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

The role of statins in amyotrophic lateral sclerosis: protective or not?

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of motor neurons characterized by muscle weakness, muscle twitching, and muscle wasting. ALS is regarded as the third-most frequent neurodegenerative disease, subsequent to Alzheimer's disease (AD) and Parkinson's disease (PD). The World Health Organization (WHO) in 2007 declared that prolonged use of statins may induce development of ALS-like syndrome and may increase ALS risk. Subsequently, different studies have implicated statins in the pathogenesis of ALS. In contrast, results from preclinical and clinical studies highlighted the protective role of statins against ALS neuropathology. Recently, meta-analyses and systematic reviews illustrated no association between long-term use of statins and ALS risk. These findings highlighted controversial points regarding the effects of statins on ALS pathogenesis and risk. The neuroprotective effects of statins against the development and progression of ALS may be mediated by regulating dyslipidemia and inflammatory changes. However, the mechanism for induction of ALS neuropathology by statins may be related to the dysregulation of liver X receptor signaling (LXR) signaling in the motor neurons and reduction of cholesterol, which has a neuroprotective effect against ALS neuropathology. Nevertheless, the exact role of statins on the pathogenesis of ALS was not fully elucidated. Therefore, this narrative review aims to discuss the role of statins in ALS neuropathology.

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.

Management of amyotrophic lateral sclerosis in clinical practice: Results of the expert consensus using the Delphi methodology

Amyotrophic lateral sclerosis (ALS) is a rare disease characterized by a progressive and irreversible degeneration of upper and lower motor neurons leading to death. In France, limited data exist describing the criteria used in clinical practice for diagnosis and follow-up, and how novel therapies may fit in. The objective of this Delphi panel was to obtain an overview of current French practices in ALS diagnosis, management, and follow-up by determining the scales and criteria used in clinical practice outside of clinical trials, as well as the place of a future treatment like AMX0035, acting on endoplasmic reticulum (ER) stress and mitochondrial dysfunction, in the current therapeutic strategies. A questionnaire was administered to 24 ALS healthcare providers practicing in ALS centers in France. Two rounds of remote voting were organized, before proposition of final consensus statements. Consensus was considered reached when at least 66% of the voters agreed. Consensus were obtained to define the new Gold Coast criteria as the ones used in clinical practice to establish the diagnosis of ALS, thus replacing the revised El Escorial criteria, considered too complex and now mainly used to characterize the patient populations to be included in clinical trials. The clinical factors considered to establish ALS diagnosis are mainly the demonstration of progression of the motor deficit and elimination of differential diagnoses. The ALSFRS-R scale is used in daily clinical practice to assess patient's functional impairment in terms of number of points lost, with the bulbar, respiratory, and fine motor subscores being the most important to evaluate independently. A critical medical need was identified regarding the provision of new therapeutic alternatives in ALS. The panel members would support the earliest management of patients. In this landscape, based on data from a very encouraging phase II (Centaur trial), AMX0035 represents a new tool of choice in current treatment strategies for all patients for whom experts are confident in the diagnosis of ALS, in combination with riluzole. These results will need to be confirmed by the ongoing phase III trial (Phoenix trial).

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.

Evidence-based position paper on Physical and Rehabilitation Medicine practice for people with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease that affects both upper and lower motor neurons and is fatal in its course. This evidence-based position paper represents the official position of the UEMS PRM Section. The aim of the paper is to define the role of the physical and rehabilitation medicine (PRM) physician and PRM professional practice for people with ALS. A systematic review of the literature and a consensus procedure by means of a Delphi process have been performed involving the delegates of all European countries represented in the UEMS PRM Section. The systematic literature review is reported together with thirty-two recommendations resulting from the Delphi procedure. The responsibility of the PRM physician is functional assessment of persons with ALS and delivering the optimal and most effective PRM program of care. The rehabilitation program of patients with ALS should be delivered and monitored by the multiprofessional team, with the PRM physician as principal coordinator.

Corneal Confocal Microscopy to Image Small Nerve Fiber Degeneration: Ophthalmology Meets Neurology

Neuropathic pain has multiple etiologies, but a major feature is small fiber dysfunction or damage. Corneal confocal microscopy (CCM) is a rapid non-invasive ophthalmic imaging technique that can image small nerve fibers in the cornea and has been utilized to show small nerve fiber loss in patients with diabetic and other neuropathies. CCM has comparable diagnostic utility to intraepidermal nerve fiber density for diabetic neuropathy, fibromyalgia and amyloid neuropathy and predicts the development of diabetic neuropathy. Moreover, in clinical intervention trials of patients with diabetic and sarcoid neuropathy, corneal nerve regeneration occurs early and precedes an improvement in symptoms and neurophysiology. Corneal nerve fiber loss also occurs and is associated with disease progression in multiple sclerosis, Parkinson's disease and dementia. We conclude that corneal confocal microscopy has good diagnostic and prognostic capability and fulfills the FDA criteria as a surrogate end point for clinical trials in peripheral and central neurodegenerative diseases.

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.

Reproductive History and Age of Onset for Women Diagnosed with Amyotrophic Lateral Sclerosis: Data from the National ALS Registry: 2010-2018

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurological disease of largely unknown etiology with no cure. The National ALS Registry is a voluntary online system that collects demographic and reproductive history (females only) data from patients with ALS. We will examine the association between demographic and reproductive history among female patients aged >18 years and various ages of onset for ALS.

METHODS

Data from a cross-sectional study were collected and examined for 1,018 female ALS patients. Patient characteristics examined were demographics including race, BMI, and familial history of ALS. Among patients, information on reproductive history, including age at menopause, ever pregnant, and age at first pregnancy was collected. Unadjusted and adjusted logistic regression models were used to estimate OR and 95% CI in this study.

RESULTS

Women were more likely to be diagnosed with ALS before age 60 if they were nonwhite (p = 0.015), had attended college (p = 0.0012), had a normal BMI at age 40 (p < 0.0001), completed menopause before age 50 (p < 0.0001), and had never been pregnant (p = 0.046) in the univariate analysis. Women diagnosed with ALS before age 60 were also more likely to have limb site of onset (p < 0.0001). In the multivariate analysis, those who completed menopause before age 50 were more likely to be diagnosed with ALS before age 60 (OR = 1.8, 95% CI: 1.4-2.3) compared with women who completed menopause at or after age 50, after controlling for race, ever pregnant, age at first pregnancy, family history of ALS, education status, smoking history, and BMI at age 40. For women who were diagnosed with ALS before age 50, the odds of them entering menopause before age 50 climb to 48.7 (95% CI: 11.8, 200.9). The mean age of ALS diagnosis for women who completed menopause before age 50 was 58 years and 64 years for women who entered menopause after age 50 (p < 0.0001).

CONCLUSION

Women who reported completing menopause before age 50 were significantly more likely to be diagnosed with ALS before age 60 compared with those who reported entering menopause after age 50. More research is needed to determine the relationship between female reproductive history, especially regarding endogenous estrogen exposure and early-onset ALS.

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 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.