Background: Compared to the adult onset of multiple sclerosis (AOMS), both early-onset (EOMS) and late-onset (LOMS) are much less frequent, but are often under- or misdiagnosed. The aims of the present study were: 1. To compare demographic and clinical features of individuals with EOMS, AOMS and LOMS, and 2. To identify predictors for disability progression from relapsing remitting MS (RRMS) to secondary progressive MS (SPMS). Method: Data were taken from the Isfahan Hakim MS database. Cases were classified as EOMS (MS onset $\le$ 18 years), LOMS (MS onset >50 years) and AOMS (MS >18 and $\le$ 50 years). Patients’ demographic and clinical (initial symptoms; course of disease; disease patterns from MRI; disease progress) information were gathered and assessed. Kaplan–Meier and Cox proportional hazard regressions were conducted to determine differences between the three groups in the time lapse in conversion from relapsing remitting MS to secondary progressive MS. Results: A total of 2627 MS cases were assessed; of these 127 were EOMS, 84 LOMS and 2416 AOMS. The mean age of those with EOMS was 14.5 years; key symptoms were visual impairments, brain stem dysfunction, sensory disturbances and motor dysfunctions. On average, 24.6 years after disease onset, 14.2% with relapsing remitting MS (RRMS) were diagnosed with secondary progressive MS (SPMS). The key predictor variable was a higher Expanded Disability Status Scale (EDSS) score at disease onset. Compared to individuals with AOMS and LOMS, those with EOMS more often had one or two relapses in the first two years, and more often gadolinium-enhancing brain lesions. For individuals with AOMS, mean age was 29.4 years; key symptoms were sensory disturbances, motor dysfunctions and visual impairments. On average, 20.5 years after disease onset, 15.6% with RRMS progressed to SPMS. The key predictors at disease onset were: a higher EDSS score, younger age, a shorter inter-attack interval and spinal lesions. Compared to individuals with EOMS and LOMS, individuals with AOMS more often had either no or three and more relapses in the first two years. For individuals with LOMS, mean age was 53.8 years; key symptoms were motor dysfunctions, sensory disturbances and visual impairments. On average, 14 years after disease onset, 25.3% with RRMS switched to an SPMS. The key predictors at disease onset were: occurrence of spinal lesions and spinal gadolinium-enhancement. Compared to individuals with EOMS and AOMS, individuals with LOMS more often had no relapses in the first two years, and higher EDSS scores at disease onset and at follow-up. Conclusion: Among a large sample of MS sufferers, cases with early onset and late onset are observable. Individuals with early, adult and late onset MS each display distinct features which should be taken in consideration in their treatment.

Objective We systematically reviewed the literature on COVID-19 in patients with multiple sclerosis (MS). Methods We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Google Scholar, and World Health Organization database from December 1, 2019, to December 18, 2020. Three conference abstract databases were also searched. We included any types of studies that reported characteristics of patients with MS with COVID-19. Results From an initial 2,679 publications and 3,138 conference abstracts, 87 studies (67 published articles and 20 abstracts) consisting of 4,310 patients with suspected/confirmed COVID-19 with MS met the inclusion criteria. The female/male ratio was 2.53:1, the mean (SD) age was 44.91 (4.31) years, the mean disease duration was 12.46 (2.27), the mean Expanded Disability Status Scale score was 2.54 (0.81), the relapsing/progressive ratio was 4.75:1, and 32.9% of patients had at least 1 comorbidity. The most common symptoms were fever (68.8%), followed by cough (63.9%), fatigue/asthenia (51.2%), and shortness of breath (39.5%). In total, 837 of 4,043 patients with MS with suspected/confirmed COVID-19 (20.7%) required hospitalization, and 130 of 4,310 (3.0%) died of COVID-19. Among suspected/confirmed patients, the highest hospitalization and mortality rates were in patients with no disease-modifying therapies (42.9% and 8.4%), followed by B cell–depleting agents (29.2% and 2.5%). Conclusion Our study suggested that MS did not significantly increase the mortality rate from COVID-19. These data should be interpreted with caution as patients with MS are more likely female and younger compared with the general population where age and male sex seem to be risk factors for worse disease outcome.

In December 2019, a novel coronavirus causing an infectious respiratory disease (COVID-19) was identified, which since then has developed into a pandemic with higher rates of mortality in older individuals and those with underlying medical conditions. 1 Multiple sclerosis (MS) is an immune-mediated neurologic disease which requires long-term treatment with immunotherapies that have been shown to increase the risk of infections. 2 As a result, there is significant anxiety among patients and neurologists during the pandemic regarding the infection outcome in this patient population. We present a patient with MS treated with fingolimod who was diagnosed with COVID-19 and had a favorable outcome.