Epidemiology of myasthenia gravis in France: Incidence, prevalence, and comorbidities based on national healthcare insurance claims data.

BACKGROUND: The European literature has reported high variability in the incidence and prevalence rates of myasthenia gravis (MG), but no specific epidemiological data for France have been published. This study aimed to assess the incidence and prevalence rates of myasthenia gravis in France based on data extracted from the French National Health Insurance Claims Database (the SNIIRAM database). METHODS: We conducted a retrospective repeated cross-sectional population study from 2008 to 2018 using a representative sample of the French population (Échantillon généraliste des bénéficiaires) covered by health insurance. We calculated the incidence, prevalence, and sex ratio of MG and screened for comorbidities associated with MG (standardized to the general population). RESULTS: In total, 331 MG patients were identified between 2008 and 2018. The average incidence of MG in France was 50 per million person-years, while the mean prevalence was 465 per million people. The female-to-male ratio was 1.33. The Incidence of MG gradually increased from 40years of age for women and 60 for men. Thymoma was present for 5.1% of MG patients and a thymectomy was performed for 4.7%. Thyroid disease was the most prevalent autoimmune comorbidity, affecting approximately 8.5% of cases. MG patients had an increased cancer risk, with a standardized rate ratio of 2.38 (95% CI: 1.64-3.46). CONCLUSION: The incidence and prevalence rates of MG are significantly higher than those previously reported in the literature and the incidence increases with age. The excess risk of cancer raises concerns for MG patients, in particular, concerning the management of immunosuppressive drugs.

Impact of methodological choices in comparative effectiveness studies: application in natalizumab versus fingolimod comparison among patients with multiple sclerosis.

BACKGROUND: Natalizumab and fingolimod are used as high-efficacy treatments in relapsing-remitting multiple sclerosis. Several observational studies comparing these two drugs have shown variable results, using different methods to control treatment indication bias and manage censoring. The objective of this empirical study was to elucidate the impact of methods of causal inference on the results of comparative effectiveness studies. METHODS: Data from three observational multiple sclerosis registries (MSBase, the Danish MS Registry and French OFSEP registry) were combined. Four clinical outcomes were studied. Propensity scores were used to match or weigh the compared groups, allowing for estimating average treatment effect for treated or average treatment effect for the entire population. Analyses were conducted both in intention-to-treat and per-protocol frameworks. The impact of the positivity assumption was also assessed. RESULTS: Overall, 5,148 relapsing-remitting multiple sclerosis patients were included. In this well-powered sample, the 95% confidence intervals of the estimates overlapped widely. Propensity scores weighting and propensity scores matching procedures led to consistent results. Some differences were observed between average treatment effect for the entire population and average treatment effect for treated estimates. Intention-to-treat analyses were more conservative than per-protocol analyses. The most pronounced irregularities in outcomes and propensity scores were introduced by violation of the positivity assumption. CONCLUSIONS: This applied study elucidates the influence of methodological decisions on the results of comparative effectiveness studies of treatments for multiple sclerosis. According to our results, there are no material differences between conclusions obtained with propensity scores matching or propensity scores weighting given that a study is sufficiently powered, models are correctly specified and positivity assumption is fulfilled.

Rationale for off-label treatments use in primary progressive multiple sclerosis: A review of the literature.

BACKGROUND: Until recently, few therapeutic options, other than symptomatic treatment, were available for patients with primary progressive multiple sclerosis (PPMS). Ocrelizumab is the only approved treatment in this indication, and only since 2017. However, many patients in France are receiving off-label treatments for PPMS, mainly rituximab, mycophenolate mofetil, methotrexate, cyclophosphamide, and azathioprine. OBJECTIVE: To evaluate published data concerning the efficacy of these five treatments frequently used as off-label disease-modifying therapies. METHODS: We reviewed and summarized the studies published in Pubmed since the inception of the database. RESULTS: Evidence from randomized controlled trials is lacking to support the use of these treatments as disease-modifying therapies in PPMS. CONCLUSION: The literature lacks dedicated studies to support the off-label use of these disease-modifying therapies in PPMS. However, some limited data are available in the literature suggesting that the use of rituximab and cyclophosphamide could potentially be of some interest in specific subpopulations.

Secondary progressive multiple sclerosis: A national consensus paper on diagnostic criteria.

BACKGROUND: In clinical practice, the diagnosis of secondary progressive multiple sclerosis (SPMS) is often delayed, retrospective and non-reproducible, as there are no consensus criteria that define the advent of SPMS. Early identification of SPMS is essential to improve patient care. METHODS: Eight regional board meetings in France involving 56 multiple sclerosis (MS) experts (neurologists) were convened to discuss diagnostic criteria for SPMS. Subsequently, a national board meeting of 13 neurologists (with an expert representing each geographical region) was held to review points of convergence or divergence between regions and to develop a national consensus document. RESULTS: Based on the discussions from the regional boards, the MS experts at the national board retained the worsening of the EDSS score, with compatible clinical features, as the only consensus criterion for the diagnosis of SPMS in clinical practice. The patient should have experienced during at least the previous 6 months and in the absence of any relapse, a worsening in the EDSS score of +1.0 point (if the previous EDSS was≤5.0) or of +0.5 point (if the previous EDSS was≥5.5), with a pyramidal or cerebellar functional system score≥2 and without setting a minimum EDSS score; or, in case of a stable EDSS score≥4.0, a worsening of a functional score. This worsening should be confirmed within 3 to 6 months. According to the MS experts, the patient's age, duration of illness and a minimal threshold EDSS score are only risk factors for transition to SPMS. Patient reports during consultation and cognitive impairment are important warning signs, which should trigger an objective assessment with specific tests or closer monitoring. Clinical relapse and/or MRI activities are non-discriminatory for making the diagnosis of SPMS. CONCLUSIONS: The experts defined precise diagnostic criteria adapted to clinical practice for earlier identification of SPMS, paving the way for better management of this stage of the disease.

Dimethyl fumarate and teriflunomide for multiple sclerosis in a real-life setting: a French retrospective cohort study.

BACKGROUND AND PURPOSE: Dimethyl fumarate (DMF) and teriflunomide are approved oral disease-modifying treatments for relapsing-remitting multiple sclerosis (MS). Phase 3 trials established these agents to be effective and generally well tolerated, although comparative efficacy and discontinuation rates are still unknown. The aim of this study was to assess real-world efficacy and discontinuation of DMF and teriflunomide in patients with relapsing-remitting MS. METHODS: This retrospective observational cohort study was carried out in a French administrative region between March 2014 and July 2017. Patients who were followed by private or hospital neurologists were included. Efficacy and tolerance of the two treatments were assessed and compared by multivariate analysis, considering the duration of MS, annualized relapse rate and Expanded Disability Status Scale score at treatment initiation, treatment duration, type of prescriber and tobacco use. RESULTS: We identified 189 DMF- and 157 teriflunomide-treated patients who had been treated for 22 ± 10 months. After correction for confounders, DMF more efficiently reduced the annualized relapse rate after 2 years than teriflunomide (0.06 vs. 0.21; P = 0.03). DMF-treated patients had more clinical and biological adverse events, resulting in a higher rate of treatment discontinuation (28% vs. 12%, P = 0.03). CONCLUSION: In this retrospective cohort study, DMF demonstrated significantly better efficacy over 2 years than teriflunomide, but tolerance to teriflunomide was better.

Fixed 50:50 mixture of nitrous oxide and oxygen to reduce lumbar-puncture-induced pain: a randomized controlled trial.

BACKGROUND AND PURPOSE: Lumbar puncture (LP) has been frequently performed for more than a century. This procedure is still stressful and often painful. The aim of the study was to evaluate the efficacy of a fixed 50% nitrous oxide-oxygen mixture compared to placebo to reduce immediate procedural pain and anxiety during LP. METHODS: A randomized controlled trial was conducted involving adults who needed a cerebrospinal fluid analysis. Patients were randomly assigned to inhale either a fixed 50% nitrous oxide-oxygen mixture (50% N2 O-O2 ) or medical air (22% O2 -78% N2 ). Cutaneous application of a eutectic mixture of local anaesthetics was systematically done and all LPs were performed with pencil point 25G needles (20G introducer needle). The primary end-point was the maximal pain level felt by the patient during the procedure, the maximal anxiety level being a secondary outcome, both measured using a numerical rating scale (0-10). RESULTS: A total of 66 consecutive patients were randomized. The analysis was intention to treat. The maximal pain was 4.9 ± 2.7 for the 33 patients receiving air and 2.7 ± 2.7 for the 33 receiving 50% N2 O-O2 (P = 0.002). Similarly, the maximal LP-induced anxiety was 4.5 ± 3.1 vs. 2.6 ± 2.6 (P = 0.009), respectively. The number needed to treat to avoid one patient undergoing significant pain (pain score ≥ 4/10) was 2.75. Body mass index >25 kg/m2 was significantly associated with higher pain intensity (P = 0.03). No serious adverse events were attributable to 50% N2 O-O2 inhalation. CONCLUSIONS: Inhalation of a fixed 50% N2 O-O2 mixture is efficient to reduce LP-induced pain and anxiety.

Cognitive impairment in a population-based study of patients with multiple sclerosis: differences between late relapsing-remitting, secondary progressive and primary progressive multiple sclerosis.

BACKGROUND AND PURPOSE: Few studies have investigated the differences in cognitive skills between the three subtypes of multiple sclerosis (MS) and they confounded the course of the disease with the duration of the disease and the physical disability. Moreover, they were not population based. METHODS: This was a retrospective analysis of cognitive testing from the database of a French programme for MS care. The pattern and the frequency of cognitive impairment in secondary progressive (SP), primary progressive (PP) and late relapsing-remitting (LRR, disease duration of more than 10 years) MS were compared. RESULTS: A total of 101 patients with MS (41 LRRMS, 37 SPMS, 23 PPMS) were included. 63.0% had a significant cognitive impairment. After controlling for age, sex, Expanded Disability Status Scale, disease duration and education level, patients with SPMS were at least 2-fold more frequently impaired than patients with LLRMS in information processing speed (P = 0.005), executive functions (P = 0.04), verbal fluency (P = 0.02), verbal episodic memory (P = 0.04), working memory (P = 0.02) and visuospatial construction (P = 0.01). The number of patients with at least one or two deficient cognitive domain(s) was higher in the SPMS group than in the LRRMS group (P = 0.002 and P < 0.001). Patients with PPMS were more frequently impaired in verbal fluency (P = 0.046) than patients with LRRMS and they more often presented at least one impaired cognitive domain (P = 0.03). SPMS and PPMS groups differed only for visuospatial construction (P = 0.02). CONCLUSION: In this population-based study, patients with a progressive subtype of MS were more frequently and more severely impaired than patients with RRMS, even after more than 10 years of disease.

Evaluation of the application of the European guidelines for the diagnosis and clinical care of amyotrophic lateral sclerosis (ALS) patients in six French ALS centres.

BACKGROUND AND PURPOSE: Our objective was to evaluate the extent to which the 2005 recommendations of the European Federation of Neurological Sciences (EFNS) on the multidisciplinary management of amyotrophic lateral sclerosis (ALS) are followed in clinical practice. METHODS: This was a multicentre observational study involving six French ALS referral centres receiving prevalent and incident cases. Recommendations were translated into ad hoc questions referring to key aspects of management, and their application was evaluated by a clinical research assistant who independently examined the medical charts (MCs). When necessary, an independent board-certified neurologist answered the questions based on examination of the MC and interview of the caring neurologist. Questions regarding diagnosis and communication were put to patients in a self-administered questionnaire. RESULTS: In all, 376 patients [176 incident, 200 prevalent cases; median age at diagnosis 62.8 years (interquartile range 55.7-72.3); sex ratio 1.37; 27.3% bulbar onset] were included. All the topics covered in the recommendations were evaluated: diagnostic delay (e.g. mean 13.6 months, associated with age and onset); breaking the news (e.g. criteria for communication quality were satisfactory in more than 90%); multidisciplinary and sustained support (e.g. clinic visits were scheduled every 2-3 months in 90%). Also considered were whether riluzole had been offered, symptom management, genetic testing, ventilation, communication defects, enteral nutrition, palliative and end-of-life care. Characteristics associated with poor compliance with some guidelines (schedule of visits, delayed riluzole initiation) were also identified. CONCLUSION: This is the first evaluation of the application of the EFNS recommendations for the management of ALS in a nationwide sample. The results allow us to highlight areas for improvement.

Evaluation of quality of life and fatigue in radiologically isolated syndrome.

BACKGROUND: Radiologically isolated syndrome (RIS) is a new subtype entity described at the very left of the demyelinating disease spectrum, where spatial dissemination of T2-weighted lesions can be documented on MRI in subjects with no history of neurological symptoms. OBJECTIVES: This study was a longitudinal assessment of health-related quality of life (HRQOL) and fatigue in RIS patients. METHODS: Non-converted RIS patients were evaluated at the time of diagnosis, and at 1 and 2 years of follow-up; their scores were compared with scores in clinically isolated syndrome (CIS) patients and age-matched controls. RESULTS: Sociodemographic characteristics were comparable at baseline. There was no statistical difference between RIS and CIS groups in terms of cerebrospinal fluid (CSF) positivity or T2 lesion load. For HRQOL evaluations, RIS patients scored the same as controls, while CIS patients scored lower. Fatigue was detectable in both RIS and CIS patients compared with baseline and with controls. Mental HRQOL scores decreased significantly for RIS patients during follow-up. CONCLUSION: HRQOL impairment and fatigue were detectable during follow-up in both non-converted RIS and CIS patients.

A prospective observational post-marketing study of natalizumab-treated multiple sclerosis patients: clinical, radiological and biological features and adverse events. The BIONAT cohort.

BACKGROUND AND PURPOSE: BIONAT is a French multicentric phase IV study of natalizumab (NTZ)-treated relapsing-remitting multiple sclerosis (MS) patients. The purpose of this study was to collect clinical, radiological and biological data on 1204 patients starting NTZ, and to evaluate the clinical/radiological response to NTZ after 2 years of treatment. METHODS: Patients starting NTZ at 18 French MS centres since June 2007 were included. Good response to NTZ was defined by the absence of clinical and radiological activity. Data analysed in this first report on the BIONAT study focus on patients who started NTZ at least 2 years ago (n = 793; BIONAT2Y ). RESULTS: NTZ was discontinued in 17.78% of BIONAT2Y. The proportion of patients without combined disease activity was 45.59% during the first two successive years of treatment. Systematic dosage of anti-NTZantibodies (Abs) detected only two supplementary patients with anti-NTZ Abs compared with strict application of recommendations. A significant decrease of IgG,M concentrations at 2 years of treatment was found. CONCLUSIONS: The efficacy of NTZ therapy on relapsing-remitting MS in a real life setting is confirmed in the BIONAT cohort. The next step will be the identification of biomarkers predicting response to NTZ therapy and adverse events.

[Unilateral Creutzfeld-Jakob disease: report of a probable case on electroclinical, MRI and biological criteria]. / Maladie de Creutzfeld-Jakob unilatérale: à propos d'un cas probable sur les critères électrocliniques, IRM et biologiques.

We report the case of a 70-year-old man who developed probable unilateral Creutzfeldt-Jakob disease. Clinically, he presented with right hemiparesis, progressive aphasia, temporospatial disorientation and cerebellar ataxia and later on, myoclonia. The MRI showed a hypersignal from the left caudate in DWI with decreased ADC. Repeated electroencephalograms showed a slow background rhythm in the left hemisphere with superimposed periodic, biphasic and triphasic sharp-wave complexes in the left temporal region. Death occurred after 5weeks. Although exceptional, unilateral Creutzfeldt-Jakob disease was retained as possible.

Prior suggestive symptoms in one-third of patients consulting for a "first" demyelinating event.

OBJECTIVE: To evaluate the prevalence of prior inflammatory events in patients consulting for a first inflammatory neurological event and improve early diagnosis of multiple sclerosis. METHODS: During the initial visit, the neurologist gave patients a self-administered questionnaire containing 72 questions regarding previous symptoms lasting >24 h. During the follow-up visit, the neurologist validated the symptoms and collected information about the current attack. RESULTS: The cohort included 178 patients (74% women, mean age (SD) 33.7 (10.1) years). The main reason for the initial visit was visual disturbance and sensory troubles in limbs. Mean (SD) global Expanded Disability Status Scale score was 1.4 (1.1), 46% of brains MRIs were positive according to Barkhof-Tintoré criteria, 41% had abnormal white blood cell count in cerebrospinal fluid and 71% had immunoglobin G oligoclonal bands. Prior symptoms suggestive of demyelination were reported by 79 patients (44%), validated by the neurologist for 70% (55 patients) and identified only by the neurologist in four patients. Sequelae were observed in 14 patients with validated prior symptoms (26%). The self-administered questionnaire showed an overall sensitivity of 93% and specificity of 80% for identifying patients with prior symptoms suggestive of demyelination. CONCLUSION: A patient-administered questionnaire subsequently validated by the neurologist demonstrated that 33% of patients consulting for a first demyelinating event had prior symptoms suggestive of central nervous system demyelination that had gone unnoticed, and almost 70% had either sequelae of prior demyelination or McDonald criteria for dissemination in space. Such a questionnaire could be a useful tool for earlier diagnosis of multiple sclerosis.

Are there differences between cephalic and extracephalic cutaneous allodynia in migraine patients?

Cutaneous allodynia (CA), pain in response to innocuous cutaneous stimuli, is recognized as a sign of central sensitization during migraine episodes. It is either restricted within the pain area on the ipsilateral head, or extends within and outside the head. Moreover, CA can be elicited in response to thermal (heat or cold) and/or mechanical stimuli. This raises the question as to whether cephalic and extracephalic CAs share the same properties. We assessed cephalic and extracephalic CAs in migraine episodic patients using a questionnaire completed at home during migraine attacks. A total of 67 episodic migraine patients (58 women, nine men; 4013 years old) addressed all questions in the questionnaire. Forty-nine patients (73%) cited one or more allodynic symptoms during or immediately after the migraine attack. Almost all 49 patients reported cephalic CA, whereas 24 (49%) also reported extracephalic CA. Occurrence and extension of CA correlated (P = 0.005) with headache intensity. Modalities of cephalic and extracephalic CA were different (chi2 = 12.03; P = 0.002), extracephalic CA being mostly thermal (75%) whereas cephalic CA was mostly mechanical (92%). This suggests that cephalic and extracephalic CAs involve different mechanisms.

[Longitudinal study of health related quality of life in multiple sclerosis: correlation with MRI parameters]. / Étude longitudinale de la qualité de vie dans la sclérose en plaques : corrélation aux paramètres morphométriques de l'imagerie.

INTRODUCTION: Health related quality of life (HRQOL) is often affected in multiple sclerosis (MS). Nevertheless, to our knowledge, there is no longitudinal study in the literature about the correlation between MRI parameters and HRQOL in MS patients. METHODS: We included 28 patients with clinically definite relapsing remitting MS. All patients initiated subcutaneous interferon beta-1a therapy. To assess HRQOL, we used the SEP-59 scale, the French validated translation of MSQOL-54, and the MusiQoL scale. Conventional MRI was performed every year. Lesion load (LL) and brain atrophy were automatically measured using SepINRIA, a free software developed by INRIA in Sophia Antipolis. RESULTS: The mean EDSS score was 1.7 and disease duration was 2.5 years. Our results revealed that HRQOL was significantly correlated to T1 and T2-LL with both SEP-59 and MusiQoL scales. T1-LL was better correlated with physical dimensions and T2-LL was better correlated with mental components. At 1-year follow-up, patients whose MRI showed either an increase of T1 LL or at least one gadolinium enhancing lesion had a worse HRQOL at the end of the study. Initial brain parenchymal fraction (BPF) measure was also correlated with the long-term follow-up HRQOL. EDSS scored at the end of the study had not significantly changed (1.3; P>0.05). CONCLUSION: Our study revealed pertinent clinicoradiological correlations between HRQOL and MRI parameters in our cohort.

[Functional stereotactic radiosurgery: Indications and perspectives]. / Radiochirurgie fonctionnelle : indications et perspectives.

Stereotactic radiosurgery (SRS) is a non-invasive technique that enables to create brain focal lesions with a high precision and localization. Thus, functional brain disorders can be treated by SRS in case of pharmacoresistance or inoperability. To date, treatment of trigeminal neuralgia is the most described and known indication. Other indications will be developed in the future like movement disorders, refractory epilepsy, obsessive compulsive disorder and severe depression. We present here a review of actual and future indications of functional brain SRS with their level of evidence. All these SRS treatments have to be strictly conducted by trained teams with an excellent collaboration between radiation physicists, medical physicists, neurosurgeons, neurologists, psychiatrists and probably neuroradiologists.

Impact of rapid enterovirus molecular diagnosis on the management of infants, children, and adults with aseptic meningitis.

Enteroviruses (EV) are the main etiological agents of aseptic meningitis. Diagnosis is made by detecting the genome using RT-PCR. The aim of the study was to evaluate the impact of a positive diagnosis on the management of infants, children, and adults. During 2005, 442 patients were admitted to hospital with suspected meningitis. Clinical and laboratory data and initial treatment were recorded for all patients with enteroviral meningitis. The turnaround time of tests and the length of hospital stay were analyzed. The results showed that EV-PCR detected EV in 69 patients (16%), 23% (16/69) were adults. About 18% of CSF samples had no pleocytosis. After positive PCR results, 63% of children were discharged immediately (mean 2 hr 30 min) and 95% within 24 hr. Infants and adults were discharged later (after 1.8 and 2 days, respectively). The use of antibiotics was significantly lower in children than in infants and adults. The PCR results allowed discontinuation of antibiotics in 50-60% of all patients treated. Patients received acyclovir in 16% of cases (7% children vs. 50% adults) and 23% (11% vs. 69%) underwent a CT scan. Clinical data were compared between patients whose positive EV-PCR results were available within 24 hr (n = 32) and those whose results were available > 24 hr after collection of CSF (n = 14). Duration of antibiotic treatment (difference: 2.3 days; P = 0.05) was reduced between the two groups. No statistical difference in the length of stay was observed. The EV-PCR assay should be performed daily in hospital laboratory practice and considered as part of the initial management of meningitis.