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).

French National Protocol for genetic of amyotrophic lateral sclerosis

Relationships between genes and amyotrophic lateral sclerosis (ALS) have been widely accepted since the first studies highlighting pathogenic mutations in the SOD1 gene 30years ago. Over the last three decades, scientific literature has clearly highlighted the central role played by genetic factors in the disease, in both clinics and pathophysiology, as well as in therapeutics. This implies that health professionals who care for patients with ALS are increasingly faced with patients and relatives eager to have answers to questions related to the role of genetic factors in the occurrence of the disease and the risk for their relatives to develop ALS. In order to address these public health issues, the French ALS network FILSLAN proposed to the Haute Autorité de santé (HAS) the drafting of a French National Protocol (PNDS) on ALS genetics. This PNDS was developed according to the "method for developing a national diagnosis and care protocol for rare diseases" published by the HAS in 2012 (methodological guide for PNDS available on the HAS website: http://www.has-sante.fr/). This document aims to provide the most recent data on the role of genes in ALS and to detail the implications for diagnosis and care.

Phenotypic variability in amyotrophic lateral sclerosis

Clinically, ALS phenotypes depend on the areas of the body that are affected, the different degrees of involvement of upper and lower motor neurons, the degrees of involvement of other systems, particularly cognition and behavior, and rates of progression. Phenotypic variability of ALS is characteristic and can be declined on the distribution of motor manifestations but also on the presence of extra-motor signs present in a variable manner in ALS patients. Neuropathologically, ALS is defined by the loss of UMN and LMN and the presence of two representative motor neuronal cytoplasmic inclusions, Bunina bodies and 43kDa Transactivation Response DNA Binding Protein (TDP-43) - positive cytoplasmic inclusions. The distribution of cytopathology and neuronal loss in patients is variable and this variability is directly related to phenotypic variability. Key regulators of phenotypic variability in ALS have not been determined. The functional decrement of TDP-43, and region-specific neuronal susceptibility to ALS, may be involved. Due to the selective vulnerability among different neuronal systems, lesions are multicentric, region-oriented, and progress at different rates. They may vary from patient to patient, which may be linked to the clinicopathological variability across patients.

Staging amyotrophic lateral sclerosis: A new focus on progression

Amyotrophic lateral sclerosis (ALS) is a heterogenous motoneuronal neurodegenerative condition with a panel of phenotypes exhibiting different clinical patterns. Two compounds are currently available for the treatment of ALS but the majority of trials have failed to show a positive effect on prognosis. One of the explanations which could be put forward involves the way efficacy is evaluated: clinicians agree that the ALSFRS-revised scale used in all trials does not fit with highlighting a positive effect. So, the development and validation of new tools allowing a reliable assessment of ALS has become a key issue in clinical research. Over the last three years, two functional scales (the King's College and MiToS staging systems) have been proposed. These scales rely on two different approaches to ALS: an anatomical and prognostic concept, and loss of autonomy. Both scales propose five stages. We will discuss below the contribution of these two scales to clinical evaluation and the questions which remain to be resolved in the future.

Hypermetabolism is a deleterious prognostic factor in patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

The aim of this study was to investigate patients with amyotrophic lateral sclerosis in order to determine their nutritional, neurological and respiratory parameters, and survival according to metabolic level.

METHODS

Nutritional assessment included resting energy expenditure (REE) measured by indirect calorimetry [hypermetabolism if REE variation (ΔREE) > 10%] and fat mass (FM) using impedancemetry. Neurological assessment included the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised score. Survival analysis used the Kaplan-Meier method and multivariate Cox model.

RESULTS

A total of 315 patients were analysed. Median age at diagnosis was 65.9 years and 55.2% of patients were hypermetabolic. With regard to the metabolic level (ΔREE: < 10%, 10-20% and >20%), patients with ΔREE > 20% initially had a lower FM(29.7% vs. 32.1% in those with ΔREE ≤10%; P = 0.0054). During follow-up, the median slope of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised tended to worsen more in patients with ΔREE > 20% (-1.4 vs. -1.0 points/month in those with ΔREE ≤10%; P = 0.07). Overall median survival since diagnosis was 18.4 months. ΔREE > 20% tended to increase the risk of dying compared with ΔREE ≤10% (hazard ratio, 1.33; P = 0.055). In multivariate analysis, an increased REE:FM ratio was independently associated with death (hazard ratio, 1.005; P = 0.001).

CONCLUSIONS

Hypermetabolism is present in more than half of patients with amyotrophic lateral sclerosis. It modifies the body composition at diagnosis, and patients with hypermetabolism >20% have a worse prognosis than those without hypermetabolism.

Classifications of neurogenetic diseases: An increasingly complex problem

Neurodegenerative disorders represent a wide group of diseases affecting the central and/or peripheral nervous system. Many of these disorders were described in the 19th century, but our genetic knowledge of them is recent (over the past 25 years). However, the continual discovery of disease-causing gene mutations has led to difficulties in the classification of these diseases. For this reason, our present proposals for updating and simplifying the classification of some of these conditions (Charcot-Marie-Tooth diseases, distal hereditary motor neuropathies, hereditary sensory and autonomic neuropathies, hereditary spastic ataxias, hereditary spastic paraplegias and hereditary spastic ataxias) are expounded here.

Epidemiology of amyotrophic lateral sclerosis: A review of literature

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of motor neurons, resulting in worsening weakness of voluntary muscles until death occurs from respiratory failure. The incidence of ALS in European populations is two to three people per year per 100,000 of the general population. In Europe, crude prevalences range from 1.1/100,000 population in Yugoslavia to 8.2/100,000 in the Faroe Islands. Major advances have been made in our understanding of the genetic causes of ALS, whereas the contribution of environmental factors has been more difficult to assess and large-scale studies have not yet revealed a replicable, definitive environmental risk factor. The only established risk factors to date are older age, male gender and a family history of ALS. Median survival time from onset to death is usually 3 years from the first appearance of symptoms. Older age and bulbar onset are consistently reported to have poorer outcomes. However, there are conflicting data regarding gender, diagnostic delay and El Escorial criteria. The rate of symptom progression has been revealed to be an independent prognostic factor. Psychosocial factors and impaired cognitive function are negatively related to ALS outcome, while nutritional status and respiratory function are also related to ALS prognosis. The effect of enteral nutrition on survival is still unclear, although noninvasive positive pressure ventilation (NIPPV) has been found to improve survival. These findings have relevant implications for the design of future trials.

Population-based epidemiology of amyotrophic lateral sclerosis (ALS) in an ageing Europe--the French register of ALS in Limousin (FRALim register)

BACKGROUND AND PURPOSE

The main objective of establishing the French register of amyotrophic lateral sclerosis (ALS) in the Limousin region (FRALim), was to assess the incidence of ALS, in this ageing region of Europe, over a 12-year period (2000-2011).

METHODS

Patients were included if they lived in Limousin at the time of diagnosis of ALS according to El Escorial revised criteria and were identified by at least one of the following sources: (i) the French national body coordinating ALS referral centres; (ii) public and private hospitals in the region; (iii) health insurance data related to long-term diseases.

RESULTS

The FRALim register identified 279 incident cases (2000-2011). The crude and European population standardized incidences of ALS were as high as 3.19/100,000 person-years of follow-up (95% CI 2.81-3.56) and 2.58/100,000 person-years of follow-up (95% CI 2.27-2.89) respectively. Median age at onset was 70.8 years (interquartile range 63.1-77.1). The standardized sex incidence ratio (male/female) was 1.3 overall, but 1.1 under the age of 65 years, 1.7 between 65 and 75 years and 1.9 above 75 years. The exhaustiveness of the register has been estimated at 98.4% (95% CI 95.6-99.4) by capture-recapture analysis.

CONCLUSION

It was possible for the first time in France to monitor accurately the incidence of ALS over a long time period. It appears to be in the upper range of data reported in western countries. Patterns displayed here might anticipate the epidemiology of ALS in ageing western countries.