Myelin oligodendrocyte glycoprotein antibody and N-methyl-d-aspartate receptor antibody overlapping syndrome: insights from the recent case reports.

The overlapping of two or more types of neural autoantibodies in one patient has increasingly been documented in recent years. The coexistence of myelin oligodendrocyte glycoprotein (MOG) and N-methyl-d-aspartate receptor (NMDAR) antibodies is most common, which leads to a unique condition known as the MOG antibody and NMDAR antibody overlapping syndrome (MNOS). Here, we have reviewed the pathogenesis, clinical manifestations, paraclinical features, and treatment of MNOS. Forty-nine patients with MNOS were included in this study. They were young males with a median onset age of 23 years. No tumors were observed in the patients, and 24 of them reported prodromal symptoms. The most common clinical presentations were psychiatric symptoms (35/49) and seizures (25/49). Abnormalities on magnetic resonance imaging involved the brainstem (11/49), cerebellum (9/49), and parietal lobe (9/49). Most patients mostly responded to immunotherapy and had a good long-term prognosis. However, the overall recurrence rate of MNOS was higher than that of mono antibody-positive diseases. The existence of concurrent NMDAR antibodies should be suspected in patients with MOG antibody-associated disease having psychiatric symptoms, seizures, movement disorders, or autonomic dysfunction. Similarly, serum MOG antibody testing should be performed when patients with anti-NMDAR encephalitis present with atypical clinical manifestations, such as visual impairment and limb weakness, and neuroradiological findings, such as optic nerve, spinal cord, or infratentorial involvement or meningeal enhancement. Early detection of the syndrome and prompt treatment can be beneficial for these patients, and maintenance immunosuppressive therapy is recommended due to the high overall recurrence rate of the syndrome.

Type 2 herpes simplex virus-induced anti-N-methyl-D-aspartate receptor encephalitis responsive to immunoglobulin monotherapy.

Herpes simplex virus-2 encephalitis (HSV2E) in immunocompetent adults is exceptionally rare, and the subsequent onset of autoimmune encephalitis after HSV2E is even less common. This report presents the inaugural Chinese case of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) induced by HSV2E, confirmed via metagenomic next-generation sequencing (mNGS). The patient demonstrated a favorable response to intravenous immunoglobulin (IVIG) monotherapy. This case emphasizes the importance of considering autoimmune encephalitis in patients exhibiting new or recurrent neurological symptoms after HSV2E recovery. Comprehensive mNGS and neuronal antibody testing are essential for timely diagnosis. Moreover, IVIG monotherapy can serve as an effective treatment for NMDARE induced by HSV2, providing a viable alternative, particularly when steroid therapy is contraindicated.

Bilateral hearing loss as the initial presentation of reversible Wernicke's encephalopathy with splenial lesion.

BACKGROUND: Wernicke's encephalopathy (WE) is an acute neurological syndrome resulting from thiamine (vitamin B1) deficiency. It has been recognized increasingly in non-alcoholic patients, such as in the condition of malnutrition. Recent literature has shed light on uncommon symptoms and neuroimaging findings. CASE REPORT: We reported a case of a 44-year-old male who initially presented with bilateral hearing loss, and exhibited abnormality in the splenium of the corpus callosum on magnetic resonance imaging (MRI) diffusion-weighted imaging sequence. On the following day the patient developed new symptoms, including unstable walking, double vision and hallucination. The subsequent brain MRI demonstrated lesions involving periaqueductal grey matter and bilateral medial thalamus, indicating the diagnosis of WE. Empirical treatment with intravenous thiamine resulted in complete clinical and radiological resolution. CONCLUSION: To the best of our knowledge, the current case is the first report of WE in literature with uncommon but reversible manifestations. This case warns us to maintain a heightened level of suspicion for WE in malnourished patients with neurological deficits, despite the possibility of atypical presentations encompassing bilateral hearing disturbances and unusual neuroradiological results. Early diagnosis and timely administration of thiamine in WE are likely to lead to a favorable outcome and full recovery.

Effects of Hypertension on Alzheimer's Disease: Updates in Pathophysiological and Neuroimaging Findings.

Alzheimer's disease (AD) is recognized as the leading cause of dementia, imposing a significant economic toll on society. Despite the emergence of novel therapeutic approaches for AD, their efficacy and safety mandates further validation through rigorous clinical trials. In this context, hypertension (HTN) has garnered considerable attention as an amendable risk factor for AD. Research indicates that hypertension during midlife is associated with an elevated risk of AD in later years, influencing both the onset and progression of the disease. Nevertheless, the relationship between AD and hypertension in the later stages of life remains a subject of debate. Moreover, the consequences of blood pressure reduction on cognitive function, along with the optimal pharmacological interventions and therapeutic thresholds for hypertension, have emerged as pivotal areas of inquiry. This review synthesizes findings on epidemiology, neuroimaging, and biomarkers, and the effects of antihypertensive medications to elucidate the link between hypertension and cognitive performance. We particularly investigate how hypertension and AD are related by plasma sulfide dysregulation, offering possible indicators for future diagnosis and therapy.

Phenotyping the late- and younger-onset neuronal surface antibody-mediated autoimmune encephalitis: a multicenter study.

Neuronal surface antibody-mediated autoimmune encephalitis (NSAE) occurs across a wide age range. However, few studies focused on the onset age and their related characteristics. We aimed to explore the age-dependent profile of NSAE. A total of 134 patients with a definite diagnosis of NSAE were retrospectively enrolled from 3 tertiary hospitals between July 2014 and August 2020. Demographic, clinical, therapeutic, and prognostic data were collected and compared between the late- (≥45) and younger-onset (<45) groups. The results showed that 56 (41.8%) patients were classified as late-onset NSAE, and 78 (58.2%) as younger-onset NSAE. There were more males, especially in the late-onset group (P = 0.036). Prodromal symptoms were more common in the younger-onset group (P = 0.004). Among the onset symptoms, more late-onset patients presented as seizures, while more younger-onset patients presented as psychiatric symptoms. Throughout the disease course, the late-onset patients were more likely to have memory dysfunction (P < 0.001), but less likely to have central hypoventilation (P = 0.045). The late-onset patients also had a significantly lower modified Rankin Scale score on admission (P = 0.042), required intensive care unit (ICU) admission less frequently during hospitalization (P = 0.042) and had a shorter hospital stay (P = 0.014). Our study revealed that the late- and younger-onset NSAE had a distinct spectrum of demographic features, presentations, and prognoses. More attention is needed for the younger-onset patients, given a higher disease severity on admission, more frequent requirement for ICU admission and longer length of stay.

Myelin oligodendrocyte glycoprotein antibody-associated disease preceding primary central nervous system lymphoma: causality or coincidence?

INTRODUCTION: Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphomatous malignancy that affects the brain, spinal cord, leptomeninges, or eyes, in the absence of systemic diffusion. Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a newly identified benign immune-mediated CNS inflammatory disorder with specific anti-MOG antibody seropositivity. These two seemingly unrelated nosological entities both have abundant clinical and radiological manifestations, and whether there is a potential link between them is unclear. CASE REPORT: We describe a 49-year-old man who presented progressive headache, dizziness, and unsteady gait with multifocal scattered T2 hyperintensities with contrast enhancement. The serum anti-MOG antibody test was positive, and a brain biopsy showed inflammatory infiltration. Initially, he was diagnosed with MOGAD and his condition improved after corticosteroid therapy. The patient relapsed with exacerbation of symptoms and neuroimaging showed new mass-forming lesions four months later. A second brain biopsy confirmed PCNSL. DISCUSSION: This is the first report of histologically confirmed successive MOGAD and PCNSL. Our case broadens the phenotypic spectrum of sentinel lesions in PCNSL. Though rare, PCNSL should be considered in patients diagnosed with benign CNS inflammatory disorder and responding well to steroid treatment when their clinical symptoms worsen and the imaging deteriorates. A timely biopsy is critical for accurate diagnosis and appropriate therapy.

Kelch-like protein 11 antibody-associated paraneoplastic neurological syndrome: A state-of-the-art review.

The Kelch-like protein 11 antibody-associated paraneoplastic neurological syndrome (KLHL 11-PNS) was first identified in 2019. This novel antibody, targeting the intracellular KLHL 11 antigen, can be detected in serum and cerebrospinal fluid using tissue-based and cell-based assays. It is thought to be a biomarker for a T-cell autoimmunity response. The most likely immunopathogenesis of KLHL 11-PNS appears to be linked to cytotoxic T-cell-mediated neuronal injury and loss. Patients have adult-male predilection, rhombencephalitis (brainstem and / or cerebellar involvement), and a robust oncological correlation with testicular germ cell tumors (predominately seminoma). Brain magnetic resonance imaging demonstrated T2 / fluid-attenuated inversion recovery hyperintensities and atrophy of the temporal lobe, cerebellum, and brainstem. Most patients responded poorly to immunotherapy and oncotherapy and thus had a poor long-term prognosis. We review the literature and provide an update of current knowledge regarding KLHL 11-PNS, including epidemiology, underlying mechanism, clinical presentations, paraclinical and oncological findings, diagnostic workup, and treatment approaches.

Seizures and epilepsy in multiple sclerosis, aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-associated disease.

Seizure is one of the manifestations of central nervous system inflammatory demyelinating diseases, which mainly include multiple sclerosis (MS), aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Acute symptomatic seizures secondary to MS/AQP4-NMOSD/MOGAD occur in the acute phase of the diseases, and are more frequent in MOGAD. In contrast, recurrent nonprovoked seizures, mainly attributed to autoimmune-associated epilepsy, occur in the nonacute phase of the diseases. Seizures in MS/AQP4-NMOSD/MOGAD mostly have a focal onset. MS patients with concomitant systemic infections, earlier onset, and greater disease activity are more likely to have seizures, whereas factors such as greater MS severity, the presence of status epilepticus, and cortical damage indicate a greater risk of developing epilepsy. In MOGAD, cerebral cortical encephalitis and acute disseminated encephalomyelitis (ADEM)-like phenotypes (predominately ADEM and multiphasic disseminated encephalomyelitis) indicate a greater seizure risk. Multiple relapses with ADEM-like phenotypes predict epilepsy in pediatrics with MOGAD. Pathophysiologically, acute symptomatic seizures in MS are associated with neuronal hyperexcitability secondary to inflammation and demyelination. Chronic epilepsy in MS is largely due to gliosis, neuronal dysfunction, and synaptic abnormalities. The mainstay of treatment for seizures secondary to MS/AQP4-NMOSD/MOGAD consists of immunotherapy along with antiseizure medications. This critical review discusses the most-updated evidence on epidemiology, clinical correlates, and inflammatory mechanisms underlying seizures and epilepsy in MS/AQP4-NMOSD/MOGAD. Treatment cautions including drug-drug interactions and the impact of treatments on the diseases are outlined. We also highlight pitfalls and challenges in managing such patients and future research perspectives to address unsolved questions.

Lymphomatosis cerebri: a rare diffuse leukoencephalopathy you should never miss.

INTRODUCTION: Lymphomatosis cerebri (LC) is a rare variant of primary central nervous system lymphoma that diffusely involves throughout the brain. In recent years, increasingly reported cases have notably broadened the spectrum of clinical and radiological features; however, it remains a great diagnostic challenge. CASE REPORT: We reported an atypical case of LC presented with subacute onset of focal neurological deficits and diffuse T2 hyperintensities without contrast enhancement on magnetic resonance imaging. He was initially considered as inflammatory leukoencephalopathy and received empirical corticosteroids, showing a dramatically clinical response. Three months later, the patient relapsed with deteriorating symptoms and enlarged brain lesions with mass-like enhancement. A diagnosis of LC was finally established according to the radiological and pathological findings. DISCUSSION: Though rare, LC should always be kept as a differential diagnosis of diffuse leukoencephalopathy. Neurologists should be aware of every detailed information about LC to avoid a delay of diagnostic biopsy in clinical practice.

Evaluation of brain and spinal cord lesion distribution criteria at disease onset in distinguishing NMOSD from MS and MOG antibody-associated disorder.

OBJECTIVE: To validate the recently proposed imaging criteria in distinguishing aquaporin-4 antibody (AQP4-ab)-seropositive neuromyelitis optica spectrum disorder (NMOSD) from multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein antibody-associated disorder (MOG-AD) at disease onset in a Chinese population. METHODS: We enrolled 241 patients in this retrospective study, including 143 AQP4-ab-seropositive NMOSD, 73 MS, and 25 MOG-AD. Cacciaguerra's criteria were described as fulfillment of at least 2/5 conditions including the absence of the combined juxtacortical/cortical lesions, the presence of longitudinal extensive transverse myelitis (LETM) lesions, the presence of periependymal-lateral ventricles lesions, the absence of Dawson's fingers lesions, and the absence of periventricular lesions. RESULTS: Fulfillment of at least 3/5 conditions was able to differentiate NMOSD from MS with a good diagnostic performance (accuracy = 0.92, sensitivity = 0.91, specificity = 0.93), yet failed to differentiate NMOSD from MOG-AD. LETM lesions showed the highest accuracy (0.78), sensitivity (0.70), and specificity (0.97) for NMSOD. CONCLUSION: Our research suggested the utility of Cacciaguerra's criteria in a Chinese population at disease onset. A better diagnostic performance in NMOSD could be attained with at least 3/5 conditions fulfilled. Yet their utility in distinguishing NMOSD from MOG-AD was limited.

Clinical, imaging, and follow-up observations of patients with anti-GABAB receptor encephalitis.

PURPOSE: Anti-gamma-aminobutyric acid B (anti-GABAB) receptor encephalitis is a newly described type of autoimmune encephalitis. We report a case series of patients diagnosed with anti-GABAB receptor encephalitis in China, focusing on their presentations, laboratory and imaging results, and outcomes, as well as the treatment strategies which were employed. METHODS: Data from patients diagnosed with anti-GABAB receptor encephalitis in the Second Affiliated Hospital, School of Medicine, Zhejiang University, from January 2014 to June 2015 were retrospectively collected and analyzed. Based on specific diagnostic criteria, seven cases were included. RESULTS: Six of the seven patients were males, and a median age at presentation of 56 years (range: 4-71 years). Seizures were the most common initial symptom, and all patients developed symptoms of typical limbic encephalitis during their disease course. Additional types of autoantibodies were identified in four patients. After presentation, three patients were found to have small cell lung cancer and one patient was eventually diagnosed with thymoma. All patients accepted first-line immune therapy, but only one chose tumor treatment. The three tumor-free patients had a good outcome, whereas those with tumors had a poor one. Finally, there were no relapses during follow-up. CONCLUSION: Anti-GABAB receptor encephalitis is a rare, unique autoimmune disease, and is often associated with tumors. It should be considered in the differential diagnosis for middle and senior-aged patients who present with predominantly limbic encephalitis symptoms. Importantly, earlier recognition of this potentially treatable condition could improve its overall prognosis.

Subarachnoid Hemorrhage due to Spinal Cord Schwannoma Presenting Findings Mimicking Meningitis.

BACKGROUND: Subarachnoid hemorrhage (SAH) of spinal origin is uncommon in clinical practice, and spinal schwannomas associated with SAH are even more rarely reported. We report an unusual case of spinal SAH mimicking meningitis with normal brain computed tomography (CT)/magnetic resonance imaging (MRI) and negative CT angiography. Cerebrospinal fluid examination results were consistent with the manifestation of SAH. Spinal MRI performed subsequently showed an intradural extramedullary mass. The patient received surgery and was finally diagnosed with spinal cord schwannoma. METHOD: A retrospective chart review of the patient was performed. RESULTS: We describe a case of SAH due to spinal cord schwannoma. Our case highlights the importance of careful history taking and complete evaluation. CONCLUSION: We emphasize that spinal causes should always be ruled out in patients with angionegative SAH and that schwannoma should be considered in the differential diagnosis of SAH etiologies even though rare.

Variant Type of Posterior Reversible Encephalopathy Syndrome with Diffuse Cerebral White Matter and Brainstem Involvement Associated with Intracranial Hemorrhage.

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological syndrome characterized by reversible vasogenic edema typically at a posterior location of the cerebrum. PRES with prominent brainstem or basal ganglia involvement is defined as central-variant, which is rare. We herein report an atypical case of a 35-year-old man with a 2-year history of untreated hypertension who complained of recurrent dizziness. The patient presented with brainstem and diffuse white matter involvement associated with intracranial hemorrhage and recovered fully after therapy. Recognition of this uncommon benign syndrome as a potentially treatable disorder can be of great importance.

Reliability and validity of the Chinese version of the Neurological Disorders Depression Inventory for Epilepsy (C-NDDI-E).

OBJECTIVE: The aim of this study was to evaluate the clinical reliability and validity of the Chinese version of the Neurological Disorders Depression Inventory for Epilepsy (C-NDDI-E). METHODS: A total of 248 Chinese patients with epilepsy underwent psychometric tests, including the Chinese version of the Mini International Neuropsychiatric Interview (C-MINI), the Chinese version of the Beck Depression Inventory - II (C-BDI-II), and the C-NDDI-E. RESULTS: None of the patients had difficulties understanding or completing the C-NDDI-E. Cronbach's α coefficient was 0.824. At a cutoff score of ≥14, the C-NDDI-E had a sensitivity of 0.854, a specificity of 0.899, a positive predictive value of 0.625, and a negative predictive value of 0.969. The scores for the C-NDDI-E were positively correlated with those for the C-BDI-II (P<0.001). CONCLUSION: The C-NDDI-E is a reliable and valid screening tool for the detection of major depression in Chinese patients with epilepsy.

Baló's concentric sclerosis with spontaneous remission and favorable prognosis.

Introduction: Baló's concentric sclerosis (BCS) is a rare type of central nervous system demyelinating disorder. Most patients with BCS are treated with corticosteroids, and spontaneous remission has seldom been described. Case presentation: A 46-year-old man presented with a subacute-onset headache and memory loss. Brain magnetic resonance imaging (MRI) revealed multiple onion-shaped ring lesions with mild enhancement in the outermost ring. A brain biopsy revealed significant myelin loss. The diagnosis of BCS was established based on the MRI results and pathological findings. Interestingly, the patient recovered almost completely without immunotherapy, with repeated brain MRI at the 1-year follow-up showing an obvious reduction in the extent of the lesions. Conclusion: Neurologists should improve the recognition of the typical MRI features of BCS to avoid unnecessary biopsies. Although rare, spontaneous remission can be observed in clinical practice.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS): contemporary advances and current controversies.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory syndrome with characteristic clinical, radiological, and pathological features, and can be effectively treated with corticosteroid-based immunotherapies. The exact pathogenesis of CLIPPERS remains unclear, and specific diagnostic biomarkers are not available. According to the 2017 diagnostic criteria, probable CLIPPERS should be considered in middle-aged patients with subacute onset of pontocerebellar symptoms and typical punctuate and curvilinear gadolinium enhancement lesions ("salt-and-pepper" appearance) located in the hindbrain (especially pons) on magnetic resonance imaging. In addition, CLIPPERS-mimics, such as central nervous system (CNS) lymphoma, and several antibody-associated autoimmune CNS diseases (e.g., myelin oligodendrocyte glycoprotein antibody-associated disease, autoimmune glial fibrillary acidic protein astrocytopathy, and anti-N-methyl-D-aspartate receptor encephalitis), should be extensively excluded. The prerequisite for definite CLIPPERS is the perivascular T-cell-predominant inflammatory infiltration observed on pathological analysis. A biopsy is strongly suggested when clinical/radiological red flags are present. Most patients with CLIPPERS respond well to corticosteroids and have a good prognosis. Long-term low-dose corticosteroid maintenance therapy or corticosteroids coupled with immunosuppressants are recommended to prevent the recurrence of the syndrome. The potential progression of CLIPPERS to lymphoma has been suggested in some cases; therefore, at least 2-year clinical and radiological follow-up is essential. Here, we critically review the recent developments and provided an update on the clinical characteristics, diagnostic criteria, differential diagnoses, and therapeutic management of CLIPPERS. We also discuss the current controversies in this context that can be resolved in future research studies.

Anti-adenylate kinase 5 encephalitis: Clinical characteristics, diagnosis, and management of this rare entity.

The spectrum and understanding of antibody-positive autoimmune encephalitis (AE) have expanded over the past few decades. In 2007, a rare subtype of AE known as anti-adenylate kinase 5 (AK5) encephalitis, was first reported. This disease is more common in elderly males, with limbic encephalitis as the core phenotype (characterized by subacute anterograde amnesia, sometimes with psychiatric symptoms, and rarely with seizures). Brain magnetic resonance imaging typically demonstrated initial temporal lobe T2/fluid-attenuated inversion recovery hyperintensities, and subsequent atrophy. No concomitant tumors have been found yet. AK5 antibody, targeting the intracellular antigen, is a biomarker for a non-paraneoplastic T-cell autoimmunity response, and can be detected in serum and cerebrospinal fluid using tissue-based and cell-based assays. Cytotoxic T-cell-mediating neuronal injury and loss play a pivotal role in the immunopathogenesis of anti-AK5 encephalitis. Patients mostly show poor response to immunotherapy and thus a poor prognosis in the long run. Herein, we review the literature and provide updated knowledge of this less-known entity, focusing on clinical characteristics, paraclinical findings, diagnosis process, and therapeutic approaches.

Late-onset neuromyelitis optica spectrum disorder mimicking stroke in an elderly Chinese man: Case report.

Context: Few cases of neuromyelitis optica spectrum disorder (NMOSD) with an onset older than 75 years old have been reported.Finding: Herein, we report an 81-year-old Chinese male initially suspected of acute stroke but was ultimately diagnosed with NMOSD.Conclusion: Even in the elderly, a diagnosis of NMOSD should be considered for patients with myelitis, especially those with longitudinally extensive spinal cord involvement. Testing for aquaporin 4 antibody in this scenario is recommended for further confirmation. Once diagnosed, careful consideration of treatment options and close monitoring of side effects are important to improve prognosis in elderly patients.

Case Report: Neuromyelitis Optica Spectrum Disorder With Progressive Elevation of Cerebrospinal Fluid Cell Count and Protein Level Mimicking Infectious Meningomyelitis: A Diagnostic Challenge.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune-mediated idiopathic inflammatory demyelinating disease with a typical clinical presentation of optic neuritis, acute myelitis, and area postrema syndrome. Most NMOSD patients are seropositive for disease-specific and pathogenic aquaporin-4 (AQP4) antibodies, which are key markers for the NMOSD diagnosis. Herein, we report an atypical case of a 41-year-old man who complained of intractable hiccups and vomiting at disease onset, followed by fever, headache, back pain, progressive paresthesia, and weakness of extremities later on. Magnetic resonance imaging revealed longitudinally extensive transverse myelitis. Cerebrospinal fluid analysis showed progressive increases in the white blood cell count and the protein level, which were accompanied by the deterioration of clinical manifestations. The patient was initially suspected of infectious meningomyelitis but was finally diagnosed with NMOSD. This case with distinct cerebrospinal fluid findings broadens the phenotypic spectrum of NMOSD. Furthermore, it also highlights the clinical value of AQP4 antibody test for early definitive diagnosis and proper treatment.