Incidence of COVID-19 after vaccination in people with multiple sclerosis in Argentina: Data from the nationwide registry RelevarEM.

The objective of the study was to evaluate the incidence of COVID-19 after complete vaccination in people with multiple sclerosis (PwMS) included in the Argentinean MS and NMOSD registry (RelevarEM, NCT03375177). METHODS: cohort study conducted between May 2021 and December 2021. The primary outcome was the appearance of infection during the follow-up time (at least three months after complete vaccination (second dose)). Data was collected through the contact between the treating physician and the patient. Specific information was requested (date, symptoms, need for hospitalization, ventilatory assistance, treatment, and evolution). The contact was made every 30 days during the period of 3 months after the full dose vaccination. A positive COVID-19 case was defined according to the definition established by the Ministry of Health in Argentina. Cumulative incidence was reported by Kaplan Meier survival curves as well as incidence density. RESULTS: A total of 576 PwMS were included, mean age 45.2 ± 13 years, 432 (75%) RRMS, 403 (70%) were female. The mean and median time of follow-up after the second dose was 91 ± 17 and 94 ± 21 days respectively. Most frequent first and second dose received was Astra-Zeneca vaccine, followed by Sputnik V vaccine. During follow-up a total of twenty COVID-19 cases were observed for a total exposure time of 39,557 days. The overall cumulative incidence for the observed period was 3.4% (SE 0.4%) with an overall incidence density of 5 × 10.000 patients/day (95%CI 0.7-12). We observed more cases in woman than men with an incidence density of 6 × 10.000 patients/day (95%CI 0.9-9) vs. 3 × 10.000 patients/day (95%CI 0.2-6) respectively, but not significantly different (IRR 1.7 95% CI 0.56-7.37 p = 0.15). CONCLUSION: we found an incidence density of breakthrough COVID-19 infection of 5 × 10.000 patients/day (95%CI 0.7-12) after vaccination in Argentina.

Clinical and demographic characteristics of male MS patients included in the national registry-RelevarEM. Does sex or phenotype make the difference in the association with poor prognosis?

BACKGROUND: In multiple sclerosis demographics there is a well-known female prevalence and male patients have been less specifically evaluated in clinical studies, though some clinical differences have been reported between sexes. OBJECTIVE: The objective of this study was to assess clinical and demographic differences between male and female patients included in the national Argentine MS Registry-RelevarEM. MATERIAL AND METHODS: This study was observational, retrospective, and was based on the data of 3099 MS patients included as of 04 April 2021. The statistical analysis plan included bivariate analyses with the crude data and also after adjustment for the MS phenotype, further categorized as progressive-onset MS or relapsing-onset MS. In the adjusted analysis, the Mantel-Haenszel odds ratio was compared to the crude odds ratio, to account for the phenotype as a confounder. RESULTS: The data from 1,074 (34.7%) men and 2,025 (65.3%) women with MS diagnosis were analysed. Males presented primary progressive disease two times more often than women (11% and 5%, respectively). In the crude analyses by sex, the presence of exclusively infratentorial lesions in the magnetic resonance imaging studies was more frequent in males than in females, but after adjustment by MS onset phenotype, such difference was only present in males with relapsing-onset MS (p = 0.00006). Similarly, worse Expanded Disability Status Scale scores were confirmed only in men with relapsing-onset disease after phenotype adjustment (p = 0.02). CONCLUSION: We did not find any statistically significant clinical or demographic difference between sexes when the progressive MS phenotype was specifically considered. However, the differences we found between the clinical phenotypes are in line with the literature and highlight the importance of stratifying the analyses by sex and phenotype when designing MS studies.

Susac Syndrome: A differential diagnosis of white matter lesions.

INTRODUCTION: Susac Syndrome is an autoimmune endotheliopathy affecting capillaries and precapillary arterioles of the brain, inner ear and retina. The classic symptom triad includes visual disturbances, hypoacusia, and encephalopathy, but is rarely fully manifest at onset. The syndrome typically follows an active fluctuating monophasic course. Typical imaging findings on brain magnetic resonance show central fiber microischemias/microinfarctions of the corpus callosum known as "snow balls", as well as lineal infarcts and upper callosal fiber involvement. Fluorescein angiography and tonal audiometry are important tools to confirm diagnosis, even in patients who are asymptomatic for visual or auditory disturbances. We describe 8 patients with Susac Syndrome treated at our center and compare findings to those of other published case series. METHODS: Eight adults with Susac Syndrome diagnosed between January 2007 and August 2016 at our center, in Buenos Aires, Argentina are described. Magnetic Brain Resonance, fluorescein angiography, tonal audiometry, a complete serologic battery and lumbar puncture were performed to all patients. RESULTS: The majority of patients were males, and average age at diagnosis was 37.5 years (range: 22-52 yrs). Two patients presented full clinical triad at onset, while the remaining developed visual and/or auditory disturbances later during the course of disease. All cases manifested varied neurological symptoms including pyramidal and/or sensory tract symptoms, amnesic disorders, ataxia and vertigo. Psychiatric manifestations such as disinhibition, aggressive behavior, paranoid ideation and hallucinations were also present. Seven patients suffered at least one relapse. Typical central corpus callosum fiber ischemias/infarcts, also known as snowball lesions were visible in all patients. Spokes, icicles, periventricular lesions and internal capsule "string of beads" patterns were observed on diffusion weighted images. Four cases presented fornix microischemias/microinfarctions, 5 juxtacortical involvement and 3 infratentorial infarcts. Leptomeningeal involvement was evident in only 1 patient after rabies vaccination. Fluorescein angiography was abnormal in 7 cases. Tonal audiometry revealed unilateral hypoacusia in 5 patients, 3 with low frequency hearing loss. Immunosuppressive treatment was indicated in all cases. Patient follow up ranged between 6 months and 9 years, only 1 patient was lost to follow up after three years. CONCLUSION: Susac Syndrome is probably both underdiagnosed and misdiagnosed. Early and aggressive immunosuppressive treatment is indicated in order to prevent potential disabilities.