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

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-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.