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Introduction/Aims: Multifocal motor neuropathy (MMN) is a rare disease for which epidemiological and clinical data are limited. We conducted a nationwide survey to determine disease prevalence, incidence, clinical profile, and current treatment status in Japan. Methods: A nationwide survey was conducted in 2021 using an established epidemiological method. Questionnaires were sent to all neurology and pediatric neurology departments in Japan. An initial questionnaire was administered to determine the number of patients with and incidence of MMN. A second questionnaire was administered to collect detailed clinical information. The European Federation of Neurological Societies/Peripheral Nerve Society 2010 guidelines were used as diagnostic criteria. Results: The estimated number of patients with MMN was 507. The estimated prevalence was 0.40 per 100,000 individuals. Detailed clinical profiles were available for 120 patients. The male‐to‐female ratio was 2.3:1 and the median onset age was 42 years. The median disease duration at diagnosis was 25 months. Most patients presented with upper limb‐dominant muscle weakness. Motor nerve conduction blocks were found in 62% of patients and positive anti‐GM1 IgM antibody results in 54%. A total of 117 (98%) patients received immunoglobulin therapy, and 91% of them showed improvement. At the time of the last visit (median, 82 months from treatment initiation), 89 (74%) patients were receiving maintenance immunoglobulin therapy. A slight progression of neurological deficits was observed during follow‐up. Discussion: Most patients with MMN in Japan received induction and maintenance immunoglobulin therapies, which appear to suppress long‐term disease progression. [ABSTRACT FROM AUTHOR]

Background and Aims: Guillain‐Barré syndrome (GBS) is an acute, self‐limited, immune‐mediated peripheral neuropathy. Current treatments for GBS include intravenous immunoglobulin (IVIg) and plasma exchange, which may not sufficiently benefit severely affected patients. This study evaluated the efficacy and safety of eculizumab add‐on therapy to IVIg (standard‐of‐care treatment) in patients with severe GBS. Methods: This phase 3, multicenter, double‐blind, randomized, placebo‐controlled clinical trial (NCT04752566), enrolled Japanese adults (age ≥ 18 years) with severe GBS (Hughes functional grade [FG] score FG3 or FG4/FG5 within 2 weeks of onset of GBS). Participants were randomized 2:1 to receive intravenous infusion of eculizumab or placebo (once weekly for 4 weeks) with IVIg treatment with 20 weeks of follow‐up. Primary efficacy endpoint was the time to first reach FG score ≤1 (able to run). Key secondary endpoints were proportion of participants achieving FG ≤1 at weeks 8 and 24 and FG improvement ≥3 at week 24. Pharmacodynamic analysis of serum free C5 concentration over time was performed. Safety was evaluated. Results: The analysis included 57 participants (eculizumab, n = 37; placebo, n = 20). Primary endpoint was not achieved (hazard ratio, 0.9; 95% CI, 0.45–1.97; p =.89). Key secondary endpoints did not reach statistical significance. Serum C5 concentration was reduced by 99.99% at 1 h postdose and sustained to week 5 but returned to baseline at the end of follow‐up period. No new safety signals for eculizumab were identified. Interpretation: Although well tolerated, eculizumab treatment did not show significant effects on motor function recovery compared to placebo in patients with GBS. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that patients with amyotrophic lateral sclerosis (ALS) have hyperexcitability in both the motor cortex and peripheral motor axons, but the relationship between central and peripheral excitability has not been fully disclosed.Methods: Threshold tracking transcranial magnetic stimulation (TMS) and motor nerve excitability testing were prospectively performed in 53 patients with ALS and 50 healthy subjects, and their relations to compound muscle action potential (CMAP) amplitude and revised ALS Functional Rating Scale were cross-sectionally analysed.Results: Compared with controls, patients with ALS showed both cortical and peripheral hyperexcitability; TMS showed reduced short-interval intracortical inhibition (interstimulus interval 1-7 ms) (p<0.001) and shortened silent period (p<0.05), and median nerve excitability testing revealed greater changes in depolarising threshold electrotonus (TEd) and greater superexcitability (p<0.0001, both), suggesting reduced axonal potassium currents. Significant correlations between cortical and peripheral excitability indices were not found. Greater changes in TEd (90-100 ms) (R=-0.33, p=0.03) and superexcitability (R=0.36, p=0.01) were associated with smaller amplitude of CMAP, whereas cortical excitability indices had no correlation with CMAP amplitude. More rapid motor functional decline was associated with only greater TEd (90-100 ms) (β=0.46, p=0.001).Conclusions: Our results suggest that in ALS, cortical excitability is continuously high regardless of the extent of the peripheral burden, but peripheral hyperexcitability is associated with the extent of the peripheral burden and disease evolution speed. Alterations of ion channel function may play an important role in ALS pathophysiology. [ABSTRACT FROM AUTHOR]

Introduction: This study assessed the morphological changes and diffusion tensor imaging (DTI)-derived parameters of the brachial plexus using magnetic resonance neurography (MRN) in patients with anti-myelin-associated glycoprotein (anti-MAG) neuropathy. Methods: Eight patients with anti-MAG neuropathy underwent MRN of the brachial plexus with 3-dimensional (3D) short tau inversion recovery (STIR) and DTI sequences. Two neuroradiologists and a neurologist qualitatively assessed nerve hypertrophy on 3D STIR MRN. The cross-sectional area (CSA) of the nerve roots was measured. Quantitative analyses of fractional anisotropy (FA) and axial, radial, and mean diffusivity (AD, RD, and MD) were obtained after postprocessing on DTI and manual segmentation. Results: There was nerve hypertrophy in 37.5% of the patients with anti-MAG neuropathy. All patients with anti-MAG neuropathy with nerve hypertrophy were refractory to rituximab therapy. The CSA of the nerve roots was inversely correlated with FA and positively correlated with MD and RD. FA decreased in the nerve roots and inversely correlated with disease duration. Conclusions: Nerve hypertrophy appears in the proximal portion of peripheral nerves, such as the brachial plexus, in patients with anti-MAG neuropathy. Altered diffusion in the nerve roots might be associated with the loss of myelin integrity due to the demyelination process in anti-MAG neuropathy. [ABSTRACT FROM AUTHOR]

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein [M-protein], and skin changes) is a rare systemic disorder characterized by various symptoms caused by underlying plasma cell (PC) dyscrasia. Detection of monoclonal PCs is mandatory for the diagnosis of POEMS syndrome; however, the usefulness of EuroFlow-based next-generation flow cytometry (EuroFlow-NGF) in POEMS syndrome for detecting monoclonal PCs in bone marrow (BM) and the gating strategy suitable for flow cytometry study of POEMS syndrome remain unknown. We employed EuroFlow-NGF-based single-tube eight-color multiparameter flow cytometry (MM-flow) and established a new gating strategy (POEMS-flow) to detect the monoclonal PCs in POEMS syndrome, gating CD38 broadly from dim to bright and CD45 narrowly from negative to dim compared to MM-flow. MM-flow detected monoclonal PCs in 9/25 (36.0%) cases, including 2/2 immunofixation electrophoresis (IFE)-negative cases (100%). However, POEMS-flow detected monoclonal PCs in 18/25 cases (72.0%), including 2/2 IFE-negative cases (100%). POEMS-flow detected monoclonal PCs with immunophenotypes of CD19 - in 17/18 (94.4%). In six cases where post-treatment samples were available, the size of the clones was significantly reduced after the treatment (P = 0.031). POEMS-flow can enhance the identification rate of monoclonal PCs in POEMS syndrome and become a valuable tool for the diagnosis of POEMS syndrome., (© 2024. The Author(s).)

POEMS syndrome is a multisystem disorder associated with monoclonal plasma cell proliferation and the overproduction of vascular endothelial growth factors. The prognosis of POEMS syndrome has significantly improved owing to anti-myeloma treatments such as thalidomide and autologous stem cell transplantation. Therefore, early diagnosis and appropriate treatment are becoming increasingly important. A thorough and comprehensive evaluation of both systemic symptoms and laboratory abnormalities associated with the disease is essential for early diagnosis. The collaboration between neurology and hematology is indispensable to ensure proper treatment.

Background and Objectives: To investigate the current epidemiology, clinical profile, and treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) using a nationwide survey in Japan., Methods: We conducted a nationwide survey using an epidemiologic method established in 2021. Questionnaire sheets were sent to the hospital departments of neurology and pediatric neurology throughout Japan. A primary questionnaire was used to determine the number of patients and their prevalence, and a second questionnaire was used to collect detailed clinical information., Results: The primary survey showed that the estimated number of patients with CIDP was 4,180, with a prevalence of 3.3 per 100,000 persons. In the secondary survey, detailed clinical data were available for 1,257 patients. The male-to-female ratio was 1.5:1, and the median age at onset was 52 years. Typical CIDP was the most frequent subtype (52%), followed by distal (17%) and multifocal/focal CIDP (17%). Initial treatments included immunoglobulin therapy (72%), corticosteroids (15%), and others (13%). Among patients with CIDP, 78% had a progressive/relapsing course, 14% did not respond to first-line treatments, and 18% could not walk independently at the last visit. Among the subtypes, typical CIDP had the most severe disability before treatment (44% of patients could not walk independently). However, they showed a more favorable response to treatment than those with distal or multifocal CIDP. In the subgroup analyses, logistic regression analyses showed that younger age at onset, no muscle atrophy, and abnormal median-normal sural sensory nerve responses were associated with a higher probability of independent walking., Discussion: Our study represents the largest cohort study on CIDP to demonstrate the current epidemiologic and clinical status of CIDP in Japan. Clinical subtypes seem to be associated with different treatment responses and outcomes; therefore, an appropriate treatment strategy according to the pathophysiology of each subtype is required to improve the prognosis of CIDP.

Women of childbearing age can develop autoimmune or hereditary neuromuscular disorders, which can exacerbate during pregnancy. Stabilizing disease activity during pregnancy has a positive impact on pregnancy and delivery outcomes. Selection of therapeutic agents during pregnancy should be based on the evaluation of the risks and benefits involved. Generally, spontaneous vaginal delivery is recommended; however, preterm and emergency cesarean deliveries may become necessary. Novel agents such as biologics and nucleic acid drugs have been introduced in clinical practice in recent years. These novel agents have provided significant benefit to patients with neuromuscular disorders, although verification of their safety profile in pregnant women is an important issue that should be addressed.

The Japanese Society of Neurology discusses research, education, and medical care in the field of neurology and makes recommendations to the national government. Dr. Mizusawa, the former representative director of the Japanese Society of Neurology, selected committee members and made "Recommendations for Promotion of Research for Overcoming Neurological Diseases" in 2013. After that, the Future Vision Committee was established in 2014, and these recommendations have been revised once every few years by the committee. This time, the Future Vision Committee made the latest recommendations from 2020 to 2021. In this section I, we will discuss clinical and research topics of neurology categorized by the methodology, including genetic research, translational research, nucleic acid therapies, iPS research, and nursing/welfare.

The percentage of female faculty members in university hospitals remain low in Japan. This is especially true for the posts of lecturer and above. It remains difficult for women to continue working at university hospitals after going through various life events. However, this situation is definitely changing. There are many challenging and rewarding jobs that can only be found in university hospitals, and I hope that many female doctors will consider a career in a university as one of their options.

The Japanese Society of Neurology discusses research, education, and medical care in the field of neurology and makes recommendations to the national government. Dr. Mizusawa, the former representative director of the Japanese Society of Neurology, selected committee members and made "Recommendations for Promotion of Research for Overcoming Neurological Diseases" in 2013. After that, the Future Vision Committee was established in 2014, and these recommendations have been revised once every few years by the committee. This time, the Future Vision Committee made the latest recommendations from 2020 to 2021. In this document, the general part is 1) What is neurological disease? 2) Current status of neurological disease overcoming research, 3) Significance and necessity of neurological disease overcoming research, 4) Research promotion system for overcoming neurological disease, 5) the roadmap for overcoming neuromuscular diseases, 6) a summary version of these recommendations are explained using figures that are easy for the general public to understand.