[Stiff-Person Syndrome: Results of the First Nationwide Survey in Japan].

Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder characterized by progressive axial muscle stiffness, central nervous system hyperexcitability, and painful stimulus-sensitive muscle spasms. A nationwide survey performed in 2018 showed the estimated prevalence of SPS was 0.2 per 100,000 population. Most patients with SPS had antibodies against glutamic acid decarboxylase 65, followed by antibodies to the glycine receptor α-subunit. Usually, patients with SPS showed favorable outcomes; however, some studies have reported intractable SPS. Early diagnosis and aggressive immunotherapy are necessary for management of patients with SPS.

CHCHD2 P14L, found in amyotrophic lateral sclerosis, exhibits cytoplasmic mislocalization and alters Ca2+ homeostasis.

CHCHD2 and CHCHD10, linked to Parkinson's disease and amyotrophic lateral sclerosis-frontotemporal dementia (ALS), respectively, are mitochondrial intermembrane proteins that form a heterodimer. This study aimed to investigate the impact of the CHCHD2 P14L variant, implicated in ALS, on mitochondrial function and its subsequent effects on cellular homeostasis. The missense variant of CHCHD2, P14L, found in a cohort of patients with ALS, mislocalized CHCHD2 to the cytoplasm, leaving CHCHD10 in the mitochondria. Drosophila lacking the CHCHD2 ortholog exhibited mitochondrial degeneration. In contrast, human CHCHD2 P14L, but not wild-type human CHCHD2, failed to suppress this degeneration, suggesting that P14L is a pathogenic variant. The mitochondrial Ca2+ buffering capacity was reduced in Drosophila neurons expressing human CHCHD2 P14L. The altered Ca2+-buffering phenotype was also observed in cultured human neuroblastoma SH-SY5Y cells expressing CHCHD2 P14L. In these cells, transient elevation of cytoplasmic Ca2+ facilitated the activation of calpain and caspase-3, accompanied by the processing and insolubilization of TDP-43. These observations suggest that CHCHD2 P14L causes abnormal Ca2+ dynamics and TDP-43 aggregation, reflecting the pathophysiology of ALS.

Reliability and consistency of the Japanese version of the Primary Lateral Sclerosis Functional Rating Scale.

BACKGROUND: Primary lateral sclerosis (PLS) is an extremely rare condition; therefore, to date no clinical studies have been conducted. The Primary Lateral Sclerosis Functional Rating Scale (PLSFRS) was developed in the United States of America. The PLSFRS is a crucial assessment scale for international collaborative research and future clinical trials for PLS. It is useful for evaluating medical conditions through face-to-face assessments and telephone interviews such as when a face-to-face assessment is not possible due to disasters or the burden of hospital visits. This study assessed the reliability and consistency of in-person and telephone interviews using the Japanese version of the PLSFRS. METHODS: We enrolled 19 Japanese patients who met the specific criteria for inclusion at the six collaborating institutions. The PLSFRS assessments were performed by two evaluators at defined time points and analyzed for intra-rater and inter-rater reliability and consistency between the in-person and telephone interviews. RESULTS: The Japanese version of the PLSFRS was developed by a specialized company and translator, and modified to consider the Japanese lifestyle through a consensus among motor neuron specialists. The quadratic-weighted kappa coefficients for the intra-rater and the inter-rater agreement were substantial (intra-rater: 0.691-1.000, inter-rater: 0.634-1.000). Moreover, the intraclass correlation coefficient for the PLSFRS total score was 0.997 (95% confidence interval, 0.992-0.999). CONCLUSIONS: This study provides results regarding the Japanese version of the PLSFRS intra-rater and inter-rater reliability and consistency between in-person and telephone interviews.

Intermediate phenotype between CMT2Z and DIGFAN associated with a novel MORC2 variant: a case report.

Charcot-Marie-Tooth disease type 2Z is caused by MORC2 mutations and presents with axonal neuropathy. MORC2 mutations can also manifest as developmental delay, impaired growth, dysmorphic facies, and axonal neuropathy (DIGFAN). We report a patient exhibiting an intermediate phenotype between these diseases associated with a novel MORC2 variant. A literature review revealed that the genotype‒phenotype correlation in MORC2-related disorders is complex and that the same mutation can cause a variety of phenotypes.

Factors associated with a placebo effect in Parkinson's disease in clinical trials: a meta-analysis.

OBJECTIVES: Outcomes of clinical trials of treatment in patients with Parkinson's disease (PD) may be influenced by placebo effects. The aim of this study was to determine the factors associated with placebo effects in Parkinson's disease (PD) for guidance with design of future clinical trials. METHODS: Factors associated with placebo effects in PD were examined in a meta-analysis using a random effects model with pooling of placebo effects on the Unified Parkinson's Disease Rating Scale part III (UPDRS III) or Movement Disorder Society sponsored revision of UPDRS III (MDS-UPDRS III). The following prespecified variables were included in the analyses: with or without drug at baseline, with or without a placebo run-in phase, with or without motor fluctuation, published year, number of study sites, placebo administration period, age, sex, disease duration, and daily levodopa dose. Publication bias was assessed by visual inspection of funnel plots and adjusted using the trim-and-fill method. RESULTS: Thirty-eight articles with a total of 4828 subjects satisfied the inclusion criteria. There was a significant placebo effect using UPDRS III or MDS-UPDRS III (SMD = - 0.25; 95% CI - 0.35 to - 0.14; p < 0.001, I2 = 92%). Subgroup and/or multivariate meta-regression analyses revealed that placebo effects were associated with advanced PD (p = 0.04), drug exposure at baseline (p < 0.001), placebo administration period (p < 0.001), and disease duration (p < 0.01). CONCLUSIONS: The results of this study are important as guidance in design of future clinical trials in which the influence of placebo effects is minimized.

Ultra-high dose methylcobalamin and other emerging therapies for amyotrophic lateral sclerosis.

PURPOSE OF REVIEW: Recent development in understanding the pathophysiology of amyotrophic lateral sclerosis (ALS) has led to increasing number of promising test drugs in the pipeline along with the existing ones. We will review these agents focusing on ultra-high dose methylcobalamin, which is pending approval in Japan. Clinical trial design best suited for ALS will also be discussed. RECENT FINDINGS: The most recent phase 3 trial (JETALS) of ultra-high dose methylcobalamin demonstrated significant slowing of ALSFRSR changes (0.5/month), with marked reduction of serum homocysteine levels in the initial double-blind period. The post hoc analysis of the previous phase 2/3 study (E761 trial; Eisai) showed that it prolonged survival of ALS patients, if started within 1 year of onset, but the previous studies suggested its efficacy even in later stages, depending upon the rate of progression. Phase 3 trial of AMX0035 or Relyvrio on the other hand showed negative results despite the promising phase 2 data. The latter did not adjust the disease progression rate before entry. SUMMARY: Ultra-high dose methylcobalamin is not a vitamin supplement but a novel disease-modifying therapy for ALS, and it emphasizes homocysteine as a key factor in the disease process. Clinical trial design must include entering patients early and with similar rates of progression using pretrial observation periods for meaningful results, since ALS is a chronologically heterogenous condition with similar phenotypes.

Complete nanopore repeat sequencing of SCA27B (GAA-FGF14 ataxia) in Japanese.

BACKGROUND: Although pure GAA expansion is considered pathogenic in SCA27B, non-GAA repeat motif is mostly mixed into longer repeat sequences. This study aimed to unravel the complete sequencing of FGF14 repeat expansion to elucidate its repeat motifs and pathogenicity. METHODS: We screened FGF14 repeat expansion in a Japanese cohort of 460 molecularly undiagnosed adult-onset cerebellar ataxia patients and 1022 controls, together with 92 non-Japanese controls, and performed nanopore sequencing of FGF14 repeat expansion. RESULTS: In the Japanese population, the GCA motif was predominantly observed as the non-GAA motif, whereas the GGA motif was frequently detected in non-Japanese controls. The 5'-common flanking variant was observed in all Japanese GAA repeat alleles within normal length, demonstrating its meiotic stability against repeat expansion. In both patients and controls, pure GAA repeat was up to 400 units in length, whereas non-pathogenic GAA-GCA repeat was larger, up to 900 units, but they evolved from different haplotypes, as rs534066520, located just upstream of the repeat sequence, completely discriminated them. Both (GAA)≥250 and (GAA)≥200 were enriched in patients, whereas (GAA-GCA)≥200 was similarly observed in patients and controls, suggesting the pathogenic threshold of (GAA)≥200 for cerebellar ataxia. We identified 14 patients with SCA27B (3.0%), but their single-nucleotide polymorphism genotype indicated different founder alleles between Japanese and Caucasians. The low prevalence of SCA27B in Japanese may be due to the lower allele frequency of (GAA)≥250 in the Japanese population than in Caucasians (0.15% vs 0.32%-1.26%). CONCLUSIONS: FGF14 repeat expansion has unique features of pathogenicity and allelic origin, as revealed by a single ethnic study.

Clinical and Pathological Features of FTDP-17 with MAPT p.K298_H299insQ Mutation.

BACKGROUND: MAPT is a causative gene in frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), a hereditary degenerative disease with various clinical manifestations, including progressive supranuclear palsy, corticobasal syndrome, Parkinson's disease, and frontotemporal dementia. OBJECTIVES: To analyze genetically, biochemically, and pathologically multiple members of two families who exhibited various phenotypes of the disease. METHODS: Genetic analysis included linkage analysis, homozygosity haplotyping, and exome sequencing. We conducted tau protein microtubule polymerization assay, heparin-induced tau aggregation, and western blotting with brain lysate from an autopsy case. We also evaluated abnormal tau aggregation by using anti-tau antibody and PM-PBB3. RESULTS: We identified a variant, c.896_897insACA, p.K298_H299insQ, in the MAPT gene of affected patients. Similar to previous reports, most patients presented with atypical parkinsonism. Biochemical analysis revealed that the mutant tau protein had a reduced ability to polymerize microtubules and formed abnormal fibrous aggregates. Pathological study revealed frontotemporal lobe atrophy, midbrain atrophy, depigmentation of the substantia nigra, and four-repeat tau-positive inclusions in the hippocampus, brainstem, and spinal cord neurons. The inclusion bodies also stained positively with PM-PBB3. CONCLUSIONS: This study confirmed that the insACA mutation caused FTDP-17. The affected patients showed symptoms resembling Parkinson's disease initially and symptoms of progressive supranuclear palsy later. Despite the initial clinical diagnosis of frontotemporal dementia in the autopsy case, the spread of lesions could explain the process of progressive supranuclear palsy. The study of more cases in the future will help clarify the common pathogenesis of MAPT mutations or specific pathogeneses of each mutation.

The clinical practice guideline for the management of amyotrophic lateral sclerosis in Japan-update 2023.

Amyotrophic lateral sclerosis (ALS) is an adult-onset intractable motor neuron disease characterized by selective degeneration of cortical neurons in the frontotemporal lobe and motor neurons in the brainstem and spinal cord. Impairment of these neural networks causes progressive muscle atrophy and weakness that spreads throughout the body, resulting in life-threatening bulbar palsy and respiratory muscle paralysis. However, no therapeutic strategy has yet been established to halt ALS progression. Although evidence for clinical practice in ALS remains insufficient, novel research findings have steadily accumulated in recent years. To provide updated evidence-based or expert consensus recommendations for the diagnosis and management of ALS, the ALS Clinical Practice Guideline Development Committee, approved by the Japanese Society of Neurology, revised and published the Japanese clinical practice guidelines for the management of ALS in 2023. In this guideline, disease-modifying therapies that have accumulated evidence from randomized controlled trials were defined as "Clinical Questions," in which the level of evidence was determined by systematic reviews. In contrast, "Questions and Answers" were defined as issues of clinically important but insufficient evidence, according to reports of a small number of cases, observational studies, and expert opinions. Based on a literature search performed in February 2022, recommendations were reached by consensus, determined by an independent panel, reviewed by external reviewers, and submitted for public comments by Japanese Society of Neurology members before publication. In this article, we summarize the revised Japanese guidelines for ALS, highlighting the regional and cultural diversity of care processes and decision-making. The guidelines cover a broad range of essential topics such as etiology, diagnostic criteria, disease monitoring and treatments, management of symptoms, respiration, rehabilitation, nutrition, metabolism, patient instructions, and various types of care support. We believe that this summary will help improve the daily clinical practice for individuals living with ALS and their caregivers.

Constipation in patients with motor neuron disease: A retrospective longitudinal study.

Background: Constipation has been recently recognized as a complication associated with motor and autonomic dysfunction in patients with motor neuron disease (MND), typified by amyotrophic lateral sclerosis (ALS). However, the long-term characteristics of constipation remain unclear in patients with MND. We longitudinally investigated the prevalence and risk factors of constipation in a consecutive cohort of patients with MND. Methods: Data from Japanese patients with MND enrolled in a single-center registry from June 2017 to December 2021 were retrospectively investigated. The diagnosis of ALS was based on the updated Awaji criteria, and other MND subtypes were also included. The presence or absence of constipation symptoms was determined by referring to the Rome III criteria. The clinical backgrounds and symptoms of patients with and without constipation were compared. Results: Among 155 consecutive patients (female, 63; age, 66.5 ± 12.4 years), 30.3% had constipation at diagnosis and 52.9% after a median follow-up of 18 months. Univariate analysis showed that female sex, use of tracheostomy and invasive ventilation, and delivery of enteral nutrition were more frequent in the constipation group. The Revised Amyotrophic Lateral Sclerosis Functional Rating Scale score was significantly lower in the constipation group, especially for the sub-items related to physical motor function. Multivariate analysis showed that the use of enteral nutrition was an independent risk of constipation, with an odds ratio of 3.69 (95% CI, 1.49-9.17; p = 0.005). Conclusion: Constipation had a high prevalence in patients with MND with impaired motor function. Controlling defecation is important in patients with MND, especially during enteral nutrition.

Nonconvulsive status epilepticus in patients with acute subarachnoid hemorrhage is associated with negative arterial spin labeling on peri-ictal magnetic resonance images.

Purpose: Non-convulsive status epilepticus (NCSE) is characterized by repetitive or continuous seizures without convulsions. Arterial spin labeling (ASL) is useful for assessing hyperperfusion due to neurovascular unit coupling in patients with NCSE; subarachnoid hemorrhage (SAH) impairs the neurovascular unit. We hypothesized that the sensitivity of ASL in detecting NCSE is low in patients with SAH during the acute phase. Methods: Based on ASL findings obtained within 48 h after the clinical suspicion of focal-onset NCSE, we divided 34 patients into ASL-negative (no hyperperfusion; n = 10) and ASL-positive (confirmed hyperperfusion; n = 24) groups. We further divided the two groups according to the NCSE etiology: patients who were diagnosed with NCSE within 14 days after SAH onset (acute SAH, n = 11) and patients with NCSE due to factors other acute SAH (n = 23) and compared their characteristics. Results: In 10 of the 34 patients (29.4 %) the ASL findings were normal. The rate of acute SAH was significantly higher in ASL-negative- (n = 8, 80.0 %) than ASL-positive patients (n = 3, 12.5 %). The rate of patients in aphasic status was significantly lower in ASL-negative patients (n = 1, 10 %) than in ASL-positive patients (n = 12, 50.0 %). Conclusion: Normal ASL findings alone should not be used to exclude a diagnosis of NCSE particularly in patients in the acute phase of SAH with deterioration or no improvement in consciousness.

A Case of Anti-NXP2 Antibody-positive Juvenile Dermatomyositis with Characteristic Fascial Thickening on Muscle Ultrasound and Improvement with Immunotherapy.

We herein report a 12-year-old boy who presented with a fever, erythematous rash on the cheeks, back pain, and dysphagia. Blood tests revealed increased creatine kinase levels, and muscle ultrasonography (MUS) revealed characteristic fascial thickening in the lumbar paraspinal muscles, where myalgia was prominent. Sarcoplasmic expression of myxovirus-resistant protein A on a muscle biopsy and the presence of anti-nuclear matrix protein 2 (NXP2) antibodies confirmed the diagnosis of dermatomyositis. Prednisolone and intravenous immunoglobulin therapy improved the clinical and laboratory parameters as well as fascial thickening. MUS is useful for evaluating fasciitis associated with anti-NXP2 autoantibodies and monitoring therapeutic efficacy.

Prevalence, Clinical Profiles, and Prognosis of Stiff-Person Syndrome in a Japanese Nationwide Survey.

BACKGROUND AND OBJECTIVES: To elucidate current epidemiologic, clinical, and immunologic profiles and treatments of stiff-person syndrome (SPS) in Japan. METHODS: A nationwide mail survey was conducted using an established method. Data processing sheets were sent to randomly selected departments of internal medicine, neurology, pediatrics, psychiatry, and neurosurgery in hospitals and clinics throughout Japan to identify patients with SPS who were seen between January 2015 and December 2017. RESULTS: Thirty cases were identified as glutamic acid decarboxylase 65 (GAD65)-positive SPS cases on the basis of detailed clinical data of 55 cases. Four patients had α1 subunit of glycine receptor (GlyR) antibodies, and 1 patient had both GAD65 and GlyR antibodies. The total estimated number of patients with GAD65-positive SPS was 140, and the estimated prevalence was 0.11 per 100,000 population. The median age at onset was 51 years (range, 26-83 years), and 23 (76%) were female. Of these, 70% had classic SPS, and 30% had stiff-limb syndrome. The median time from symptom onset to diagnosis was significantly longer in the high-titer GAD65 antibody group than in the low-titer group (13 months vs 2.5 months, p = 0.01). The median modified Rankin Scale (mRS) at baseline was 4, and the median mRS at the last follow-up was 2. Among the 29 GAD65-positive patients with ≥1 year follow-up, 7 received only symptomatic treatment, 9 underwent immunotherapy without long-term immunotherapy, and 13 received long-term immunotherapy such as oral prednisolone. The coexistence of type 1 diabetes mellitus and the lack of long-term immunotherapy were independent risk factors for poor outcome (mRS ≥3) in the GAD65-positive patients (odds ratio, 15.0; 95% CI 2.6-131.6; p = 0.001; odds ratio, 19.8; 95% CI 3.2-191.5; p = 0.001, respectively). DISCUSSION: This study provides the current epidemiologic and clinical status of SPS in Japan. The symptom onset to the diagnosis of SPS was longer in patients with high-titer GAD65 antibodies than in those with low-titer GAD65 antibodies. The outcome of patients with SPS was generally favorable, but more aggressive immunotherapies are necessary for GAD65-positive patients with SPS.

Stent retrieval for free-floating thrombus attached to carotid artery stenosis: A report of two cases.

Background: We report two cases who underwent mechanical thrombectomy using a stent retriever in advance of urgent carotid artery stenting (CAS) for carotid artery stenosis with free-floating thrombus (FFT). Case Description: Two patients showing symptomatic carotid artery stenosis with FFT underwent urgent endovascular surgery due to progressive neurological symptoms. The first case showed an FFT with 70% internal carotid artery (ICA) stenosis. After the completion of the common and external carotid artery balloon and distal ICA filter protection, we deployed a 6-mm-diameter stent retriever in the distal part of the stenosis. The white thrombus was retrieved; the angiographic shadow of the FFT disappeared; and CAS was performed. In the second case, due to a 90% severe stenosis lesion with FFT, balloon angioplasty was performed on the lesion using the push wire of the stent retriever. After angioplasty, the stent retriever was smoothly retrieved, and CAS was performed. Postoperative magnetic resonance imaging showed an increase in cerebral embolism in the first case; however, the patient's neurological symptoms improved. The second case showed in-stent plaque protrusion and required two additional stent placements; the patient showed no worsening of his neurological symptoms. Conclusion: In cases of carotid artery stenosis with FFT, it is technically possible to retrieve a thrombus with a stent retriever. Although thrombus removal may help reduce the risk of ischemic complications in a series of urgent CAS procedures, there are concerns such as mechanical irritation to the carotid artery plaque, and its indications and alternative treatments should be carefully considered.

Segmental Zoster Paresis Accompanied by Horner's Syndrome.

We herein report a 90-year-old immunocompromised woman who developed right upper limb weakness and right ptosis with a miotic pupil 1 week after oral therapy for zoster on the right T2 dermatome. The right pupil was dilated with instillation of 1% apraclonidine, indicating Horner's syndrome. The patient was treated with intravenous acyclovir and methylprednisolone. Focal weakness related to zoster, generally known as segmental zoster paresis, improved over five months, but Horner's syndrome remained. We suggest that aggressive intravenous treatment should be considered for rare cases of zoster that occur with a combination of these two neurological conditions.

The necessity to improve disaster preparedness among patients with amyotrophic lateral sclerosis and their families.

Disaster preparation is an important issue for patients with amyotrophic lateral sclerosis (ALS). However, to the best of our knowledge, no studies have investigated disaster preparedness among patients with ALS. In this study, we aimed to investigate disaster preparation in patients with ALS and their caregivers, including their families, in Japan. We conducted a nationwide webinar in September 2022 titled "ALS Café" and distributed a self-report questionnaire to participants with questions about awareness of disaster preparedness, social countermeasures, stockpiles, and electricity demand. Forty-eight patients with ALS (27 male; average age 60.0 ± 9.3 years) and 23 caregivers (8 male; 55.7 ± 9.9 years) responded. The median revised ALS Functional Rating Scale score was 30.5, and 25% of the patients with ALS were on a ventilator. More than 70% of the respondents answered that they were not prepared for disasters, increasing to 89% in patients not using ventilators. In the event of their phones being down, 86% of the respondents had no plans for alternative means of communication. <30% of the respondents, including ventilator users, had secured human resources for transportation. Twenty-five percent of the respondents did not stockpile food and beverages, and 12% of the ventilator users had no government-recommended ventilator preparation equipment. Thus, although patients with ALS and their families with ventilators have a high awareness of disaster preparedness, their awareness remains insufficient. Furthermore, patients with ALS and their families without ventilators have a low awareness of disaster preparedness. Therefore, better education regarding disaster preparedness is necessary for these groups.

Autosomal Recessive Spinocerebellar Ataxia Type 9 With a Response to Phosphate Repletion: A Case Report.

Objective: Autosomal recessive spinocerebellar ataxia type 9 (SCAR9) has received attention due to its potential response to coenzyme Q10 (CoQ10) supplementation; however, the response has so far been limited and variable. Methods: We report a SCAR9 patient with severe hypophosphatemia who responded well to CoQ10 and phosphate repletion. Results: A 70-year-old man (the offspring of a consanguineous marriage) presented with cerebellar ataxia and intense fatigue after exercise. Whole-exome sequencing identified a novel homozygous deletion mutation (NM_020247.5:c.1218_1219del) in COQ8A. We thus diagnosed him with SCAR9. Supplementation of CoQ10 alleviated his symptoms, with the Scale for the Assessment and Rating of Ataxia (SARA) dropping from 16 to 14. During the course of the disease, he demonstrated continuous hypophosphatemia caused by renal phosphate wasting. Gait dysfunction due to weakness and eye movement was partially alleviated, and SARA dropped from 17 to 13 after phosphate repletion. Discussion: Phosphate repletion should be considered for patients with severe hypophosphatemia without any apparent subjective symptoms. In this case, phosphate repletion could have improved myopathy leading to partial improvement in the patient's symptoms. Further analyses regarding the association between COQ8A mutation and phosphate wasting are required to elucidate the detailed pathogenesis. Classification of Evidence: This provides Class IV evidence. This is a single observational study without controls.

Cranial geometry in patients with dystonia and Parkinson's disease.

Abnormal skull shape has been reported in brain disorders. However, no studies have investigated cranial geometry in neurodegenerative disorders. This study aimed to evaluate the cranial geometry of patients with dystonia or Parkinson's disease (PD). Cranial computed tomography images of 36 patients each with idiopathic dystonia (IDYS), PD, and chronic subdural hematoma (CSDH) were analyzed. Those with IDYS had a significantly higher occipital index (OI) than those with CSDH (p = 0.014). When cephalic index (CI) was divided into the normal and abnormal groups, there was a significant difference between those with IDYS and CSDH (p = 0.000, α = 0.017) and between PD and CSDH (p = 0.031, α = 0.033). The age of onset was significantly correlated with the CI of IDYS (τ = - 0.282, p = 0.016). The Burke-Fahn-Marsden Dystonia Rating Scale motor score (BFMDRS-M) showed a significant correlation with OI in IDYS (τ = 0.372, p = 0.002). The cranial geometry of patients with IDYS was significantly different from that of patients with CSDH. There was a significant correlation between age of onset and CI, as well as between BFMDRS-M and OI, suggesting that short heads in the growth phase and skull balance might be related to the genesis of dystonia and its effect on motor symptoms.