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Objective: Comorbid anxiety occurs often in MS and is associated with disability progression. Polygenic scores offer a possible means of anxiety risk prediction but often have not been validated outside the original discovery population. We aimed to investigate the association between the Generalized Anxiety Disorder 2-item scale polygenic score with anxiety in MS., Methods: Using a case-control design, participants from Canadian, UK Biobank, and United States cohorts were grouped into cases (MS/comorbid anxiety) or controls (MS/no anxiety, anxiety/no immune disease or healthy). We used multiple anxiety measures: current symptoms, lifetime interview-diagnosed, and lifetime self-report physician-diagnosed. The polygenic score was computed for current anxiety symptoms using summary statistics from a previous genome-wide association study and was tested using regression., Results: A total of 71,343 individuals of European genetic ancestry were used: Canada (n = 334; 212 MS), UK Biobank (n = 70,431; 1,390 MS), and the USA (n = 578 MS). Meta-analyses identified that in MS, each 1-SD increase in the polygenic score was associated with ~50% increased odds of comorbid moderate anxious symptoms compared to those with less than moderate anxious symptoms (OR: 1.47, 95% CI: 1.09-1.99). We found a similar direction of effects in the other measures. MS had a similar anxiety genetic burden compared to people with anxiety as the index disease., Interpretation: Higher genetic burden for anxiety was associated with significantly increased odds of moderate anxious symptoms in MS of European genetic ancestry which did not differ from those with anxiety and no comorbid immune disease. This study suggests a genetic basis for anxiety in MS., (© 2024 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background and Purpose: Pediatric-onset multiple sclerosis (PoMS) is associated with high health care use. To plan resource allocation for this patient group, knowledge of the incidence rate and prevalence is important. However, such studies are scarce, few are population-based, and the methodology varies widely. We aimed to address this knowledge gap by performing a nationwide study of the incidence rate and prevalence of PoMS in Sweden, an area of high multiple sclerosis (MS) incidence and prevalence., Methods: MS cases were identified by linking two nationwide registers, the National Patient Register and the Swedish MS Registry. MS cases having their first central nervous system demyelinating event or MS clinical onset before age 18 years were classified as pediatric onset. Incidence rate and prevalence were estimated annually over the study period (2006-2016) for the total population and stratified by sex and age group (<12, 12-15, and 16-17 years). Temporal trends and ratios between sexes and age groups were estimated., Results: We identified 238 incident cases from 2006 to 2016, corresponding to an overall crude incidence rate of 1.12 per 100,000 person-years and an overall crude prevalence of 2.82 per 100,000 population. There was a higher incidence rate among females and the highest age category. The overall incidence rate and prevalence estimates remained stable during the study period., Conclusions: Sweden exhibits a consistently high incidence rate and prevalence of PoMS that has remained stable over time. This knowledge serves as a tool to aid in planning resource allocation and health services for this patient population., (© 2024 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background and Objectives: Clinical onset of multiple sclerosis (MS) after the age of 50 years is uncommon and associated with a less favorable natural history. The differences in long-term outcomes in patients with late-onset MS (LOMS, onset 50 years or older) and adult-onset MS (AOMS, onset 18 years or older and younger than 50 years) during the disease-modifying therapy (DMT) era have been less studied. This study aimed to compare patient characteristics, DMT exposure, and disability progression in Swedish patients with LOMS and AOMS over 2 decades (2001-2022)., Methods: The nationwide Swedish MS registry was searched for patients with an onset of MS between January 1, 2001, and December 31, 2018, with symptom onset at age 18 years or older and ≥2 recorded Expanded Disability Status Scale (EDSS) scores. Clinical and demographic parameters and exposure to DMT were compared between LOMS and AOMS. Time to disability milestones (EDSS 4 and 6) was assessed using Kaplan-Meier curves and Cox proportional hazards regression models adjusted for sex, disease course, calendar year at onset, and DMT exposure., Results: Among 8739 patients with MS who met inclusion criteria, 1,028 (11.8%) were LOMS. Primary progressive MS was more frequently diagnosed in LOMS compared with that in AOMS (25.2% vs 4.5%; p < 0.001). Most of the patients had been prescribed DMT, but more rarely in LOMS compared with AOMS (74.7% vs 95.6%; p < 0.001). Less than half of patients with LOMS had been exposed to a high-efficacy DMT (45.8%) compared with 73.5% of AOMS ( p < 0.001). The risk of reaching disability milestones was greater for LOMS compared with that for AOMS (EDSS 4; adjusted hazard ratio [aHR] 2.71; 95% CI 2.22-3.30; p < 0.001, and EDSS 6; aHR 2.67; 95% CI 2.12-3.36; p < 0.001)., Discussion: This study distinguishes LOMS as a particularly vulnerable group and clinically supports close vigilance of these patients. Further studies are needed to assess and clarify the benefit of DMT usage in older adults with MS.

Objective: There has been interest in a possible negative association between HIV and multiple sclerosis (MS). We aimed to compare the risk of MS in a cohort of individuals living with HIV to that in the general population., Methods: Population-based health data were accessed for 2 cohorts of HIV-positive persons from Sweden and British Columbia, Canada. Incident MS was identified using MS registries or a validated algorithm applied to administrative data. Individuals with HIV were followed from 1 year after the first clinical evidence of HIV or the first date of complete administrative health data (Canada = April 1, 1992 and Sweden = January 1, 2001) until the earliest of incident MS, emigration, death, or study end (Canada = March 31, 2020 and Sweden = December 31, 2018). The observed MS incidence rate in the HIV-positive cohort was compared to the expected age-, sex-, calendar year-, income-specific, and region of birth-specific rates in a randomly selected sample of >20% of each general population. The standardized incidence ratio (SIR) for MS following the first antiretroviral therapy exposure ("ART-exposed") was also calculated., Results: The combined Sweden-Canada cohort included 29,163 (75% men) HIV-positive persons. During 242,248 person-years of follow-up, 14 incident MS cases were observed in the HIV-positive cohort, whereas 26.19 cases were expected. The SIR for MS in the HIV-positive population was 0.53 (95% confidence interval [CI] = 0.32-0.90). The SIR for MS following the first ART exposure was 0.55 (95% CI = 0.31-0.96)., Interpretation: This international population-based study demonstrated a lower risk of MS among HIV-positive individuals, and HIV-positive ART-exposed individuals. These findings provide support for further exploration into the relationship among HIV, ART, and MS. ANN NEUROL 2024;95:487-494., (© 2023 The Authors. Annals of Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background: People with multiple sclerosis (PwMS) face health and social challenges of living with a chronic and potentially disabling condition. To disclose or conceal MS at work may critically affect individuals' work situation, career opportunities, and health. PwMS may experience a dilemma when assessing if the possible benefits of disclosing the diagnosis outweigh the possible risks. However, concealing in the long-term may have health implications and prevent opportunities for support and work adjustments. Few studies have examined what drives PwMS to disclose or conceal MS at work and the consequences of these ways of managing MS., Objectives: To explore the reasons PwMS report for disclosing and/or concealing their MS diagnosis in the workplace, as well as the consequences they have experienced., Methods: A web-based survey of PwMS was conducted in 2021. All individuals aged 20-50 listed in the Swedish MS registry were invited to participate. The response rate was 52% and among these participants, 3,810 (86%) completed questions regarding workplace disclosure and/or concealment of MS. Free-text responses on these topics were analyzed using inductive content analysis., Results: It was common to disclose MS in the workplace (85%). Identified drivers for disclosure and concealment related to four categories: Work-related, Social, Personal and Circumstantial. Work-related drivers focused on employment or protecting one's career, and changing one's work situation versus maintaining it. Social drivers included the need for support, addressing or preventing stigma, and being considerate of others. Personal drivers were linked to moral values/personal beliefs and processing of the diagnosis. Circumstantial drivers related to involuntary or unforeseen events, timing factors, one's medical condition and external opinion/advice. Identified consequences for disclosure and concealment related to three categories: Work-life, Social, and Personal. Work-life consequences included work arrangements, and career opportunities. Social consequences were linked to MS awareness, stigma, interactions and social support, as well as dynamics of work relationships. Personal consequences involved levels of disease acceptance, and attitudes toward managing MS., Conclusion: PwMS often described the question of disclosure as challenging and navigated it with caution, as both disclosure and concealment can yield favorable and unfavorable outcomes., Competing Interests: JD and AM: salaries funded partly by unrestricted research grants from Celgene/Bristol-Myers Squibb. CM previously been partly funded by an unrestricted research grant from Biogen and Celgene/Bristol-Myers Squibb when employed by Karolinska Institutet, and now employed by Macanda, a market access consulting company that collaborates with several pharmaceutical companies. EF: salary funded partly by an unrestricted research grant from Biogen and has received unrestricted research grants from Celgene/Bristol-Myers Squibb and speaker’s fees from Merck. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Dervish, Arfuch, Murley, McKay, Machado, Wennman-Larsen and Friberg.)

Importance: Multiple sclerosis (MS) severity may be informed by premorbid sociodemographic factors., Objective: To determine whether premorbid education, income, and marital status are associated with future MS disability and symptom severity, independent of treatment, in a universal health care context., Design, Setting, and Participants: This nationwide observational cohort study examined data from the Swedish MS Registry linked to national population registries from 2000 to 2020. Participants included people with MS onset from 2005 to 2015 and of working age (aged 23 to 59 years) 1 year and 5 years preceding disease onset., Exposures: Income quartile, educational attainment, and marital status measured at 1 and 5 years preceding disease onset., Main Outcome and Measures: Repeated measures of Expanded Disability Status Scale (EDSS) scores and patient-reported Multiple Sclerosis Impact Scale (MSIS-29) scores. Models were adjusted for age, sex, relapses, disease duration, and treatment exposure. Secondary analyses further adjusted for comorbidity. All analyses were stratified by disease course (relapse onset and progressive onset)., Results: There were 4557 patients (mean [SD] age, 37.5 [9.3] years; 3136 [68.8%] female, 4195 [92.1%] relapse-onset MS) with sociodemographic data from 1-year preonset of MS. In relapse-onset MS, higher premorbid income and education correlated with lower disability (EDSS, -0.16 [95% CI, -0.12 to -0.20] points) per income quartile; EDSS, -0.47 [95% CI, -0.59 to -0.35] points if tertiary educated), physical symptoms (MSIS-29 physical subscore, -14% [95% CI, -11% to -18%] per income quartile; MSIS-29 physical subscore, -43% [95% CI, -35% to -50%] if tertiary educated), and psychological symptoms (MSIS-29 psychological subscore, -12% [95% CI, -9% to -16%] per income quartile; MSIS-29 psychological subscore, -25% [95% CI, -17% to -33%] if tertiary educated). Marital separation was associated with adverse outcomes (EDSS, 0.34 [95% CI, 0.18 to 0.51]; MSIS-29 physical subscore, 35% [95% CI, 12% to 62%]; MSIS-29 psychological subscore, 25% [95% CI, 8% to 46%]). In progressive-onset MS, higher income correlated with lower EDSS (-0.30 [95% CI, -0.48 to -0.11] points per income quartile) whereas education correlated with lower physical (-34% [95% CI, -53% to -7%]) and psychological symptoms (-33% [95% CI, -54% to -1%]). Estimates for 5-years preonset were comparable with 1-year preonset, as were the comorbidity-adjusted findings., Conclusions and Relevance: In this cohort study of working-age adults with MS, premorbid income, education, and marital status correlated with disability and symptom severity in relapse-onset and progressive-onset MS, independent of treatment. These findings suggest that socioeconomic status may reflect both structural and individual determinants of health in MS.

Background and Objectives: Depression is common in multiple sclerosis (MS) and is associated with faster disability progression. The etiology of comorbid depression in MS remains poorly understood. Identification of individuals with a high risk of depression, through polygenic scores (PGS), may facilitate earlier identification. Previous genetic studies of depression considered depression as a primary disorder, not a comorbidity, and thus, findings may not generalize to MS. Body mass index (BMI) is a risk factor of both MS and depression, and its association may highlight differences in depression in MS. To improve the understanding of comorbid depression in MS, we will investigate PGS in people with MS, with the hypothesis that a higher depression PGS is associated with increased odds for comorbid depression in MS., Methods: Samples from 3 sources (Canada, UK Biobank, and the United States) were used. Individuals were grouped into cases (MS/comorbid depression) and compared with 3 control groups: MS/no depression, depression/no immune disease, and healthy persons. We used 3 depression definitions: lifetime clinical diagnoses, self-reported diagnoses, and depressive symptoms. The PGS were tested in association with depression using regression., Results: A total of 106,682 individuals of European genetic ancestry were used: Canada (n = 370; 213 with MS), UK Biobank (n = 105,734; 1,390 with MS), and the United States (n = 578 with MS). Meta-analyses revealed individuals with MS and depression had a higher depression PGS compared with both individuals with MS without depression (odds ratio range per SD 1.29-1.38, p < 0.05) and healthy controls (odds ratio range per SD 1.49-1.53, p < 0.025), regardless of the definition applied and when sex stratified. The BMI PGS was associated with depressive symptoms ( p ≤ 0.001). The depression PGS did not differ between depression occurring as a comorbid condition with MS or as the primary condition (odds ratio range per SD 1.03-1.13, all p > 0.05)., Discussion: A higher depression genetic burden was associated with approximately 30%-40% increased odds of depression in European genetic ancestry participants with MS compared with those without depression and was no different compared with those with depression and no comorbid immune disease. This study paves the way for further investigations into the possible use of PGS for assessing psychiatric disorder risk in MS and its application to non-European genetic ancestries., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To estimate risks for all-cause mortality and for severe COVID-19 in multiple sclerosis patients and across relapsing-remitting multiple sclerosis patients exposed to disease-modifying therapies., Methods: We conducted a Swedish nationwide population-based multi-register linkage cohort study and followed all multiple sclerosis patients (n = 17,692 in March 2020), individually age-, sex-, and region-matched to five population-based controls (n = 86,176 in March 2020) during March 2020-June 2021. We compared annual all-cause mortality within and across cohorts, and assessed incidence rates and relative risks for hospitalization, intensive care admission, and death due to COVID-19 in relation to disease-modifying therapy use, using Cox regression., Results: Absolute all-cause mortality among multiple sclerosis patients was higher from March to December 2020 than in previous years, but relative risks versus the population-based controls were similar to preceding years. Incidence rates of hospitalization, intensive care admission, and death due to COVID-19 remained in line with those for all-cause hospitalization, intensive care admission, and mortality. Among relapsing-remitting patients on rituximab, trends for differences in risk of hospitalization due to COVID-19 remained in the demographics-, socioeconomic status-, comorbidity-, and multiple sclerosis severity-adjusted model., Interpretation: Risks of severe COVID-19-related outcomes were increased among multiple sclerosis patients as a whole compared to population controls, but risk increases were also seen for non-COVID-19 hospitalization, intensive care admission, and mortality, and did not significantly differ during the pandemic compared to pre-pandemic years. The risk conveyed by disease-modifying therapies was smaller than previously assumed, likely as a consequence of the possibility to better control for confounders., (© 2022 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Objectives: Multiple sclerosis (MS) is a chronic neurodegenerative disease of the central nervous system. Identifying MS at the population level is important for disease surveillance and allocation of resources. The Swedish National Patient Registry (NPR) has been used to study the epidemiology of MS, but the accuracy of this resource is not known. We aimed to validate a definition of MS using the Swedish NPR in Värmland County using a longitudinal cohort design., Materials and Methods: Data were extracted from the NPR, the Total Population Register, the Swedish MS Register, and medical records for the years 2001-2013. Fifteen algorithms of hospitalizations and clinic visits for MS were developed and compared with findings in medical records, which acted as the "gold standard" definition. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were estimated., Results: Of 805 eligible persons identified in the NPR, 763 had MS (94.8%) according to medical records. Of these, 544 (71.3%) were also registered in the SMSreg. The case definition that had a well-balanced sensitivity and specificity required three or more clinic or hospital visits for MS (sensitivity of 85.3% (95% CI: 82.6-87.8) and specificity of 81.0% (95%CI: 65.9-91.4)., Conclusions: Multiple case definitions with high sensitivity and moderate specificity were found, suggesting that the NPR can be used to accurately identify persons with MS., (© 2021 The Authors. Acta Neurologica Scandinavica published by John Wiley & Sons Ltd.)

To investigate whether cerebrospinal fluid (CSF) markers differ between pediatric-onset multiple sclerosis (PoMS, onset < 18 years) and adult-onset (AoMS), and whether these markers are associated with clinical outcomes among PoMS. Prospective nationwide registry study of incident MS, including persons with a CSF sample < 3 years post-MS onset. We compared CSF oligoclonal band (OCB) status, immunoglobulin G (IgG) index levels, and mononuclear cell count between PoMS and AoMS. Within the PoMS cohort we analyzed the association between CSF markers, relapse rate and Expanded Disability Status Scale (EDSS) score, using negative binomial regression and generalized estimating equations, respectively. The cohort consisted of 130 PoMS and 3228 AoMS cases. The PoMS group had higher odds of OCB-positivity (odds ratio: 2.70; 95% CI 1.21-7.67). None of the CSF markers were associated with relapse rate in the PoMS cohort; however, OCB-positivity was associated with higher EDSS scores. This study suggested that PoMS more commonly display CSF evidence for intrathecal IgG production than AoMS. Further, we found evidence of a relationship between OCB-positivity and subsequent disability, suggesting that they could play a role in the prognostication of MS in children., (© 2021. The Author(s).)

Objective: To evaluate risks of disease reactivity during pregnancy and postpartum following rituximab (RTX) and natalizumab (NTZ) suspension in women with MS., Methods: An observational cohort study of all women with MS disease onset before childbirth between 2006 and 2017. Women were identified through the Swedish MS Registry, a nationwide clinical register, with substratification into 3 groups: women who suspended RTX and NTZ within 6 months before conception and women who were not treated with any disease-modifying treatment (DMT) within 1 year of conception. The primary outcome was the annualized relapse rate (ARR) during pregnancy and 1 year postpartum., Results: We identified 2,386 women with MS onset before a live birth; of these, 76 women suspended RTX and 53 suspended NTZ, and 457 were untreated within 1 year before conception. In all women, regardless of the treatment type, the ARR declined from 0.05-0.04 prepregnancy to 0.03-0.02 during pregnancy, returning to prepregnancy rates at 3-6 months (0.05) postpartum. In the suspended cohort, 76% (98/129) of women resumed a DMT after delivery. The relapse rate 1 year postpartum was significantly higher in the suspended NTZ women compared with the suspended RTX women (adjusted rate ratio [aRR] 7.65, 95% CI 2.47-23.6) and was lower in the suspended RTX women compared with the untreated women (aRR 0.21, 95% CI 0.08-0.61)., Conclusion: Disease reactivity during the postpartum period was lower among women with MS who suspended RTX before pregnancy, relative to those who suspended NTZ and untreated women. These findings suggest that RTX may exert long-acting effects on MS disease activity that encompass pregnancy and postpartum periods., Classification of Evidence: This study provides Class IV evidence that in patients with MS who were on treatment before pregnancy, RTX reduces clinical disease activity compared with NTZ in the postpartum period., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To evaluate quality of life (QoL), measured by the EQ-5D, in adults with pediatric-onset multiple sclerosis (POMS) or adult-onset multiple sclerosis (AOMS) and explore determinants of QoL in both groups., Methods: Data were collected from the nationwide Swedish multiple sclerosis (MS) registry. Demographic characteristics, EQ-5D-3 level, Multiple Sclerosis Impact Scale (MSIS-29) score, Expanded Disability Status Scale (EDSS) score, Symbol Digit Modalities Test score, relapses, and disease-modifying therapy (DMT) exposure were collected on an approximately annual basis (2011-2019). Patients with definite MS with ≥2 EQ-5D measurements collected between ages 18 and 50 were included. The principal outcome was the EQ-5D visual analogue scale (EQ-VAS) score. Linear mixed models compared all available EQ-VAS scores between patients with POMS and patients with AOMS and determinants of EQ-VAS among patients with POMS and patients with AOMS (assessed separately)., Results: A total of 5,094 persons met inclusion criteria: 354 (6.9%) had POMS. A total of 21,357 unique EQ-5D scores were recorded. Most participants were female (70.0%) with a relapsing-onset disease course (98.1%). There was no difference in EQ-VAS scores between patients with POMS and patients with AOMS following adjustment for confounders (β-coefficient for patients with POMS vs patients with AOMS [reference]: 0.99; 95% confidence interval -0.89 to 2.87). Experiencing a relapse, severe neurologic disability (EDSS ≥6.0 vs <3.0), and higher MSIS-29 psychological score were consistently associated with lower QoL, while higher information processing efficiency and exposure to first-line DMTs were associated with higher QoL scores in both groups., Conclusions: There were no differences in QoL between patients with POMS and patients with AOMS in adulthood. Findings provide support for a focus on reducing neurologic disability and improving psychological status as approaches to potentially improve the QoL of persons with MS., (Copyright © 2019 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: Depression is common in multiple sclerosis (MS), but its impact on disability worsening has not yet been determined. We explored the risk of disability worsening associated with depression in a nationwide longitudinal cohort., Methods: This retrospective cohort study used linked data from 3 Swedish nationwide registries: the MS Register, National Patient Register, and Prescribed Drug Register. Two incident cohorts were developed: cohort 1 included all registered cases of MS in the MS Registry (2001-2014) with depression defined as ≥1 ICD-10 code for depression; and cohort 2 comprised all cases of MS in the MS Registry (2005-2014) with depression defined as ≥1 prescription filled for an antidepressant. Cox regression models were used to compare the risk of reaching sustained disability milestone scores of 3.0, 4.0, and 6.0 on the Expanded Disability Status Scale (EDSS) between persons with MS with and without depression., Results: Cohort 1 included 5,875 cases; 502 (8.5%) had depression. Cohort 2 had 3,817 cases; 1,289 (33.8%) were prescribed an antidepressant. Persons with depression were at a significantly higher risk of reaching sustained EDSS scores of 3.0, 4.0, and 6.0, with hazard ratios of 1.50 (95% confidence interval [CI] 1.20-1.87), 1.79 (95% CI 1.40-2.29), and 1.89 (95% CI 1.38-2.57), respectively. A similar increased risk among persons exposed to antidepressants was observed, with hazard ratios of 1.37 (95% CI 1.18-1.60), 1.93 (95% CI 1.61-2.31), and 1.86 (95% CI 1.45-2.40) for sustained EDSS scores of 3.0, 4.0, and 6.0, respectively., Conclusion: Persons with MS and comorbid depression had a significantly increased risk of disability worsening. This finding highlights the need for early recognition and appropriate treatment of depression in persons with MS., (Copyright © 2019 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: Persons who develop multiple sclerosis (MS) at a young age may bear a higher genetic risk load than persons who develop MS later in life; however, the contribution of familial influence to the risk of MS, in relation to onset age, has not been established., Objective: To investigate the familial risk of MS at two extremes of the spectrum of MS onset age: early onset (first MS symptom < 18 years of age) and late onset (first MS symptom ≥ 50 years)., Methods: Nationwide registries in Sweden were used to identify cases of MS and controls, and their familial relations. We estimated the odds ratio (OR) of an MS diagnosis for individuals with a relative diagnosed with early-onset or late-onset MS compared with those whose relatives did not have MS, using a nested case-control design., Results: 629 early-onset and 1148 late-onset MS patients were identified and matched to 10 controls from the general population by age and sex. The OR of MS for individuals with a first-degree relative diagnosed with early-onset MS was 10.86 (95% CI 6.87-17.17); and for late-onset MS was 8.08 (95% CI 6.12-10.67)., Conclusions: Our findings demonstrate no substantial differences in familial risk in persons with early- and late-onset MS.

Objective: Emerging evidence suggests that comorbidity may influence disability outcomes in multiple sclerosis (MS); we investigated the association between psychiatric comorbidity and MS disability progression in a large multiclinic population., Methods: This retrospective cohort study accessed prospectively collected information from linked clinical and population-based health administrative databases in the Canadian provinces of British Columbia and Nova Scotia. Persons with MS who had depression, anxiety, or bipolar disorder were identified using validated algorithms using physician and hospital visits. Multivariable linear regression models fitted using an identity link with generalized estimating equations were used to determine the association between psychiatric comorbidity and disability using all available Expanded Disability Status Scale (EDSS) scores., Results: A total of 2,312 incident cases of adult-onset MS were followed for a mean of 10.5 years, during which time 35.8% met criteria for a mood or anxiety disorder. The presence of a mood or anxiety disorder was associated with a higher EDSS score (β coefficient = 0.28, p = 0.0002, adjusted for disease duration and course, age, sex, socioeconomic status, physical comorbidity count, and disease-modifying therapy exposure). Findings were statistically significant among women (β coefficient = 0.31, p = 0.0004), but not men (β coefficient 0.22, p = 0.17)., Conclusion: Presence of psychiatric comorbidities, which were common in our incident MS cohort, increased the severity of subsequent neurologic disability. Optimizing management of psychiatric comorbidities should be explored as a means of potentially mitigating disability progression in MS., (© 2018 American Academy of Neurology.)

Background: Physical activity may be neuroprotective in multiple sclerosis (MS). One review (2011) of exercise and MS disability was inconclusive, but highlighted the need for more studies., Objective: To perform an updated systematic literature review examining the relationship between physical activity and physical ability outcomes in persons with MS., Methods: EMBASE and MEDLINE were searched for original interventional studies (2011-2016) evaluating exercise on quantitative outcomes of physical disability in MS. We also assessed any reported adverse outcomes., Results: Of the 153 articles identified, 12 were included; 3 examined endurance training; 6 resistance training; and 3 explored less conventional exercises, specifically, tai chi, kickboxing, and vestibular rehabilitation, each lasting 5-24 weeks. In total, 568 unique individuals were included, and >10 different scales used to assess outcomes. Endurance training provided benefits in walking ability, while mindfulness exercises (tai chi and vestibular rehabilitation), and dynamic workouts (kickboxing) led to improvements in balance and coordination. Resistance training alone did not improve walking ability, but improved lower limb muscular strength and endurance. When resistance and endurance training were combined, improvements were seen in mobility, balance and coordination. Four studies assessed discontinuation; most reported a return to pre-intervention function. Adverse outcomes were reported in 6 studies, and appeared generally mild, ranging from mild muscle soreness to exacerbation of MS symptoms., Conclusions: Physical activity was associated with measurable benefits on ability outcomes, but continuation is likely required to maintain benefits. While adverse events were generally mild, approximately half of studies actually reported safety outcomes., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Several environmental and lifestyle factors have been associated with multiple sclerosis (MS) risk, including some pharmacological treatments. We systematically reviewed the literature on prescription drug exposure and MS risk., Methods: Six databases were searched for original observational studies reporting drug exposure and MS risk published before 2017., Results: Thirteen articles fulfilled inclusion criteria. Exposure to neither amiloride nor valproic acid was associated with MS (adjusted hazard ratio (adj.HR = 1.34;95% CI:0.81-2.20; adj.HR = 1.30;95%CI:0.44-3.80, respectively). Four studies explored oral contraceptive exposure and reported no association with MS; while a single study found an increased risk (odds ratio [adj.OR] = 1.52;95%CI:1.21-1.91). While penicillin exposure was associated with reduced risk of developing MS (adj.OR = 0.5;95%CI:0.3-0.9), a later study observed an elevated risk for penicillin (adj.OR = 1.21;95%CI:1.10-1.27) and all antibiotics (adj.OR = 1.41;95%CI:1.29-1.53), which was potentially attributed to underlying infection. Anti-tumor necrosis factor-alpha (TNFα) was not associated with MS risk in persons with inflammatory bowel disease (standard morbidity ratio = 4.2;95%CI:0.1-23.0) and arthritis (standardized incidence ratio = 1.38;95%CI:0.69-2.77); however, men exposed to anti-TNFα who also had arthritis and individuals with ankylosing spondylitis were at an increased risk (standardized incidence ratios = 3.91;95%CI:1.47-10.42 and 3.48;95%CI:1.45-8.37, respectively). A reduced risk of MS was observed with exposure to the beta2-adrenergic agonist fenoterol (adj.OR = 0.58;95%CI:0.45-0.76), and the sedating histamine 1-receptor antagonists (adj.OR = 0.2;95%CI:0.1-0.8), but not the non-sedating equivalent (adj.OR = 0.8;95%CI:0.4-1.6)., Conclusions: The suggestion that some drugs may prevent MS is intriguing and warrants further study. In addition, further pharmacovigilance is needed to assess the safety of anti-TNFα drugs in specific populations in the context of MS risk., (Copyright © 2017 John Wiley & Sons, Ltd.)

Background: Persons with multiple sclerosis (MS) use health resources with greater frequency than the general population. However, little is known regarding which patient characteristics might contribute., Objective: The study aimed to evaluate characteristics associated with healthcare use in MS patients., Methods: Consecutive MS clinic attendees were recruited (September-November 2010), with clinical, demographic, and patient-completed questionnaires collected at 3 visits over 2 years. Linkage with administrative data (hospital, physician, and pharmacy records) provided healthcare use outcomes until December 31, 2013. Findings were reported as adjusted rate ratios (adjRRs) using negative binomial regression., Results: A total of 340 MS patients with a mean (SD) age of 48.4 (12.0) years and subsequent follow-up of 3.1 (0.34) years were included. Fatigue and high physical comorbidity count (≥3 vs. none) were significantly associated with higher rates of physician encounters (adjRRs: 1.37 and 1.52, respectively), prescriptions filled (adjRRs: 1.25 and 1.40), and hospitalizations (adjRRs: 4.02 and 3.45). In addition, anxiety, disruptive pain, and perceived functional cognitive difficulties were associated with higher rates of physician encounters and prescriptions dispensed (adjRR ranged from 1.28 to 1.48)., Discussion: The presence of fatigue and higher physical comorbidity burden were associated with higher rates of health services use. Findings have implications for those examining healthcare burden or organizing health services for persons with MS., (© 2018 S. Karger AG, Basel.)

Multiple sclerosis (MS) is a chronic disease of the central nervous system with an unidentified etiology. We systematically reviewed the literature on the possible risk factors associated with MS disease onset, relapses and progression from 1960 to 2012 by accessing six databases and including relevant systematic reviews, meta-analyses, case-control or cohort studies. The focus was on identifying modifiable risk factors. Fifteen systematic reviews and 169 original articles were quality assessed and integrated into a descriptive review. Best evidence, which included one or more prospective studies, suggested that lower exposure to sunlight and/or lower serum vitamin D levels were associated with an increased risk of developing MS onset and subsequent relapses, but a similar quality of evidence was lacking for disease progression. Prospective studies indicated that cigarette smoking may increase the risk of MS as well as accelerate disease progression, but whether smoking altered the risk of a relapse was largely unknown. Infections were implicated in both risk of developing MS and relapses, but data for progression were lacking. Specifically, exposure to the Epstein-Barr virus, particularly if this manifested as infectious mononucleosis during adolescence, was associated with increased MS risk. Upper respiratory tract infections were most commonly associated with an increase in relapses. Relapse rates typically dropped during pregnancy, but there was no strong evidence to suggest that pregnancy itself altered the risk of MS or affected long-term progression. Emerging research with the greatest potential to impact public health was the suggestion that obesity during adolescence may increase the risk of MS; if confirmed, this would be of major significance., (Copyright © 2016. Published by Elsevier B.V.)

Background: Poor adherence to the disease-modifying therapies (DMTs) for multiple sclerosis (MS) may attenuate clinical benefit. A better understanding of characteristics associated with non-adherence could improve outcomes., Objective: To evaluate characteristics associated with non-adherence to injectable DMTs., Methods: Consecutive patients from four Canadian MS Clinics were assessed at three time points over two years. Clinical and demographic information included self-reported DMT use, missed doses in the previous 30 days, health behaviors, and comorbidities. Non-adherence was defined as <80% of expected doses taken. We employed generalized estimating equations to examine characteristics associated with non-adherence at all time points with findings reported as adjusted odds ratios (OR)., Results: In all, 485 participants reported use of an injectable DMT, of whom 107 (22.1%) were non-adherent over the study period. Non-adherence was associated with a lower Expanded Disability Status Scale score (0-2.5 vs 3.0-5.5, OR: 1.80; 95% confidence interval (CI): 1.06-3.04), disease duration (⩽5 vs <5 years, OR: 2.23; 95% CI: 1.10-4.52), alcohol dependence (OR: 2.14; 95% CI: 1.23-3.75), and self-reported cognitive difficulties, measured by the Health Utilities Index-3 (OR: 1.55; 95% CI: 1.08-2.22)., Conclusions: Nearly one-quarter of participants were non-adherent during the study. Alcohol dependence, perceived cognitive difficulties, longer disease duration, and mild disability status were associated with non-adherence. These characteristics may help healthcare professionals identify patients at greatest risk of poor adherence.

Background: Self-report and pharmacy records are often used to measure adherence rates to disease-modifying therapies (DMTs) in multiple sclerosis (MS), but little is known about how the sources compare., Objective: Compare self-report and pharmacy records for assessing DMT use and adherence rates., Methods: Demographic information, self-reported DMT use, and missed DMT doses in the previous 30 days were obtained from consecutive MS patients attending an MS clinic and linked to pharmacy records. A medication possession ratio (MPR) was calculated using pharmacy records for the year before and after the visit; MPR <80% defined nonadherence. Agreement between self-report and pharmacy records was assessed using Cohen's kappa (κ)., Results: Of 326 participants, 135 reported using an injectable DMT. There was near-perfect and perfect agreement between self-report and pharmacy records for DMT use (κ = 0.95; 95% CI 0.91-0.98) and DMT agent (κ = 1.00). Nonadherence was estimated at 13% (17/128) from the 30-days self-report compared to 30% (34/113) and 43% (53/123) in the year pre- and post-clinic visit from pharmacy records, indicating moderate to fair agreement (year prior: κ = 0.41; 95% CI 0.22-0.59; year post: κ = 0.22; 95% CI 0.09-0.36)., Conclusions: Patients self-reports closely reflected pharmacy records when assessing DMT use and product. Moderate to fair agreement was found when comparing adherence rates between sources., (© 2017 S. Karger AG, Basel.)

Background: Depression and anxiety are common among people with multiple sclerosis (MS), as are adverse health behaviours, but the associations between these factors are unclear., Objective: To evaluate the associations between cigarette smoking, alcohol use, and depression and anxiety in MS in a cross-Canada prospective study., Methods: From July 2010 to March 2011 we recruited consecutive MS patients from four MS clinics. At three visits over two years, clinical and demographic information was collected, and participants completed questionnaires regarding health behaviours and mental health., Results: Of 949 participants, 75.2% were women, with a mean age of 48.6 years; most had a relapsing-remitting course (72.4%). Alcohol dependence was associated with increased odds of anxiety (OR: 1.84; 95% CI: 1.32-2.58) and depression (OR: 1.53; 95% CI: 1.05-2.23) adjusting for age, sex, Expanded Disability Status Scale (EDSS), and smoking status. Smoking was associated with increased odds of anxiety (OR: 1.29; 95% CI: 1.02-1.63) and depression (OR: 1.37; 95% CI: 1.04-1.78) adjusting for age, sex, EDSS, and alcohol dependence. Alcohol dependence was associated with an increased incidence of depression but not anxiety. Depression was associated with an increased incidence of alcohol dependence., Conclusion: Alcohol dependence and smoking were associated with anxiety and depression. Awareness of the effects of adverse health behaviours on mental health in MS might help target counselling and support for those 'at risk'., (© The Author(s), 2015.)

Multiple sclerosis (MS) is a chronic central nervous system disease that is associated with progressive loss of myelin and subsequent axonal degeneration. Cholesterol is an essential component of mammalian cellular and myelin membranes. In this systematic review, we examined the relationship between levels of cholesterol and markers of cholesterol turnover in circulation and/or cerebrospinal fluid (CSF) and disease outcomes in adults with clinically isolated syndrome (CIS) or confirmed MS. Studies suggest that elevated levels of circulating low density lipoprotein cholesterol (LDL), total cholesterol, and particularly, apolipoprotein B and oxidized LDL are associated with adverse clinical and MRI outcomes in MS. These relationships were observed as early as CIS. The studies also suggest that oxysterols, cholesterol precursors, and apolipoprotein E may be markers of specific disease processes in MS, but more research is required to elucidate these processes and relationships. Taken together, the data indicate that cholesterol and markers of cholesterol turnover have potential to be used clinically as biomarkers of disease activity and may even be implicated in the pathogenesis of MS., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This article presents the findings of a population-based study conducted in Ontario and British Columbia, Canada, on pediatric-onset multiple sclerosis (PoMS). The study found that the incidence rate of PoMS remained stable between 2003 and 2019, while the prevalence increased over time. The study highlights the need for appropriate resource allocation to support the growing PoMS population. The document provides information on the selection of cases, demographic characteristics, and compares the incidence and prevalence rates in Canada to other regions. It also discusses long-term outcomes and prognostic indicators of pediatric MS. [Extracted from the article]

Background: Multiple sclerosis (MS) quality of care guidelines are consensus-based. The effectiveness of the recommendations is unknown. Objective: To determine whether clinic-level quality of care affects clinical and patient-reported outcomes. Methods: This nationwide observational cohort study included patients with adult-onset MS in the Swedish MS registry with disease onset 2005–2015. Clinic-level quality of care was measured by four indicators: visit density, magnetic resonance imaging (MRI) density, mean time to commencement of disease-modifying therapy, and data completeness. Outcomes were Expanded Disability Status Scale (EDSS) and patient-reported symptoms measured by the Multiple Sclerosis Impact Scale (MSIS-29). Analyses were adjusted for individual patient characteristics and disease-modifying therapy exposure. Results: In relapsing MS, all quality indicators benefitted EDSS and physical symptoms. Faster treatment, frequent visits, and higher data completeness benefitted psychological symptoms. After controlling for all indicators and individual treatment exposures, faster treatment remained independently associated with lower EDSS (−0.06, 95% confidence interval (CI): −0.01, −0.10) and more frequent visits were associated with milder physical symptoms (MSIS-29 physical score: −16.2%, 95% CI: −1.8%, −29.5%). Clinic-level quality of care did not affect any outcomes in progressive-onset disease. Conclusion: Certain quality of care indicators correlated to disability and patient-reported outcomes in relapse-onset but not progressive-onset disease. Future guidelines should consider recommendations specific to disease course. [ABSTRACT FROM AUTHOR]

Background: There is a paucity of information on maternal multiple sclerosis (MS) and risk of adverse pregnancy and perinatal outcomes. Objective: The aim of this study was to determine the association between MS and risks of adverse pregnancy and perinatal outcomes in women with MS. In women with MS, the influence of exposure to disease-modifying therapy (DMT) was also investigated. Methods: Population-based retrospective cohort study on singleton births to mothers with MS and matched MS-free mothers from the general population in Sweden between 2006 and 2020. Women with MS were identified through Swedish health care registries, with MS onset before child's birth. Results: Of 29,568 births included, 3418 births were to 2310 mothers with MS. Compared with MS-free controls, maternal MS was associated with increased risks of elective caesarean sections, instrumental delivery, maternal infection and antepartum haemorrhage/ placental abruption. Compared with offspring of MS-free women, neonates of mothers with MS were at increased risks of medically indicated preterm birth and being born small for gestational age. DMT exposure was not associated with increased risks of malformations. Conclusions: While maternal MS was associated with a small increased risk of few adverse pregnancy and neonatal outcomes, DMT exposure close to pregnancy was not associated with major adverse outcomes. [ABSTRACT FROM AUTHOR]

Background: Most previous multiple sclerosis (MS) brain atrophy studies using MS impact scale 29 (MSIS-29) or symbol digit modalities test (SDMT) have been cross-sectional with limited sets of clinical outcomes. Objectives: To investigate which brain and lesion volume metrics show the strongest long-term associations with the expanded disability status scale (EDSS), SDMT, and MSIS-29, and whether MRI-clinical associations vary with age. Methods: We acquired MRI and clinical data from a real-world Swedish MS cohort. FreeSurfer and SPM Lesion Segmentation Tool were used to obtain brain parenchymal, cortical and subcortical grey matter, thalamic and white matter fractions as well as T1- and T2-lesion volumes. Mixed-effects and rolling regression models were used in the statistical analyses. Results: We included 989 persons with MS followed for a median of 9.3 (EDSS), 10.1 (SDMT), and 9.3 (MSIS-29) years, respectively. In a cross-sectional analysis, the strength of the associations of the MRI metrics with the EDSS and MSIS-29 was found to drastically increase after 40–50 years of age. Low baseline regional grey matter fractions were associated with longitudinal increase of EDSS and physical MSIS-29 scores and decrease in SDMT scores and these atrophy measures were stronger predictors than the lesion volumes. Conclusions: The strength of MRI-clinical associations increase with age. Grey matter volume fractions are stronger predictors of long-term disability measures than lesion volumes. [ABSTRACT FROM AUTHOR]

Background: The primary objective of this study was to analyse the association between multiple sclerosis (MS) disease-modifying therapy (DMT) exposure and hospitalisation in patients infected with COVID-19. Methods: Associations between MS DMT exposure and COVID-19 hospitalisation were analysed using univariable and multi-variable-clustered propensity score weighted logistic regression, where the models were clustered on the individual patients to control for patients contributing multiple COVID-19 episodes. Findings: As of 18 January 2021, a total of 476 reported COVID-19 cases had been recorded in MS patients in the Swedish MS registry. Of these, 292 (61.3%) had confirmed COVID-19. The mean value (standard deviation (SD)) age at infection was 44.0 years (11.6). Of the 292 confirmed infections, 68 (23.2%) required hospitalisation. A total of 49 of the 164 confirmed COVID-19 patients on rituximab at baseline (29.9%) required hospitalisation, compared to a rate of 12.7% for all other DMTs combined. Rituximab in confirmed COVID-19 patients was associated with 2.95 times the odds of hospitalisation relative to any other DMT combined (odds ratio = 2.95; 95% confidence interval (CI) = 1.48–5.87). Interpretation: Rituximab treatment, known to increase the risk of severe infections in general, also confers such a risk for MS patients with COVID-19, in comparison with other MS DMTs. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to explore the longitudinal relationship between multiple sclerosis (MS) relapses and information processing efficiency among persons with relapsing–remitting MS. Methods: We conducted a Swedish nationwide cohort study of persons with incident relapsing–remitting MS (2001–2019). Relapse information and symbol digit modalities test (SDMT) scores were obtained from the Swedish MS Registry. Follow‐up was categorized into 2 periods based on relapse status: "relapse" (90 days pre‐relapse to 730 days post‐relapse, subdivided into 10 periods) and "remission." Linear mixed models compared SDMT scores during the relapse periods to SDMT scores recorded during remission (reference) with results reported as β‐coefficients and 95% confidence intervals (CIs), adjusted for age, sex, SDMT type (written vs oral), time‐varying, disease‐modifying therapy exposure and sequence of SDMT. Results: Over a mean (SD) follow‐up of 10.7 (4.3) years, 31,529 distinct SDMTs were recorded among 3,877 persons with MS. There was a significant decline in information processing efficiency that lasted from 30 days pre‐relapse up to 550 days post‐relapse, with the largest decline occurring 0 to 30 days post‐relapse (β‐coefficient: −4.00 (95% CI = −4.61 to −3.39), relative to the period of remission. Interpretation: We found evidence of cognitive change up to 1 month prior to relapse onset. The reduction in SDMT lasted 1.5 years and was clinically significant up to 3 months post‐relapse. These results suggest that the effects of a relapse on cognition are longer than previously thought and highlight the importance of reducing relapse rates as a potential means of preserving cognitive function. ANN NEUROL 2022;91:417–423 [ABSTRACT FROM AUTHOR]

Under-coding of secondary conditions in coded hospital health data: Impact of co-existing conditions, death status and number of codes in a record. People with multiple sclerosis (MS) have high rates of health care use, including hospitalizations, one of the most costly forms of care. While specificity is typically high based on hospital claims, this is not universal, and positive predictive values may be quite low for some conditions.[7] Thus, it is likely that some individuals without MS were captured in the MS cohort. [Extracted from the article]

Background: Studies assessing the prevalence of depression and anxiety in multiple sclerosis (MS) have used various ascertainment methods that capture different constructs. The relationships between these methods are incompletely understood. Psychiatric comorbidity is associated with lower health-related quality of life (HRQOL) in MS, but the effects of past diagnoses of depression and anxiety on HRQOL are largely unknown. We compared the prevalence of depression and anxiety in persons with MS using administrative data, self-reported physician diagnoses, and symptom-based measures and compared characteristics of persons classified as depressed or anxious by each method. We evaluated whether HRQOL was most affected by previous diagnoses of depression or anxiety or by current symptoms. Methods: We linked clinical and administrative data for 859 participants with MS. HRQOL was measured by the Health Utilities Index Mark 3. We classified participants as depressed or anxious using administrative data, self-reported physician diagnoses, and the Hospital Anxiety and Depression Scale. Multivariable linear regression examined whether diagnosed depression or anxiety affected HRQOL after accounting for current symptoms. Results: Lifetime prevalence estimates for depression were approximately 30% regardless of methods used, but 35.8% with current depressive symptoms were not captured by either administrative data or self-reported diagnoses. Prevalence estimates of anxiety ranged from 11% to 19%, but 65.6% with current anxiety were not captured by either administrative data or self-reported diagnoses. Previous diagnoses did not decrease HRQOL after accounting for current symptoms. Conclusions: Depression and, to a greater extent, anxiety remain underdiagnosed and undertreated in MS; both substantially contribute to reduced HRQOL in MS. [ABSTRACT FROM AUTHOR]

Background: Poor adherence to the disease-modifying therapies (DMTs) for multiple sclerosis (MS) may attenuate clinical benefit. A better understanding of characteristics associated with non-adherence could improve outcomes. Objective: To evaluate characteristics associated with non-adherence to injectable DMTs. Methods: Consecutive patients from four Canadian MS Clinics were assessed at three time points over two years. Clinical and demographic information included self-reported DMT use, missed doses in the previous 30 days, health behaviors, and comorbidities. Non-adherence was defined as <80% of expected doses taken. We employed generalized estimating equations to examine characteristics associated with non-adherence at all time points with findings reported as adjusted odds ratios (OR). Results: In all, 485 participants reported use of an injectable DMT, of whom 107 (22.1%) were non-adherent over the study period. Non-adherence was associated with a lower Expanded Disability Status Scale score (0-2.5 vs 3.0-5.5, OR: 1.80; 95% confidence interval (CI): 1.06-3.04), disease duration (≥5 vs <5 years, OR: 2.23; 95% CI: 1.10-4.52), alcohol dependence (OR: 2.14; 95% CI: 1.23-3.75), and self-reported cognitive difficulties, measured by the Health Utilities Index-3 (OR: 1.55; 95% CI: 1.08-2.22). Conclusions: Nearly one-quarter of participants were non-adherent during the study. Alcohol dependence, perceived cognitive difficulties, longer disease duration, and mild disability status were associated with non-adherence. These characteristics may help healthcare professionals identify patients at greatest risk of poor adherence. [ABSTRACT FROM AUTHOR]

Background: Depression and anxiety are common among people with multiple sclerosis (MS), as are adverse health behaviours, but the associations between these factors are unclear. Objective: To evaluate the associations between cigarette smoking, alcohol use, and depression and anxiety in MS in a cross-Canada prospective study. Methods: From July 2010 to March 2011 we recruited consecutive MS patients from four MS clinics. At three visits over two years, clinical and demographic information was collected, and participants completed questionnaires regarding health behaviours and mental health. Results: Of 949 participants, 75.2% were women, with a mean age of 48.6 years; most had a relapsing−remitting course (72.4%). Alcohol dependence was associated with increased odds of anxiety (OR: 1.84; 95% CI: 1.32–2.58) and depression (OR: 1.53; 95% CI: 1.05–2.23) adjusting for age, sex, Expanded Disability Status Scale (EDSS), and smoking status. Smoking was associated with increased odds of anxiety (OR: 1.29; 95% CI: 1.02–1.63) and depression (OR: 1.37; 95% CI: 1.04–1.78) adjusting for age, sex, EDSS, and alcohol dependence. Alcohol dependence was associated with an increased incidence of depression but not anxiety. Depression was associated with an increased incidence of alcohol dependence. Conclusion: Alcohol dependence and smoking were associated with anxiety and depression. Awareness of the effects of adverse health behaviours on mental health in MS might help target counselling and support for those ‘at risk’. [ABSTRACT FROM AUTHOR]

Background: Fatigue is commonly reported by people with multiple sclerosis (MS). Comorbidity is also common in MS, but its association with the presence of fatigue or fatigue changes over time is poorly understood. Methods: Nine hundred forty-nine people with definite MS were recruited from four Canadian centers. The Fatigue Impact Scale for Daily Use and a validated comorbidity questionnaire were completed at three visits over 2 years. Participants were classified into groups with no fatigue versus any fatigue. Logistic regression was used to determine the relationship between fatigue and each comorbidity at baseline, year 1, year 2, and overall. Results: The incidence of fatigue during the study was 38.8%. The prevalence of fatigue was greater in those who were older (P = .0004), had a longer time since symptom onset (P = .005), and had greater disability (P < .0001). After adjustment, depression (odds ratio [OR], 2.58; 95% confidence interval [CI], 2.03-3.27), irritable bowel syndrome (OR, 1.71; 95% CI, 1.18-2.48), migraine (OR, 1.69; 95% CI, 1.27-2.27), and anxiety (OR, 1.57; 95% CI, 1.15-2.16) were independently associated with fatigue that persisted during the study. There was also an individual-level effect of depression on worsening fatigue (OR, 1.49; 95% CI, 1.08-2.07). Conclusions: Comorbidity is associated with fatigue in MS. Depression is associated with fatigue and with increased risk of worsening fatigue over 2 years. However, other comorbid conditions commonly associated with MS are also associated with persistent fatigue, even after accounting for depression. Further investigation is required to understand the mechanisms by which comorbidities influence fatigue. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a chronic central nervous system disease with a highly heterogeneous course. The aetiology of MS is not well understood but is likely a combination of both genetic and environmental factors. Approximately 85% of patients present with relapsing-remitting MS (RRMS), while 10–15% present with primary progressive MS (PPMS). PPMS is associated with an older onset age, a different sex ratio, and a considerably more rapid disease progression relative to RRMS. We systematically reviewed the literature to identify modifiable risk factors that may be associated with these different clinical courses. We performed a search of six databases and integrated twenty observational studies into a descriptive review. Exposure to Epstein-Barr virus (EBV) appeared to increase the risk of RRMS, but its association with PPMS was less clear. Other infections, such as human herpesvirus-6 and chlamydia pneumoniae, were not consistently associated with a specific disease course nor was cigarette smoking. Despite the vast literature examining risk factors for the development of MS, relatively few studies reported findings by disease course. This review exposes a gap in our understanding of the risk factors associated with the onset of PPMS, our current knowledge being predominated by relapsing-onset MS. [ABSTRACT FROM AUTHOR]