Clinical Onset and Multiple Sclerosis Relapse after SARS-CoV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with several neurological disorders including headache, facial palsy, encephalitis, stroke, demyelinating disorders. The present report will discuss cases of multiple sclerosis (MS) onset and relapse both beginning early after SARS-CoV-2 infection. In both cases, magnetic resonance imaging (MRI) showed widespread bilateral subcortical and periventricular active lesions. Serum IgG against SARS-CoV-2 Spike antigens confirmed seroconversion with titers that are considered not definitely protective against possible reinfection. We hypothesize that SARS-CoV-2 infection, as previously reported for other viruses, could drive an active inflammatory response that can contribute either to the onset of MS or its relapse. The presented data further support the importance of vaccination in individuals with MS.

Citrullinated myelin induces microglial TNFα and inhibits endogenous repair in the cuprizone model of demyelination

Background Microglia are the primary phagocytes of the central nervous system and are responsible for removing damaged myelin following demyelination. Previous investigations exploring the consequences of myelin phagocytosis on microglial activation overlooked the biochemical modifications present on myelin debris. Such modifications, including citrullination, are increased within the inflammatory environment of multiple sclerosis lesions. Methods Mouse cortical myelin isolated by ultracentrifugation was citrullinated ex vivo by incubation with the calcium-dependent peptidyl arginine deiminase PAD2. Demyelination was induced by 6 weeks of cuprizone (0.3%) treatment and spontaneous repair was initiated by reversion to normal chow. Citrullinated or unmodified myelin was injected into the primary motor cortex above the cingulum bundle at the time of reversion to normal chow and the consequent impact on remyelination was assessed by measuring the surface area of myelin basic protein-positive fibers in the cortex 3 weeks later. Microglial responses to myelin were characterized by measuring cytokine release, assessing flow cytometric markers of microglial activation, and RNAseq profiling of transcriptional changes. Results Citrullinated myelin induced a unique microglial response marked by increased tumor necrosis factor α (TNFα) production both in vitro and in vivo. This response was not induced by unmodified myelin. Injection of citrullinated myelin but not unmodified myelin into the cortex of cuprizone-demyelinated mice significantly inhibited spontaneous remyelination. Antibody-mediated neutralization of TNFα blocked this effect and restored remyelination to normal levels. Conclusions These findings highlight the role of post-translation modifications such as citrullination in the determination of microglial activation in response to myelin during demyelination. The inhibition of endogenous repair induced by citrullinated myelin and the reversal of this effect by neutralization of TNFα may have implications for therapeutic approaches to patients with inflammatory demyelinating disorders.

Recurrent ataxia and dysarthria in myelin oligodendrocyte glycoprotein antibody-associated disorder

The spectrum of central nervous system demyelinating disorders is vast and heterogeneous and, often, with overlapping clinical presentations. Misdiagnosis might occur in some cases with serious therapeutic repercussions. However, introduction of several new biomarkers such as aquaporin-4 IgG and myelin oligodendrocyte glycoprotein IgG has made distinction between diseases such as multiple sclerosis and myelin oligodendrocyte glycoprotein antibody-associated disorder easier. Here, we report a case of a 15-year-old male patient with subacute multifocal neurological presentation without encephalopathy, eventually diagnosed as myelin oligodendrocyte glycoprotein antibody-associated disorder.

Epilepsy in patients with MOG antibody disease

Introduction. MOG (anti-myelin oligodendrocyte glycoprotein) antibody disease is a group of demyelinating disorders of the central nervous system, in which antibodies attack the glycoproteins on the oligodendrocyte myelin membrane. The aim of the study was to evaluate the course of the disease in patients with MOG antibody disease with epilepsy. Materials and methods. We examined 11 patients (5 men and 6 women) with MOG antibody disease aged from 2 months to 46 years. Three case studies were described when patients with MOG antibody disease had epileptic seizures. Results and discussion. Epileptic seizures preceded the diagnosis of MOG antibody disease in the first patient. The disease presented as right-sided optic neuritis in the second patient. Seven years later, an epileptic seizure occurred after childbirth, when the BBB could have become permeable to circulating MOG antibodies. The disease presented with headache in the third patient. Right-sided optic neuritis and ataxia developed after an acute viral respiratory infection. Myelitis was diagnosed, and an epileptic seizure occurred one year later. The patient had a combination of CADASIL syndrome with MOG antibody disease. Conclusion. Epileptic seizures are common in patients with MOG antibody disease. In addition to antiepileptic therapy, treatment of MOG antibody disease is crucial. This leads to good seizure control and a favourable prognosis.

Pediatric Optic Neuritis: Description of Four Cases and Review of the Literature

Pediatric optic neuritis (PON) may be a clinically isolated and self-limiting event or may present in the context of underlying neurologic, infective, or systemic disease. PON has a high impact on the quality of life as it may or may not evolve into other acquired demyelinating syndromes (ADSs), such as multiple sclerosis (MS), neuromyelitis optica (NMO), or other syndromes related to the myelin oligodendrocyte glycoprotein IgG antibodies (MOG-IgG). These different PON phenotypes present variable clinical and radiological features, plasma and liquor biomarkers, and prognosis. We describe four pediatric cases presenting clinically with ON, with different etiopathogenetic pictures: one case had a probable infective etiology, while the others were associated with different demyelinating disorders (MS, NMO, syndrome related to MOG-IgG). We discuss the possible evolution of presenting ON in other ADSs, based on recent literature. A careful evaluation of the clinical and investigation findings and the natural course of PON is necessary to define its pathogenic pathway and evolution. Further prolonged follow-up studies are needed to highlight the predictors of PON evolution, its potential sequelae, and the best treatment options.

Diagnostic significance of IgG and albumin indices versus oligoclonal band types in demyelinating disorders

AimsThe laboratory diagnosis of demyelinating inflammatory disorders (DIDs) relies on both intrathecal oligoclonal band (OCB) positivity and IgG index. Although OCB typing remains the gold-standard test for DIDs, it can be laborious and ambiguous, complicating diagnostics, and unduly increasing diagnostic time. We examined whether serum or cerebrospinal fluid (CSF) parameters can classify OCB types and, thus, be used as a replacement test to standard OCB typing.MethodsWe retrospectively analysed >1000 prospectively collected samples of patients with DIDs and quantified albumin and IgG levels in the CSF and serum. We determined OCB types by isoelectric focusing combined with immunofixation and evaluated the diagnostic accuracies of IgG and albumin indices in discriminating OCB types by receiver operating characteristic curves and multinomial regression.ResultsAn IgG index cut-off of 0.589 differentiated types 2/3 from types 1/4 (area under the curve 0.780, 95% CI 0.761 to 0.812, p<0.001; specificity: 71.10%, sensitivity: 73.45%). Albumin quotient cut-off values of 6.625 and of 6.707 discriminated type 1 from type 4 and type 2 from type 3, respectively (specificity: <55%, sensitivity: <75%). Female sex, age, IgG index, CSF IgG and serum albumin were associated with different OCB types.ConclusionsOur study reveals that IgG and albumin index can differentiate OCB types with adequate accuracy, especially if refined by age and gender.