Clinical, paraclinical and outcome features of 166 patients with acute anti-GQ1b antibody syndrome.

BACKGROUND & PURPOSE: In this retrospective study, we aimed at defining the clinical, paraclinical and outcome features of acute neurological syndromes associated with anti-GQ1b antibodies. RESULTS: We identified 166 patients with neurological symptoms appearing in less than 1 month and anti-GQ1b antibodies in serum between 2012 and 2022. Half were female (51%), mean age was 50 years (4-90), and the most frequent clinical features were areflexia (80% of patients), distal upper and lower limbs sensory symptoms (78%), ophthalmoplegia (68%), sensory ataxia (67%), limb muscle weakness (45%) and bulbar weakness (45%). Fifty-three patients (32%) presented with complete (21%) and incomplete (11%) Miller Fisher syndrome (MFS), thirty-six (22%) with Guillain-Barre syndrome (GBS), one (0.6%) with Bickerstaff encephalitis (BE), and seventy-three (44%) with mixed MFS, GBS & BE clinical features. Nerve conduction studies were normal in 46% of cases, showed demyelination in 28%, and axonal loss in 23%. Anti-GT1a antibodies were found in 56% of cases, increased cerebrospinal fluid protein content in 24%, and Campylobacter jejuni infection in 7%. Most patients (83%) were treated with intravenous immunoglobulins, and neurological recovery was complete in 69% of cases at 1 year follow-up. One patient died, and 15% of patients relapsed. Age > 70 years, initial Intensive Care Unit (ICU) admission, and absent anti-GQ1b IgG antibodies were predictors of incomplete recovery at 12 months. No predictors of relapse were identified. CONCLUSION: This study from Western Europe shows acute anti-GQ1b antibody syndrome presents with a large clinical phenotype, a good outcome in 2/3 of cases, and frequent relapses.

Benefits of Individualized Training in Fatigued Patients with Multiple Sclerosis.

INTRODUCTION: Chronic fatigue is the most common and debilitating symptom in people with multiple sclerosis (PwMS). Recently, exercise has been proven to alleviate chronic fatigue and improve physical functions. Tailoring the training intervention to the potential fatigue causes could optimize the beneficial effects of training on fatigue. The objective of this study was to compare the effectiveness of an individualized (IND) vs a traditional (TRAD) exercise intervention in reducing chronic fatigue. METHODS: Twenty-nine PwMS with high chronic fatigue were randomly assigned to 12 weeks of either a TRAD or IND exercise intervention. TRAD comprised aerobic and resistance exercises according to the guidelines for PwMS. IND specifically addressed identified individual weaknesses. Participants visited the laboratory before and after training for the following assessments: patient reported outcomes (fatigue, quality of life, depression questionnaires), incremental cycling test (V̇O2peak), and cycling fatigue test (maximal voluntary contraction, MVC; rating of perceived exertion, RPE). RESULTS: Similar improvements in fatigue, depression and quality of life were observed between groups (p > 0.05). Compared to TRAD, IND induced a significant greater increase in V̇O2peak (+21.0 ± 13.9 vs 6.8 ± 11.5%, p < 0.05) and a greater reduction in RPE at a given submaximal intensity (-30.3 ± 18.9 vs -12.1 ± 20.4%, p < 0.001), whereas MVC increased similarly in both groups (p > 0.05). CONCLUSIONS: Although tailored exercise improved similarly fatigue and other subjective parameters (depression, quality of life, sleep quality) compared to than traditional exercise interventions, prescribing an individualized intervention led to greater improvement in V̇O2peak (but not maximal strength) and perception of effort. This may have positive functional consequences for patients.

Congenital myasthenic syndromes in adults: clinical features, diagnosis and long-term prognosis.

Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous diseases caused by mutations affecting neuromuscular transmission. Even if the first symptoms mainly occur during childhood, adult neurologists must confront this challenging diagnosis and manage these patients throughout their adulthood. However, long-term follow-up data from large cohorts of CMS patients are lacking and the long-term prognosis of these patients is largely unknown. We report the clinical features, diagnostic difficulties, and long-term prognosis of a French nationwide cohort of 235 adult patients with genetically confirmed CMS followed in 23 specialized neuromuscular centres. Data were retrospectively analysed. Of the 235 patients, 123 were female (52.3%). The diagnosis was made in adulthood in 139 patients, 110 of whom presented their first symptoms before the age of 18. Mean follow-up time between first symptoms and last visit was 34 years (SD = 15.1). Pathogenic variants were found in 19 disease-related genes. CHRNE-low expressor variants were the most common (23.8%), followed by variants in DOK7 (18.7%) and RAPSN (14%). Genotypes were clustered into four groups according to the initial presentation: ocular group (CHRNE-LE, CHRND, FCCMS), distal group (SCCMS), limb-girdle group (RAPSN, COLQ, DOK7, GMPPB, GFPT1), and a variable-phenotype group (MUSK, AGRN). The phenotypical features of CMS did not change throughout life. Only four genotypes had a proportion of patients requiring intensive care unit (ICU) admission that exceeded 20%: RAPSN (54.8%), MUSK (50%), DOK7 (38.6%) and AGRN (25.0%). In RAPSN and MUSK patients most ICU admissions occurred before age 18 years and in DOK7 and AGRN patients at or after 18 years of age. Different patterns of disease course (stability, improvement and progressive worsening) may succeed one another in the same patient throughout life, particularly in AGRN, DOK7 and COLQ. At the last visit, 55% of SCCMS and 36.3% of DOK7 patients required ventilation; 36.3% of DOK7 patients, 25% of GMPPB patients and 20% of GFPT1 patients were wheelchair-bound; most of the patients who were both wheelchair-bound and ventilated were DOK7 patients. Six patients died in this cohort. The positive impact of therapy was striking, even in severely affected patients. In conclusion, even if motor and/or respiratory deterioration could occur in patients with initially moderate disease, particularly in DOK7, SCCMS and GFPT1 patients, the long-term prognosis for most CMS patients was favourable, with neither ventilation nor wheelchair needed at last visit. CHRNE patients did not worsen during adulthood and RAPSN patients, often severely affected in early childhood, subsequently improved.

High-Efficacy Therapy Discontinuation vs Continuation in Patients 50 Years and Older With Nonactive MS.

Importance: A recent randomized clinical trial concluded that discontinuing medium-efficacy therapy might be a reasonable option for older patients with nonactive multiple sclerosis (MS), but there is a lack of data on discontinuing high-efficacy therapy (HET). In younger patients, the discontinuation of natalizumab and fingolimod is associated with a risk of rebound of disease activity. Objective: To determine whether discontinuing HET in patients 50 years and older with nonactive MS is associated with an increased risk of relapse compared with continuing HET. Design, Setting, and Participants: This observational cohort study used data from 38 referral centers from the French MS registry (Observatoire Français de la Sclérose en Plaques [OFSEP] database). Among 84704 patients in the database, data were extracted for 1857 patients 50 years and older with relapsing-remitting MS treated by HET and with no relapse or magnetic resonance imaging activity for at least 2 years. After verification of the medical records, 1620 patients were classified as having discontinued HET or having remained taking treatment and were matched 1:1 using a dynamic propensity score (including age, sex, disease phenotype, disability, treatment of interest, and time since last inflammatory activity). Patients were included from February 2008 to November 2021, with a mean (SD) follow-up of 5.1 (2.9) years. Data were extracted in June 2022. Exposures: Natalizumab, fingolimod, rituximab, and ocrelizumab. Main Outcomes and Measures: Time to first relapse. Results: Of 1620 included patients, 1175 (72.5%) were female, and the mean (SD) age was 54.7 (4.8) years. Among the 1452 in the HET continuation group and 168 in the HET discontinuation group, 154 patients in each group were matched using propensity scores (mean [SD] age, 57.7 [5.5] years; mean [SD] delay since the last inflammatory activity, 5.6 [3.8] years; mean [SD] follow-up duration after propensity score matching, 2.5 [2.1] years). Time to first relapse was significantly reduced in the HET discontinuation group compared with the HET continuation group (hazard ratio, 4.1; 95% CI, 2.0-8.5; P < .001) but differed between HETs, with a hazard ratio of 7.2 (95% CI, 2.1-24.5; P = .001) for natalizumab, 4.5 (95% CI, 1.3-15.5; P = .02) for fingolimod, and 1.1 (95% CI, 0.3-4.8; P = .85) for anti-CD20 therapy. Conclusion and Relevance: As in younger patients, in patients 50 years and older with nonactive MS, the risk of relapse increased significantly after stopping HETs that impact immune cell trafficking (natalizumab and fingolimod). There was no significant increase in risk after stopping HETs that deplete B-cells (anti-CD20 therapy). This result may inform decisions about stopping HETs in clinical practice.

Control of disease activity with large extended-interval dosing of rituximab/ocrelizumab in highly active pediatric multiple sclerosis.

Recent studies in adults suggested that extended-interval dosing of rituximab/ocrelizumab (RTX/OCR) larger than 12 months was safe and could improve safety. This was an observational cohort study of very active pediatric-onset multiple sclerosis (PoMS) (median (range) age, 16 (12-17) years) treated with RTX/OCR with 6 month standard-interval dosing (n = 9) or early extended-interval dosing (n = 12, median (range) interval 18 months (12-25)). Within a median (range) follow-up of 31 (12-63) months after RTX/OCR onset, one patient (standard-interval) experienced relapse and no patient showed disability worsening or new T2-weighted lesions. This study suggests that the effectiveness of RTX/OCR is maintained with a median extended-interval dosing of 18 months in patients with very active PoMS.

Hereditary transthyretin amyloidosis in middle-aged and elderly patients with idiopathic polyneuropathy: a nationwide prospective study.

BACKGROUND: Hereditary transthyretin amyloidosis (ATTRv) is an adult-onset autosomal dominant disease resulting from TTR gene pathogenic variants. ATTRv often presents as a progressive polyneuropathy, and effective ATTRv treatments are available. METHODS: In this 5 year-long (2017-2021) nationwide prospective study, we systematically analysed the TTR gene in French patients with age >50 years with a progressive idiopathic polyneuropathy. RESULTS: 553 patients (70% males) with a mean age of 70 years were included. A TTR gene pathogenic variant was found in 15 patients (2.7%), including the Val30Met TTR variation in 10 cases. In comparison with patients with no TTR gene pathogenic variants (n = 538), patients with TTR pathogenic variants more often presented with orthostatic hypotension (53 vs. 21%, p = .007), significant weight loss (33 vs 11%, p = .024) and rapidly deteriorating nerve conduction studies (26 vs. 8%, p = .03). ATTRv diagnosis led to amyloid cardiomyopathy diagnosis in 11 cases, ATTRv specific treatment in all cases and identification of 15 additional ATTRv cases among relatives. CONCLUSION: In this nationwide prospective study, we found ATTRv in 2.7% of patients with age >50 years with a progressive polyneuropathy. These results are highly important for the early identification of patients in need of disease-modifying treatments.

Comparison of 2 Methods for Estimating Multiple Sclerosis-Related Mortality.

BACKGROUND AND OBJECTIVES: Determining whether multiple sclerosis (MS) causes death is challenging. Our objective was to contrast 2 frameworks to estimate probabilities of death attributed to MS (PMS) and other causes (Pother): the cause-specific framework (CSF), which requires the causes of death, and the excess mortality framework (EMF), which does not. METHODS: We used data from the Observatoire Français de la Sclérose en Plaques (OFSEP, n = 37,524) and from a comparative subset where causes of death were available (4,004 women with relapsing-onset MS [R-MS]). In CSF, the probabilities were estimated using the Aalen-Johansen method. In EMF, they were estimated from the excess mortality hazard, which is the additional mortality among patients with MS as compared with the expected mortality in the matched general population. PMS values were estimated at 30 years of follow-up, (1) with both frameworks in the comparative subset, by age group at onset, and (2) with EMF only in the OFSEP population, by initial phenotype, sex, and age at onset. RESULTS: In the comparative subset, the estimated 30-year PMS values were greater using EMF than CSF: 10.9% (95% CI 8.3-13.6) vs 8.7% (6.4-11.8) among the youngest and 20.4% (11.3-29.5) vs 16.2% (8.7-30.2) for the oldest groups, respectively. In the CSF, probabilities of death from unknown causes ranged from 1.5% (0.7-3.0) to 6.4% (2.5-16.4), and even after their reallocation, PMS values remained lower with CSF than with EMF. The estimated probabilities of being alive were close using the 2 frameworks, and the estimated POther (EMF vs CSF) was 2.6% (2.5-2.6) vs 2.1% (1.2-3.9) and 18.1% (16.9-19.3) vs 26.4% (16.5-42.2), respectively, for the youngest and oldest groups. In the OFSEP population, the estimated 30-year PMS values ranged from 7.5% (6.4-8.7) to 24.0% (19.1-28.9) in patients with R-MS and from 25.4% (21.1-29.7) to 36.8% (28.3-45.3) in primary progressive patients, depending on sex and age. DISCUSSION: EMF has the great advantage of not requiring death certificates, their quality being less than optimal. Conceptually, it also seems more relevant because it avoids having to state, for each individual, whether death was directly or indirectly caused by MS or whether it would have occurred anyway, which is especially difficult in such chronic diseases.

A Comprehensive Evaluation of Multiple Sclerosis-Related Fatigue with a Special Focus on Fatigability.

INTRODUCTION: Fatigue is the most common and disabling symptom in multiple sclerosis (MS), being reported by 55% to 78% of patients with MS (PwMS). Etiology of MS-related fatigue remains poorly understood, but an increased neuromuscular fatigability (i.e., greater loss of torque during exercise) could contribute to this phenomenon. This study aimed to characterize the correlates of MS-related fatigue in PwMS using a comprehensive group of physiological and psychosocial measures, with a particular focus on fatigability. METHODS: Forty-two relapsing-remitting PwMS and 20 healthy subjects were recruited. PwMS were assigned in two groups (high (HF) and low (LF) fatigue) based on two fatigue questionnaires (Fatigue Severity Scale and Modified Fatigue Impact Scale). The main outcomes of this study are derived from incremental cycling completed to task failure (i.e., inability to pedal around 60 rpm). Maximal voluntary contraction (MVC), rating of perceived exertion, and central and peripheral parameters measured using transcranial magnetic and peripheral nerve stimulation were assessed in the knee extensor muscles before, during, and after the fatiguing task. Other potential correlates of fatigue were also tested. RESULTS: MVC torque decreased to a greater extent for the HF group than LF group after the third common stage of the incremental fatiguing exercise (-15.7% ± 6.6% vs -5.9% ± 13.0%, P < 0.05), and this occurred concurrently with a higher rating of perceived exertion for HF (11.8 ± 2.5 vs 9.3 ± 2.6, P < 0.05). Subjective parameters (depression, quality of life) were worse for HF compared with LF and healthy subjects ( P < 0.001). Moreover, MVC torque loss at the final common stage and maximal heart rate explained 29% of the variance of the Modified Fatigue Impact Scale. CONCLUSIONS: These results provide novel insight into the relationship between MS-related fatigue and fatigability among PwMS. The HF group exhibited greater performance fatigability, likely contributing to a higher perceived exertion than the LF group when measured during a dynamic task.

Clinical and electrophysiological characteristics of women with X-linked Charcot-Marie-Tooth disease.

BACKGROUND: X-Linked Charcot-Marie-Tooth disease type 1 (CMTX1) is characterized by gender differences in clinical severity. Women are usually clinically affected later and less severely than men. However, their clinical presentation appears to be heterogenous. Our aim was to extend the phenotypic description in a large series of women with CMTX1. METHODS: We retrospectively evaluated 263 patients with CMTX1 from 11 French reference centers. Demographic, clinical, and nerve conduction data were collected. The severity was assessed by CMT Examination Score (CMTES) and Overall Neuropathy Limitations Scale (ONLS) scores. We looked for asymmetrical strength, heterogeneous motor nerve conduction velocity (MNCV), and motor conduction blocks (CB). RESULTS: The study included 137 women and 126 men from 151 families. Women had significantly more asymmetric motor deficits and MNCV than men. Women with an age of onset after 19 years were milder. Two groups of women were identified after 48 years of age. The first group represented 55%, with women progressing as severely as men, however, with a later onset age. The second group had mild or no symptoms. Some 39% of women had motor CB. Four women received intravenous immunoglobulin before being diagnosed with CMTX1. CONCLUSIONS: We identified two subgroups of women with CMTX1 who were over 48 years of age. Additionally, we have demonstrated that women with CMTX can exhibit an atypical clinical presentation, which may result in misdiagnosis. Therefore, in women presenting with chronic neuropathy, the presence of clinical asymmetry, heterogeneous MNCV, and/or motor CB should raise suspicion for X-linked CMT, particularly CMTX1, and be included in the differential diagnosis.

Anti-AGO1 Antibodies Identify a Subset of Autoimmune Sensory Neuronopathy.

BACKGROUND AND OBJECTIVES: Autoantibodies (Abs) improve diagnosis and treatment decisions of idiopathic neurologic disorders. Recently, we identified Abs against Argonaute (AGO) proteins as potential autoimmunity biomarkers in neurologic disorders. In this study, we aim to reveal (1) the frequency of AGO1 Abs in sensory neuronopathy (SNN), (2) titers and IgG subclasses, and (3) their clinical pattern including response to treatment. METHODS: This retrospective multicentric case/control study screened 132 patients with SNN, 301 with non-SNN neuropathies, 274 with autoimmune diseases (AIDs), and 116 healthy controls (HCs) for AGO1 Abs through ELISA. Seropositive cases were also tested for IgG subclasses, titers, and conformation specificity. RESULTS: AGO1 Abs occurred in 44 patients, comprising significantly more of those with SNN (17/132 [12.9%]) than those with non-SNN neuropathies (11/301 [3.7%]; p = 0.001), those with AIDs (16/274 [5.8%]; p = 0.02), or HCs (0/116; p < 0.0001). Ab titers ranged from 1:100 to 1:100,000. IgG subclass was mainly IgG1, and 11/17 AGO1 Ab-positive SNN (65%) had a conformational epitope. AGO1 Ab-positive SNN was more severe than AGO1 Ab-negative SNN (e.g., SNN score: 12.2 vs 11.0, p = 0.004), and they more frequently and more efficiently responded to immunomodulatory treatments than AGO1 Ab-negative SNN (7/13 [54%] vs 6/37 [16%], p = 0.02). Regarding the type of treatments more precisely, this significant difference was confirmed for the use of IV immunoglobulins (IVIg) but not for steroids or second-line treatments. Multivariate logistic regression adjusted for potential confounders showed that AGO1 Ab positivity was the only predictor of response to treatment (OR 4.93, 1.10-22.24 95% CI, p = 0.03). DISCUSSION: Although AGO Abs are not specific for SNN, based on our retrospective data, they may identify a subset of cases with SNN with more severe features and a possibly better response to IVIg. The significance of AGO1 Abs in clinical practice needs to be explored on a larger series.

Frontal headache in a patient with right temporal epilepsy: A video-EEG case report of ictal epileptic headache.

BACKGROUND: Ictal epileptic headache (IEH) is caused by a focal epileptic seizure. The diagnosis can be challenging when the headache is isolated without any other symptoms. CASE REPORT: A 16-year-old girl presented with a 5-year history of bilateral frontotemporal headaches with severe intensity lasting for 1-3 min. Past medical, physical, and developmental histories were unremarkable. Head magnetic resonance imaging showed right hippocampal sclerosis. The diagnosis of pure IEH was confirmed by video-electroencephalographic monitoring. The onset and cessation of frontal headache correlated with a right temporal discharge. The patient was diagnosed with right mesial temporal lobe epilepsy. Two years later, her seizures increased despite antiseizure medications. A right anterior temporal lobectomy was performed. The patient remained seizure-free and headache-free for 10 years. CONCLUSION: IEH should be considered in the differential diagnosis of brief and isolated headache, even if the headache is diffuse or contralateral to the epileptogenic focus.

Improving the decision to switch from first- to second-line therapy in multiple sclerosis: A dynamic scoring system.

BACKGROUND: In relapsing-remitting multiple sclerosis (RRMS), early identification of suboptimal responders can prevent disability progression. OBJECTIVE: We aimed to develop and validate a dynamic score to guide the early decision to switch from first- to second-line therapy. METHODS: Using time-dependent propensity scores (PS) from a French cohort of 12,823 patients with RRMS, we constructed one training and two validation PS-matched cohorts to compare the switched patients to second-line treatment and the maintained patients. We used a frailty Cox model for predicting individual hazard ratios (iHRs). RESULTS: From the validation PS-matched cohort of 348 independent patients with iHR ⩽ 0.69, we reported the 5-year relapse-free survival at 0.14 (95% confidence interval (CI) 0.09-0.22) for the waiting group and 0.40 (95% CI 0.32-0.51) for the switched group. From the validation PS-matched cohort of 518 independent patients with iHR > 0.69, these values were 0.37 (95% CI 0.30-0.46) and 0.44 (95% CI 0.37-0.52), respectively. CONCLUSIONS: By using the proposed dynamic score, we estimated that at least one-third of patients could benefit from an earlier switch to prevent relapse.

Kappa Free Light Chain Biomarkers Are Efficient for the Diagnosis of Multiple Sclerosis: A Large Multicenter Cohort Study.

BACKGROUND AND OBJECTIVES: Kappa free light chains (KFLC) seem to efficiently diagnose MS. However, extensive cohort studies are lacking to establish consensus cut-offs, notably to rule out non-MS autoimmune CNS disorders. Our objectives were to (1) determine diagnostic performances of CSF KFLC, KFLC index, and KFLC intrathecal fraction (IF) threshold values that allow us to separate MS from different CNS disorder control populations and compare them with oligoclonal bands' (OCB) performances and (2) to identify independent factors associated with KFLC quantification in MS. METHODS: We conducted a retrospective multicenter study involving 13 French MS centers. Patients were included if they had a noninfectious and nontumoral CNS disorder, eligible data concerning CSF and serum KFLC, albumin, and OCB. Patients were classified into 4 groups according to their diagnosis: MS, clinically isolated syndrome (CIS), other inflammatory CNS disorders (OIND), and noninflammatory CNS disorder controls (NINDC). RESULTS: One thousand six hundred twenty-one patients were analyzed (675 MS, 90 CIS, 297 OIND, and 559 NINDC). KFLC index and KFLC IF had similar performances in diagnosing MS from nonselected controls and OIND (p = 0.123 and p = 0.991 for area under the curve [AUC] comparisons) and performed better than CSF KFLC (p < 0.001 for all AUC comparisons). A KFLC index of 8.92 best separated MS/CIS from the entire nonselected control population, with better performances than OCB (p < 0.001 for AUC comparison). A KFLC index of 11.56 best separated MS from OIND, with similar performances than OCB (p = 0.065). In the multivariate analysis model, female gender (p = 0.003), young age (p = 0.013), and evidence of disease activity (p < 0.001) were independent factors associated with high KFLC index values in patients with MS, whereas MS phenotype, immune-modifying treatment use at sampling, and the FLC analyzer type did not influence KFLC index. DISCUSSION: KFLC biomarkers are efficient tools to separate patients with MS from controls, even when compared with other patients with CNS autoimmune disorder. Given these results, we suggest using KFLC index or KFLC IF as a criterion to diagnose MS. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that KFLC index or IF can be used to differentiate patients with MS from nonselected controls and from patients with other autoimmune CNS disorders.

Investigating the Long-term Effect of Pregnancy on the Course of Multiple Sclerosis Using Causal Inference.

BACKGROUND AND OBJECTIVES: The question of the long-term safety of pregnancy is a major concern in patients with multiple sclerosis (MS), but its study is biased by reverse causation (women with higher disability are less likely to experience pregnancy). Using a causal inference approach, we aimed to estimate the unbiased long-term effects of pregnancy on disability and relapse risk in patients with MS and secondarily the short-term effects (during the perpartum and postpartum years) and delayed effects (occurring beyond 1 year after delivery). METHODS: We conducted an observational cohort study with data from patients with MS followed in the Observatoire Français de la Sclérose en Plaques registry between 1990 and 2020. We included female patients with MS aged 18-45 years at MS onset, clinically followed up for more than 2 years, and with ≥3 Expanded Disease Status Scale (EDSS) measurements. Outcomes were the mean EDSS score at the end of follow-up and the annual probability of relapse during follow-up. Counterfactual outcomes were predicted using the longitudinal targeted maximum likelihood estimator in the entire study population. The patients exposed to at least 1 pregnancy during their follow-up were compared with the counterfactual situation in which, contrary to what was observed, they would not have been exposed to any pregnancy. Short-term and delayed effects were analyzed from the first pregnancy of early-exposed patients (who experienced it during their first 3 years of follow-up). RESULTS: We included 9,100 patients, with a median follow-up duration of 7.8 years, of whom 2,125 (23.4%) patients were exposed to at least 1 pregnancy. Pregnancy had no significant long-term causal effect on the mean EDSS score at 9 years (causal mean difference [95% CI] = 0.00 [-0.16 to 0.15]) or on the annual probability of relapse (causal risk ratio [95% CI] = 0.95 [0.93-1.38]). For the 1,253 early-exposed patients, pregnancy significantly decreased the probability of relapse during the perpartum year and significantly increased it during the postpartum year, but no significant delayed effect was found on the EDSS and relapse rate. DISCUSSION: Using a causal inference approach, we found no evidence of significantly deleterious or beneficial long-term effects of pregnancy on disability. The beneficial effects found in other studies were probably related to a reverse causation bias.

Effects of socioeconomic status on excess mortality in patients with multiple sclerosis in France: A retrospective observational cohort study.

Background: The effects of socio-economic status on mortality in patients with multiple sclerosis is not well known. The objective was to examine mortality due to multiple sclerosis according to socio-economic status. Methods: A retrospective observational cohort design was used with recruitment from 18 French multiple sclerosis expert centers participating in the Observatoire Français de la Sclérose en Plaques. All patients lived in metropolitan France and had a definite or probable diagnosis of multiple sclerosis according to either Poser or McDonald criteria with an onset of disease between 1960 and 2015. Initial phenotype was either relapsing-onset or primary progressive onset. Vital status was updated on January 1st 2016. Socio-economic status was measured by an ecological index, the European Deprivation Index and was attributed to each patient according to their home address. Excess death rates were studied according to socio-economic status using additive excess hazard models with multidimensional penalised splines. The initial hypothesis was a potential socio-economic gradient in excess mortality. Findings: A total of 34,169 multiple sclerosis patients were included (88% relapsing onset (n = 30,083), 12% progressive onset (n = 4086)), female/male sex ratio 2.7 for relapsing-onset and 1.3 for progressive-onset). Mean age at disease onset was 31.6 (SD = 9.8) for relapsing-onset and 42.7 (SD = 10.8) for progressive-onset. At the end of follow-up, 1849 patients had died (4.4% for relapsing-onset (n = 1311) and 13.2% for progressive-onset (n = 538)). A socio-economic gradient was found for relapsing-onset patients; more deprived patients had a greater excess death rate. At thirty years of disease duration and a year of onset of symptoms of 1980, survival probability difference (or deprivation gap) between less deprived relapsing-onset patients (EDI = -6) and more deprived relapsing-onset patients (EDI = 12) was 16.6% (95% confidence interval (CI) [10.3%-22.9%]) for men and 12.3% (95%CI [7.6%-17.0%]) for women. No clear socio-economic mortality gradient was found in progressive-onset patients. Interpretation: Socio-economic status was associated with mortality due to multiple sclerosis in relapsing-onset patients. Improvements in overall care of more socio-economically deprived patients with multiple sclerosis could help reduce these socio-economic inequalities in multiple sclerosis-related mortality. Funding: This study was funded by the ARSEP foundation "Fondation pour l'aide à la recherche sur la Sclérose en Plaques" (Grant Reference Number 1122). Data collection has been supported by a grant provided by the French State and handled by the "Agence Nationale de la Recherche," within the framework of the "Investments for the Future" programme, under the reference ANR-10-COHO-002, Observatoire Français de la Sclérose en Plaques (OFSEP).

How is neuromuscular fatigability affected by perceived fatigue and disability in people with multiple sclerosis?

Whereas fatigue is recognized to be the main complaint of patients with multiple sclerosis (PwMS), its etiology, and particularly the role of resistance to fatigability and its interplay with disability level, remains unclear. The purposes of this review were to (i) clarify the relationship between fatigue/disability and neuromuscular performance in PwMS and (ii) review the corticospinal and muscular mechanisms of voluntary muscle contraction that are altered by multiple sclerosis, and how they may be influenced by disability level or fatigue. Neuromuscular function at rest and during exercise are more susceptible to impairement, due to deficits in voluntary activation, when the disability is greater. Fatigue level is related to resistance to fatigability but not to neuromuscular function at rest. Neurophysiological parameters related to signal transmission such as central motor conduction time, motor evoked potentials amplitude and latency are affected by disability and fatigue levels but their relative role in the impaired production of torque remain unclear. Nonetheless, cortical reorganization represents the most likely explanation for the heightened fatigability during exercise for highly fatigued and/or disabled PwMS. Further research is needed to decipher how the fatigue and disability could influence fatigability for an ecological task, especially at the corticospinal level.

Conformation-stabilizing ELISA and cell-based assays reveal patient subgroups targeting three different epitopes of AGO1 antibodies.

Autoantibodies (Abs) are biomarkers for many disease conditions and are increasingly used to facilitate diagnosis and treatment decisions. To guarantee high sensitivity and specificity, the choice of their detection method is crucial. Via cell-based assays, we recently found 21 patients with neurological diseases positive for antibodies against argonaute (AGO), 10 of which having a neuropathy (NP). Here, we established a simple and conformation-sensitive ELISA with the aim to distinguish between AGO1 Abs against conformational epitopes and non-conformational epitopes and to reveal further characteristics of AGO1 antibodies in NP and autoimmune disease (AID). In a retrospective multicenter case/control and observational study, we tested 434 patients with NP, 274 disease controls with AID, and 116 healthy controls (HC) for AGO1 Abs via conformation-stabilizing ELISA. Seropositive patients were also tested for conformation-specificity via comparative denaturing/stabilizing ELISA (CODES-ELISA), CBA positivity, AGO1 titers and IgG subclasses, and AGO2 reactivity. These parameters were statistically compared among different epitope-specific patient groups. We found Abs in 44 patients, including 28/434 (6.5%) NP, 16/274 (5.8%) AID, and 0/116 (0%) HC. Serum reactivity was consistently higher for AGO1 than AGO2. Globally among the 44 AGO1 Abs-positive patients, 42 were also tested in CBA for AGO1 Abs positivity and 15 (35.7%) were positive. Furthermore, 43 were tested for conformation-specificity and 32 (74.4%) bound a conformational epitope. Among the subgroups of highly positive patients (ELISA z-score >14) with sera binding conformational epitopes (n=23), 14 patient sera were also CBA positive and 9 bound a second conformational but CBA-inaccessible epitope. A third, non-conformational epitope was bound by 11/43 (15.6%). Among the epitope-specific patient subgroups, we found significant differences regarding the Abs titers, IgG subclass, and AGO2 reactivity. When comparing AGO1 Abs-positive NP versus AID patients, we found the conformation-specific and CBA inaccessible epitope significantly more frequently in AID patients. We conclude that 1) conformational ELISA was more sensitive than CBA in detecting AGO1 Abs, 2) serum reactivity is higher for AGO1 than for AGO2 at least for NP patients, 3) AGO1 Abs might be a marker-of-interest in 6.5% of NP patients, 4) distinguishing epitopes might help finding different patient subgroups.

Prevalence of fatigue and its explicative variables among people with multiple sclerosis.

BACKGROUND: Fatigue is the most prevalent symptom among people with multiple sclerosis (PwMS). Although exercise effectively reduces fatigue, the relationship between daily physical activity and fatigue has only recently been demonstrated. OBJECTIVE: The aim of this study was to evaluate the prevalence of fatigue and to understand the relationship with several variables in French PwMS. METHODS: Data were collected from 191 PwMS using Modified Fatigue Impact Scale (MFIS) and Fatigue Severity Scale (FSS) for fatigue, and the Godin Leisure-Time Exercise Questionnaire (GLTEQ) for physical activity. RESULTS: 110 PwMS (57%), 35 PwMS (18%) and 46 PwMS (24%) were considered as fatigued, non-fatigued and in the grey zone, respectively. Greater physical activity was observed in non-fatigued PwMS (20.2±19.8) compared to fatigued PwMS (12.5±14.1). FSS and MFIS scores were associated with physical activity (r = -0.28 and r = -0.25, respectively, p < 0.05). Using multivariate analysis, disability, physical activity and being unemployed explained 21% of the variance of the MFIS. CONCLUSIONS: The present study confirms that physical activity and fatigue are associated. Disability and unemployment status should also to be consider when assessing fatigue. Activity-oriented health policies should be redesigned to improve fatigue among PwMS.

Usefulness and prognostic value of diagnostic tests in patients with possible chronic inflammatory demyelinating polyradiculoneuropathy.

INTRODUCTION/AIMS: Recent guidelines define chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and possible CIDP. The aims of our study were to evaluate the value of diagnostic tests to support the diagnosis of CIDP in patients with possible CIDP and to identify prognostic factors of therapeutic success. METHODS: We conducted an observational retrospective two-center study between 2014 and 2019. We selected patients with a clinical presentation suggesting CIDP, but whose electrodiagnostic (EDX) test results did not meet the EFNS/PNS 2021 criteria. We analyzed epidemiologic and clinical features, axonal loss on EDX, cerebrospinal fluid (CSF), somatosensory evoked potentials (SSEPs), plexus magnetic resonance imaging (MRI), nerve biopsy, and therapeutic response. RESULTS: We selected 75 patients, among whom 30 (40%) responded to treatment. The positivity rates of CSF analysis, MRI and SSEPs were not influenced by the clinical presentation or by the delay between symptom onset and medical assessment. A high protein level in CSF, female gender, and a relapsing-remitting course predicted the therapeutic response. DISCUSSION: It is important to properly diagnose suspected CIDP not meeting EFNS/PNS 2021 EDX criteria by using supportive criteria. Specific epidemiological factors and a raised CSF protein level predict a response to treatment. Further prospective studies are needed to improve diagnosis and the prognostic value of diagnostic tests in CIDP.