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

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.

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.

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.

Fatigue in amyotrophic lateral sclerosis and correlated factors

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that leads to muscle weakness and paralysis. Fatigue is a disabling symptom, frequently reported in ALS, but remains under-investigated in this population. Thus, an accurate investigation of this symptom and possible associated factors in this clinical condition is needed to assist in the establishment of an adequate treatment approach.

OBJECTIVE

To investigate the presence of fatigue in individuals with ALS and possible factors correlated with this symptom.

METHODS

Sixty-five individuals with sporadic ALS participated in the present study. Demographic, clinical, and functional aspects were investigated. Evaluations involved the Fatigue Severity Scale (FSS), ALS Functional Scale (ALSRFS-R), and Quality of Life (QoL) questionnaire (ALSAQ-40). Descriptive and correlation analyses were performed with SPSS statistical program for Windows version 19.0 (IBM Corp., Armonk, NY, USA).

RESULTS

Among the 65 individuals evaluated, 44.6% (n = 29) presented fatigue based on the FSS. The mean fatigue intensity was 5.4 ± 1.2 and only 10.4% used a specific medication for fatigue. Differences between the groups with and without fatigue were found regarding sex (p = 0.049), pain intensity (p = 0.026), functioning (p = 0.004), disease severity (p = 0.029), and QoL (p = 0.000). Fatigue was correlated with pain intensity (r = 0.425; p = 0.001), muscle strength (r = - 0.356; p = 0.004), functioning (r = - 0.363; p = 0.003), and QoL (r = 0.481; p = 0.000). No correlations were found with age, time since diagnosis, cramps, or other mobility parameters.

CONCLUSIONS

Fatigue is a common symptom among individuals with ALS and may be present in all stages of the disease. This symptom was correlated with worse functioning, poorer QoL, greater pain intensity, disease severity, muscle weakness, and the female sex in individuals with 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.

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.

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.

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.

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.

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.