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.

[Frameless trigeminal neuralgia radiosurgery with a dedicated linear accelerator: From equipment commissioning to initial clinical results]. / Radiochirurgie des névralgies trigéminales avec accélérateur linéaire dédié sans cadre invasif : de la mise en service de l'appareil aux premiers résultats cliniques.

PURPOSE: Radiosurgery for the treatment of trigeminal neuralgia delivers a very high dose in a single fraction, over a few millimeters, at a single isocenter placed along the nerve. We present here the different steps that have been performed to validate small beams by conical collimators, and report the clinical results of the first patients treated on Novalis Tx®, frameless. MATERIAL AND METHODS: First, the geometric accuracy of 4 and 6mm conical collimators was evaluated using Winston-Lutz tests; then dosimetric data acquisition was performed using high spatial resolution detectors (PTW 60019 microdiamond and a PTW 60017 E-diode). The corrective factors of the TRS 483 report were applied to calculate the collimator aperture factors. These dosimetric data were then compared with the data implemented in the iPlan® treatment planning system. Then end-to-end tests were performed to control the entire treatment process using an anthropomorphic phantom "STEEV". Between 2020 and 2022, 18 patients were treated for refractory trigeminal neuralgia on Novalis Tx®, frameless, with Exactrac® repositioning. A total of 17 patients were evaluated (one was lost to follow-up) using the BNI score for pain assessment and MRI with a median follow-up of 12 months. RESULTS: The quality criteria of geometric and dosimetric accuracy were met for the 6-mm cone but not for the 4-mm cone. All patients were treated with a 6-mm cone with a dose of 90Gy prescribed at the isocenter at the root entry zone. Initial pain control was obtained in 70.5% of our patients, and 53% maintained pain control with a median follow-up of 12 months. All recurrences occurred within 3 to 6 months after radiosurgery. No brainstem toxicity was observed. Six patients had non-disabling facial hypoesthesia, half of whom already had pretreatment hypoesthesia. CONCLUSION: The treatment of trigeminal neuralgia on a dedicated linear accelerator is a highly technical treatment whose accuracy and safety are paramount. The physical measurements allowed the commissioning of the technique with a 6mm cone. Our first clinical results are in accordance with the literature.

Upper motor neuron assessment in amyotrophic lateral sclerosis using the patellar tendon reflex and motor-evoked potentials to the lower limbs.

Amyotrophic lateral sclerosis (ALS) diagnosis relies on signs of progressive damage to both lower motoneuron (LMN), given by clinical examination and electromyography (EMG), and upper motoneuron (UMN), given by clinical examination only. Recognition of UMN involvement, however, is still difficult, so that diagnostic delay often remains too long. Shortening the time to clinical and genetic diagnosis is essential in order to provide accurate information to patients and families, avoid time-consuming investigations and for appropriate care management. This study investigates whether combined patellar tendon reflex recording with motor-evoked potentials to the lower limbs (T-MEP-LL) is relevant to assess corticospinal function in ALS, so that it might serve as a tool improving diagnosis. T-MEP-LL were recorded in 135 patients with suspected motor neuron disease (MND) from February 2010 to March 2021. The sensitivity, specificity, and ability to improve diagnosis when added to Awaji and Gold Coast criteria were determined. The main finding of the study is that T-MEP-LL can detect UMN dysfunction with a 70% sensitivity and 63% specificity when UMN clinical signs are lacking. The sensitivity reaches 82% when considering all MND patients. Moreover, at first evaluation, using T-MEP-LL to quantify reflex briskness and to measure central conduction time, can improve the diagnostic accuracy. T-MEP-LL is easy to perform and does not need any electrical stimulation, making the test rapid, and painless. By the simultaneous quantification of both UMN and LMN system, it could also help to identify different phenotype with more accuracy than clinical examination in this broad-spectrum pathology. The question whether T-MEP-LL could further be a real biomarker need further prospective studies.

Paradigm shifts in multiple sclerosis management: Implications for daily clinical practice.

Multiple sclerosis (MS) is the most common chronic inflammatory neurological disease. The emergence of disease-modifying therapies (DMTs) has greatly improved disease activity control and progression of disability in MS patients. DMTs differ in their mode of action, route of administration, efficacy, and safety profiles, offering multiple options for clinicians. Personalized medicine aims at tailoring the therapeutic strategy to patients' characteristics and disease activity but also patients' needs and preferences. New therapeutic options have already changed treatment paradigms for patients with active relapsing MS (RMS). The traditional approach consists in initiating treatment with moderate-efficacy DMTs and subsequently, escalating to higher-efficacy DMTs when there is evidence of clinical and/or radiological breakthrough activity. Recent real-world studies suggest that initiation of high-efficacy DMTs from disease onset can improve long-term outcomes for RMS patients. In this article, we review different treatment strategies and discuss challenges associated with personalized therapy.

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.

Revised guidelines of the French headache society for the diagnosis and management of migraine in adults. Part 3: Non-pharmacological treatment.

The French Headache Society proposes updated French guidelines for the management of migraine. This article presents the third part of the guidelines, which is focused on the non-pharmacological treatment of migraine, including physical exercise, dietary supplements and plants, diets, neuromodulation therapies, acupuncture, behavioral interventions and mindfulness therapy, patent foramen ovale closure and surgical nerve decompression.

Revised guidelines of the French headache society for the diagnosis and management of migraine in adults. Part 2: Pharmacological treatment.

The French Headache Society proposes updated French guidelines for the management of migraine. This article presents the second part of the guidelines, which is focused on the pharmacological treatment of migraine, including both the acute treatment of attacks and the prophylaxis of episodic migraine as well as chronic migraine with and without medication overuse. The specific situations that can be encountered in women with migraine are also discussed, including pregnancy, menstrual migraine, contraception and hormonal replacement therapy.

Revised guidelines of the French Headache Society for the diagnosis and management of migraine in adults. Part 1: Diagnosis and assessment.

The French Headache Society proposes updated French guidelines for the management of migraine. The first part of these recommendations is focused on the diagnosis and assessment of migraine. First, migraine needs to be precisely diagnosed according to the currently validated criteria of the International Classification of Headache Disorders, 3d version (ICHD-3). Migraine-related disability has to be assessed and we suggest to use the 6 questions of the headache impact test (HIT-6). Then, it is important to check for risk factors and comorbidities increasing the risk to develop chronic migraine, especially frequency of headaches, acute medication overuse and presence of depression. We suggest to use a migraine calendar and the Hospital Anxiety and Depression scale (HAD). It is also necessary to evaluate the efficacy and tolerability of current migraine treatments and we suggest to systematically use the self-administered Migraine Treatment Optimization Questionnaire (M-TOQ) for acute migraine treatment. Finally, a treatment strategy and a follow-up plan have to be proposed. Guidelines for pharmacological and non-pharmacological treatments are presented in the second and third part of the recommendations.

Interest of registries in neuropathic pain research.

Neuropathic pain is frequent in the general population, with 7 to 10% of adults presenting with chronic neuropathic pain. To date, the gold standard to evaluate treatments is based on randomized controlled trials. Nonetheless, such design is run on a limited sample and for a limited period. Moreover, many treatments will never be compared directly in sufficiently large and representative populations. A way to overcome several of these limitations is to use real-world data. Indeed, the International Association for the Study of Pain (IASP) includes a special interest group focusing on pain registries and promoting the use of such approaches. In this short narrative review, several of the main chronic pain registries are presented. The strengths and weaknesses of this approach are presented. Indication bias is frequent in observational studies because the choice of treatment is generally influenced by the patients' characteristics. However, a propensity score can be computed to adjust for these differences. The use of propensity score is briefly explained. Some data specific to neuropathic pain are discussed.

French guidelines for neuropathic pain: An update and commentary.

Neuropathic pain remains a significant unmet need. French recommendations were updated in 2020. The goal of this minireview is to provide an update on these published guidelines. Despite newer relevant studies, our proposed algorithm remains relevant. First-line treatments include serotonin-noradrenaline reuptake inhibitors (duloxetine and venlafaxine), gabapentin and tricyclic antidepressants, topical lidocaine and transcutaneous electrical nerve stimulation being specifically proposed for focal peripheral neuropathic pain. Second-line treatments include pregabalin (such position being confirmed by newer studies), tramadol, combinations and psychotherapy as add on, high-concentration capsaicin patches and botulinum toxin A being proposed specifically for focal peripheral neuropathic pain. Third-line treatments include high-frequency repetitive transcranial magnetic stimulation of the motor cortex, spinal cord stimulation and strong opioids (in the lack of alternative). Disseminating these recommendations and ensuring that they are well accepted by French practitioners will be necessary to optimize neuropathic pain management in real life.

Medication overuse headache: Updating of the French recommendations regarding the treatment strategies.

Regular and frequent use of analgesics and acute antimigraine drugs can increase the frequency of headache, and induce the transition from episodic to chronic migraine or medication-overuse headache (MOH). The one-year prevalence of this condition is between 1% and 2% in Europe, provoking substantial burden. MOH is more prevalent in people with comorbid depression, anxiety, and other chronic pain conditions. This paper aims at presenting an updating of French recommendations regarding treatments strategies. Prior French recommendations, published in 2014, were written in French. A literature search in the major medical databases including the terms "medication overuse headache", "symptomatic medication overuse", published between 2010 and 2020 was carried out. Three main strategies can be recommended and conducted in parallel: education and explanations about the negative consequences of overusing acute antimigraine drugs, discontinuation of the overused medication, and finally, preventive drug therapy and non-pharmacological prevention. Medication overuse headache remains a debated problem and evidence for the most effective treatment strategy is needed.

Migraine in multiple sclerosis and other chronic inflammatory diseases.

Migraine is a very prevalent disease worldwide and is a major cause of disability. As known for a long time, migraine is associated with neurogenic inflammation. Epidemiological studies have shown that migraine is comorbid with several chronic inflammatory diseases, including multiple sclerosis (MS), chronic inflammatory rheumatic diseases (CIRDs) and inflammatory bowel diseases (IBDs). This brief narrative review highlights some recent data supporting a link between migraine and these three chronic inflammatory diseases. Studies found that migraine prevalence is approximately two-fold higher in these diseases compared to the general population. The causal link between migraine and these chronic inflammatory diseases has not been identified yet. Here, we suggest that systemic mediators (such as cytokines) and gut microbiome make migraine worse or add significant risks. Systemic inflammation biomarkers and gut microbiome modification are certainly avenues worth exploring.

Pharmacological and non-pharmacological treatments for neuropathic pain: Systematic review and French recommendations.

Neuropathic pain remains a significant unmet medical need. Several recommendations have recently been proposed concerning pharmacotherapy, neurostimulation techniques and interventional management, but no comprehensive guideline encompassing all these treatments has yet been issued. We performed a systematic review of pharmacotherapy, neurostimulation, surgery, psychotherapies and other types of therapy for peripheral or central neuropathic pain, based on studies published in peer-reviewed journals before January 2018. The main inclusion criteria were chronic neuropathic pain for at least three months, a randomized controlled methodology, at least three weeks of follow-up, at least 10 patients per group, and a double-blind design for drug therapy. Based on the GRADE system, we provide weak-to-strong recommendations for use and proposal as a first-line treatment for SNRIs (duloxetine and venlafaxine), gabapentin and tricyclic antidepressants and, for topical lidocaine and transcutaneous electrical nerve stimulation specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a second-line treatment for pregabalin, tramadol, combination therapy (antidepressant combined with gabapentinoids), and for high-concentration capsaicin patches and botulinum toxin A specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a third-line treatment for high-frequency rTMS of the motor cortex, spinal cord stimulation (failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids (in the absence of an alternative). Psychotherapy (cognitive behavioral therapy and mindfulness) is recommended as a second-line therapy, as an add-on to other therapies. An algorithm encompassing all the recommended treatments is proposed.

Neurostimulation methods in the treatment of chronic pain.

The goal of this narrative review was to give an up-to-date overview of the peripheral and central neurostimulation methods that can be used to treat chronic pain. Special focus has been given to three pain conditions: neuropathic pain, nociplastic pain and primary headaches. Both non-invasive and invasive techniques are briefly presented together with their pain relief potentials. For non-invasive stimulation techniques, data concerning transcutaneous electrical nerve stimulation (TENS), transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), remote electrical neuromodulation (REN) and vagus nerve stimulation (VNS) are provided. Concerning invasive stimulation techniques, occipital nerve stimulation (ONS), vagus nerve stimulation (VNS), epidural motor cortex stimulation (EMCS), spinal cord stimulation (SCS) and deep brain stimulation (DBS) are presented. The action mode of all these techniques is only partly understood but can be very different from one technique to the other. Patients' selection is still a challenge. Recent consensus-based guidelines for clinical practice are presented when available. The development of closed-loop devices could be of interest in the future, although the clinical benefit over open loop is not proven yet.

Non pharmacological treatment for neuropathic pain: Invasive and non-invasive cortical stimulation.

The use of medications in chronic neuropathic pain may be limited with regard to efficacy and tolerance. Therefore, non-pharmacological approaches, using electrical stimulation of the cortex has been proposed as an alternative. First, in the early nineties, surgically-implanted epidural motor cortex stimulation (EMCS) was proven to be effective to relieve refractory neuropathic pain. Later, non-invasive stimulation techniques were found to produce similar analgesic effects, at least by means of repetitive transcranial magnetic stimulation (rTMS) targeting the primary motor cortex (M1). Following "high-frequency" rTMS (e.g., stimulation frequency ranging from 5 to 20Hz) delivered to the precentral gyrus (e.g., M1 region), it is possible to obtain an analgesic effect via the modulation of several remote brain regions involved in nociceptive information processing or control. This pain reduction can last for weeks beyond the time of the stimulation, especially if repeated sessions are performed, probably related to processes of long-term synaptic plasticity. Transcranial direct current stimulation (tDCS), another form of transcranial stimulation, using low-intensity electrical currents, generally delivered by a pair of large electrodes, has also shown some efficacy to improve patients with chronic pain syndromes. The mechanism of action of tDCS differs from that of EMCS and rTMS, but the cortical target is the same, which is M1. Although the level of evidence of therapeutic efficacy in the context of neuropathic pain is lower for tDCS than for rTMS, interesting perspectives are opened by using at-home tDCS protocols for long-term management. Now, there is a scientific basis for recommending both EMCS and rTMS of M1 to treat refractory chronic neuropathic pain, but their application in clinical practice remains limited due to practical and regulatory issues.

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.