Neurological comorbidity and survival in multiple sclerosis

Multiple sclerosis and vascular nexus: A systematic review and meta-analysis of incidence and mortality

BACKGROUND

Vascular diseases (VDs) are increasingly studied in multiple sclerosis (MS) due to their significant impact on disability and mortality. Our aim was to evaluate VD incidence rates and determine the prevalence of VD-related mortality.

MATERIAL AND METHODS

Our study followed the PRISMA 2020 guidelines. We searched PubMed, Google Scholar, Europe PMC, and Web of Science from the inception up to April 30th, 2024. Data analysis was performed using the R statistics package program. Sensitivity analysis, subgroup analysis, and meta-regression were conducted for significant heterogeneity.

RESULTS

We collected 23 studies. Patients with MS exhibited significantly higher rates of VD compared with controls. Patients with MS showed a significantly higher rate of heart failure (HF), venous thromboembolism (VTE), peripheral vascular disease (PVD), and stroke, although the incidence rate of atrial fibrillation/flutter was significantly lower compared with controls. High blood pressure tended to be lower compared with controls. The highest rate of VD was within the first 10years of follow-up, significantly for myocardial infraction, VTE, and stroke, compared with controls. Regarding mortality, the prevalence of VD-related mortality among deceased individuals with MS was 16.7% [95% CI 11.8;22.0].

CONCLUSION

Our meta-analysis revealed a significant dynamic nexus between MS and VD. MS may act as an independent risk factor for certain VDs, yet it could also be a protective factor against others. Physicians should consider VD and mortality related to VD when managing patients with MS.

Comorbidities and their association with outcomes in the multiple sclerosis population: A rapid review

INTRODUCTION

Multiple sclerosis (MS) has a high comorbidity burden. Despite known associations with adverse outcomes, a comprehensive evaluation of the specific associations between individual comorbidities and disability, treatment initiation, and mortality remains underexplored. This study aimed to review and summarize existing evidence on the association between comorbidities and these three MS outcomes.

METHODS

A rapid review spanning the period from January 2002 to October 2023 was conducted following the Cochrane Rapid Review Methods Group recommendations. MEDLINE, Embase, and the grey literature were searched to identify studies examining the effects of comorbidities on disability, treatment initiation, and mortality among individuals with MS. Data extraction and risk of bias assessments were systematically performed, with the Newcastle-Ottawa scale and A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2) criteria for observational studies and systematic reviews respectively.

RESULTS

The review included 100 primary studies, encompassing 88 different comorbidities. Most study populations were between 60-80% female, with an average age of 30-45 years at study start. The majority of included studies were conducted in Europe, North America, and Asia (specifically the Middle East). Over half (66%) of specific comorbidity-outcome relationships were examined within a single study only, and just two studies examined treatment initiation as an outcome. Methods used to assess comorbidities and outcomes varied widely and included self-report measures, medical records and diagnostic codes, and standardized clinical assessments. Depression was consistently associated with greater disability (adjusted hazard ratio (aHR): 1.50-3.59) and mortality (aHR: 1.62-3.55). Epilepsy was similarly associated with increased disability (aOR: 1.13-1.77) and increased mortality (aHR: 2.23-3.85). Diabetes was generally associated with increased mortality (aHR: 1.39-1.47), but results for disability were inconsistent. Most other conditions were examined in one or two studies only or findings varied across studies, unable to collectively indicate a clear association. Although the anxiety-disability relationship was assessed by 24 studies, the findings varied in terms of the presence, direction, and strength of a possible association, requiring nuanced interpretation.

CONCLUSIONS

This study identifies relationships between various comorbidities and three outcomes in MS, providing a foundation for future research and clinical guidelines. People with psychiatric, metabolic, and neurological conditions may be at a higher risk of MS disease progression and may therefore benefit from the targeted treatment of their comorbidities. Overall, comorbidities have varying associations with MS outcomes and individual associations require further exploration. However, there is evidence that some comorbidities indicate worse disability and higher mortality risk, and present barriers to initiating MS treatment, making the prevention and management of comorbidities an integral piece of MS patient care.

PROTOCOL

The protocol for this rapid review was registered on PROSPERO (ID: CRD42023475565) and published on Protocol Exchange (https://doi.org/10.21203/rs.3.pex-2438/v1).

Stroke risk in multiple sclerosis: a critical appraisal of the literature

Observational studies suggest that the occurrence of stroke on multiple sclerosis (MS) patients is higher compared to the general population. MS is a heterogeneous disease that involves an interplay of genetic, environmental and immune factors. The occurrence of stroke is subject to a wide range of both modifiable and non-modifiable, short- and long-term risk factors. Both MS and stroke share common risk factors. The immune mechanisms that underlie stroke are similar to neurodegenerative diseases and are attributed to neuroinflammation. The inflammation in autoimmune diseases may, therefore, predispose to an increased risk for stroke or potentiate the effect of conventional stroke risk factors. There are, however, additional determinants that contribute to a higher risk and incidence of stroke in MS. Due to the challenges that are associated with their differential diagnosis, the objective is to present an overview of the factors that may contribute to increased susceptibility or occurrence of stroke in MSpatients by performing a review of the available to date literature. As both MS and stroke can individually detrimentally affect the quality of life of afflicted patients, the identification of factors that contribute to an increased risk for stroke in MS is crucial for the prompt implementation of preventative therapeutic measures to limit the additive burden that stroke imposes.

The prevalence of restless legs syndrome (RLS) in patients with multiple sclerosis (MS): a systematic review and meta-analysis-an update

INTRODUCTION

The prevalence of restless legs syndrome (RLS) is reported to vary in patients with multiple sclerosis (MS) in studies which are conducted in different populations. The goal of this systematic review and meta-analysis is to update the prevalence of RLS in MS cases.

METHODS

We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Google Scholar, and gray literature including references from identified studies and conference abstracts which were published up to June 2021. Data on the total number of participants, first author, country, disease duration, number of controls, mean patient age, male and female numbers, mean EDSS, and number of cases and/or controls with RLS were extracted from the included studies.

RESULTS

The literature search revealed 855 articles; after deleting duplicates, 530 remained. For the meta-analysis, 75 studies were included (Fig. 1). In six articles, the authors did not differentiate between CIS and MS cases when reporting RLS cases. In total, 15,411 MS/CIS patients were evaluated and 4309 had RLS. The pooled prevalence of RLS was 28% (95% CI: 24-33%). The pooled prevalence of RLS in men was 22% (95% CI: 17-26%), and the pooled prevalence of RLS in women was 30% (95% CI: 25-35%). The pooled prevalence of RLS in controls was 8% (95% CI: 6-10%).

CONCLUSION

The results of this systematic review and meta-analysis show that the pooled prevalence of RLS is 28% in MS cases and 8%. The pooled prevalence is higher in women than men (30% vs 22%).

Stroke Outcomes and Hyperacute Treatment Utilization in Multiple Sclerosis

BACKGROUND

People with MS (pwMS) have higher prevalence of comorbidities at disease onset and face increased risk of developing cardiovascular disorders. Stroke is of particular concern for this population with previous neurological disability. However, data on stroke outcomes and resource utilization in those pwMS remains scarce.

OBJECTIVE

To assess the risk of adverse stroke outcomes and hyperacute treatment utilization for pwMS in a U.S. population-based sample of hospitalized patients.

METHODS

This study identified patients discharged with a diagnosis of ischemic stroke in the 2018 National Inpatient Sample. We compared the discharge outcomes and hyperacute stroke treatment utilization in MS (n = 2,795) versus non-MS patients (n = 682.730). Regression models adjusted for cardiovascular risk factors and hospital characteristics were used to account for the complex sampling design.

RESULTS

The odds of a good discharge were 32% less likely to occur in pwMS (adj.OR 0.68 [95%CI 0.58-0.81], p<0.001). However, this was not associated with an increased risk of mortality. PwMS had a 57% reduction in the risk of receiving endovascular thrombectomy (EVT) (adj.OR 0.43 [95%CI 0.22-0.83], p = 0.01) but no difference in rates of thrombolysis.

CONCLUSION

Patients with MS have lower rates of good discharge outcomes and EVT with ischemic stroke, despite similar rates of thrombolysis.

Prognostic impact of epileptic seizures in multiple sclerosis varies according to time of occurrence and etiology

BACKGROUND AND PURPOSE

Epileptic seizures occur more often in patients with multiple sclerosis (MS) than in the general population. Their association with the prognosis of MS remains unclear. This study was undertaken to evaluate whether epileptic seizures may be a prognostic marker of MS disability, according to when the seizure occurs and its cause.

METHODS

Data were extracted from a population-based registry of MS in Lorraine, France. Kaplan-Meier curves and log-rank tests were used to compare the probability of different levels of irreversible handicap during the course of MS in patients who experience epileptic seizures or do not, according to the chronology and the cause of the first epileptic seizure.

RESULTS

Among 6238 patients, 134 had experienced at least one epileptic seizure (2.1%), and 82 (1.2%) had seizures secondary to MS. Patients with epileptic seizure as a first symptom of MS (14 patients) had the same disease progression as other relapsing-remitting MS patients. Patients who developed epileptic seizures during the course of MS (68 patients) had a higher probability of reaching Expanded Disability Status Scale = 3.0 (p = 0.006), 6.0 (p = 0.003), and 7.0 (p = 0.004) than patients without an epileptic background. Patients with a history of epileptic seizures unrelated to MS also had a worse prognosis than patients without an epileptic background.

CONCLUSIONS

Epileptic seizures might be viewed as a "classic MS relapse" in terms of prognosis if occurring early in MS, or as a marker of MS severity if developing during the disease. Epileptic diseases other than MS may worsen the course of MS.

Seizures and multiple sclerosis‑more than an epidemiological association (Review)

In order to increase the quality of life of patients with epilepsy, it is essential to develop tools that facilitate early disease diagnosis and encourage the use of individualized therapies. The association between seizures and other neurological pathologies is well known but incompletely explained, with multiple sclerosis (MS)-seizures correlation being a relevant example. In this context, the present review aimed to highlight the most important facts related to the association between the heterogeneous group of epileptic pathology and MS, in order to provide initial directions for establishing a diagnostic and therapeutic protocol. The first part reviewed the most relevant epidemiological and clinical data on seizures; MS association. Subsequently, it highlighted the most common and actually accepted pathophysiological mechanisms that try to explain the association between the two pathologies. Finally, the importance of paraclinical investigations and the optimal choice of antiseizure-based therapies with respect to seizures associated with MS are presented, also revealing several directions that should be explored in the near future.

Prevalence of Seizure/Epilepsy in Patients with Multiple Sclerosis: A Systematic Review and Meta-Analysis

Background

Seizure and epilepsy are among the initial symptoms of multiple sclerosis (MS), yet different prevalence rates are reported for them in the previous studies. The goal of this systematic review is to estimate the pooled prevalence of seizure and epilepsy in patients with MS.

Methods

We searched PubMed, Scopus, EMBASE, Web of Science, google scholar, and gray literature including references from identified studies and conference abstracts published up to October 2019. The search strategy included the MeSH terms and text words as ((Epilepsies OR Seizure Disorder OR Seizure Disorders OR Awakening Epilepsy OR Epilepsy, Awakening OR Epilepsy, Cryptogenic OR Cryptogenic Epilepsies OR Cryptogenic Epilepsy OR Epilepsies, Cryptogenic OR epilepsy OR seizure) AND (Multiple Sclerosis OR Sclerosis, Multiple) OR Sclerosis, Disseminated) OR Disseminated Sclerosis) OR MS (Multiple Sclerosis)) OR Multiple Sclerosis, Acute Fulminating).

Results

The literature review resulted in 4860 articles; 2593 articles remained after eliminating the duplicates. For the final analysis, 39 articles were included, 9 of which were conference abstracts. The pooled prevalence of seizure in MS cases was 2%, 95% confidence interval (CI)(1%-3%) (I² = 91.8%, P < 0.001). The pooled prevalence of epilepsy in MS cases was 3%, 95% CI (2%-4%) (I2 = 92.9%, P < 0.001). The pooled prevalence of epilepsy in Asia, Europe, and America was 6%, 3%, and 3%, respectively. The level of heterogeneity decreased after subgroup analysis in Asian and American subgroups. Meta-regression analysis showed continent is not a source of heterogeneity (coefficient = -0.007, P = 0.6).

Conclusions

The result of this systematic review shows that the pooled prevalence of seizure and epilepsy among MS patients is 2% and 3%, respectively.

Evaluating the Risk of Macrovascular Events and Mortality Among People With Multiple Sclerosis in England

Importance

People with multiple sclerosis (MS) are associated with an increased risk of cardiovascular disease and mortality; however, evidence from population-based studies is sparse.

Objective

To assess whether the risk of macrovascular events and mortality differs among people with MS compared with a matched population without MS in England.

Design, Setting, and Participants

A population-based retrospective matched cohort study was conducted in general practices registered with the Clinical Practice Research Datalink in England between January 1, 1987, and September 30, 2018, with a mean (SD) follow-up of 11.3 (6.5) years. A total of 12 251 patients with MS were matched with up to 6 people without MS (n = 72 572) by age, sex, and general practice. People with 3 or more diagnoses of MS recorded during the study period were included. The first MS diagnosis was considered as index date.

Exposures

Multiple sclerosis status. Analyses were also stratified by sex.

Main Outcomes and Measures

Main outcomes were acute coronary syndrome, cerebrovascular disease, any macrovascular disease (including peripheral arterial disease), and mortality (all-cause mortality and cardiovascular disease-specific mortality). Cox proportional hazards regression and Fine and Gray proportional subhazard regression models were used to assess differences in rates.

Results

A total of 12 251 people with MS (66.9% women; mean [SD] age, 44.9 [13.3] years) were matched with 72 572 people without MS (69.8% women; mean [SD] age, 44.9 [13.3] years). As compared with people without MS, people with MS were associated with a 28% increased hazard of acute coronary syndrome (hazard ratio [HR], 1.28; 95% CI, 1.09-1.51), 59% increased hazard of cerebrovascular disease (HR, 1.59; 95% CI, 1.32-1.92), 32% increased hazard of any macrovascular disease (HR, 1.32; 95% CI, 1.15-1.52), 3.5-fold increased hazard of all-cause mortality (HR, 3.46; 95% CI, 3.28-3.65), and 1.5-fold increased hazard in cardiovascular disease mortality (HR, 1.47; 95% CI, 1.27-1.71). Differences in macrovascular events were more pronounced among women than men. Mortality risk was also higher for women than men. Treatment with lipid-lowering medications (mainly statins) was associated with lower mortality rates among people with MS.

Conclusions and Relevance

This study suggests that MS is associated with an increased risk of cardiovascular and cerebrovascular disease that is not completely accounted for by traditional vascular risk factors. Given the adverse effects of these comorbidities on outcomes in patients with MS, further investigation is needed.

Trends and characteristics of infection-related hospital admissions in multiple sclerosis patients in Southwest Finland in 2009-2018

BACKGROUND

Multiple sclerosis (MS) patients are at increased risk for infections. The aim of this study was to investigate the trends in hospital admissions of patients with MS and to identify the factors predisposing to infection-related admissions.

METHODS

Hospital admissions with MS as a primary or an auxiliary diagnosis in the hospital district of Southwest Finland in 2009-2018 were searched and MS patients with infection admissions compared with other MS patients in the hospital district. Data were derived from hospital registries, patient charts and the Finnish MS register. Group comparisons were performed using Pearson´s chi-squared test, Fisher´s exact test or Wilcoxon rank sum test. Overdispersion-adjusted Poisson regression was used to analyze the annual admission numbers and multivariable logistic regression to examine the predictors of infection-related admissions.

RESULTS

1380 hospital admissions for 532 patients were identified. The annual number of admissions decreased by 8.9% annually (p<0.001). Proportion of infection-related admissions declined from 26.5% to 19.5% (p = 0.049). The patients with infection admissions were on average 8.2 years older (p<0.001), more often male (p<0.001), had on average 5.3 years longer disease duration (p<0.001), more disability (median EDSS 5.0 vs. 2.0; p<0.001), more often progressive disease (p<0.001) and more comorbidities (p = 0.006) than other MS patients. Disease modifying therapies (DMTs) were used less often by patients with infection admissions (p<0.001). Infection admissions were not associated with the number of recent relapses. In-hospital mortality was higher in the infection-related admissions (3.57% vs 0.29%; p<0.001). Only 14.3% of patients with over two infection admissions had a DMT during the study period.

CONCLUSION

Hospital admissions, with or without an infection, have become more infrequent in MS patients of Southwest Finland over the decade from 2009 to 2018. Infection-related admissions were associated with lesser use of DMTs, older age, male gender and disability.

Relevance of cerebrospinal fluid findings in patients with multiple sclerosis and seizures

Seizures occur 2-3 times more frequently in Multiple Sclerosis (MS) patients compared to the general population. The prevalence of seizures is reported to be 1.5-7.8% in MS population. However, it is unclear if seizure is an indirect symptom of neuroinflammation in MS. In our study, we explored the relevance of cerebrospinal fluid (CSF) findings in this unique patient cohort with MS and seizures. We retrospectively reviewed the charts of 32 MS patients with subsequent seizures (MSSS) and 12 patients with seizures followed by MS (SFMS). These two study groups were compared with two control groups - MS without seizures (MSNOS) and seizures without MS (SNOMS). Clinical characteristics and CSF findings between these groups were compared using boot strapped independent t-test. The CSF lymphocyte percentage of the SFMS group (95.6 ± 3) was significantly higher compared to MSNOS (66.0 ± 36.9, p = .04) and SNOMS (81.7 ± 10.0, p = .03). The CSF IgG index was significantly higher in SFMS group (1.9 ± 1.2, p = .02) as compared to MSSS group (0.99 ± 0.4). Patients with seizures as initial symptom of MS may have higher degree of CNS inflammation. Nonspecific clinical symptoms and atypical imaging findings in patients presenting with seizures may warrant close monitoring for development of MS.

Multiple sclerosis and stroke: a systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) and stroke are two common causes of death and disability worldwide. The relationship between these two diseases remains unclear. Effective early preventative measures and treatments are available to reduce the morbidity and mortality of acute stroke. The objectives of our systematic review are to estimate the risk of stroke in patients with MS and to collate related studies to draw preliminary conclusions that may improve clinical practice.

METHOD

Relevant studies were systematically searched in MEDLINE, Embase, the Chinese Biomedical Literature Database (CBM), the China National Knowledge Infrastructure and the VIP database of Chinese periodicals from January 1983 to May 2017, with no restrictions on language. Patients included in this review were adults who suffered from MS. Review Manager 5.3 software program was used to pool data and calculate the risk ratio (RR) and its 95% confidence interval (CI). We also performed heterogeneity and sensitivity analyses and evaluated bias in the meta-analysis.

RESULTS

Nine studies including more than 380,000 participants that met our inclusion criteria were incorporated into the meta-analysis. During different follow-up periods, patients with MS had an increased risk of any type of stroke [RR = 3.48, 95% CI (1.59, 7.64), P = 0.002 for 1 year; RR = 2.45, 95% CI (1.90, 3.16), P < 0.00001 for 10-13 years]. The total prevalence of stroke (any type) in patients with MS exceeded expectations compared to different groups [Comparing with general veteran: RR = 2, 95% CI (1.19, 3.38), P = 0.009. Comparing with general population: RR = 2.93, 95% CI (1.13, 7.62), P = 0.03]. Furthermore, ischemic stroke was particularly more common in the MS population than in people without MS [RR = 6.09, 95% CI (3.44, 10.77), P < 0.00001].

CONCLUSION

Compared with the general population, people with MS have an increased risk of developing any type of stroke and ischemic stroke in particular. Consistent results were obtained from patients of different sexes and age groups. Preventative measures and treatments should be administered at earlier time points to improve patient outcomes.

Epilepsy and associated mortality in patients with multiple sclerosis

BACKGROUND AND PURPOSE

We aimed to determine the prevalence of epilepsy in patients with multiple sclerosis (MS) at diagnosis, the risk of developing epilepsy after the diagnosis of MS and the relative risk of mortality associated with epilepsy.

METHODS

We used the UK Clinical Practice Research Data-link to identify 2526 patients with incident MS and 9980 age-, sex- and index year-matched non-MS controls from 1997 to 2006. Logistic regression was used to estimate odds ratios [95% confidence interval (CI)] for epilepsy and Cox regression was used to estimate hazard ratios (HRs) (95% CI) for epilepsy and mortality.

RESULTS

Patients with incident MS were on average 45 years old and 70.9% were female. At diagnosis, the prevalence of epilepsy in patients with MS was 1.30% compared with 0.57% in non-MS controls. At diagnosis, MS was associated with an adjusted odds ratio (95% CI) of 2.11 (1.36-3.27) for pre-existing epilepsy. Among epilepsy-free patients, the cumulative probabilities of developing epilepsy, first recorded within 10 years of the index date, were 2.77% for patients with MS and 0.90% for controls. MS was associated with an adjusted HR (95% CI) of 6.01 (2.94-12.29) for epilepsy. Among patients with MS, epilepsy was associated with an HR (95% CI) of 2.23 (1.02-4.84) for all-cause mortality.

CONCLUSIONS

This population-based study found an increased prevalence of epilepsy in patients with MS at diagnosis when compared with non-MS controls and the risk of developing epilepsy was also higher following the MS diagnosis. Patients with MS with epilepsy had a higher risk of mortality compared with those without.

Adult hospital admissions associated with multiple sclerosis in Finland in 2004-2014

INTRODUCTION

Treatment of multiple sclerosis (MS) has developed significantly and several new immunotherapeutic drugs have become available in Finland since 2004. We studied whether this is associated with changes in hospital admission frequencies and healthcare costs and whether admission rates due to infection have increased.

METHODS

The national Care Register for Health Care was searched for all discharges from neurological, medical, surgical, neurosurgical and intensive care units with MS as a primary diagnosis or an auxiliary diagnosis for primary infection diagnosis in 2004-2014. Only patients ≥16 years of age were included.

RESULTS

We identified 12,276 hospital admissions for 4296 individuals. The number of admissions declined by 4.6% annually (p = .0024) in both genders. Proportion of admissions with an infection as the primary diagnosis increased but no change in their frequency was found. They were longer than admissions with MS as the primary diagnosis and were associated with increased in-hospital mortality. The annual aggregate cost of hospital admissions declined by 51% during the study period.

CONCLUSIONS

This study shows that hospital admission rates and costs related to MS hospital admissions have markedly declined from 2004 to 2014 in Finland, which coincides with an increase in the use of disease-modifying therapies. Key message Hospital admission rates and costs related to MS hospital admissions have markedly declined from 2004 to 2014 in Finland. Proportion of admission related to infection has increased and they are associated with longer hospitalizations and increased in-hospital mortality pointing out the importance of infection prevention.

Comorbidity in multiple sclerosis is associated with diagnostic delays and increased mortality

OBJECTIVE

To investigate the effect of chronic comorbidity on the time of diagnosis of multiple sclerosis (MS) and on mortality in MS.

METHODS

We conducted a population-based, nationwide cohort study including all incident MS cases in Denmark with first MS symptom between 1980 and 2005. To investigate the time of diagnosis, we compared individuals with and without chronic comorbidity using multinomial logistic regression. To investigate mortality, we used Cox regression with time-dependent covariates, following study participants from clinical MS onset until endpoint (death) or to the end of the study, censuring at emigration.

RESULTS

We identified 8,947 individuals with clinical onset of MS between 1980 and 2005. In the study of time of diagnosis, we found statistically significant odds ratios for longer diagnostic delays with cerebrovascular comorbidity (2.01 [1.44-2.80]; <0.0005), cardiovascular comorbidity (4.04 [2.78-5.87]; <0.0005), lung comorbidity (1.93 [1.42-2.62]; <0.0005), diabetes comorbidity (1.78 [1.04-3.06]; 0.035), and cancer comorbidity (2.10 [1.20-3.67]; 0.009). In the mortality study, we found higher hazard ratios with psychiatric comorbidity (2.42 [1.67-3.01]; <0.0005), cerebrovascular comorbidity (2.47 [2.05-2.79]; <0.0005), cardiovascular comorbidity (1.68 [1.39-2.03]; <0.0005), lung comorbidity (1.23 [1.01-1.50]; 0.036), diabetes comorbidity (1.39 [1.05-1.85]; 0.021), cancer comorbidity (3.51 [2.94-4.19]; <0.0005), and Parkinson disease comorbidity (2.85 [1.34-6.06]; 0.007).

CONCLUSIONS

An increased awareness of both the necessity of neurologic evaluation of new neurologic symptoms in persons with preexisting chronic disease and of optimum treatment of comorbidity in MS is critical.

Examining the joint effect of disability, health behaviors, and comorbidity on mortality in MS

BACKGROUND

In multiple sclerosis (MS), comorbidities have been associated with disability progression and an increased risk of mortality. We investigated the association between comorbidities and mortality in MS after accounting for disability and health behaviors.

METHODS

We followed North American Research Committee on Multiple Sclerosis (NARCOMS) Registry participants who completed the Fall 2006 survey on comorbidities until death (reported or matched in the National Death Index) or date of last follow-up in 2014. We used proportional hazards regression to investigate the association between comorbidities and mortality, controlling for demographic, clinical, health behavior, and disability factors.

RESULTS

Of 9,496 participants meeting the inclusion criteria, 502 (5.3%) were deceased. Most participants reported having ≤3 comorbid conditions (70.9% survivors, 76.9% decedents). In individual regression models, vascular, visual, and mental comorbidities were associated with increased mortality risk after adjustment for factors associated with survival. When combined into a single model, vascular (hazard ratio 1.269; 1.041-1.547), visual (1.490; 1.199-1.852), and mental comorbidities (excluding anxiety, 1.239; 1.024-1.499) remained independently associated with an increased risk of mortality.

CONCLUSIONS

Presence of comorbidities was independently associated with an increased risk of mortality as compared to absence of comorbidities after adjusting for factors associated with survival. Specifically, vascular, visual, and mental comorbidities increased the risk of mortality. This highlights the need for clinicians to attend to these comorbidities, which can be modified by treatments or other interventions, and potentially reduce the risk of mortality in persons with MS who have these conditions.

Fatigue and Comorbidities in Multiple Sclerosis

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.

Effect of comorbidity on mortality in multiple sclerosis

Objective:

We aimed to compare survival in the multiple sclerosis (MS) population with a matched cohort from the general population, and to evaluate the association of comorbidity with survival in both populations.

Methods:

Using population-based administrative data, we identified 5,797 persons with MS and 28,807 controls matched on sex, year of birth, and region. We estimated annual mortality rates. Using Cox proportional hazards regression, we evaluated the association between comorbidity status and mortality, stratifying by birth cohort, and adjusting for sex, socioeconomic status, and region. We compared causes of death between populations.

Results:

Median survival from birth in the MS population was 75.9 years vs 83.4 years in the matched population. MS was associated with a 2-fold increased risk of death (adjusted hazard ratio 2.40; 95% confidence interval: 2.24–2.58). Several comorbidities were associated with increased hazard of death in both populations, including diabetes, ischemic heart disease, depression, anxiety, and chronic lung disease. The magnitude of the associations of mortality with chronic lung disease, diabetes, hypertension, and ischemic heart disease was lower in the MS population than the matched population. The most common causes of death in the MS population were diseases of the nervous system and diseases of the circulatory system. Mortality rates due to infectious diseases and diseases of the respiratory system were higher in the MS population.

Conclusion:

In the MS population, survival remained shorter than expected. Within the MS population, comorbidity was associated with increased mortality risk. However, comorbidity did not preferentially increase mortality risk in the MS population as compared with controls.

A systematic review of the incidence and prevalence of comorbidity in multiple sclerosis: overview

Background:

Comorbidity is an area of increasing interest in multiple sclerosis (MS).

Objective:

The objective of this review is to estimate the incidence and prevalence of comorbidity in people with MS and assess the quality of included studies.

Methods:

We searched the PubMed, SCOPUS, EMBASE and Web of Knowledge databases, conference proceedings, and reference lists of retrieved articles. Two reviewers independently screened abstracts. One reviewer abstracted data using a standardized form and the abstraction was verified by a second reviewer. We assessed study quality using a standardized approach. We quantitatively assessed population-based studies using the I² statistic, and conducted random-effects meta-analyses.

Results:

We included 249 articles. Study designs were variable with respect to source populations, case definitions, methods of ascertainment and approaches to reporting findings. Prevalence was reported more frequently than incidence; estimates for prevalence and incidence varied substantially for all conditions. Heterogeneity was high.

Conclusion:

This review highlights substantial gaps in the epidemiological knowledge of comorbidity in MS worldwide. Little is known about comorbidity in Central or South America, Asia or Africa. Findings in North America and Europe are inconsistent. Future studies should report age-, sex- and ethnicity-specific estimates of incidence and prevalence, and standardize findings to a common population.

A systematic review of the incidence and prevalence of cardiac, cerebrovascular, and peripheral vascular disease in multiple sclerosis

BACKGROUND

Findings regarding the prevalence of vascular comorbidities in multiple sclerosis (MS) are conflicting.

OBJECTIVE

The objective of this review is to estimate the incidence and prevalence of vascular comorbidities and predisposing comorbidities in persons with MS and to assess the quality of the included studies.

METHODS

The PubMed, EMBASE, SCOPUS and Web of Knowledge databases, conference proceedings, and reference lists of retrieved articles were searched. One reviewer abstracted data using a standardized data collection form, while the second reviewer verified the abstraction. Included studies were assessed qualitatively. Quantitatively, we assessed studies using the I² statistic, and conducted meta-analyses for population-based studies only.

RESULTS

The prevalence of hypertension and hyperlipidemia exceeded 10% in the MS population and increased with age. While the prevalence of ischemic heart disease, congestive heart failure, and stroke were less than 5% overall, the prevalence of these conditions exceeded expectations when compared to the general population. Cardiac valvular disease, however, affected the MS population less often than expected. Problems with study quality were common.

CONCLUSION

Despite the relatively high prevalence of some vascular comorbidities in the MS population, important gaps exist in our understanding of their epidemiology. Most of our knowledge is based on studies conducted in a small number of regions.

A systematic review of the incidence and prevalence of sleep disorders and seizure disorders in multiple sclerosis

Background:

Several studies have suggested that comorbid neurologic disorders are more common than expected in multiple sclerosis (MS).

Objective:

To estimate the incidence and prevalence of comorbid seizure disorders and sleep disorders in persons with MS and to evaluate the quality of studies included.

Methods:

The PUBMED, EMBASE, Web of Knowledge, and SCOPUS databases, conference proceedings, and reference lists of retrieved articles were searched. Two reviewers independently screened abstracts to identify relevant articles, followed by full-text review of selected articles. We assessed included studies qualitatively and quantitatively (I² statistic), and conducted meta-analyses among population-based studies.

Results:

We reviewed 32 studies regarding seizure disorders. Among population-based studies the incidence of seizure disorders was 2.28% (95% CI: 1.11–3.44%), while the prevalence was 3.09% (95% CI: 2.01–4.16%). For sleep disorders we evaluated 18 studies; none were population-based. The prevalence ranged from 0–1.6% for narcolepsy, 14.4–57.5% for restless legs syndrome, 2.22–3.2% for REM behavior disorder, and 7.14–58.1% for obstructive sleep apnea.

Conclusion:

This review suggests that seizure disorders and sleep disorders are common in MS, but highlights gaps in the epidemiological knowledge of these conditions in MS worldwide. Other than central-western Europe and North America, most regions are understudied.