Here, we report a case of antineutrophil cytoplasmic antibody (ANCA)-associated central nervous system (CNS) vasculitis that mimicked a brain tumor. The patient presented with progressive right upper arm weakness. Brain magnetic resonance imaging (MRI) revealed large tumor-like lesions in the left frontal and parietal lobes, with patchy and irregular enhancement with gadolinium and edema. Based on the clinical course and radiological findings, a brain tumor was suspected, and stereotactic brain biopsy was performed. Brain histopathology revealed necrotic tissue and lymphocyte infiltration around small vessels and blood vessel walls. Although the patient's clinical course and pathological findings suggested primary angiitis of CNS (PACNS), double staining for myeloperoxidase (MPO) and CD31 (a neutrophil marker) revealed infiltration of MPO-positive neutrophils in the blood vessel walls. Therefore, we diagnosed the patient with ANCA-associated CNS vasculitis. Because CNS vasculitis, including PACNS, presents nonspecific clinical findings and can depict brain tumor-like MRI findings, CNS vasculitis should be carefully differentiated from brain tumors. Additionally, double staining for MPO and CD31 might be useful for evaluating the pathogenesis of CNS vasculitis.

Chronic cerebrospinal fluid leak with spinal cord compression can mimic the symptoms of ALS, with a snake-eyes appearance on MRI.

Background Few studies have examined B cells among patients with anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), including brain pathology. Objective To describe cases of tumefactive MOGAD with B-cell dominant central nervous system (CNS) infiltration. Methods In this study, we reviewed three cases with clinical and brain histopathological features with tumefactive MOGAD. Results Forty-nine cases of tumefactive brain lesions (TBL) between January 2003 and December 2023 were included; of these, seven had MOGAD. Three underwent a brain biopsy. B-cell dominant CNS infiltration was observed in two cases. In two cases with B-cell dominant CNS infiltration, symptoms included fever, headache, nausea, somnolence, and focal neurological deficits. Cerebrospinal fluid examination revealed both mild pleocytosis and negative oligoclonal IgG bands. Magnetic resonance imaging of the brain revealed large abnormal lesions extending from the basal ganglia to the parietotemporal lobe in both cases. These cases showed a good response to steroids; however, one case relapsed. Brain pathology showed demyelination and perivascular lymphocytic infiltration. One showed small vessel vasculitis. Deposition of the activated complement component was absent or rarely observed. Loss of MOG was observed in two cases. Conclusion MOGAD could exhibit B-cell dominant CNS infiltration and small vessel vasculitis. MOGAD should be considered in differential diagnosis of TBL.

Interferon β and glatiramer acetate are the disease-modifying drugs (DMDs) considered relatively safe for use in pregnant women with multiple sclerosis (MS); however, the safety profile of dimethyl fumarate (DMF) and natalizumab (NTZ) in this population remains inconclusive. Here, we present four cases of pregnant women with MS who were treated with DMF and NTZ (n = 2 patients, each) during their pregnancy and discuss our observations with the use of these drugs and the clinical courses of the patients. We retrospectively examined relapse of MS during pregnancy and after delivery; duration of exposure to DMDs; maternal, fetal, and neonatal adverse events; breastfeeding; and timing of resumption of DMDs. The two patients treated with DMF discontinued treatment 5 or 6 weeks after the discovery of pregnancy. DMF was resumed 1 week postpartum, and mixed breastfeeding was initiated. Brain magnetic resonance imaging in one patient 9 months after delivery revealed a new lesion; however, it was not classified as a clinical relapse. In two patients treated with NTZ, the dosing interval was extended to 6 weeks after the discovery of pregnancy. One patient discontinued NTZ at 30 weeks and the other at 25 weeks of gestation, as a slight restriction in fetal growth was observed owing to hyperemesis gravidarum. Both patients opted for formula feeding, and no relapse was observed within 1 year postpartum. Additionally, no abnormalities were observed in any of the patients during the perinatal period, and their development was normal. Investigation of drug safety in pregnant and parturient women primarily relies on registries, postmarketing surveillance, and case reports due to ethical limitations on conducting randomized controlled trials. Our findings demonstrated that DMF and NTZ were not contraindicated during pregnancy or the perinatal period in women with MS; nevertheless, vigilant monitoring is essential to ensure the safety of these drugs.

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease of the central nervous system caused by the John Cunningham virus. Various brain regions are affected by PML. Therefore, patients with PML show various neurological symptoms. However, tremors are rare neurological symptoms of PML. A 49-year-old man developed intermittent slow tremor in the left hand, bilateral dysesthesia and gait disturbance. Brain magnetic resonance imaging showed hyperintense lesions in the right parietofrontal lobe, right thalamus, left middle cerebellar peduncle, left dentate nucleus, pons and medulla oblongata on fluid-attenuated inversion recovery images. The patient was positive for HIV antibodies. In addition, HIV-1 RNA was increased. Quantitative real-time polymerase chain reaction identified John Cunningham virus DNA in the cerebrospinal fluid; HIV-associated PML was diagnosed. Surface electromyography showed 3-Hz grouped discharges in the left flexor carpi ulnaris and extensor carpi radialis, which were consistent with Holmes tremor (HT). Although we administered antiretroviral therapy and mirtazapine, the neurological and radiological findings progressively worsened, and the patient died on day 90. Including the present case, there have been 10 reported cases of PML with HT. Although tremors are rarely observed in PML, HT might be a common tremor phenotype in patients with PML. If the neurologist observes HT in patients with multiple brain lesions, PML should be considered.

BackgroundThis study aimed to clarify the need for disease-modifying drug (DMD) treatment in elderly patients with multiple sclerosis (MS) aged 50 years or older. MS is an autoimmune, demyelinating disease of the central nervous system that predominantly affects young women. Various DMDs are effective in preventing relapses and slowing the progression of disability in patients with MS. Although disease activity in MS is believed to decrease with aging, a consensus on the appropriate DMD treatment for elderly patients with MS is lacking.MethodologyThis study included elderly patients with MS (>50 years old). We compared the occurrence of relapses, worsening of disability, and conversion to secondary progressive MS (SPMS) between patients with DMD treatment and those without. Logistic regression analysis was performed to determine the predictors of these outcomes. Confounding factors were adjusted using propensity scores.ResultsFrom January 1991 to October 2022, 76 elderly patients with MS were included. The mean age at the last visit was 57.4 +/- 6.3 years, with 51 patients being female. The mean age of onset of MS was 37.1 +/- 10.1 years. Fiftyfour patients were included in the DMD treatment group. The overall relapse rate was 38% (33% and 48% in the DMD treatment and untreated groups, respectively). No significant differences in relapse rates (p = 0.72) or in the Expanded Disability Status Scale (EDSS) scores were identified between the two groups. Kaplan Meier curves showed no differences in the time to first relapse within five years between the two groups. Additionally, no significant predictors of relapse were identified. Among 61 patients with relapsing remitting MS, 25% converted to SPMS during the observation period. Logistic regression analysis showed that older age at the final visit and the presence of brainstem lesions at the age of 50 years were associated with a higher rate of transition to SPMS.ConclusionsIn the present study, no significant difference was found in the rate of relapse, disability progression, and conversion to SPMS between the DMD treatment and untreated groups in elderly patients with MS. Therefore, in patients without long-term relapse, no poor prognostic functional factors or predictors of conversion to SPMS, discontinuation of DMDs may be considered. In addition, the presence of brainstem lesions at 50 years of age may predict the conversion to SPMS. Thus, the continuation of DMD or conversion to an appropriate DMD should be considered in patients with brainstem lesions at 50 years of age.

Although immune checkpoint inhibitors (ICIs) are widely used to treat unresectable malignant tumors, they can cause undesirable side effects called immune-related adverse events, including neurological toxicities. Here, we describe a case of ICI-related peripheral neuropathy (irPN) with characteristic cerebrospinal fluid (CSF) findings. In addition to pleocytosis and increased protein levels, the present case showed increased levels of CSF soluble interleukin-2 receptor (sIL-2R), IL-6, and IL-10, suggesting activated T cell-related autoimmunity. We believe that CSF cytokines and sIL-2R could be novel biomarkers of irPN.

Rhabdomyolysis is a known side effect of levetiracetam. In general, a patient with rhabdomyolysis complains of muscle pain and swelling. Herein, we report four cases of asymptomatic levetiracetam-induced rhabdomyolysis. In all the four cases, the seizures resolved after more than five days. The patients received continuous fluid replacement from the time they were admitted to our hospital. However, serum creatine kinase (CK) levels continued to rise without symptoms consistent with rhabdomyolysis. The serum CK level improved rapidly when levetiracetam was replaced with lacosamide. Because levetiracetam occasionally causes asymptomatic rhabdomyolysis, routine blood tests should be performed after its initiation.

Here, we report a case of IgG4-related brain pseudotumor (IgG4-BP) in a 39-year-old woman, mimicking central nervous system (CNS) lymphoma. She presented with headache, fever, and fatigue. Her medical history was notable for appearance of a tumefactive brain lesion seven years before. Brain biopsy performed at the age of 32 revealed nonspecific inflammatory changes, and her condition improved with oral low-dose steroid therapy. Magnetic resonance imaging performed at the age of 39 identified a hyperintensity lesion with edema located at the medial temporal lobe region adjacent to the inferior horn of the left lateral ventricle on fluid-attenuated inversion recovery images, which showed gadolinium-contrast enhancement on T1-weighted images and a slightly hyperintensity signal on diffusion-weighted images. Methionine-positron emission tomography (PET) depicted a high methionine uptake in the lesion. Additionally, soluble levels of interleukin (IL)-2 receptor (sIL-2R) and IL-10 were increased in cerebrospinal fluid (CSF). Based on these findings, we suspected CNS lymphoma and performed partial resection of the brain lesion. Pathological examination revealed prominent lymphocytic infiltration associated with plasma cell infiltration. Most of the plasma cells were immunoreactive for IgG4. Storiform fibrosis and partially obliterative phlebitis were concomitantly observed. Thus, the patient was diagnosed as having IgG4-BP. To the best of our knowledge, this is the first case report of IgG4-BP with detailed findings obtained by CSF testing, methionine-PET, and pathological examination. Because IgG4-related diseases can present as a pseudotumor that mimics CNS lymphoma, it is essential to carefully differentiate IgG4-BP from CNS lymphoma.

Progressive multifocal leukoencephalopathy (PML) is a fatal central nervous system demyelinating disease that affects immunocompromised patients. Although rare, transplant recipients can develop PML. We report the case of a 60-year-old woman who developed PML 21 years after renal transplantation. Although the clinical course and findings mimicked brain tumor, PML was diagnosed by identification of JCV DNA in CSF and brain pathological findings. Mefloquine and mirtazapine were administered, and immunosuppressants were discontinued. Thereafter, neurological symptoms and radiological findings stabilized. PML can develop in transplant recipients a long time after transplantation. In posttransplantation PML, discontinuation of immunosuppressants may contribute to better outcomes. Therefore, the possibility of immunosuppressant discontinuation should be carefully evaluated.

Objectives To assess a case of paraneoplastic aquaporin-4 (AQP4)-immunoglobulin G (IgG)-seropositive neuromyelitis optica spectrum disorder (NMOSD) associated with teratoma and determine whether it is a paraneoplastic neurologic disorder. Methods A single case study and literature review of 5 cases. Results A 27-year-old woman presented with diplopia, facial nerve palsy, paraplegia, sensory dysfunction of lower limbs, dysuria, nausea, and vomiting. Spinal cord MRI detected an extensive longitudinal lesion in the spinal cord, and brain MRI detected abnormal lesions in the right cerebral peduncle and tegmentum of the pons. CSF analysis revealed positive oligoclonal IgG bands (OCBs). The patient tested positive for AQP4-IgG, confirming a diagnosis of NMOSD. An abdominal CT scan detected an ovarian tumor. After steroid therapy and tumor removal, the patient progressively improved, with only mild sensory dysfunction. Histopathologic analysis of the tumor revealed a teratoma and the presence of glial fibrillary acidic protein (GFAP)(+) neural tissue with AQP4 immunoreactivity, accompanied by lymphocyte infiltration. Including the present case, there have been 6 reported cases of AQP4-IgG-seropositive NMOSD associated with ovarian teratoma (mean onset age, 32.7 years). Of these patients, 5 (83%) presented with nausea and/or vomiting, positive OCB, and dorsal brainstem involvement. Pathologic analyses of the teratoma were available in 5 cases, including the present case, revealing neural tissue with AQP4 immunoreactivity and lymphocyte infiltration in all cases. Conclusions This study suggests that ovarian teratoma may trigger the development of AQP4-IgG-seropositive NMOSD. Further studies are needed to elucidate the pathogenesis of teratoma-associated NMOSD.

Background and Objective To elucidate the relationship between melanoma cell adhesion molecule (MCAM)-expressing lymphocytes and pathogenesis of CNS inflammatory demyelinating diseases (IDDs). Methods Patients with multiple sclerosis (MS) (n = 72) and neuromyelitis optica spectrum disorder (NMOSD, n = 29) were included. We analyzed the frequency and absolute numbers of MCAM(+) lymphocytes (memory helper T [mTh] cells, naive helper T cells, CD8(+) T cells, and B cells) in the peripheral blood (PB) and the CSF of patients with MS and NMOSD, treated with/without disease-modifying drugs (DMDs) or steroids, using flow cytometry. Results The frequency of MCAM(+) cells was higher in the mTh cell subset than that in other lymphocyte subsets. A significant increase in the frequency and the absolute number of MCAM(+) mTh cells was observed in the PB of patients with NMOSD, whereas no increase was observed in the PB of patients with MS. The frequency of CSF MCAM(+) mTh cells was higher in relapsing patients with MS and NMOSD than that in the control group. Although there was no difference in the frequencies of MCAM(+) lymphocytes among the DMD-treated groups, fingolimod decreased the absolute number of MCAM(+) lymphocytes. Discussion MCAM(+) mTh cells were elevated in the CSF of relapsing patients with MS and in both the PB and CSF of patients with NMOSD. These results indicate that MCAM contributes to the pathogenesis of MS and NMOSD through different mechanisms. MCAM could be a therapeutic target of CNS IDDs, and further study is needed to elucidate the underlying mechanism of MCAM in CNS IDD pathogenesis.

Background: Eculizumab is a humanized monoclonal antibody that targets complement protein C5 and inhibits terminal complement-mediated damage at the neuromuscular junction. Recently, the REGAIN study showed that eculizumab was effective and well tolerated in patients with anti-acetylcholine receptor antibody-positive refractory generalized myasthenia gravis (gMG). However, there is no consensus regarding which kind of patients with gMG are selected to preferentially receive eculizumab. Methods: Between January and December 2018, we followed 1388 patients with MG at seven hospitals located in Tokyo and Chiba. We evaluated the clinical features of MG and the patients' quality of life. Clinical status and severity were determined by the recommendations of the Myasthenia Gravis Foundation of America. Results: Of 1388 patients with MG, 12 (0.9%) patients received eculizumab. A total of 11 patients who were anti-acetylcholine receptor antibody-positive with refractory gMG (M:F = 3:8) completed the 26-week treatment with eculizumab. The disease subtypes represented included five cases of early onset MG, one of late-onset MG, and five of thymoma-associated MG. Overall, seven patients had experienced myasthenic crisis. The mean quantitative MG score ranged from 18.6 at baseline to 9.1 at week 26 (p = 0.008). Similarly, the mean MG activities of daily living score ranged from 10.8 at baseline to 4.2 at week 26 (p = 0.002). There were marked improvements in all patients' quality of life status. Overall, seven patients were able to reduce the dose of prednisolone at week 26. All but one patient did not require additional rescue treatment. Overall, one patient with early onset MG could not continue the eculizumab treatment due to nausea and vertigo. Conclusion: We demonstrate that eculizumab provided remarkable benefits for refractory gMG in practical real-world experience as well as in the REGAIN study. Patients with refractory gMG with myasthenia crisis and thymoma-associated MG are suitable for eculizumab administration.

Immunoglobulin G4-related disease (IgG4)-related disease is a newly recognized form of immune-mediated disease, which is characterized by IgG4+ lymphoplasmacytic infiltration and fibrosis in the systemic organs. Although aortitis/periaortitis is a phenotype of IgG4-related disease, the relationship between cerebrovascular disease and IgG4-related disease remains unclear. Herein, we report the case of a 49-year-old man with recurrent stroke induced by IgG4-related arteritis. Case reports or studies examining the association between IgG4-related arteritis and stroke are limited. Although a definitive link between IgG4-related arteritis and stroke has not been established, IgG4-related arteritis should be considered as an etiology in patients with recurrent idiopathic stroke.

•MG is the most common neuromuscular complication of PD-1 inhibitors. •PD-1 inhibitor-associated MG is complicated by myositis and myocarditis. •PD-1 inhibitor-associated MG is frequently more severe than idiopathic MG. •This is the first case with PD-1 inhibitor-associated MG with a history of thymoma.

May 6, 2019April 9, 2019Free AccessMelanoma cell adhesion molecule-expressing memory helper T cells in CNS-demyelinating diseases (P2.2-085)Ryotaro Ikeguchi, Yuko Shimizu, Wakiro Sato, Takashi Yamamura, and Kazuo KitagawaAuthors Info & AffiliationsApril 9, 2019 issue92 (15_supplement)https://doi.org/10.1212/WNL.92.15_supplement.P2.2-085 Letters to the Editor

•Videofluoroscopic examination of swallowing is useful to identify cause of dysphasia.•EMG using hooked-wire electrodes is useful to identify cause of bulbar symptoms.•In individuals with bulbar symptoms, sarcoid myopathy should be considered.•Cricopharyngeal myotomy was effective in relieving bulbar symptoms.

Background: It is often difficult to accurately differentiate tumefactive demyelinating lesions (TDLs) from gliomas using MRI. Objective: To investigate the utility of proton magnetic resonance spectroscopy (MRS) in differentiating TDLs from gliomas. Methods: Cohort 1 included 6 patients with TDLs and 5 with gliomas (3 high-grade), as assessed using a 1.5T MR unit. Cohort 2 included 6 patients with TDLs and 17 patients with gliomas (8 high-grade), as assessed using a 3.0T MR unit. Single-voxel proton MRS was performed to compare the following metabolite area ratios: choline (Cho)/creatine (Cr), N-acetylaspartate (NAA)/Cr, and Cho/NAA in both cohorts. Correlations between the target-to-normal-tissue ratio (TNR) obtained using methionine-positron emission tomography (MET-PET) and each MRS metabolite ratio were examined in a subset of cohort 2 (4 patients with TDLs and 11 with gliomas). Results: Mean Cho/NAA ratio was significantly higher in gliomas than in TDLs or MS in cohort 1 (p < 0.05). Mean Cho/NAA ratio was significantly higher in high-grade gliomas than in TDLs in both cohorts (p(s) < 0.05). In the receiver operating characteristic analysis, high-grade glioma rather than TDL was indicated when the Cho/NAA ratio was >1.72 (the area under the curve was 0.958, and the maximum sensitivity and specificity were 100% and 87%, respectively). A significant positive correlation was observed between Cho/NAA ratio and the MET-PET TNR (r(2) = 0.35, p < 0.05). Conclusion: MRS effectively differentiates TDLs from high-grade gliomas. Therefore, the clinical use of MRS is likely to enhance patient outcomes.