Introduction: Since the onset of the novel coronavirus pandemic, several neurological complications secondary to SARS‐CoV‐2 infection have been reported, affecting central nervous system, peripheral nervous system and neuromuscular junction.Case report: We present the case of a 77‐year‐old man who developed bulbar myasthenia gravis (MG) eight weeks after SARS‐CoV‐2 infection. The search for serum antibodies against the acetylcholine receptor and the muscle‐specific tyrosine kinase (MuSK), performed by radioimmunoassay (RIA), and the search of low‐density lipoprotein receptor‐related protein 4 antibodies, performed by immunohistochemistry, resulted negative, while anti‐MuSK antibodies were detected by cell‐based assay (CBA). The patient was treated with pyridostigmine (60 mg four times a day) with unsatisfactory clinical response, followed by immunosuppressive therapy (azathioprine 1.5 mg/kg/day) with improvement of MG symptoms after two months of treatment.Discussion: Several viral diseases have been described as associated with the onset of MG, although the underlying mechanisms are not yet fully understood. Similarly, a growing number of scientific reports suggest a correlation between SARS‐CoV‐2 infection and autoimmune diseases. The interest of our case lies in the timing of the MG onset (after 2 months from infection), together with the unusual late onset of anti‐MuSK MG. These elements suggest that coronavirus infection may act as a trigger of the disease. We confirm the importance of CBA in the serological diagnosis of RIA‐negative MG.

Background and Purpose: Stroke is reported as a consequence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in several reports. However, data are sparse regarding the details of these patients in a multinational and large scale. Methods: We conducted a multinational observational study on features of consecutive acute ischemic stroke, intracranial hemorrhage, and cerebral venous or sinus thrombosis among SARS-CoV-2–infected patients. We further investigated the risk of large vessel occlusion, stroke severity as measured by the National Institutes of Health Stroke Scale, and stroke subtype as measured by the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) criteria among patients with acute ischemic stroke. In addition, we explored the neuroimaging findings, features of patients who were asymptomatic for SARS-CoV-2 infection at stroke onset, and the impact of geographic regions and countries’ health expenditure on outcomes. Results: Among the 136 tertiary centers of 32 countries who participated in this study, 71 centers from 17 countries had at least 1 eligible stroke patient. Of 432 patients included, 323 (74.8%) had acute ischemic stroke, 91 (21.1%) intracranial hemorrhage, and 18 (4.2%) cerebral venous or sinus thrombosis. A total of 183 (42.4%) patients were women, 104 (24.1%) patients were <55 years of age, and 105 (24.4%) patients had no identifiable vascular risk factors. Among acute ischemic stroke patients, 44.5% (126 of 283 patients) had large vessel occlusion; 10% had small artery occlusion according to the TOAST criteria. We observed a lower median National Institutes of Health Stroke Scale (8 [3–17] versus 11 [5–17]; P =0.02) and higher rate of mechanical thrombectomy (12.4% versus 2%; P <0.001) in countries with middle-to-high health expenditure when compared with countries with lower health expenditure. Among 380 patients who had known interval onset of the SARS-CoV-2 and stroke, 144 (37.8%) were asymptomatic at the time of admission for SARS-CoV-2 infection. Conclusions: We observed a considerably higher rate of large vessel occlusions, a much lower rate of small vessel occlusion and lacunar infarction, and a considerable number of young stroke when compared with the population studies before the pandemic. The rate of mechanical thrombectomy was significantly lower in countries with lower health expenditures.

Background and purpose: Although two doses of COVID‐19 vaccine elicited a protective humoral response in most persons with multiple sclerosis (pwMS), a significant group of them treated with immunosuppressive disease‐modifying therapies (DMTs) showed less efficient responses.Methods: This prospective multicenter observational study evaluates differences in immune response after a third vaccine dose in pwMS.Results: Four hundred seventy‐three pwMS were analyzed. Compared to untreated patients, there was a 50‐fold decrease (95% confidence interval [CI] = 14.3–100.0, p < 0.001) in serum SARS‐CoV‐2 antibody levels in those on rituximab, a 20‐fold decrease (95% CI = 8.3–50.0, p < 0.001) in those on ocrelizumab, and a 2.3‐fold decrease (95% CI = 1.2–4.6, p = 0.015) in those on fingolimod. As compared to the antibody levels after the second vaccine dose, patients on the anti‐CD20 drugs rituximab and ocrelizumab showed a 2.3‐fold lower gain (95% CI = 1.4–3.8, p = 0.001), whereas those on fingolimod showed a 1.7‐fold higher gain (95% CI = 1.1–2.7, p = 0.012), compared to patients treated with other DMTs.Conclusions: All pwMS increased their serum SARS‐CoV‐2 antibody levels after the third vaccine dose. The mean antibody values of patients treated with ocrelizumab/rituximab remained well below the empirical "protective threshold" for risk of infection identified in the CovaXiMS study (>659 binding antibody units/mL), whereas for patients treated with fingolimod this value was significantly closer to the cutoff.

Purpose: We performed a pharmacovigilance study of 10 drugs used in patients with relapsing-remitting multiple sclerosis (RR-MS). Our aim was to provide an overview of the safety of these drugs by the evaluation of reported expected and unexpected adverse reactions. Patients and methods: We collected and analyzed adverse drug reactions from RR-MS patients belonging to four hospitals in three Italian regions, for a period of 24 months. Results: We received a total of 411 adverse reactions, of which 84.18% were expected and only 15.82% were unexpected. We found no correlation between the number of reported adverse reactions and the route of administration (injectable/intravenous drugs N=224, oral drugs N=187). However, oral agents have caused a greater number of unexpected moderate-to-severe adverse reactions while, in injectable and infusion therapies, they have been evaluated as mild–moderate adverse reactions. Conclusion: Our results underscore the importance of monitoring the safety profile of multiple sclerosis therapies, with particular attention to oral agents that have been introduced later in the clinical practice.

Background: Amyloid-related imaging abnormalities (ARIA) have gained significance in the context of anti-amyloid therapies (AATs), exhibiting clinical and radiological manifestations that overlap with Cerebral Amyloid Angiopathy-related inflammation (CAA-ri). This review aims to elucidate the similarities and differences between spontaneous (sARIA) and drug-induced ARIA (dARIA). Methods: We conducted a narrative review comparing sARIA and dARIA, focusing on their underlying mechanisms, clinical presentations, and implications for diagnosis and treatment. Results: Both sARIA and dARIA are characterized by similar pathophysiological mechanisms involving amyloid deposits and neuroinflammation. Notably, ARIA can manifest as ARIA-E (edema) or ARIA-H (hemorrhage), with varying incidence rates in clinical trials. The review highlights that while sARIA occurs independently from treatment, dARIA is associated with AAT and can lead to significant symptomatic presentations. Conclusions: Understanding the continuum between sARIA and dARIA is crucial for improving diagnostic criteria, risk stratification, and therapeutic approaches. The proposed unified framework emphasizes the need for consensus in managing these conditions and advancing future research in amyloid-related diseases.