Cerebellar Progressive Multifocal Leukoencephalopathy Mimicking Anti-Yo-Antibody-Associated Rapidly Progressive Cerebellar Syndrome.

A 58-year-old woman with a history of systemic lupus erythematosus (SLE) who was taking prednisolone and mycophenolate mofetil presented with gait disturbances that progressively worsened over a period of 3 months. Her blood test and cerebrospinal fluid (CSF) examination results did not indicate active SLE. Initial brain magnetic resonance imaging (MRI) revealed a small spotty lesion in the left cerebellar peduncle. The clinical course was consistent with rapidly progressive cerebellar syndrome (RPCS), which sometimes involves neuronal antibodies. The line blot assay detected anti-Yo antibodies, but no malignancy was found. Immunohistological techniques using rat brain sections yielded a negative result for anti-Yo antibodies. The second MRI revealed a focal lesion and surrounding spotty lesion in the left cerebellar peduncle, which was consistent with the punctate pattern observed in progressive multifocal leukoencephalopathy (PML). The CSF JCV-DNA test indicated the presence of cerebellar PML. Immunosuppressants were reduced, and mefloquine and mirtazapine were initiated. After approximately 2 years and 1 month, the CSF JCV-DNA results became negative. Cerebellar PML may exhibit a clinical course that is consistent with RPCS. The punctate pattern should be recognized as an early manifestation of PML. The CSF JCV-DNA copy number may serve as a useful indicator of PML stabilization.

Case report: Reversible brain atrophy with low titer anti-amphiphysin antibodies related to gastric adenocarcinoma.

Amphiphysin (AMPH) autoimmunity is associated with a variety of neurological complications, including encephalitis, peripheral neuropathy, myelopathy, and cerebellar syndrome. Its diagnosis is based on clinical neurological deficits and the presence of serum anti-AMPH antibodies. Active immunotherapy, such as intravenous immunoglobulins, steroids, and other immunosuppressive therapies, has been reported to be effective in most patients. However, the extent of recovery varies depending on the case. Herein, we report the case of a 75-year-old woman with semi-rapidly progressive systemic tremors, visual hallucinations, and irritability. Upon hospitalization, she developed a mild fever and cognitive impairment. Brain magnetic resonance imaging (MRI) showed semi-rapidly progressive diffuse cerebral atrophy (DCA) over 3 months, while no clear abnormal intensities were observed. The nerve conduction study revealed sensory and motor neuropathy in the limbs. The fixed tissue-based assay (TBA) failed to detect antineuronal antibodies; however, based on commercial immunoblots, the presence of anti-AMPH antibodies was suspected. Therefore, serum immunoprecipitation was performed, which confirmed the presence of anti-AMPH antibodies. The patient also had gastric adenocarcinoma. High-dose methylprednisolone, and intravenous immunoglobulin were administered and tumor resection was performed, resulting in resolution of the cognitive impairment and improvement in the DCA on the post-treatment MRI. After immunotherapy and tumor resection, the patient's serum was analyzed using immunoprecipitation, which showed a decrease in the level of anti-AMPH antibodies. This case is noteworthy because the DCA showed improvement after immunotherapy and tumor resection. Additionally, this case demonstrates that negative TBA with positive commercial immunoblots do not necessarily indicate false positive results.

[Main Syndrome and Antibody Effects of Autoimmune Encephalitis Caused by Antineuronal Surface Antibodies: An Update].

Since the discovery of a series of antineuronal surface antibodies (NSAs), the diagnostic approach and management of patients with autoimmune encephalitis (AE) and related disorders have undergone a "paradigm shift." However, recent topics described below are also announcing the dawn of the next era in the practice of patients with AE. As the clinical spectrum of NSA-associated AE expands, some types of AE (e.g., anti-DPPX antibody-associated and anti-IgLON5 antibody-associated disorders) can be misclassified into reconsider diagnosis when using the previously published diagnostic criteria. Nobel active immunization animal models of NSA-associated disorders (e.g., anti-NMDAR encephalitis model) can remarkably emphasize the understanding of the pathophysiological effects and main syndrome induced by NSAs. Additionally, several international clinical trials (e.g., rituximab, inebilizumab, ocrelizumab, bortezomib, and rozanolixizumab) for AE treatments, including anti-NMDAR encephalitis, have been implemented. Data from these clinical trials can be used to establish the best treatment of AE.

Leucine-rich Glioma-inactivated 1 Encephalitis Followed by Isaacs Syndrome: Alternating Presence of Pathogenic Autoantibodies to Leucine-rich Glioma-inactivated 1 and Contactin-associated Protein-like 2.

The coexistence of leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) autoantibodies in the same individual is surprisingly often observed. We herein report the first case of LGI1 encephalitis followed by Isaacs syndrome in which LGI1 and CASPR2 antibodies in the serum and cerebrospinal fluid (CSF) were measured during the entire disease course. After the resolution of limbic encephalitis, LGI1 antibodies disappeared from the CSF simultaneously with the appearance of CASPR2 antibodies in the serum. The alternating presence of these pathogenic autoantibodies along with the clinical and phenotypic alternations suggested that LGI1 encephalitis was associated with CASPR2 autoantibody production in the peripheral tissue, leading to CASPR2-associated Isaacs syndrome.

Neurosyphilis presenting as autoimmune limbic encephalitis: A case report and literature review.

RATIONALE: Neurosyphilis presenting as limbic encephalitis (LE) is an important differential diagnosis of autoimmune LE (ALE) defined by Graus in 2016. However, data on the clinical differences and similarities between neurosyphilis presenting as LE and ALE are limited. Herein, we report neurosyphilis presenting as ALE that fulfilled the main items of the Graus ALE criteria. Moreover, a literature review of neurosyphilis presenting as LE was performed. PATIENT CONCERNS: A 66-year-old Japanese man developed nonconvulsive status epilepticus. He presented with progressive personality change and working memory deficits within 3 months prior to admission. A hyperintense lesion localized in the bilateral medial temporal area was observed on T2-weighted fluid-attenuated inversion recovery brain magnetic resonance imaging. Cerebrospinal fluid analysis showed mild pleocytosis and the presence of oligoclonal band. However, in-house assays did not detect antineuronal antibodies. Electroencephalogram showed lateralized rhythmic delta activity in the right temporal area. The serum and cerebrospinal fluid serological and antigen tests for syphilis had positive results. DIAGNOSIS: ALE was initially suspected based on the patient's symptoms and ancillary test findings that fulfilled the Graus ALE criteria. However, based on the positive confirmatory test results for syphilis, a diagnosis of neurosyphilis was eventually made. INTERVENTION: The patient received intravenous midazolam, oral levetiracetam, and lacosamide to control nonconvulsive status epilepticus. In addition, he was treated with intravenous benzylpenicillin at a dose of 24 million units/day for 14 days. OUTCOMES: The patient's cognitive function relatively improved after antibiotic treatment. However, he presented with persistent mild working memory deficit, which was evaluated with the Wechsler Adult Intelligence Scale, 3rd edition. Therefore, on day 103 of hospitalization, he was transferred to another hospital for rehabilitation and long-term care due to limitations in performing activities of daily living. LESSONS: The present case was diagnosed with neurosyphilis presenting as ALE, but meanwhile, in most case, neurosyphilis presenting as LE developed at a slower progressive rate, and it had a broader or restricted involvement on brain MRI than ALE based on the literature review. Therefore, an appropriate differential diagnosis of LE can be obtained by identifying clinical differences between the 2 conditions.

[Anti-NMDAR Encephalitis with Poor Recovery on Steroid Pulse and IVIg: Practical Approach to Intensive Immunotherapy].

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is a well-defined autoimmune encephalitis that is responsive to early intensive immunotherapy. Recent international consensus regarding treatment of NMDARE provides a practical treatment algorithm for immunotherapy escalation, while considering a patient's age, disease severity, and other background information. First-line immunotherapy, which includes an intravenous (IV) corticosteroid pulse with the addition of either intravenous immunoglobulins (IVIg) or plasma exchange, should be offered to all NMDARE-diagnosed patients as soon as possible. In cases where insufficient improvement follows a repeat of the first-line combination therapy (assessed on day 14 after the initial treatment), second-line immunotherapy comprising rituximab or an IV cyclophosphamide pulse (IVCPA) is considered. Per the recent expert consensus, rituximab is preferred to IVCPA as the second-line drug of choice, although the use of either drug in the treatment of NMDARE is off-label. Most patients show gradual improvement in the first few weeks following the introduction of second-line therapy, although repeated and alternating use of both drugs is often required. Some patients, whose NMDARE was refractory to the aforementioned therapies, have also been successfully treated with tocilizumab or bortezomib. Moreover, several international clinical trials involving rituximab, inebilizumab, bortezomib, and rozanolixizumab in the treatment of autoimmune encephalitis (AE, which includes NMDARE) are being conducted to establish high-grade evidence for the treatment of AE.

[Cryptococcal Meningitis with Inadequate Response to Antifungal Therapy or Drug-Induced Side Effects That Make It Difficult to Continue Treatment: Eleven Clinical Issues in Medical Practice].

Cryptococcal meningoencephalitis is mainly caused by Cryptococcus neoformans and accounts for 90% of fungal meningitis cases in Japan. Cryptococcal meningoencephalitis is a rare disease, and similar to tuberculosis meningitis. It often exhibits subacute or chronic progression symptoms such as headache, fever, coma, personality changes, and memory disturbance. Cryptococcal meningoencephalitis often develops in immunosuppressed hosts, but can sometimes occur in healthy individuals, and the mortality rate is 10-25%, indicating a poor prognosis. For the treatment of cryptococcal meningoencephalitis, introduction therapy using a combination of liposomal amphotericin B and flucytosine is recommended. However, in practice, cryptococcal meningoencephalitis is refractory and often requires prolonged treatment; therefore, it is the most difficult to treat among the central nervous system infections. We discuss the following 11 issues: I. Sustainability of first-line treatments, II. Treatment options in case of decreased renal function, III. Association with increased intracranial pressure IV. Causes of visual impairment, V. Necessary steps when symptoms/laboratory findings worsen during antifungal treatment, VI. Cerebral infarction, VII. Difficulty in controlling underlying and comorbid diseases, VIII. Indications for lumbar and ventricular drainage (Ommaya reservoir placement), IX. Pros and cons of concomitant use of corticosteroids, X. Treatment evaluation index: usefulness of head MRI, and XI. Determining the end of treatment and the need for preventive medication.

Novel qEEG Biomarker to Distinguish Anti-NMDAR Encephalitis From Other Types of Autoimmune Encephalitis.

OBJECTIVE: To establish the diagnostic biomarker of electroencephalogram (EEG) to distinguish between anti-N-methyl-d-aspartate receptor encephalitis (NMDARE) and other types of autoimmune encephalitis (other AEs). METHODS: We reviewed the clinical records of 90 patients with acute encephalitis who were treated in our institution between January 2014 and October 2020. We enrolled the patients who fulfilled the diagnostic criteria for possible AE (pAE) defined by Graus et al. (pAE criteria) and then classified into definite NMDARE and other AEs. We investigated the main syndrome and analyzed all admission EEGs using EEG power value (PV). Statistical significance was tested using the Mann-Whitney U test or Fisher's exact test. RESULTS: Twenty-five patients fulfilled the pAE criteria and were classified into 9 with definite NMDARE (median age: 21 years; 8 women) and 12 with other AEs (median age: 37.5 years; 6 women). Four were eventually excluded. Speech dysfunction (9/9 vs. 4/12, p = 0.005) and movement disorders (6/9 vs. 1/12, p = 0.016) were more frequent in NMDARE than in other AEs. The PV analyses revealed the novel quantitative EEG (qEEG) index, namely, fast slow ratio (FSR) (PV of total beta/PV of total theta + delta). The median FSR (0.139 vs. 0.029, p = 0.004) was higher for NMDARE than other AEs, and the receiver operating characteristic curve area of FSR was 0.86 (95% CI 0.70-1.00). A cutoff value of 0.047 yielded a specificity of 0.75 and a sensitivity of 1.00. Focusing on patients who did not meet the "probable NMDARE criteria" in Graus 2016 (proNMDARE criteria) (n = 10), the pretest probability of NMDAR antibody test was 0.30 (3/10), which increased in patients with an FSR greater than the cutoff (n = 5) to 0.60 (3/5). CONCLUSIONS: The NMDARE group highlighted speech dysfunction and movement disorders, and a novel qEEG index FSR accurately distinguished the NMDARE patients from other AEs. The FSR is a promising diagnostic marker for NMDARE that indicates the positive results of NMDAR antibodies in patients with AE when combined with the proNMDARE criteria.

Characteristics of clinical relapses and patient-oriented long-term outcomes of patients with anti-N-methyl-D-aspartate receptor encephalitis.

OBJECTIVE: The main syndrome of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is well-characterized, however, the difference in main symptoms between the initial episode and relapses and patient-oriented long-term outcomes has not been previously described. METHODS: To investigate the difference in syndrome symptoms between episodes and patient-oriented outcomes, we administered a structured questionnaire survey for the patients with anti-NMDARE or their family members. From the answers, we analyzed the frequency of main symptoms (e.g., prodromes, abnormal behaviors, memory deficit, speech disorders, involuntary movements, hypo-ventilation) between episodes and patient-oriented outcomes that included the recovery rate for return to previous work or school. RESULTS: Fifty-six patients were enrolled, and 14 (25%) showed clinical relapse. Details of symptoms at relapse were obtained from 11 patients. Prodrome (27% vs. 96%, p < 0.001), decreased level of consciousness (55% vs. 88%, p = 0.021), seizures (36% vs. 77%, p = 0.012), and involuntary movements (27% vs. 84%, p < 0.001) were significantly less frequent at relapse than initial episode. Although 80% (35/44) of the patients achieved favorable long-term outcomes (modified Rankin Scale score, 0-2), only 61% (27/44) returned to their previous work or school life. CONCLUSION: Anti-NMDARE can relapse with milder and more limited symptoms than those of initial episode, and some patients did not return to their previous activities even after achieving a neurologically favorable outcome.

Case report: Anti-N-methyl-D-aspartate receptor antibody-associated autoimmunity triggered by primary central nervous system B-cell lymphoma.

Background: We herein detail our experience with a unique patient with a primary central nervous system (PCNS) B-cell lymphoma concomitant with anti-N-methyl-d-aspartate receptor (NMDAR) antibodies that satisfied the criteria of "probable anti-NMDAR encephalitis (ProNMDARE)" based on the Graus criteria 2016. Case presentation: A 73-year-old Japanese woman presented with acute pyrexia, agitation, and disturbance of consciousness. She gradually developed a reduction in speech frequency and truncal dystonia causing abnormal posture. Brain magnetic resonance imaging (MRI) demonstrated high-intensity lesions in the bilateral frontal lobes, and her cerebrospinal fluid revealed mild pleocytosis. She was diagnosed with acute encephalitis and treated with acyclovir and intravenous dexamethasone; however, no improvement was observed. She was transferred to our hospital 6 weeks after the onset of her symptoms, and anti-NMDAR antibodies were identified in her cerebrospinal fluid through indirect immunolabeling with rat brain frozen sections and cell-based assays with NR1/NR2 transfected HEK cells. Follow-up MRI showed enlargement of the lesions in the right frontal lobe with gadolinium enhancement, suggesting a brain tumor. Stereotactic surgery was implemented, with subsequent pathological examination revealing that the tumor was consistent with diffuse large B-cell lymphoma (DLBCL) without evidence of systemic satellite lesions. Stereotactic irradiative therapies were then added to her treatment regimen, which partly improved her neurological symptoms with only mild cognitive dysfunction still remaining. A decrease in anti-NMDAR antibody titer was also confirmed after immunotherapy and tumor removal. Conclusions: We herein report our experience with a novel case of PCNS-DLBCL masquerading as anti-NMDAR encephalitis that satisfied the diagnostic criteria of "proNMDARE." Treatment, including tumor removal, ameliorated disease severity and antibody titers of the patient. Our findings suggest that anti-NMDAR antibody-associated autoimmunity can be triggered by PCNS B-cell tumors, although primary brain tumors need to be excluded before establishing a diagnosis of autoimmune encephalitis.

Acute autoimmune transverse myelitis following COVID-19 vaccination: A case report.

RATIONALE: Transverse myelitis is an infectious or noninfectious inflammatory spinal cord syndrome. We report a rare case of transverse myelitis following vaccination against COVID-19. PATIENT CONCERNS: A 70-year-old male presented with progressive sensorimotor dysfunction of the bilateral lower limbs 7 days after receiving the mRNA-1273 vaccine against COVID-19. Spinal magnetic resonance imaging revealed intramedullary lesions with gadolinium enhancement on the Th1/2 and Th5/6 vertebral levels. Cerebrospinal fluid (CSF) testing showed a mildly increased level of total protein and positive oligoclonal bands (OCB). DIAGNOSIS: The patient was diagnosed with acute transverse myelitis. INTERVENTION: The patient received 5 days of intravenous methylprednisolone pulse (1000 mg/day) followed by oral prednisolone (30 mg/day with gradual tapering). OUTCOMES: The patient fully recovered from muscle weakness of the lower limbs. He was discharged from our hospital and able to independently walk without unsteadiness. LESSON: This is a rare case of transverse myelitis following COVID-19 vaccination. Positive OCB in CSF in the present case highlights the possibility of autoimmune processes, including polyclonal activation of B lymphocytes, following vaccination.

Severe relapse of anti-NMDA receptor encephalitis 5 years after initial symptom onset.

Anti-NMDAR encephalitis is characterized by abnormal behavior, cognitive dysfunction, seizures, disturbance of consciousness, central hypoventilation, and movement disorders, with a tendency to occur in younger women. Immunotherapy and tumor removal, where applicable, are effective for this disorder. However, previous papers have shown neurological relapse in 12-24% of cases. We present a case of anti-NMDAR encephalitis relapse 5 years after the initial episode. Although the relapse was much more severe than the initial episode, she recovered with aggressive therapy using first- and second-line immunotherapies. Anti- NMDAR encephalitis could relapse with a more severe clinical course after several years. Aggressive immunotherapy including cyclophosphamide must be necessary even for recurrent cases of anti-NMDAR encephalitis.

Central Nervous System Involvement of Intravascular Large B-Cell Lymphoma on 18F-FDG PET/CT.

Intravascular large B-cell lymphoma is a rare subtype of extranodal diffuse large B-cell lymphoma. We present a case of intravascular large B-cell lymphoma with central nervous system involvement that can be detected on F-FDG PET and may be useful for applications in biopsy and diagnosis.

2-Aminobutyric acid modulates glutathione homeostasis in the myocardium.

A previous report showed that the consumption of glutathione through oxidative stress activates the glutathione synthetic pathway, which is accompanied by production of ophthalmic acid from 2-aminobutyric acid (2-AB). We conducted a comprehensive quantification of serum metabolites using gas chromatography-mass spectrometry in patients with atrial septal defect to find clues for understanding myocardial metabolic regulation, and demonstrated that circulating 2-AB levels reflect hemodynamic changes. However, the metabolism and pathophysiological role of 2-AB remains unclear. We revealed that 2-AB is generated by an amino group transfer reaction to 2-oxobutyric acid, a byproduct of cysteine biosynthesis from cystathionine. Because cysteine is a rate-limiting substrate for glutathione synthesis, we hypothesized that 2-AB reflects glutathione compensation against oxidative stress. A murine cardiomyopathy model induced by doxorubicin supported our hypothesis, i.e., increased reactive oxygen species are accompanied by 2-AB accumulation and compensatory maintenance of myocardial glutathione levels. Intriguingly, we also found that 2-AB increases intracellular glutathione levels by activating AMPK and exerts protective effects against oxidative stress. Finally, we demonstrated that oral administration of 2-AB efficiently raises both circulating and myocardial glutathione levels and protects against doxorubicin-induced cardiomyopathy in mice. This is the first study to demonstrate that 2-AB modulates glutathione homeostasis in the myocardium.

A case of anti-nuclear matrix protein 2 antibody positive myopathy associated with lung cancer.

Myositis-specific autoantibodies (MSAs) are associated with myositis. Anti-nuclear matrix protein 2 (NXP-2) antibody was recently identified as a major MSA and was observed mostly in juvenile dermatomyositis. We report the case of a 44-year-old man who presented with myopathy with anti-NXP-2 antibody and large cell carcinoma of the lung. He was hospitalized because of myalgia and edema of limbs. Neurological examination revealed mild proximal-dominant weakness in all four extremities, and laboratory studies showed elevated creatine kinase level (6,432 IU/l). Needle electromyography showed myogenic patterns. MRI of the lower limbs demonstrated inflammatory lesions in the thighs. Biopsied specimen from the left quadriceps femoris muscle showed mild mononuclear inflammatory infiltrate surrounding muscle fibres but no fiber necrosis. He was diagnosed with myopathy based on neurological examinations and clinical symptoms. His chest X-ray and CT showed tumor shadow on the right upper lung field, but CT didn't indicate the findings of interstitial lung disease. This was surgically removed, and a histological diagnosis of non-small cell lung cancer was suspected. He was also treated with definitive chemoradiotherapy before and after operation. His symptoms of myopathy promptly remitted with the preoperative chemotherapy. His serum analysis was positive for the anti-NXP-2. Further investigation and experience of MSAs are necessary to evaluate the therapeutic strategy against cancer-associated myopathy/myositis.

[Malignant lymphoma presented as recurrent multiple cranial nerve palsy after spontaneous regression of oculomotor nerve palsy: A case report].

We report the case of a 62-year-old man who presented with malignant lymphoma as recurrent multiple cranial nerve palsy after spontaneous regression of oculomotor nerve palsy. He developed ptosis and diplopia due to right oculomotor nerve palsy. Brain MRI/MRA showed no abnormality, and he recovered with conservative medical management. Three months later, he showed diplopia due to right abducens nerve palsy and facial pain and trigeminal sensory loss. Neurological examination revealed multiple cranial nerve palsy involved cranial nerve III, V, IX, and X of the right side. Serum soluble interleukin-2 receptor levels were normal, and cerebrospinal fluid examination was unremarkable. Steroid and subsequent intravenous immunoglobulin therapy didn't improve his symptoms. Six weeks after his admission, he showed rapid enlargement of the cervical lymph node and the right tonsil, and post-contrast T1-weighted MRI showed enlargement and enhancement of the left infraorbital nerve, the bilateral cavernous sinus, the bilateral facial nerves, and the left trigeminal nerve. The histopathologic examination of the tonsil biopsy revealed diffuse large B cell lymphoma. The cause of these symptoms was thought to be infiltrating the cavernous sinus, and adjacent nerves. Spontaneous regression of malignant lymphoma is an exceptional event, but this possibility should be considered so as to the correct diagnosis and proper treatment.

Administration of high dose eicosapentaenoic acid enhances anti-inflammatory properties of high-density lipoprotein in Japanese patients with dyslipidemia.

OBJECTIVE: It has been reported that high-density lipoprotein (HDL) loses anti-inflammatory function and promotes atherosclerosis under pathological conditions. However, no pharmacological therapy to improve HDL function is currently available. We aimed to evaluate the effect of oral administration of eicosapentaenoic acid (EPA) on HDL function. METHODS: Japanese patients with dyslipidemia were treated with EPA (1800 mg/day, 4 weeks), and anti-inflammatory functions of HDL were assessed utilizing in vitro cell-based assays. RESULTS: The EPA treatment did not change serum cholesterol and triglyceride levels, but it significantly increased EPA concentrations in the serum and HDL fraction. The EPA/arachidonic acid ratio in the HDL was in proportion to that in the serum, suggesting that the orally administered EPA was efficiently incorporated into the HDL particles. The HDL after EPA treatment showed significantly increased activity of anti-oxidative enzyme, paraoxonase-1. In addition, the EPA-rich HDL significantly improved endothelial cell migration, and markedly inhibited cytokine-induced expression of vascular cell adhesion molecule-1, in human umbilical vein endothelial cells, compared to HDL before the EPA treatment. Moreover, the EPA-rich HDL augmented cholesterol efflux capacity from macrophages. CONCLUSION: Oral administration of EPA regenerated anti-oxidative and anti-inflammatory functions of HDL, and promoted cholesterol efflux from macrophages. Therefore, EPA may transform "dysfunctional HDL" to "functional", in patients with coronary risk factors.