Increased Intrathecal B and Plasma Cells in Patients With Anti-IgLON5 Disease

Background and ObjectivesDespite detection of autoantibodies, anti-IgLON5 disease was historically considered a tau-associated neurodegenerative disease, with limited treatment options and detrimental consequences for the patients. Observations in increasing case numbers hint toward underlying inflammatory mechanisms that, early detection provided, open a valuable window of opportunity for therapeutic intervention. We aimed to further substantiate this view by studying the CSF of patients with anti-IgLON5.MethodsWe identified 11 patients with anti-IgLON5 from our database and compared clinical, MRI, and CSF findings with a cohort of 20 patients with progressive supranuclear palsy (PSP) (as a noninflammatory tauopathy) and 22 patients with functional neurologic disorder.ResultsPatients with anti-IgLON5 show inflammatory changes in routine CSF analysis, an increase in B-lymphocyte frequency, and the presence of plasma cells in comparison to the PSP-control group and functional neurologic disease controls. Patients with intrathecal plasma cells showed a clinical response to rituximab.DiscussionOur findings indicate the importance of inflammatory mechanisms, in particular in early and acute anti-IgLON5 cases, which may support the use of immune-suppressive treatments in these cases. The main limitation of the study is the small number of cases due to the rarity of the disease.

Taking phenomenology beyond the first-person perspective: conceptual grounding in the collection and analysis of observational evidence

Phenomenology has been adapted for use in qualitative health research, where it’s often used as a method for conducting interviews and analyzing interview data. But how can phenomenologists study subjects who cannot accurately reflect upon or report their own experiences, for instance, because of a psychiatric or neurological disorder? For conditions like these, qualitative researchers may gain more insight by conducting observational studies in lieu of, or in conjunction with, interviews. In this article, we introduce a phenomenological approach to conducting this kind of observational research. The approach relies on conceptual grounding to focus a study on specific aspects of the participants’ experiences. Moreover, the approach maintains the openness to novel discoveries that qualitative research requires while also providing a structured framework for data collection and analysis. To illustrate its practical application, we use examples of hemispatial neglect—a neurologic disorder in which patients characteristically lack awareness of their own illness and bodily capacities. However, the approach that we describe can be applied more broadly to the study of complex illness experiences and other experiential alterations.

Two different presentations of de novo variants of CSNK2B: two case reports

Background Poirier–Bienvenu neurodevelopmental syndrome is a neurologic disorder caused by mutations in the CSNK2B gene. It is mostly characterized by early-onset seizures, hypotonia, and mild dysmorphic features. Craniodigital syndrome is a recently described disorder also related to CSNK2B, with a single report in the literature. Objective To report two unrelated cases of children harboring CSNK2B variants (NM_001320.6) who presented with distinct diseases. Case report Case 1 is a 7-month-old, Caucasian, female patient with chief complaints of severe hypotonia and drug-refractory myoclonic epilepsy, with a likely pathogenic de novo variant c.494A>G (p.His165Arg). Case 2 is a 5-year-old male, Latino patient with craniodigital intellectual disability syndrome subjacent to a de novo, likely pathogenic variant c.94G>T (p.Asp32Tyr). His dysmorphic features included facial dysmorphisms, supernumerary nipples, and left-hand postaxial polydactyly. Conclusion This report suggest that the CSNK2B gene may be involved in the physiopathology of neurodevelopmental disorders and variable dysmorphic features.

Growth and Overall Health of Patients with SLC13A5 Citrate Transporter Disorder

We were interested in elucidating the non-neurologic health of patients with autosomal recessive SLC13A5 Citrate Transporter (NaCT) Disorder. Multiple variants have been reported that cause a loss of transporter activity, resulting in significant neurologic impairment, including seizures, as well as motor and cognitive dysfunction. Additionally, most patients lack tooth enamel (amelogenesis imperfecta). However, patients have not had their overall health and growth described in detail. Here we characterized the non-neurologic health of 15 patients with medical records uploaded to Ciitizen, a cloud-based patient medical records portal. Ciitizen used a query method for data extraction. Overall, the patients’ records suggested a moderate number of gastrointestinal issues related to feeding, reflux, vomiting and weight gain and a diverse number of respiratory complaints. Other organ systems had single or no abnormal diagnoses, including liver, renal and cardiac. Growth parameters were mostly in the normal range during early life, with a trend toward slower growth in the few adolescent patients with data available. The gastrointestinal and pulmonary issues may at least partially be explained by the severity of the neurologic disorder. More data are needed to clarify if growth is impacted during adolescence and if adult patients develop or are protected from non-neurologic disorders.

Epilepsy-causing Reelin mutations result in impaired secretion and intracellular degradation of mutant proteins

Autosomal dominant lateral temporal epilepsy (ADLTE) is a genetically heterogeneous neurologic disorder clinically characterized by focal seizures with auditory symptoms and/or aphasia. About 20% of ADLTE families segregate disease-causing heterozygous mutations in RELN, a brain-expressed gene encoding the secreted protein Reelin. Using a cell-based secretion assay, we show that pathogenic RELN mutations abolish or significantly reduce secretion of mutant proteins, and that this secretion defect results from impaired trafficking of mutant Reelin along the secretory pathway. Confocal immunofluorescence analysis of transiently transfected cells shows that Reelin mutant proteins are degraded by the autophagy system, as revealed by increased formation of autophagosomes immunoreacting with the autophagy markers p62 and LC3. In addition, LC3 immunoblotting shows a significant increase of autophagy flux due to mutant overexpression. Finally, we show that the secretion defect of mutant proteins can be partially rescued by small-molecule correctors. Altogether, these results suggest that Reelin mutant proteins are not properly secreted and that they are degraded through the autophagy pathway.

20-Year-old female with fever, cough, and dyspnea: Acute lupus pneumonitis during the pandemic of coronavirus disease 2019 (COVID-19)

Acute lupus pneumonitis (ALP) is a rare first-presenting manifestation of systemic lupus erythematosus (SLE). The characteristic symptoms are rapid onset of fever, cough (sometimes with hemoptysis), and dyspnea. ALP may progress to acute respiratory distress syndrome (ARDS), and it is a potentially fatal disease unless treated. Coronavirus disease 19 (COVID-19) has overlaps with ALP in terms of clinical presentation, and laboratory and radiological findings. This report describes a case of a young female patient presenting with ARDS during the pandemic of COVID-19. She had pancytopenia, elevated CRP, ferritin, and liver indices resembling macrophage activation syndrome. She also had hepatosplenomegaly, a small spleen infarct, adenopathy, minimal pleural, and pericardial effusion. After excluding COVID-19 by PCR and antibody tests, and other infections by cultures, with the help of antinuclear antibody and anti–double-stranded DNA, SLE and ALP were diagnosed, and she was treated with high-dose steroid and intravenous immunoglobulin. In conclusion, if patients presenting with pneumonia or ARDS have one or more of the findings of arthritis, serositis, rash, oral/nasopharyngeal ulcerations, cytopenias, and renal or neurologic disorder, SLE and ALP should be considered in differential diagnoses. Because of the high mortality rate of ALP reaching up to 50%, early diagnosis and immunosuppressive therapy are of vital importance.

Argonaute Autoantibodies as Biomarkers in Autoimmune Neurologic Diseases

ObjectiveTo identify and characterize autoantibodies (Abs) as novel biomarkers for an autoimmune context in patients with central and peripheral neurologic diseases.MethodsTwo distinct approaches (immunoprecipitation/mass spectrometry–based proteomics and protein microarrays) and patients' sera and CSF were used. The specificity of the identified target was confirmed by cell-based assay (CBA) in 856 control samples.ResultsUsing the 2 methods as well as sera and CSF of patients with central and peripheral neurologic involvement, we identified Abs against the family of Argonaute proteins (mainly AGO1 and AGO2), which were already reported in systemic autoimmunity. AGO-Abs were mostly of immunoglobulin G 1 subclass and conformation dependent. Using CBA, AGO-Abs were detected in 21 patients with a high suspicion of autoimmune neurologic diseases (71.4% were women; median age 57 years) and only in 4/856 (0.5%) controls analyzed by CBA (1 diagnosed with small-cell lung cancer and the other 3 with Sjögren syndrome). Among the 21 neurologic patients identified, the main clinical presentations were sensory neuronopathy (8/21, 38.1%) and limbic encephalitis (6/21, 28.6%). Fourteen patients (66.7%) had autoimmune comorbidities and/or co-occurring Abs, whereas AGO-Abs were the only autoimmune biomarker for the remaining 7/21 (33.3%). Thirteen (61.9%) patients were treated with immunotherapy; 8/13 (61.5%) improved, and 3/13 (23.1%) remained stable, suggesting an efficacy of these treatments.ConclusionsAGO-Abs might be potential biomarkers of autoimmunity in patients with central and peripheral nonparaneoplastic neurologic diseases. In 7 patients, AGO-Abs were the only biomarkers; thus, their identification may be useful to suspect the autoimmune character of the neurologic disorder.Classification of EvidenceThis study provides Class III evidence that AGO-Abs are more frequent in patients with autoimmune neurologic diseases than controls.

A Neurodegenerative Phenotype Associated With Sjögren-Larsson Syndrome

Sjögren-Larsson syndrome (SLS) is a rare neurologic disorder caused by pathogenic sequence variants in ALDH3A2 and characterized by ichthyosis, spasticity, intellectual disability, and a crystalline retinopathy. Neurologic symptoms develop in the first 2 years of life. Except for worsening ambulation due to spastic diplegia and contractures, the neurologic disease has been considered static and a neurodegenerative course is distinctly unusual. We describe a young child with Sjögren-Larsson syndrome who exhibited an early and severely progressive neurologic phenotype that may have been triggered by a febrile rotavirus infection. Together with 7 additional published cases of these atypical patients, we emphasize that a neurodegenerative course can be an extreme outcome for a minority of patients with Sjögren-Larsson syndrome.

Rare paraneoplastic syndrome of prostatic cancer: limbic encephalitis: a case report

Introduction Limbic encephalitis is an autoimmune neurologic disorder, often of paraneoplastic origin, that seldom complicates prostatic tumors. The nonspecificity of symptoms makes the diagnosis sometimes difficult to establish. Prognosis is essentially determined by comorbidities and sensorineural and cognitive sequelae. Clinical case A 66-year-old Caucasian patient known to have prostatic small-cell neuroendocrine adenocarcinoma under hormonal therapy developed complex partial epileptic seizures associated with rapidly aggravating severe memory impairment. The tripod of autoimmune limbic encephalitis diagnosis was based on the clinical aspect of brain’s functional deterioration, electroencephalography aspect, and γ-aminobutyric acid type B anti-receptor antibody positivity. Clinical, diagnostic, and therapeutic management as well as evolutionary risks were further analyzed. Conclusion Limbic encephalitis is an extremely rare presentation of neurologic paraneoplastic syndromes. A better knowledge of this entity would help better manage diagnostic and therapeutic difficulties and reduce the risk of possible sequelae.