Épidémiologie de la SLA

Potential of neuroimaging as a biomarker in amyotrophic lateral sclerosis: from structure to metabolism

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motor neuron degeneration. The development of ALS involves metabolite alterations leading to tissue lesions in the nervous system. Recent advances in neuroimaging have significantly improved our understanding of the underlying pathophysiology of ALS, with findings supporting the corticoefferent axonal disease progression theory. Current studies on neuroimaging in ALS have demonstrated inconsistencies, which may be due to small sample sizes, insufficient statistical power, overinterpretation of findings, and the inherent heterogeneity of ALS. Deriving meaningful conclusions solely from individual imaging metrics in ALS studies remains challenging, and integrating multimodal imaging techniques shows promise for detecting valuable ALS biomarkers. In addition to giving an overview of the principles and techniques of different neuroimaging modalities, this review describes the potential of neuroimaging biomarkers in the diagnosis and prognostication of ALS. We provide an insight into the underlying pathology, highlighting the need for standardized protocols and multicenter collaborations to advance ALS research.

Minimizing the Diagnostic Delay in Amyotrophic Lateral Sclerosis: The Role of Nonneurologist Practitioners

Introduction

Amyotrophic lateral sclerosis (ALS), usually fatal in a few years, is a neurodegenerative disorder where the diagnostic delay, although variable according to the studies, remains too long. The main objective of this study was to determine the average time to diagnose ALS and the role of each physician, general practitioner (GP), or specialist (neurologist or not) involved in the management of these patients. The secondary objective was to propose some simple schemes to quickly identify an ALS suspicion with the aim to reduce this delay. Patients and Methods. This retrospective study evaluated the diagnostic delay (and other intermediate delays) of 90 ALS patients registered in the ALS Center of Bordeaux (France) in 2013. The main clinical signs encountered (and their order of appearance) were studied.

Results

The average diagnostic delay was 17 months, with a median diagnostic delay of 12 months. The average diagnostic delay was 2.7 months between the first symptoms and the first complaint to GP, followed by an additional 6.5 month delay before the patient's first visit to a neurologist. This period could be shortened, especially if GP performed additional tests quickly (p=0.01), as the time spent consulting various specialists often extends this crucial step. Overall, diagnostic delay accounted for 40% of the total duration of the disease progression.

Conclusion

In relation to total survival time, the diagnostic delay of ALS appears to be proportionately very long, sometimes longer than that observed in previous studies (because it also included the total delay to diagnostic or treatment initiation). The rapid execution of useful additional tests by the first medical doctor, often GP (with the help of a neurologist), considerably reduces the diagnostic delay. The central role of GP seems to be crucial in the management of patients with ALS. The main objective is, of course, to initiate appropriate treatment and care as soon as possible. Finally, based on our results, we also provide a short practical diagram to help nonneurologist practitioners to quickly discuss the diagnosis of ALS in case of some specific symptoms (“red flags”).

Amyotrophic Lateral Sclerosis and Primary Biliary Cirrhosis Overlap Syndrome: Two Cases Report

Amyotrophic lateral sclerosis (ALS) is a disease of which the underlying etiology and pathogenesis are unknown. Numerous data indicate an important role of the immune system and mitochondrial function in the disease. Primary biliary cirrhosis (PBC) is an autoimmune liver disease resulting from a combination of genetic and environmental risk factors. Patients with PBC develop innate and adaptive immune reactions against mitochondrial antigens. Therefore, common mechanisms could exist in both diseases. We present two cases of ALS with PBC to explore the relationship between the two diseases from the immunological and mitochondrial aspects. Further attention should be given to immune-modulating therapy in ALS patients.

Care management in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive and fatal neurodegenerative disease characterized by progressive weakness of voluntary muscles of movement as well as those for swallowing, speech and respiration. In the absence of curative treatment, care can improve quality of life, prolong survival, and support ALS patients and their families, and also help them to anticipate and prepare for the end of life. Multidisciplinary management in tertiary centers is recommended in close collaboration with general practitioners, home carers and a dedicated health network. Patients' follow-up deals mainly with motor impairment and physical disability, adaptation, nutrition and respiratory function. Involvement of palliative care as part of the multidisciplinary team management offers patients the possibility of discussing their end of life issues. This review summarizes the different aspects of ALS care, from delivering the diagnosis to the end of life, and the organization of its management.

The value of magnetic resonance imaging as a biomarker for amyotrophic lateral sclerosis: a systematic review

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal, rapidly progressive neurodegenerative disease that mainly affects the motor system. A number of potentially neuroprotective and neurorestorative disease-modifying drugs are currently in clinical development. At present, the evaluation of a drug's clinical efficacy in ALS is based on the ALS Functional Rating Scale Revised, motor tests and survival. However, these endpoints are general, variable and late-stage measures of the ALS disease process and thus require the long-term assessment of large cohorts. Hence, there is a need for more sensitive radiological biomarkers. Various sequences for magnetic resonance imaging (MRI) of the brain and spinal cord have may have value as surrogate biomarkers for use in future clinical trials. Here, we review the MRI findings in ALS, their clinical correlations, and their limitations and potential role as biomarkers.

METHODS

The PubMed database was screened to identify studies using MRI in ALS. We included general MRI studies with a control group and an ALS group and longitudinal studies even if a control group was lacking.

RESULTS

A total of 116 studies were analysed with MRI data and clinical correlations. The most disease-sensitive MRI patterns are in motor regions but the brain is more broadly affected.

CONCLUSION

Despite the existing MRI biomarkers, there is a need for large cohorts with long term MRI and clinical follow-up. MRI assessment could be improved by standardized MRI protocols with multicentre studies.

Epidemiological surveillance of amyotrophic lateral sclerosis in Saguenay region

OBJECTIVES

The Neuromuscular Registry of Saguenay-Lac-Saint-Jean (SLSJ), Québec, Canada was established for epidemiological surveillance of neuromuscular disorders including amyotrophic lateral sclerosis (ALS). The objectives of this study are to analyze the ALS clinical characteristics of the SLSJ population and to determine the incidence rate over time by five year periods since 1985.

METHODS

The Registry was validated by a review of the medical records maintained at the CSSS de Chicoutimi, the regional university hospital and, by the estimation of the number of hospitalizations for ALS patients using the Quebec Hospital inpatient database (MED-ECHO).

RESULTS

A total of 109 patients were included. Overall, the clinical features of ALS observed in SLSJ population are similar to those described in the literature. We observed a significant increase in the incidence rate of ALS during the 2005-2009 period compared with the previous periods. This is due to a significant increase in the incidence rate among the ≥65 years old group, from 4.68 per 100,000 persons/year (CI 95% 2.88-6.48) during 1985-2004 period to 12.22 (CI 95% 7.43-17.02) during 2005-2009 period.

CONCLUSION

Given the small size of the SLSJ population, a longer observation period will be needed to confirm a new steady state incidence of ALS in this region.

Rates of progression of weight and forced vital capacity as relevant measurement to adapt amyotrophic lateral sclerosis management for patient Result of a French multicentre cohort survey

OBJECTIVES

To compare survival, to describe the progression of anthropometry, pulmonary capacity and functioning in ALS (Amyotrophic Lateral Sclerosis) and to identify the most relevant variables to adapt ALS management for patients.

METHODS

A cohort study was performed in French ALS centres between January 2003 and July 2005. Eligible patients were treated by Riluzole and had a slow vital capacity (SVC) or a forced vital capacity (FVC) at least equal to 60%. Demographic, medical and ALS characteristics were registered. Manual Muscular Testing (MMT) and ALS Functional Rating Scale (ALSFRS) were performed. Kaplan Meier method was used to analyse survival. ALS progression was measured by the percentage weight, FVC, SVC, MMT and ALSFRS loss and was analysed as longitudinal data using mixed model.

RESULTS

Three hundred and eighty three patients were included. The median survival since ALS diagnosis was 2.34 years (95%CI 2.10-2.65). Mixed model analyses revealed a more significant worsening progression of weight and FVC loss for bulbar onset. The drop of ALSFRS and SVC is similar whatever the ALS forms.

CONCLUSIONS

Rates of progression of weight and FVC should be regularly watched over to support neurologists to adapt ALS management for patients.

Familial amyotrophic lateral sclerosis in Alberta, Canada

Systematic review data demonstrate that 5% of ALS cases are familial (FALS). Causative superoxide dismutase-1 (SOD1) mutations are identified in 10-20% of FALS. Few reports of FALS epidemiology exist in Canada. We completed a retrospective review of all FALS cases within the province of Alberta between 2002 and 2011. Descriptive summaries of genotypes identified and calculation of prevalences were performed. We reviewed 946 clinic database records and 49 subjects with FALS were identified (5.2%). Clinic charts for 47/49 were available and reviewed. Causative SOD1 mutations were observed in 17/47 (36%). The SOD1 I113T mutation was identified in 11/47 unrelated patients and was associated with a less variable survival than previously reported. The period and point prevalences of FALS in Alberta are approximately 2.05 per 100,000 (95% CI 1.51-2.73) and 4.68 per 1,000,000 (95% CI 2.42-8.18), respectively. In conclusion, we report 47 cases of FALS in Alberta over the past decade. The proportion of SOD1-positive FALS cases is higher than reported elsewhere. The high proportion of I113T mutations is comparable to that previously observed in the adjacent province of British Columbia.

Amyotrophic lateral sclerosis in Sardinia, insular Italy, 1995-2009

Recent genetic studies suggest a Sardinian type of amyotrophic lateral sclerosis (ALS). Thus, ALS incidence, prevalence and survival were investigated in a large population of Sardinians aimed to disclose population-specific patterns and their temporal changes. This is a population-based incidence and prevalence study in northern and central Sardinia, insular Italy (over 700,000 population). Incidence rates were computed for the time interval 1995-2009 and by quinquennia. Prevalence was computed for prevalence days 31 December 2004 and 2009. Onset-based survival for 1995-2009 is also reported. All ALS patients (El Escorial Criteria) in the study area were retrospectively included. The ALS crude incidence from 2005-2009 was 2.5 (95 % CIs: 0.1, 4.9), 3.4 in men and 1.6 in women. Onset occurred most often between the age of 65-74 years in men and 55-64 years in women. The ALS incidence tended to increase over the period 1995-2009. The mean age at onset was 61.7 years with no difference based on gender, varying significantly from 59.9 years in 1995-1999 to 63.9 years in 2005-2009. On December 31, 2009, the ALS crude prevalence was 10.8 per 100,000 (95 % CIs: 8.6, 13.1), 13.8 in men and 8.0 in women, whereas it was 6.3 per 100,000 (95 % CIs: 4.1, 8.6) on December 31, 2004 (M:F ratio of 0.95). Mean survival from onset was 37.0 months, with no difference based on gender, and a tendency to decrease during the period 1995-2009, in relation to type and age of onset. The population-based incidence and prevalence data of ALS in Sardinians indicate an increase of the disease occurrence over the past 40 years, providing support for a population-specific variant of ALS in Sardinia.

Alterations of signaling pathways in muscle tissues of patients with amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS), a degenerative disorder of the central nervous system, manifests as progressive weakening of muscles. The diagnosis and prognosis of ALS are often unclear, so useful biomarkers are needed.

METHODS

Total proteins were extracted from muscle samples from 36 ALS, 17 spinal muscular atrophy (SMA), and 36 normal individuals. The expression levels of 134 proteins and phosphoproteins were assessed using protein pathway array analysis.

RESULTS

Seventeen proteins were differentially expressed between ALS and normal muscle, and 9 proteins were differentially expressed between ALS and SMA muscle. The low-level expression of Akt and Factor XIIIB correlates with unfavorable survival, and the risk score calculated based on these proteins predicts the survival of each individual patient.

CONCLUSIONS

Some proteins could be selected as clinically useful biomarkers. Specifically, Akt and Factor XIIIB were found to be promising biomarkers for estimating prognosis in ALS.

Modifying effect of arterial hypertension on amyotrophic lateral sclerosis

Given the high oxygen consumption of motor neurons, we sought to assess the frequency and prognostic value of arterial hypertension (affecting brain's oxygen supply) in amyotrophic lateral sclerosis (ALS). We consecutively and prospectively included all ALS patients with regular medical follow-up and documented blood pressure measurements and monitored them until death. Vascular factors diagnosed prior to the onset of motor signs in ALS patients were compared with those in a stratified, age- and gender-matched case-control population. The severity of leukoaraiosis on magnetic resonance imaging (MRI) was blindly assessed. Post mortem examinations were performed when authorized. Compared with controls (n = 408), the 102 ALS patients were significantly more likely to display hypertension (41-57%) and current smoking (15-26%). The number of years of hypertension was associated with survival (HR = 1.04 (1.01-1.07)). In a multivariate analysis, leukoaraiosis severity (HR = 1.214 (1.096-1.344)), current smoking (HR = 1.766 (1.085-2.872)) and low vital capacity (HR = 2.422 (1.266-4.633)) remained independent predictors of survival. Post mortem examinations revealed a greater frequency of leukoaraiosis in ALS patients (p = 0.02). In conclusion, the effect of chronic hypertension on survival might be exerted through abnormal neural perfusion. The higher frequency of recent hypertension in ALS patients may be due to a compensatory increase in blood pressure in response to a lower oxygen supply.

Concomitant rheumatoid arthritis and amyotrophic lateral sclerosis: report of two new cases and review of literature

To describe a rare association between rheumatoid arthritis (RA) and amyotrophic lateral sclerosis (ALS). Two new cases of patients with RA who developed amyotrophic lateral sclerosis (ALS), one receiving anti-TNFα agents, were reported. Only other five cases of this rare association have been previously described in literature. The simultaneous presence of the two diseases represents a difficult diagnostic challenge because RA may mimic some musculoskeletal symptoms of ALS. There is no evidence in favor of a common pathophysiologic mechanism, and thus the possibility of a fortuitous association must be raised. A neurotoxic side effect of various drugs for RA treatment could be considered. Casual or causal association remains a difficult choice. The possibility of a coincidental association must be raised but neurologic side effects of TNFα blockers lead to discussion.