Differences In Multiple Sclerosis Research Articles

Imaging phenotypic differences in multiple sclerosis: at the crossroads of aging, sex, race, and ethnicity.

Clear sex differences are observed in clinical and imaging phenotypes of multiple sclerosis (MS), which evolve significantly over the age spectrum, and more specifically, during reproductive milestones such as pregnancy and menopause. With neuroimaging being an outcome measure and also a key subclinical biomarker of subsequent clinical phenotype in MS, this comprehensive review aims to provide an overview of sex and hormone differences in structural and functional imaging biomarkers of MS, including lesion burden and location, atrophy, white matter integrity, functional connectivity, and iron distribution. Furthermore, how therapies aimed at altering sex hormones can impact imaging of women and men with MS over the lifespan is discussed. This review also explores the key intersection between age, sex, and race/ethnicity in MS, and how this intersection may affect imaging biomarkers of MS.

Population-Based Estimates for the Prevalence of Multiple Sclerosis in the United States by Race, Ethnicity, Age, Sex, and Geographic Region

Racial, ethnic, and geographic differences in multiple sclerosis (MS) are important factors to assess when determining the disease burden and allocating health care resources. To calculate the US prevalence of MS in Hispanic, non-Hispanic Black (hereafter referred to as Black), and non-Hispanic White individuals (hereafter referred to as White) stratified by age, sex, and region. A validated algorithm was applied to private, military, and public (Medicaid and Medicare) administrative health claims data sets to identify adult cases of MS between 2008 and 2010. Data analysis took place between 2019 and 2022. The 3-year cumulative prevalence overall was determined in each data set and stratified by age, sex, race, ethnicity, and geography. The insurance pools included 96 million persons from 2008 to 2010. Insurance and stratum-specific estimates were applied to the 2010 US Census data and the findings combined to calculate the 2010 prevalence of MS cumulated over 10 years. No exclusions were made if a person met the algorithm criteria. Prevalence of MS per 100 000 US adults stratified by demographic group and geography. The 95% CIs were approximated using a binomial distribution. A total of 744 781 persons 18 years and older were identified with MS with 564 426 cases (76%) in females and 180 355 (24%) in males. The median age group was 45 to 54 years, which included 229 216 individuals (31%), with 101 271 aged 18 to 24 years (14%), 158 997 aged 35 to 44 years (21%), 186 758 aged 55 to 64 years (25%), and 68 539 individuals (9%) who were 65 years or older. White individuals were the largest group, comprising 577 725 cases (77%), with 80 276 Black individuals (10%), 53 456 Hispanic individuals (7%), and 33 324 individuals (4%) in the non-Hispanic other category. The estimated 2010 prevalence of MS per 100 000 US adults cumulated over 10 years was 161.2 (95% CI, 159.8-162.5) for Hispanic individuals (regardless of race), 298.4 (95% CI, 296.4-300.5) for Black individuals, 374.8 (95% CI, 373.8-375.8) for White individuals, and 197.7 (95% CI, 195.6-199.9) for individuals from non-Hispanic other racial and ethnic groups. During the same time period, the female to male ratio was 2.9 overall. Age stratification in each of the racial and ethnic groups revealed the highest prevalence of MS in the 45- to 64-year-old age group, regardless of racial and ethnic classification. With each degree of latitude, MS prevalence increased by 16.3 cases per 100 000 (95% CI, 12.7-19.8; P < .001) in the unadjusted prevalence estimates, and 11.7 cases per 100 000 (95% CI, 7.4-16.1; P < .001) in the direct adjusted estimates. The association of latitude with prevalence was strongest in women, Black individuals, and older individuals. This study found that White individuals had the highest MS prevalence followed by Black individuals, individuals from other non-Hispanic racial and ethnic groups, and Hispanic individuals. Inconsistent racial and ethnic classifications created heterogeneity within groups. In the United States, MS affects diverse racial and ethnic groups. Prevalence of MS increases significantly and nonuniformly with latitude in the United States, even when adjusted for race, ethnicity, age, and sex. These findings are important for clinicians, researchers, and policy makers.

Hormone therapy and disease activity in Danish women with multiple sclerosis: A population-based cohort study.

Background and purposeSex differences in multiple sclerosis (MS) prevalence and disease course are thought to be driven by hormones. Exogenous exposure to estrogens may affect MS disease course. Thus, our aim was to investigate the association between hormone therapy (HT) and disease activity and disability accrual among women with MS.MethodsA register‐based cohort study was conducted with prospectively enrolled cases from the Danish MS registry. Information on hormone exposure was retrieved from the National Prescription Registry. Outcomes were relapse rate, relapse rate ratio, recurrent relapses, 6‐month confirmed and sustained Expanded Disability Status Scale (EDSS) milestones 4 and 6, and recurrent EDSS worsening.ResultsIn all, 3325 women were eligible for analyses, of whom 333 (10%) were ever on HT at some time during follow‐up. We found no association between HT and disability accrual, although a trend for increasing risk with increasing length of use was seen. The risk of reaching 6‐month confirmed and sustained EDSS 4 among users was 0.6 (95% confidence interval [CI] = 0.3–1.2) after <1 year of use and 1.4 (95% CI = 0.9–2.2) after >5 years of HT compared to never use. The risk of recurrent relapse was increased by 20% (95% CI = 1.0–1.4) among current users of HT compared to nonusers. However, the risk of recurrent relapses was driven by the first calendar period (1996–2005) before the introduction of high‐efficacy disease‐modifying therapy.ConclusionsOur findings from this nationwide MS population suggest that HT does not affect disability accrual in women with MS, especially if used for <5 years.

Tract-specific MRI measures explain learning and recall differences in multiple sclerosis.

Cognitive difficulties are common and a key concern for people with multiple sclerosis. Advancing knowledge of the role of white matter pathology in multiple sclerosis-related cognitive impairment is essential as both occur early in the disease with implications for early intervention. Consequently, this cross-sectional study asked whether quantifying the relationships between lesions and specific white matter structures could better explain co-existing cognitive differences than whole brain imaging measures. Forty participants with relapse-onset multiple sclerosis underwent cognitive testing and MRI at 3 Tesla. They were classified as cognitively impaired (n = 24) or unimpaired (n = 16) and differed across verbal fluency, learning and recall tasks corrected for intelligence and education (corrected P-values = 0.007–0.04). The relationships between lesions and white matter were characterized across six measures: conventional voxel-based T2 lesion load, whole brain tractogram load (lesioned volume/whole tractogram volume), whole bundle volume, bundle load (lesioned volume/whole bundle volume), Tractometry (diffusion-tensor and high angular resolution diffusion measures sampled from all bundle streamlines) and lesionometry (diffusion measures sampled from streamlines traversing lesions only). The tract-specific measures were extracted from corpus callosum segments (genu and isthmus), striato-prefrontal and -parietal pathways, and the superior longitudinal fasciculi (sections I, II and III). White matter measure-task associations demonstrating at least moderate evidence against the null hypothesis (Bayes Factor threshold < 0.2) were examined using independent t-tests and covariate analyses (significance level P < 0.05). Tract-specific measures were significant predictors (all P-values < 0.05) of task-specific clinical scores and diminished the significant effect of group as a categorical predictor in Story Recall (isthmus bundle load), Figure Recall (right striato-parietal lesionometry) and Design Learning (left superior longitudinal fasciculus III volume). Lesion load explained the difference in List Learning, whereas Letter Fluency was not associated with any of the imaging measures. Overall, tract-specific measures outperformed the global lesion and tractogram load measures. Variation in regional lesion burden translated to group differences in tract-specific measures, which in turn, attenuated differences in individual cognitive tasks. The structural differences converged in temporo-parietal regions with particular influence on tasks requiring visuospatial-constructional processing. We highlight that measures quantifying the relationships between tract-specific structure and multiple sclerosis lesions uncovered associations with cognition masked by overall tract volumes and global lesion and tractogram loads. These tract-specific white matter quantifications show promise for elucidating the relationships between neuropathology and cognition in multiple sclerosis.

Male sex chromosomal complement exacerbates the pathogenicity of Th17 cells in a chronic model of central nervous system autoimmunity

Sex differences in multiple sclerosis (MS) incidence and severity have long been recognized. However, the underlying cellular and molecular mechanisms for why male sex is associated with more aggressive disease remain poorly defined. Using a Tcell adoptive transfer model of chronic experimental autoimmune encephalomyelitis (EAE), we find that male Th17 cells induce disease of increased severity relative to female Th17 cells, irrespective of whether transferred to male or female recipients. Throughout the disease course, a greater frequency of male Th17 cells produce IFNγ, a hallmark of pathogenic Th17 responses. Intriguingly, XY chromosomal complement increases the pathogenicity of male Th17 cells. An X-linked immune regulator, Jarid1c, is downregulated in pathogenic male murine Th17 cells, and functional experiments reveal that it represses the severity of Th17-mediated EAE. Furthermore, Jarid1c expression is downregulated in CD4+ Tcells from MS-affected individuals. Our data indicate that male sex chromosomal complement critically regulates Th17 cell pathogenicity.

Differences in physical, mental, and social functions between males and females in multiple sclerosis: A multicenter cross-sectional study in China

Background Sex-specific differences in multiple sclerosis (MS) have been recognized, but few were known about how sex influences the characteristics of MS in Asian and the social burden of MS. This study aimed to investigate the symptoms, mental health, and social functions of Chinese MS patients and find differences between sexes.Methods MS patients were enrolled from January 2004 to September 2018. A questionnaire was distributed by 47 medical centers. Patients’ physical symptoms, negative emotions, interpersonal communication, social intercourse, employment condition, and suicidal thoughts and behavior were collected. Patients were asked to fill in the questionnaire independently and undergo Expanded Disability Status Scale (EDSS) measurement. Unpaired t-tests between sexes were conducted for normally distributed continuous variables. Mann-Whitney u-tests were conducted for non-normally distributed data. Chi-square tests, Fisher exact tests and rank sum tests were performed for categorical variables.Results 931 patients were enrolled and 631 were female. Frequency of fatigue and pain were higher in female MS patients (P<0.05), while male patients complained more weakness, diplopia, sexual dysfunction, and micturition and defecation dysfunction (P<0.05). Females were more likely to experience sadness and helplessness than males (P<0.05) while males were more likely to experience nonacceptance than females (P<0.05). MS had a worse influence on male patients in relationships with family and friends (P<0.05). The employment rate of MS patients was 39.31%. The frequency of suicidal attempt was 2.36%, which was higher than general population.Conclusions The study provided evidence that characteristics of MS were different between males and females, and influence in mental and social function was a common problem among MS patients. More attention should be paid to the mental health and social function of MS patients.

Long-term effects of latitude, ambient temperature, and ultraviolet radiation on the incidence of multiple sclerosis in two cohorts of US women.

Differences in multiple sclerosis (MS) risk by latitude have been observed worldwide; however, the exposures driving these associations are unknown. Ultraviolet radiation (UV) has been explored as a risk factor, and ambient temperature has been correlated with disease progression. However, no study has examined the impact of all three exposures. We examined the association between these exposures and incidence of MS within two nationwide prospective cohorts of women, the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII). Both cohorts were followed with biennial questionnaires to ascertain new diagnoses and risk factors. Time-varying exposures to latitude, cumulative average July temperature (°C), and cumulative average July erythemal UV (mW/m2) were predicted at each participant's biennially updated residential addresses. Using Cox proportional hazards models adjusted for MS risk factors, we calculated hazard ratios (HR) and 95% confidence intervals (CIs) within each cohort and pooled via meta-analyses. In multivariable models, there were suggestions that decreasing latitude (meta-analysis multivariable-adjusted HR = 0.72; 95% CI 0.55, 0.94 for women living <35.73° compared with those ≥42.15°, P-for-trend = 0.007) and increasing cumulative average July temperature (meta-analysis multivariable-adjusted HR = 0.81; 95% CI 0.72, 0.91 for each interquartile range increase [3.91°]) were associated with decreasing risk of MS. There was no evidence of heterogeneity between cohorts. We did not observe consistent associations with cumulative average UV. Our results suggest that adult exposures to decreasing latitude and increasing temperature, but not UV, were associated with reduced MS risk in these two cohorts of women. Studies of MS incidence may want to consider temperature as a risk factor.

Sex-Specific Differences in Life Span Brain Volumes in Multiple Sclerosis.

Numerous sex-specific differences in multiple sclerosis (MS) susceptibility, disease manifestation, disability progression, inflammation, and neurodegeneration have been previously reported. Previous magnetic resonance imaging (MRI) studies have shown structural differences between female and male MS brain volumes. To determine sex-specific global and tissue-specific brain volume throughout the MS life span in a real-world large MRI database. A total of 2,199 MS patients (female/male ratio of 1,651/548) underwent structural MRI imaging on either a 1.5-T or 3-T scanner. Global and tissue-specific volumes of whole brain (WBV), white matter, and gray matter (GMV) were determined by utilizing Structural Image Evaluation using Normalisation of Atrophy Cross-sectional (SIENAX). Lateral ventricular volume (LVV) was determined with the Neurological Software Tool for REliable Atrophy Measurement (NeuroSTREAM). General linear models investigated sex and age interactions, and post hoc comparative sex analyses were performed. Despite being age-matched with female MS patents, a greater proportion of male MS patients were diagnosed with progressive MS and had lower normalized WBV (P<.001), GMV (P <.001), and greater LVV (P <.001). In addition to significant stand-alone main effects, an interaction between sex and age had an additional effect on the LVV (F-statistics = 4.53, P = .033) and GMV (F-statistics = 4.59, P = .032). The sex and age interaction was retained in both models of LVV (F-statistics = 3.31, P = .069) and GMV (F-statistics = 6.1, P = .003) when disease subtype and disease-modifying treatment (DMT) were also included. Although male MS patients presented with significantly greater LVV and lower GMV during the early and midlife period when compared to their female counterparts (P <.001 for LVV and P <.019 for GMV), these differences were nullified in 60+ years old patients. Similar findings were seen within a subanalysis of MS patients that were not on any DMT at the time of enrollment. There are sex-specific differences in the LVV and GMV over the MS life span.

Multiple sclerosis in a multi-ethnic population from Northern California: a retrospective analysis, 2010\u20132016

BackgroundResearch is needed to examine differences in multiple sclerosis (MS) prevalence by race-ethnicity. The goal of this study was to quantify MS prevalence in a health care system in Northern California and examine differences in prevalence and phenotype by race-ethnicity.MethodsWe conducted a retrospective, observational cohort study of adults (2010–2016). MS prevalence estimates were standardised to distributions of gender and race-ethnicity for the underlying geographic region and stratified by gender and race-ethnicity with age adjustment. We performed a chart review of a racial-ethnic stratified sample of patients to examine disease phenotypes.Results1,058,102 patients were identified, of which 3286 had MS. The overall direct-standardised prevalence was 288.0 cases per 100,000 population (95% confidence interval: 276.3–299.8). Age-adjusted prevalence ranged from 677.0 per 100,000 among non-Hispanic black women to 49.7 per 100,000 among non-Hispanic Asian men. Non-Hispanic blacks compared with other groups more often had primary-progressive (10.0% vs. 0.0–4.0%) or progressive-relapsing MS (6.0% vs. 0.0–2.0%).ConclusionsIn this Northern Californian Cohort, between 2010 and 2016 the direct-standardised MS prevalence was estimated at 288.0 per 100,000 population, and increased over time. Non-Hispanic blacks, especially women, were disproportionately affected and had less common, earlier progressive MS phenotypes.

Decreased second to fourth digit ratios in female multiple sclerosis patients

BackgroundSex-related differences in multiple sclerosis (MS) suggest a possible role of prenatal sex hormones in the pathogenesis. The aim of this study was to investigate whether the 2D:4D ratio, considered a predictor of prenatal hormonal exposure, in MS patients differ from that in healthy controls. MethodsTwo hundred MS patients and one hundred seventy healthy control subjects with similar age and sex distribution enrolled. All participants were right-handed. The right hands of all participants were scanned using a digital scanner. Measurements of second and fourth digit lengths were made from digital scans. The 2D:4D ratio was calculated by dividing the length of the second digit by the length of the fourth digit. ResultsA total of 171 MS patients' and 159 healthy controls' digit scans included in the study. The MS group consisted of 94 females (mean age 38.32 ± 10.5) and 77 males (mean age 42.06 ± 11.8) and the control group of 86 females (mean age 40.24 ± 9.7) and 73 males (mean age 38.49 ± 11.6). 2D:4D ratios of female MS patients were significantly lower than those of healthy females (p=0.004). Although 2D:4D ratios of male patients with MS were lower than those of healthy males, this difference was not statistically significant (p=0.33). There was no significant correlation between the 2D:4D ratio, EDSS levels or duration of the disease in male or female MS patients (p<0.05). ConclusionAlthough our results suggest that a prenatal hormonal balance in favor of androgenic activity may be a risk factor for MS, complex factors mediating the actions of sex hormones on target cells should always be considered when evaluating the effects of sex hormones.

A case for gender-based approach to multiple sclerosis therapeutics

Despite established sex differences in multiple sclerosis (MS) risk and course, sex-specific efficacy and toxicity of existing MS therapies, and possible sex-specific therapeutic approaches, remain underexplored. We systematically reviewed published sex differences from Phase III pivotal trials for FDA or EMA-approved MS disease modifying therapies (DMTs), along with additional information from pharmaceutical companies, for pre-specified or post-hoc baseline characteristics, efficacy and safety outcomes by sex, and sex-specific concerns. Then, we reviewed trials testing hormonal therapies in MS. None of the Phase III clinical trials performed baseline sex-specific analyses or were powered to evaluated DMTs in menopausal/older populations. Some recent trials performed pre-specified or post-hoc stratification of outcomes by sex. Sex-specific hormonal intervention trials were limited. Adequately powered, pre-specified analyses accounting for baseline sex and age are required to maximize safety and efficacy in specific patient populations.

Sex chromosome contributions to sex differences in multiple sclerosis susceptibility and progression

Background: Why are women more susceptible to multiple sclerosis, but men have worse disability progression? Sex differences in disease may be due to sex hormones, sex chromosomes, or both. Objective: Determine whether differences in sex chromosomes can contribute to sex differences in multiple sclerosis using experimental autoimmune encephalomyelitis. Methods: Sex chromosome transgenic mice, which permit the study of sex chromosomes not confounded by differences in sex hormones, were used to examine an effect of sex chromosomes on autoimmunity and neurodegeneration, focusing on X chromosome genes. Results: T-lymphocyte DNA methylation studies of the X chromosome gene Foxp3 suggested that maternal versus paternal imprinting of X chromosome genes may underlie sex differences in autoimmunity. Bone marrow chimeras with the same immune system but different sex chromosomes in the central nervous system suggested that differential expression of the X chromosome gene Toll-like receptor 7 in neurons may contribute to sex differences in neurodegeneration. Conclusion: Mapping the transcriptome and methylome in T lymphocytes and neurons in females versus males could reveal mechanisms underlying sex differences in autoimmunity and neurodegeneration.

Long-lasting masculinizing effects of postnatal androgens on myelin governed by the brain androgen receptor.

The oligodendrocyte density is greater and myelin sheaths are thicker in the adult male mouse brain when compared with females. Here, we show that these sex differences emerge during the first 10 postnatal days, precisely at a stage when a late wave of oligodendrocyte progenitor cells arises and starts differentiating. Androgen levels, analyzed by gas chromatography/tandem-mass spectrometry, were higher in males than in females during this period. Treating male pups with flutamide, an androgen receptor (AR) antagonist, or female pups with 5α-dihydrotestosterone (5α-DHT), revealed the importance of postnatal androgens in masculinizing myelin and their persistent effect into adulthood. A key role of the brain AR in establishing the sexual phenotype of myelin was demonstrated by its conditional deletion. Our results uncover a new persistent effect of postnatal AR signaling, with implications for neurodevelopmental disorders and sex differences in multiple sclerosis.

The importance of studying sex differences in disease: The example of multiple sclerosis.

To date, scientific research has often focused on one sex, with assumptions that study of the other sex would yield similar results. However, many diseases affect males and females differently. The sex of a patient can affect the risk for both disease susceptibility and progression. Such differences can be brought to the laboratory bench to be investigated, potentially bringing new treatments back to the clinic. This method of research, known as a "bedside to bench to bedside" approach, has been applied to studying sex differences in multiple sclerosis (MS). Females have greater susceptibly to MS, while males have worse disease progression. These two characteristics of the disease are influenced by the immune system and the nervous system, respectively. Thus, sex differences in each system must be studied. Personalized medicine has been at the forefront of research recently, and studying sex differences in disease fits with this initiative. This review will discuss the known sex differences in MS and highlight how investigating them can lead to new insights and potential treatments for both men and women. © 2016 Wiley Periodicals, Inc.

Sex-Based Differences in Multiple Sclerosis (Part I): Biology of Disease Incidence.

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease that leads to neuron damage and progressive disability. One major feature of multiple sclerosis (MS) is that it affects women three times more often than men. In this chapter, we overview the evidence that the autoimmune component of MS, which predominates in the early stages of this disease, is more robust in women than in men and undergoes a sharp increase with the onset of puberty. In addition, we discuss the common rodent models of MS that have been used to study the sex-based differences in the development of central nervous system (CNS) autoimmunity. We then address the biological underpinnings of this enhanced MS risk in women by first reviewing the autoimmune mechanisms that are thought to lead to the initiation of this disease and then honing in on how these mechanisms differ between the sexes. Finally, we review what is known about the hormonal and genetic basis of these sex differences in CNS autoimmunity.

Sex-Based Differences in Multiple Sclerosis (MS): Part II: Rising Incidence of Multiple Sclerosis in Women and the Vulnerability of Men to Progression of this Disease.

It is well known that a number of autoimmune diseases including multiple sclerosis (MS) predominantly affect women and there has been much attention directed toward understanding why this is the case. Past research has revealed a number of sex differences in autoimmune responses that can account for the female bias in MS. However, much less is known about why the incidence of MS has increased exclusively in women over the past half century. The recency of this increase suggests that changing environmental or lifestyle factors are interacting with biological sex to increase MS risk predominantly in females. Indeed, a number of recent studies have identified sex-specific differences in the effect of environmental factors on MS incidence. The first part of this chapter will overview this evidence and will discuss the possible scenarios of how the environment may be interacting with autoimmune mechanisms to contribute to the preferential rise in MS incidence in women. Despite the strong female bias in MS incidence, culminating evidence from natural history studies, and imaging and pathology studies suggests that males who develop MS may exhibit a more rapid decline in disability and cognitive functioning than women. Very little is known about the biological basis of this more rapid deterioration, but some insights have been provided by studies in rodent models of demyelination/remyelination. The second part of this chapter will overview the evidence that males with relapsing-onset MS undergo a more rapid progression of disease than females and will discuss potential biological mechanisms that account for this sex difference.

Gender Differences in Multiple Sclerosis

The basis of gender differences in the prevalence and clinical progression of multiple sclerosis (MS) is not understood. Here, we identify gender-specific responses in steroid synthesis and signaling in the brains of MS patients as possible contributors to these differences. We investigated gene expression changes in these pathways and of inflammatory cytokines in MS lesions and normal-appearing white matter (NAWM) of male and female patients (n=21) and control NAWM (n=14) using quantitative polymerase chain reaction (25 MS lesions, 21 MS NAWM, and 14 control NAWM) and immunohistochemistry (3-4 sections per group). In MS lesions in males, there was local upregulation of aromatase (an enzyme involved in estrogen biosynthesis), estrogen receptor-β (ERβ), and tumor necrosis factor (TNF) mRNA; whereas in females, there was local upregulation of 3β-hydroxysteroid-dehydrogenase, a progesterone synthetic enzyme, and of progesterone receptor. Astrocytes in the rim and center of MS lesions were found to be the primary source of steroidogenic enzyme and receptor expression. Aromatase and ERα mRNA levels were positively correlated with that of TNF in primary cultures of human microglia and astrocytes; TNF caused increased ERα, suggesting that inflammatory signals stimulate estrogen signaling in this cell type. Together, these findings suggest that there are gender differences in the CNS of MS patients that may affect lesion pathogenesis, that is, in males, estrogen synthesis and signaling are induced; whereas in females, progestogen synthesis and signaling are induced. These differences may represent contributing factors to gender differences in the prevalence and course of MS.

Sex-related differences in atrophy and lesion load in multiple sclerosis patients

IntroductionPrevious studies showed gender-associated clinical and MRI differences in multiple sclerosis (MS) evolution. However, only few studies were done with nonconventional MRI techniques and no study was done in a South American MS population. The aim of this study was to investigate gender differences according to nonconventional MRI measures in patients with MS from Buenos Aires, Argentina. MethodsRelapsing-remitting MS patients (RRMS) with at least 6 years of follow up and an MRI at onset and at 6 years were included. Patients were assessed using nonconventional MRI measures: total brain volume (TBV), neocortical grey brain volume (GBV), white brain volume (WBV), lesion load (LL), % of brain volume change between onset and year 6 (% BVC) and regional brain volume change. Gender-related MRI differences were investigated using general linear model analysis. ResultsThe 45 patients were included (25 female). Mean follow up time was 7.3±0.2 years. No differences in age, EDSS at onset, DMD treatment, TBV, GBV, WBV neither LL were found between gender at baseline. Six years later, males showed a decrease in TBV (P=.002) and GBV (P≤.001) and an increase in LL (P=.02) and % BVC (P<.001) vs. females. Female patients showed a decrease in the volume of frontal subcortical region. DiscussionThis is the first study showing differences in brain volume changes between gender in MS patients from South America. Future studies will confirm our initial findings.

Multiple Sclerosis Disease-Modifying Therapy Prescribing Patterns in Ontario

Differences in Multiple sclerosis (MS) disease-modifying therapy (DMT) prescribing patterns between different groups of neurologists have not been explored. To examine concentrations of prescribing patterns and to assess if MS-specialists use a broader range of DMTs relative to general neurologists. We conducted a cross-sectional study using administrative claims databases in Ontario, Canada to link neurologists to 2009 DMT prescription data. MS specialization was defined using both practice location and prescription patterns. Lorenz curves and Gini coefficients were constructed to examine prescribing patterns, separating neurologist characteristics dichotomously and separating Avonex from the other standard DMTs (Betaseron, Rebif and Copaxone). Gini coefficient 95% confidence intervals (CIs) were derived using jack-knife statistical techniques. Prescriptions were highly concentrated with 12% of Ontario neurologists prescribing 80% of DMTs. There was a trend towards Avonex being more commonly prescribed relative to the other DMTs. When MS specialization was defined by DMT prescribing, high-volume prescribing neurologists showed a broader range of DMT prescribing (Gini 0.38-0.44) in comparison to low-volume prescribers (Gini 0.57-0.66). The majority of DMTs are prescribed by a small subset of neurologists. High-volume prescribing MS-specialists show more variability in DMT use while low-volume prescribers tend to individually focus on a narrower range of DMTs.

Diferencias en la tasa de atrofia global y regional y del volumen lesional entre género en esclerosis múltiple

IntroductionPrevious studies showed gender-associated clinical and MRI differences in multiple sclerosis (MS) evolution. However, only few studies were done with non conventional MRI techniques and no one was done in a South American MS population. The aim of this study was to investigate gender differences according to nonconventional MRI measures in patients with MS from Buenos Aires, Argentina. MethodsRelapsing-remitting MS patients (RRMS) with at least 6 years of follow up and an MRI at onset and at 6 years were included. Patients were assessed using nonconventional MRI measures: total brain volume (TBV), neocortical grey brain volume (GBV), white brain volume (WBV), lesion load (LL), % of brain volume change between onset and year 6 (% BVC) and regional brain volume change. Gender-related MRI differences were investigated using general linear model analysis. ResultsThe 45 patients were included (25 female). Mean follow up time was 7.3±0.2 years. No differences in age, EDSS at onset, DMD treatment, TBV, GBV, WBV neither LL were found between gender at baseline. Six years later, males showed a decrease in TBV (P=.002) and GBV (P≤0.001) and an increase in LL (P=.02) and % BVC (P<.001) vs. females. Female patients showed a decrease in the volume of frontal subcortical region. DiscussionThis is the first study showing differences in brain volume changes between gender in MS patients from South America. Future studies will confirm our initial findings.