Circulating plasmablasts and follicular helper T-cell subsets are associated with antibody-positive autoimmune epilepsy.

Autoimmune epilepsy (AE) is an inflammatory disease of the central nervous system with symptoms that have seizures that are refractory to antiepileptic drugs. Since the diagnosis of AE tends to rely on a limited number of anti-neuronal antibody tests, a more comprehensive analysis of the immune background could achieve better diagnostic accuracy. This study aimed to compare the characteristics of anti-neuronal antibody-positive autoimmune epilepsy (AE/Ab(+)) and antibody-negative suspected autoimmune epilepsy (AE/Ab(-)) groups. A total of 23 patients who met the diagnostic criteria for autoimmune encephalitis with seizures and 11 healthy controls (HC) were enrolled. All patients were comprehensively analyzed for anti-neuronal antibodies; 13 patients were identified in the AE/Ab(+) group and 10 in the AE/Ab(-) group. Differences in clinical characteristics, including laboratory and imaging findings, were evaluated between the groups. In addition, the immunophenotype of peripheral blood mononuclear cells (PBMCs) and CSF mononuclear cells, particularly B cells and circulating Tfh (cTfh) subsets, and multiplex assays of serum and CSF were analyzed using flow cytometry. Patients with AE/Ab(+) did not show any differences in clinical parameters compared to patients with AE/Ab(-). However, the frequency of plasmablasts within PBMCs and CSF in patients with AE/Ab(+) was higher than that in patients with AE/Ab(-) and HC, and the frequency of cTfh17 cells and inducible T-cell co-stimulator (ICOS) expressing cTfh17 cells within cTfh subsets was higher than that in patients with AE/Ab(-). Furthermore, the frequency of ICOShighcTfh17 cells was positively correlated with that of the unswitched memory B cells. We also found that IL-12, IL-23, IL-6, IL-17A, and IFN-γ levels were elevated in the serum and IL-17A and IL-6 levels were elevated in the CSF of patients with AE/Ab(+). Our findings indicate that patients with AE/Ab(+) showed increased differentiation of B cells and cTfh subsets associated with antibody production. The elevated frequency of plasmablasts and ICOS expressing cTfh17 shift in PBMCs may be indicative of the presence of antibodies in patients with AE.

[A case of myopathy, myocarditis, and encephalitis with nonconvulsive status epileptics after immune checkpoint inhibitor therapy for ureter cancer].

A 72-year-old man, who had received pembrolizumab of immune checkpoint inhibitor (ICI) over 6 months for ureter cancer, developed progressive skeletal muscle weakness, dysarthria, dyspnea, and consciousness disturbance over the past two weeks. The systemic work-up tests documented an encephalitis, myopathy, and myocarditis. Multiple autoimmune antibodies of anti-Tr, anti-titin, anti-kv1.4, anti-GM1 and anti-GD1a were positive in the serum. Although myopathy and myocarditis responded to high-dose steroid pulse therapy, encephalopathy deteriorated. Electroencephalogram showed a fluctuated pattern of rhythmic delta activity with fast waves, and a rapid response to intravenous diazepam revealed a condition of nonconvulsive status epileptics (NCSE). The patient had an uneventful course after anti-epileptic medication. The ICIs therapy may trigger a broader activation of multiple autoimmune mechanisms. When an encephalitis by immune-related adverse events does not respond to standard immunotherapy, NCSE may be a main pathophysiological mechanism, thereby anti-epileptics being an alternative treatment option.

Anti-Ma2-Associated Limbic Encephalitis after Termination of Immune Checkpoint Inhibitor Therapy for Malignant Pleural Mesothelioma.

Neurological adverse events of immune checkpoint inhibitor (ICI) therapy mostly develop within 3 months after initiation of ICI treatment. An 82-year-old male with malignant pleural mesothelioma developed anti-Ma2-associated limbic encephalitis at a delay of 18 months after the start of nivolumab therapy (3 months after termination of a 15-month course of ICI treatment). Immunotherapy with steroids and immunoglobulins resulted in moderate neurological improvement. Over the next year, malignant pleural mesothelioma gradually worsened, while the anti-Ma2 antibody test remained positive. Anti-Ma2 paraneoplastic encephalitis may occur after a delay following the discontinuation of ICI therapy.

[A case of adult-onset type II citrullinemia triggered by entering a nursing home with a good response to medium-chain triglyceride oil therapy].

A 49-year-old woman with intellectual disability and a food preference for fried chicken entered a nursing home. After nursing home diet, she developed episodic attacks of hyperammonemic encephalopathy. Her characteristic food preference and the negative results for brain and liver imaging studies suggested urea cycle disorder. A high plasma citrulline level on amino acid analysis and a genetic test for citrine gene confirmed a citrine deficiency (adult-onset type II citrullinemia). Although a low-carbohydrate diet was insufficient, a combination therapy of a low-carbohydrate diet and a medium-chain triglyceride (MCT) oil was effective. MCT oil may be a promising treatment option.

Cerebral Sinovenous Thrombosis and Subdural Hematoma as Treatment-Related Complications in Suprasellar Germ Cell Tumor Associated with Adipsic Diabetes Insipidus.

Cerebral sinovenous thrombosis (CSVT) is a rare but not a negligible complication in pediatric brain tumor. An 11-year-old male with suprasellar germ cell tumor developed treatment-related vascular complications of CSVT and subdural hematoma. The underlying mechanism of CSVT was attributed to multiple risk factors, such as adipsic diabetes insipidus, obesity, central apnea, and chemotherapy-induced endothelial injury. In an attempt to minimize the possible risk of vascular complications, including late effect in pediatric brain tumors, we would like to stress the importance of individualized supportive therapy, i.e., hormone replacement, fluid management, thromboprophylaxis, and bi-level positive airway pressure therapy.

Adult-onset Krabbe disease presenting with an isolated form of peripheral neuropathy.

INTRODUCTION: Adult-onset Krabbe disease is clinically rare and usually affects the pyramidal tracts in the central nervous system. Patients develop a spastic gait, and peripheral neuropathy sometimes occurs simultaneously. METHODS: A 55-year-old woman with consanguineous parents developed slowly progressive, asymmetric muscle weakness and atrophy in her forearms, while her ability to walk remained unaffected without pyramidal tract signs after onset at age 51 years. RESULTS: Nerve conduction studies demonstrated an asymmetric demyelinating-type peripheral neuropathy, and sural nerve biopsy documented reduced myelinated nerve fiber density with uniformly thin myelin sheaths, suggesting hypomyelination. Brain MRI demonstrated minor white-matter injury along the optic radiations, which was associated with asymptomatic, mild, prolonged latency on visual evoked potentials. Laboratory analysis documented low enzyme activity of galactocerebrosidase (GALC) and a known mutation of the GALC gene. CONCLUSION: Isolated peripheral neuropathy occurs very rarely in adult-onset Krabbe disease. Muscle Nerve 54: 152-157, 2016.

Intravenous tissue plasminogen activator for an ischemic stroke with occult double primary cancer.

BACKGROUND: In patients with advanced-stage cancer, systemic thrombolysis with tissue plasminogen activator (tPA) for hyperacute ischemic stroke is not strictly off-label, but it is at higher risk of complications (including bleeding). CASE REPORT: A 71-year-old male with unrecognizable malignancy developed a hemispheric ischemic stroke and received intra-venous tPA within 4.5 h of onset, followed by anticoagulation treatment after 24 h of throm-bolysis. Two days later, the patient had tarry stool and progressive anemia, receiving a blood transfusion. The systemic workup documented the presence of double primary cancers with advanced stage gastric and rectal cancers, and the patient subsequently received palliative care. The outcome at 3 months was a modified Rankin Scale of 5, and the patient died 6 months after the stroke. DISCUSSION: Although systemic thrombolysis with tPA for ischemic stroke in patients with advanced-stage cancer may be performed relatively safely, optimal post-thrombolysis management is important to prevent the complications.

[Cervical retro-odontoid pseudo-tumor treated with posterior decompression surgery].

A cervical retro-odontoid pseudo-tumor, which is considered as a reactive fibrocartilaginous mass, is a rare condition in cervical myelopathy. A 63-year-old male, with repeated neck axial movements by a long-term leisure-time cycling, developed subacute myelopathy. Cervical MRI showed a mass lesion at the retro-odontoid region, compressing to the upper spinal cord. After detailed systemic and local examinations that ruled out primary or metastatic malignancy and inflammatory disorders such as rheumatoid arthritis or chronic kidney diseases, a retro-odontoid pseudo-tumor was diagnosed clinically. The patient underwent posterior C1-laminectomy without tumor resection and its pathological confirmation. After the surgery, his neurological signs of cervical myelopathy improved, and a follow-up MRI one year later showed a mild reduction of the tumor size. The neuro-physicians should recognize the relatively benign pseudotumor in cervical myelopathy, because the tumor size usually shows no further enlargement or regression only after decompression surgery without tumor resection.

[Endogenous endophthalmitis and meningo-encephalitis in septic bacteremia of Klebsiella pneumoniae].

Endogenous endophthalmitis may be a rare condition in acute meningo-encephalitis. A 69-year-old compromised adult abruptly developed septic bacteremia and meningo-encephalitis by Klebsiella pneumoniae. After an improvement from initial conscious disturbance and systemic inflammatory unstable vital conditions by treatment of intensive antibiotic medications, severe unilateral endogenous endophthalmitis with impaired visual acuity was diagnosed by detailed ophthalmological assessments and it deteriorated rapidly. After early vitreous surgery with anti-biotic direct injection, the patient successfully regained visual acuity of 20/200. Among the organisms of endogenous bacterial endophthalmitis, Klebsiella pneumoniae is the worst pathogen mostly resulting in vision loss or enucleation despite any aggressive treatments. The neuro-physicians should recognize the presence of refractory endophthalmitis by Klebsiella pneumoniae, even if clinically asymptomatic, because prompt ophthalmologic diagnosis and managements may improve the outcome.

[Three cases of small brain infarction in the lateral wall of the fourth ventricle presenting with paroxysmal positional vertigo and vomiting].

A lesion responsible for central paroxysmal positional vertigo (PPV) is often found in the dorsolateral wall of the fourth ventricle. A relatively large tumor or hemorrhage in the dorsolateral wall of the fourth ventricle usually causes central PPV, but small brain infarction has hardly been reported to cause central PPV. We report three cases of a small brain infarction in the lateral wall of the fourth ventricle presenting with central PPV. All of the cases showed similar clinical features in which a given recumbent position and a sitting position caused a dizziness associated with nausea and vomiting over an acute period. The symptom lasted one to two months after the onset. In two of our cases, no neurological abnormal signs, except nystagmus, were observed, and initial differentiation of central PPV from peripheral PPV was difficult. Interruption of the vestibular nuclei-archicerebellar loop seems to be responsible for the central PPV. Recognition of the clinical features of central PPV and diffusion-weighted MRI images are important for a precise local diagnosis in small brain infarction showing PPV.