Repeated Intravenous Methylprednisolone May Prevent Deterioration of Hypertrophic Pachymeningitis in Rosai-Dorfman Disease.

Rosai-Dorfman disease (RDD) is a rare form of non-Langerhans cell histiocytosis. Although 20% of patients with RDD have spontaneous remission, some cases with central nervous system (CNS) involvement require surgery or systemic treatment. We encountered a case of RDD in which hypertrophic pachymeningitis was diffuse, eliminating the need for surgical intervention. A 72-year-old Japanese man was diagnosed with RDD based on pathological lymph node findings. Repeated intravenous methylprednisolone (IVMP) administration resolved and stabilized the hypertrophic pachymeningitis without any sequelae. If surgery or anticancer medications are contraindicated, repeated IVMP may be a good therapeutic option for CNS-associated RDD.

Non-lesional white matter changes depicted by q-space diffusional MRI correlate with clinical disabilities in multiple sclerosis.

BACKGROUND: We previously developed an optimized q-space diffusional MRI technique (normalized leptokurtic diffusion [NLD] map) to delineate the demyelinated lesions of multiple sclerosis (MS) patients. Herein, we evaluated the utility of NLD maps to discern the white matter abnormalities in normal-appearing white matter (NAWM) and the abnormalities' possible associations with physical and cognitive disabilities in MS. METHODS: We conducted a retrospective observational study of MS patients treated at our hospital (Jan. 2012 to Dec. 2022). Clinical and MRI data were collected; Processing Speed Test (PST) data were obtained when possible. For a quantitative analysis of the NLD maps, we calculated the NLD index as GVROI/GVREF, where GV is a mean grayscale value in the regions of interest (ROIs) and the reference area (REF; cerebrospinal fluid). RESULTS: One hundred-one individuals with MS were included. The lower corpus callosum and non-lesional WM NLD index were associated with worse Expanded Disability Status Scale (EDSS) and PST scores. The NLD indexes in the corpus callosum (p < 0.0001) and non-lesional white matter (p < 0.0001) were significantly reduced in progressive MS compared to relapsing-remitting MS. We categorized MS severity as moderate/severe (EDSS score ≥ 4 points) and mild (EDSS score < 4 points). The NLD indexes in the corpus callosum (p < 0.0001) and non-lesional white matter (p < 0.0001) were significantly lower in the moderate/severe MS group compared to the mild MS group. CONCLUSION: The NLD map revealed abnormalities in the non-lesional white matter, providing valuable insights for evaluating manifestations in MS patients.

[Primary Progressive Multiple Sclerosis].

Primary progressive multiple sclerosis (PPMS) is a chronic inflammatory disease of the central nervous system that leads to demyelination and neurodegeneration. PPMS is characterized by a gradual accumulation of disabilities that may occur from the initial disease onset. The pathological processes underlying PPMS are complex and include a variety of different mechanisms and pathways, including inflammation, axonal degeneration, microglial activation/oxidation byproducts, mitochondrial injury, and glutamate excitotoxicity. There is currently no disease-modifying drug approved for PPMS in Japan. However, ocrelizumab, a humanized anti-CD20 monoclonal antibody, has been approved for PPMS by the Food and Drug Administration. In addition, some disease-modifying drugs have demonstrated significant efficacy in the treatment of PPMS in clinical trials.

[Demyelinating Disease].

The diagnosis of multiple sclerosis (MS) relies on the demonstration of disease dissemination in space and time, and the exclusion of other neurological disorders. However, it is often difficult to exclude alternative diagnoses with a single MRI examination or during a short clinical course. "Red flags" are recommended as clinical and paraclinical indicators that could help suggest alternative diagnoses to MS, and may improve diagnostic accuracy.

[Multiple Sclerosis].

Treatments for multiple sclerosis have improved dramatically over the last 20 years. These treatments help to reduce relapses and prevent progression of neurodegeneration and physical disability. Other clinical trials on remyelination therapies for multiple sclerosis are ongoing. Various treatments for multiple sclerosis have been developed and are expected to enter the treatment arena soon.

Three cases of non-carryover fingolimod-PML: Is the risk in Japan increased?

Objective: To report the course of 3 recent Japanese and European cases of fingolimod-associated progressive multifocal leukoencephalopathy (PML) and to analyze its risk factors and increased incidence in Japan. Methods: Case series and literature review. Results: Fingolimod-associated PML may cause both supratentorial and infratentorial lesions and a pronounced disability. Diagnosis can be challenging because PML lesions (especially infratentorial) can be initially misdiagnosed as extensive MS lesions. Immune reconstitution inflammatory syndrome (IRIS) develops a few weeks after fingolimod discontinuation and is usually mild. Age factor and therapy duration seem to be relevant because most reported patients were older than 45 years and were treated with fingolimod for more than 3 years. Combined IgG/IgM deficiency has been identified as a possible further predisposing condition in 1 case. Another patient developed an endogenous fungal skin infection, as a sign of generally compromised cellular immune response, shortly before PML. None of the reported patients had lymphocyte counts below 200/µl. Two of the 3 reported and 4 of the 21 (19%) registered fingolimod-PML cases occurred in Japan (estimated risk of 0.652 per 1,000 compared with 0.083 per 1.000 worldwide). Conclusions: The risk of PML under fingolimod is low, but there are no reliable predictors. Despite a mild IRIS phase, it causes profound disability. Patients older than 45 years, especially with known comorbid immunodeficiencies or manifestation of other opportunistic infections, should be monitored more closely. Increased surveillance and identification of further risk factors are urgently needed in Japan.

Cytometric cell-based assays for anti-striational antibodies in myasthenia gravis with myositis and/or myocarditis.

The purposes of the present study were to identify anti-striational antibodies in myasthenia gravis (MG) patients with myositis and/or myocarditis using a combination of cell-based assays and flow cytometry (cytometric cell-based assays) and to describe the main clinical implications. Among 2,609 stored samples collected from all over Japan between 2003 and 2016, we had serum samples from 30 MG patients with myositis and/or myocarditis. Cytometric cell-based assays with titin, ryanodine receptor, and voltage-gated Kv1.4 were performed. Autoantibodies were determined by differences in phycoerythin fluorescence between the 293F cells and titin-transfected cells. MG patients with myositis and/or myocarditis as well as late-onset and thymoma-associated MG had anti-titin, anti-ryanodine receptor, and anti-Kv1.4 antibodies. In contrast, patients with early-onset MG, those with other myopathies and healthy controls did not have anti-titin or anti-Kv1.4 antibodies with some exceptions, but they possessed anti-ryanodine receptor antibodies. Thirty MG patients with myositis and/or myocarditis showed a severe generalized form, and 21 of them had thymoma. Anti-titin and anti-Kv1.4 antibodies were found in 28 (93%) and 15 (50%) patients, respectively, and all patients had at least one of these antibodies. Cytometric cell-based assays thus demonstrated that anti-striational antibodies are biomarkers of MG with myositis and/or myocarditis.