported in patients with a range of causative genetic mutations, but are not found in all patients with these mutations. Further studies are required of the heterogeneity of ALS, and genotype/phenotype correlations are required, taking note of extra-motor features.

Motor neuron disease: biomarker development for an expanding cerebral syndrome

Descriptions of motor neuron disease (MND) documented more than a century ago remain instantly recognisable to the physician. The muscle weakness, typically with signs of upper and lower motor neuron dysfunction, is uniquely relentless. Over the last 30 years, a wider cerebral pathology has emerged, despite the lack of overt cognitive impairment in the majority of patients. From the initial linkage of a small number of cases to mutations in SOD1, diverse cellular pathways have been implicated in pathogenesis. An increasingly complex clinical heterogeneity has emerged around a significant variability in survival. Defining a cellular signature of aggregated TDP-43 common to nearly all MND and a large proportion of frontotemporal dementia (FTD), has placed MND alongside more traditional cerebral neurodegeneration. With new genetic causes, most notably a hexanucleotide expansion in C9orf72 associated with both MND and FTD, the development of biomarkers against which to test therapeutic candidates is a priority.

Sensory neuropathy in progressive motor neuronopathy (pmn) mice is associated with defects in microtubule polymerization and axonal transport

Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) are now recognized as multi-system disorders also involving various non-motor neuronal cell types. The precise extent and mechanistic basis of non-motor neuron damage in human ALS and ALS animal models remain however unclear. To address this, we here studied progressive motor neuronopathy (pmn) mice carrying a missense loss-of-function mutation in tubulin binding cofactor E (TBCE). These mice manifest a particularly aggressive form of motor axon dying back and display a microtubule loss, similar to that induced by human ALS-linked TUBA4A mutations. Using whole nerve confocal imaging of pmn × thy1.2-YFP16 fluorescent reporter mice and electron microscopy, we demonstrate axonal discontinuities, bead-like spheroids and ovoids in pmn suralis nerves indicating prominent sensory neuropathy. The axonal alterations qualitatively resemble those in phrenic motor nerves but do not culminate in the loss of myelinated fibers. We further show that the pmn mutation decreases the level of TBCE, impedes microtubule polymerization in dorsal root ganglion (DRG) neurons and causes progressive loss of microtubules in large and small caliber suralis axons. Live imaging of axonal transport using GFP-tagged tetanus toxin C-fragment (GFP-TTC) demonstrates defects in microtubule-based transport in pmn DRG neurons, providing a potential explanation for the axonal alterations in sensory nerves. This study unravels sensory neuropathy as a pathological feature of mouse pmn, and discusses the potential contribution of cytoskeletal defects to sensory neuropathy in human motor neuron disease.

Osteopathic Manual Treatment for Amyotrophic Lateral Sclerosis: A Feasibility Pilot Study

Background:

Current interventions in amyotrophic lateral sclerosis (ALS) are focused on supporting quality of life (QoL) and easing pain with a multidisciplinary approach.

Objective:

Primary aim of this pilot work assessed feasibility, safety, tolerability and satisfaction of osteopathic manual treatment (OMT) in 14 ALS outpatients.

Methods:

Patients were randomized according to an initial single-blind design (12 weeks, T0-T1), in order to receive OMT (weekly for 4 weeks, and fortnightly for the following 8 weeks) versus usual-care (n=7 each group), followed by an OMT open period (T1-T2, once a week for 8 weeks, n=10). Secondary aims included blind osteopathic assessment of somatic dysfunctions (SD) for goal attainment scale (GAS) calculation, Brief Pain Inventory-short form and McGill QoL-16 items.

Results:

OMT was demonstrated feasible and safe and patients displayed high satisfaction (T1-VAS=8.34 ± 0.46; T2-VAS=8.52 ± 0.60). Considering secondary aims no significant differences emerged. Finally, at study entry (T0), a cervico-dorsal SD was found in 78% of ALS patients versus 28% of healthy matched controls (p<0.01).

Conclusion:

OMT was found feasible, safe and satisfactory in ALS. The lack of secondary aim differences can be due to the limited sample size. OMT could be an interesting option to explore in ALS.

Hypoparathyroidism: A rare mimic of amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) carries a grim prognosis. Various ALS mimics have been reported and should be excluded before confirming this diagnosis.

METHODS

We report the case of a 61-year-old man who presented with progressively worsening limb weakness and dysphagia. His examination showed mixed upper and lower motor neuron signs without sensory impairment. ALS was suspected, however, atypical diffuse pain prompted diagnostic work-up to exclude other causes.

RESULTS

Electrodiagnostic testing was suggestive of a sensorimotor polyneuropathy with superimposed diffuse active denervation suspicious for anterior horn cell degeneration. Brain MRI showed bilateral basal ganglia and thalamic calcifications. Laboratory studies confirmed the diagnosis of hypoparathyroidism. Treatment with calcium and vitamin D resulted in significant improvement at 6 months follow-up.

CONCLUSIONS

Hypoparathyroidism, a treatable endocrinopathy, can rarely present clinically as ALS. In atypical cases, this should be ruled out before making a final diagnosis. Muscle Nerve, 2016 Muscle Nerve 55: 437-439, 2017.

Supportive and symptomatic management of amyotrophic lateral sclerosis

The main aims in the care of individuals with amyotrophic lateral sclerosis (ALS) are to minimize morbidity and maximize quality of life. Although no cure exists for ALS, supportive and symptomatic care provided by a specialist multidisciplinary team can improve survival. The basis for supportive management is shifting from expert consensus guidelines towards an evidence-based approach, which encourages the use of effective treatments and could reduce the risk of harm caused by ineffective or unsafe interventions. For example, respiratory support using noninvasive ventilation has been demonstrated to improve survival and quality of life, whereas evidence supporting other respiratory interventions is insufficient. Increasing evidence implicates a causal role for metabolic dysfunction in ALS, suggesting that optimizing nutrition could improve quality of life and survival. The high incidence of cognitive dysfunction and its impact on prognosis is increasingly recognized, although evidence for effective treatments is lacking. A variety of strategies are used to manage the other physical and psychological symptoms, the majority of which have yet to be thoroughly evaluated. The need for specialist palliative care throughout the disease is increasingly recognized. This Review describes the current approaches to symptomatic and supportive care in ALS and outlines the current guidance and evidence for these strategies.

Non-Motor Symptoms in Patients Suffering from Motor Neuron Diseases

Background

The recently postulated “disease spreading hypothesis” has gained much attention, especially for Parkinson’s disease (PD). The various non-motor symptoms (NMS) in neurodegenerative diseases would be much better explained by this hypothesis than by the degeneration of disease-specific cell populations. Motor neuron disease (MND) is primarily known as a group of diseases with a selective loss of motor function. However, recent evidence suggests disease spreading into non-motor brain regions also in MND. The aim of this study was to comprehensively detect NMS in patients suffering from MND.

Methods

We used a self-rating questionnaire including 30 different items of gastrointestinal, autonomic, neuropsychiatric, and sleep complaints [NMS questionnaire (NMSQuest)], which is an established tool in PD patients. 90 MND patients were included and compared to 96 controls.

Results

In total, MND patients reported significantly higher NMS scores (median: 7 points) in comparison to controls (median: 4 points). Dribbling, impaired taste/smelling, impaired swallowing, weight loss, loss of interest, sad/blues, falling, and insomnia were significantly more prevalent in MND patients compared to controls. Interestingly, excessive sweating was more reported in the MND group. Correlation analysis revealed an increase of total NMS score with disease progression.

Conclusion

NMS in MND patients seemed to increase with disease progression, which would fit with the recently postulated “disease spreading hypothesis.” The total NMS score in the MND group significantly exceeded the score for the control group, but only 8 of the 30 single complaints of the NMSQuest were significantly more often reported by MND patients. Dribbling, impaired swallowing, weight loss, and falling could primarily be connected to motor neuron degeneration and declared as motor symptoms in MND.

Pain in Neurodegenerative Disease: Current Knowledge and Future Perspectives

Neurodegenerative diseases are going to increase as the life expectancy is getting longer. The management of neurodegenerative diseases such as Alzheimer's disease (AD) and other dementias, Parkinson's disease (PD) and PD related disorders, motor neuron diseases (MND), Huntington's disease (HD), spinocerebellar ataxia (SCA), and spinal muscular atrophy (SMA), is mainly addressed to motor and cognitive impairment, with special care to vital functions as breathing and feeding. Many of these patients complain of painful symptoms though their origin is variable, and their presence is frequently not considered in the treatment guidelines, leaving their management to the decision of the clinicians alone. However, studies focusing on pain frequency in such disorders suggest a high prevalence of pain in selected populations from 38 to 75% in AD, 40% to 86% in PD, and 19 to 85% in MND. The methods of pain assessment vary between studies so the type of pain has been rarely reported. However, a prevalent nonneuropathic origin of pain emerged for MND and PD. In AD, no data on pain features are available. No controlled therapeutic trials and guidelines are currently available. Given the relevance of pain in neurodegenerative disorders, the comprehensive understanding of mechanisms and predisposing factors, the application and validation of specific scales, and new specific therapeutic trials are needed.