Predictors of treatment switching in the Big Multiple Sclerosis Data Network.

Background: Treatment switching is a common challenge and opportunity in real-world clinical practice. Increasing diversity in disease-modifying treatments (DMTs) has generated interest in the identification of reliable and robust predictors of treatment switching across different countries, DMTs, and time periods. Objective: The objective of this retrospective, observational study was to identify independent predictors of treatment switching in a population of relapsing-remitting MS (RRMS) patients in the Big Multiple Sclerosis Data Network of national clinical registries, including the Italian MS registry, the OFSEP of France, the Danish MS registry, the Swedish national MS registry, and the international MSBase Registry. Methods: In this cohort study, we merged information on 269,822 treatment episodes in 110,326 patients from 1997 to 2018 from five clinical registries. Patients were included in the final pooled analysis set if they had initiated at least one DMT during the relapsing-remitting MS (RRMS) stage. Patients not diagnosed with RRMS or RRMS patients not initiating DMT therapy during the RRMS phase were excluded from the analysis. The primary study outcome was treatment switching. A multilevel mixed-effects shared frailty time-to-event model was used to identify independent predictors of treatment switching. The contributing MS registry was included in the pooled analysis as a random effect. Results: Every one-point increase in the Expanded Disability Status Scale (EDSS) score at treatment start was associated with 1.08 times the rate of subsequent switching, adjusting for age, sex, and calendar year (adjusted hazard ratio [aHR] 1.08; 95% CI 1.07-1.08). Women were associated with 1.11 times the rate of switching relative to men (95% CI 1.08-1.14), whilst older age was also associated with an increased rate of treatment switching. DMTs started between 2007 and 2012 were associated with 2.48 times the rate of switching relative to DMTs that began between 1996 and 2006 (aHR 2.48; 95% CI 2.48-2.56). DMTs started from 2013 onwards were more likely to switch relative to the earlier treatment epoch (aHR 8.09; 95% CI 7.79-8.41; reference = 1996-2006). Conclusion: Switching between DMTs is associated with female sex, age, and disability at baseline and has increased in frequency considerably in recent years as more treatment options have become available. Consideration of a patient's individual risk and tolerance profile needs to be taken into account when selecting the most appropriate switch therapy from an expanding array of treatment choices.

Association between brain volume and disability over time in multiple sclerosis.

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.

Reduction in Cognitive Processing Speed Surrounding Multiple Sclerosis Relapse.

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 ß-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 (ß-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.

Treatment Switching and Discontinuation Over 20 Years in the Big Multiple Sclerosis Data Network.

Background: Although over a dozen disease modifying treatments (DMTs) are available for relapsing forms of multiple sclerosis (MS), treatment interruption, switching and discontinuation are common challenges. The objective of this study was to describe treatment interruption and discontinuation in the Big MS data network. Methods: We merged information on 269,822 treatment episodes in 110,326 patients from 1997 to 2016 from five clinical registries in this cohort study. Treatment stop was defined as a clinician recorded DMT end for any reason and included treatment interruptions, switching to alternate DMTs and long-term or permanent discontinuations. Results: The incidence of DMT stopping cross the full observation period was lowest in FTY (19.7 per 100 person-years (PY) of treatment; 95% CI 19.2-20.1), followed by NAT (22.6/100 PY; 95% CI 22.2-23.0), IFNß (23.3/100 PY; 95% CI 23.2-23.5). Of the 184,013 observed DMT stops, 159,309 (86.6%) switched to an alternate DMT within 6 months. Reasons for stopping a drug were stable during the observation period with lack of efficacy being the most common reason followed by lack of tolerance and side effects. The proportion of patients continuing on most DMTs were similarly stable until 2014 and 2015 when drop from 83 to 75% was noted. Conclusions: DMT stopping reasons and rates were mostly stable over time with a slight increase in recent years, with the availability of more DMTs. The overall results suggest that discontinuation of MS DMTs is mostly due to DMT properties and to a lesser extent to risk management and a competitive market.

Multiple sclerosis lesions in motor tracts from brain to cervical cord: spatial distribution and correlation with disability.

Despite important efforts to solve the clinico-radiological paradox, correlation between lesion load and physical disability in patients with multiple sclerosis remains modest. One hypothesis could be that lesion location in corticospinal tracts plays a key role in explaining motor impairment. In this study, we describe the distribution of lesions along the corticospinal tracts from the cortex to the cervical spinal cord in patients with various disease phenotypes and disability status. We also assess the link between lesion load and location within corticospinal tracts, and disability at baseline and 2-year follow-up. We retrospectively included 290 patients (22 clinically isolated syndrome, 198 relapsing remitting, 39 secondary progressive, 31 primary progressive multiple sclerosis) from eight sites. Lesions were segmented on both brain (T2-FLAIR or T2-weighted) and cervical (axial T2- or T2*-weighted) MRI scans. Data were processed using an automated and publicly available pipeline. Brain, brainstem and spinal cord portions of the corticospinal tracts were identified using probabilistic atlases to measure the lesion volume fraction. Lesion frequency maps were produced for each phenotype and disability scores assessed with Expanded Disability Status Scale score and pyramidal functional system score. Results show that lesions were not homogeneously distributed along the corticospinal tracts, with the highest lesion frequency in the corona radiata and between C2 and C4 vertebral levels. The lesion volume fraction in the corticospinal tracts was higher in secondary and primary progressive patients (mean = 3.6 ± 2.7% and 2.9 ± 2.4%), compared to relapsing-remitting patients (1.6 ± 2.1%, both P < 0.0001). Voxel-wise analyses confirmed that lesion frequency was higher in progressive compared to relapsing-remitting patients, with significant bilateral clusters in the spinal cord corticospinal tracts (P < 0.01). The baseline Expanded Disability Status Scale score was associated with lesion volume fraction within the brain (r = 0.31, P < 0.0001), brainstem (r = 0.45, P < 0.0001) and spinal cord (r = 0.57, P < 0.0001) corticospinal tracts. The spinal cord corticospinal tracts lesion volume fraction remained the strongest factor in the multiple linear regression model, independently from cord atrophy. Baseline spinal cord corticospinal tracts lesion volume fraction was also associated with disability progression at 2-year follow-up (P = 0.003). Our results suggest a cumulative effect of lesions within the corticospinal tracts along the brain, brainstem and spinal cord portions to explain physical disability in multiple sclerosis patients, with a predominant impact of intramedullary lesions.

Spatial distribution of multiple sclerosis lesions in the cervical spinal cord.

Spinal cord lesions detected on MRI hold important diagnostic and prognostic value for multiple sclerosis. Previous attempts to correlate lesion burden with clinical status have had limited success, however, suggesting that lesion location may be a contributor. Our aim was to explore the spatial distribution of multiple sclerosis lesions in the cervical spinal cord, with respect to clinical status. We included 642 suspected or confirmed multiple sclerosis patients (31 clinically isolated syndrome, and 416 relapsing-remitting, 84 secondary progressive, and 73 primary progressive multiple sclerosis) from 13 clinical sites. Cervical spine lesions were manually delineated on T2- and T2*-weighted axial and sagittal MRI scans acquired at 3 or 7 T. With an automatic publicly-available analysis pipeline we produced voxelwise lesion frequency maps to identify predilection sites in various patient groups characterized by clinical subtype, Expanded Disability Status Scale score and disease duration. We also measured absolute and normalized lesion volumes in several regions of interest using an atlas-based approach, and evaluated differences within and between groups. The lateral funiculi were more frequently affected by lesions in progressive subtypes than in relapsing in voxelwise analysis (P < 0.001), which was further confirmed by absolute and normalized lesion volumes (P < 0.01). The central cord area was more often affected by lesions in primary progressive than relapse-remitting patients (P < 0.001). Between white and grey matter, the absolute lesion volume in the white matter was greater than in the grey matter in all phenotypes (P < 0.001); however when normalizing by each region, normalized lesion volumes were comparable between white and grey matter in primary progressive patients. Lesions appearing in the lateral funiculi and central cord area were significantly correlated with Expanded Disability Status Scale score (P < 0.001). High lesion frequencies were observed in patients with a more aggressive disease course, rather than long disease duration. Lesions located in the lateral funiculi and central cord area of the cervical spine may influence clinical status in multiple sclerosis. This work shows the added value of cervical spine lesions, and provides an avenue for evaluating the distribution of spinal cord lesions in various patient groups.

Automatic segmentation of the spinal cord and intramedullary multiple sclerosis lesions with convolutional neural networks.

The spinal cord is frequently affected by atrophy and/or lesions in multiple sclerosis (MS) patients. Segmentation of the spinal cord and lesions from MRI data provides measures of damage, which are key criteria for the diagnosis, prognosis, and longitudinal monitoring in MS. Automating this operation eliminates inter-rater variability and increases the efficiency of large-throughput analysis pipelines. Robust and reliable segmentation across multi-site spinal cord data is challenging because of the large variability related to acquisition parameters and image artifacts. In particular, a precise delineation of lesions is hindered by a broad heterogeneity of lesion contrast, size, location, and shape. The goal of this study was to develop a fully-automatic framework - robust to variability in both image parameters and clinical condition - for segmentation of the spinal cord and intramedullary MS lesions from conventional MRI data of MS and non-MS cases. Scans of 1042 subjects (459 healthy controls, 471 MS patients, and 112 with other spinal pathologies) were included in this multi-site study (n = 30). Data spanned three contrasts (T1-, T2-, and T2∗-weighted) for a total of 1943 vol and featured large heterogeneity in terms of resolution, orientation, coverage, and clinical conditions. The proposed cord and lesion automatic segmentation approach is based on a sequence of two Convolutional Neural Networks (CNNs). To deal with the very small proportion of spinal cord and/or lesion voxels compared to the rest of the volume, a first CNN with 2D dilated convolutions detects the spinal cord centerline, followed by a second CNN with 3D convolutions that segments the spinal cord and/or lesions. CNNs were trained independently with the Dice loss. When compared against manual segmentation, our CNN-based approach showed a median Dice of 95% vs. 88% for PropSeg (p ≤ 0.05), a state-of-the-art spinal cord segmentation method. Regarding lesion segmentation on MS data, our framework provided a Dice of 60%, a relative volume difference of -15%, and a lesion-wise detection sensitivity and precision of 83% and 77%, respectively. In this study, we introduce a robust method to segment the spinal cord and intramedullary MS lesions on a variety of MRI contrasts. The proposed framework is open-source and readily available in the Spinal Cord Toolbox.

Smoking and susceptibility to rheumatoid arthritis in a Swedish population-based case-control study.

Smoking is one of the most established risk factors for rheumatoid arthritis (RA). The aim of this study was to estimate how age at smoking debut, smoking cessation, duration, intensity, and cumulative dose of smoking influence the risk of developing anti-citrullinated peptide antibodies (ACPA) positive and ACPA negative RA. The present report is based on a Swedish population-based, case-control study with incident cases of RA (3655 cases, 5883 matched controls). Using logistic regression models, subjects with different smoking habits were compared regarding risk of developing the two variants of RA, by calculating odds ratios (OR) with 95% confidence intervals (CI). Smoking increased the risk of developing both ACPA positive (OR 1.9, 95% CI 1.7-2.1) and ACPA negative RA (OR 1.3, 95% CI 1.2-1.5). For both subsets of RA, there seemed to be a threshold (~ 2.5 pack years for ACPA positive RA and ~ 5 pack years for ACPA negative RA) below which no association between smoking and RA occurred. A dose-response association was observed between cumulative dose of smoking and risk of developing ACPA positive RA (p value for trend < 0.0001). Duration of smoking had a higher influence on the association between smoking and RA than did intensity of smoking. For both subsets of RA, the detrimental effect of smoking decreased after smoking cessation. Twenty years after smoking cessation, there was no longer an association between smoking and risk of ACPA negative RA, whereas the association between smoking and ACPA positive RA risk persisted and was dependent on the cumulative dose of smoking. Smoking increases the risk of both subsets of RA with a more pronounced influence on the risk of ACPA positive RA. Preventive measures in order to reduce smoking are essential and may result in a decline in RA incidence.

Importance of early treatment initiation in the clinical course of multiple sclerosis.

OBJECTIVES: The aim of this study was to identify factors influencing the long-term clinical progression of multiple sclerosis (MS). A special objective was to investigate whether early treatment decisions influence outcome. METHODS: We included 639 patients diagnosed with MS from 2001 to 2007. The median follow-up time was 99 months (8.25 years). Cox regression models were applied to identify factors correlating with the outcome variable defined as time from treatment start to irreversible score 4 of the Expanded Disability Status Scale (EDSS). RESULTS: Patients initiated on treatment later had a greater risk of reaching EDSS 4 (hazard ratio of 1.074 (95% confidence interval (CI), 1.048-1.101)), increased by 7.4% for every year of delay in treatment start after MS onset. Patients who started treatment after 3 years from MS onset reached the outcome sooner with hazard ratio of 2.64 (95% CI, 1.71-4.08) compared with the patients who started treatment within 1 year from MS onset. Baseline EDSS and age at onset were found to be predictive factors of disability progression. CONCLUSION: Early treatment initiation was associated with a better clinical outcome. In addition, we confirmed the well-established prognostic factors of late age at onset and early disability.

A significant decrease in diagnosis of primary progressive multiple sclerosis: A cohort study.

BACKGROUND: Several reports indicate changes to prevalence, incidence, female-to-male ratio in multiple sclerosis. Diagnostic criteria, course definitions and clinical management of the disease have also undergone change during the recent decades. OBJECTIVE: To investigate temporal trends in the diagnosis of primary progressive multiple sclerosis (PPMS) in Sweden. METHODS: Through the Swedish MS registry we investigated the proportion of PPMS diagnosis in birth, diagnosis and age period cohorts using Poisson regression. RESULTS: A total of 16,915 patients were categorised into six birth-cohorts from 1946 to 1975 and seven date-of-diagnosis-cohorts from 1980 to 2014. We observed a decrease in the uncorrected analysis of diagnosis of PPMS from 19.2% to 2.2% and an average decrease of 23% (p < 0.001) per 5-year birth-cohort in the adjusted analysis. An average 21% (p < 0.001) decrease per diagnosis-cohort was seen. In the age-specific diagnosis period cohorts the same decreasing trend of PPMS diagnosis was observed in almost all groups. CONCLUSION: The diagnosis of PPMS has significantly decreased in Sweden specifically after introduction of disease-modifying treatments. Such decrease can have severe impacts on the future research on PPMS. Our data also suggest that the current trend to emphasise presence or absence of inflammatory activity is already reflected in clinical practice.

The influence of immunomodulatory treatment on the clinical course of multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic disease of the central nervous system. One of the major questions concerning the clinical progression of MS, still insufficiently elaborated or confirmed, is if it can be slowed down or augmented by external factors. Immunomodulatory treatment is a disease modifiable factor shown to influence disease progression of various medical conditions. OBJECTIVE: To investigate if treatment affects the long-term clinical progression of MS, measured as time from diagnosis to score of 4 or higher of Expanded Disability Status Scale (EDSS). METHODS: Longitudinal, prospective data concerning treatment status and EDSS were collected by health professionals in the Swedish MS Registry. Study cohort comprised new diagnosed MS patients at Karolinska Hospital between 2001 and 2005. Survival analysis adjusted for suspected confounders was used with the outcome variable time from diagnosis to EDSS ≥ 4. RESULTS: Early treatment was correlated with longer time from diagnosis to EDSS ≥ 4 (HR: 1.77; 95 % CI: 1.15-2.73; p = 0.01). Additionally, the influence of the covariates-age at onset and the baseline EDSS, which were statistically significant with hazard ratios of 1.03 and 2.1, respectively, was found. CONCLUSION: Early treatment was associated with a better clinical outcome.

Multiple sclerosis patients lacking oligoclonal bands in the cerebrospinal fluid have less global and regional brain atrophy.

To investigate whether multiple sclerosis (MS) patients with and without cerebrospinal fluid (CSF) oligoclonal immunoglobulin G bands (OCB) differ in brain atrophy. Twenty-eight OCB-negative and thirty-five OCB-positive patients were included. Larger volumes of total CSF and white matter (WM) lesions; smaller gray matter (GM) volume in the basal ganglia, diencephalon, cerebellum, and hippocampus; and smaller WM volume in corpus callosum, periventricular-deep WM, brainstem, and cerebellum, were observed in OCB-positives. OCB-negative patients, known to differ genetically from OCB-positives, are characterized by less global and regional brain atrophy. This finding supports the notion that OCB-negative MS patients may represent a clinically relevant MS subgroup.

New data identify an increasing sex ratio of multiple sclerosis in Sweden.

BACKGROUND: An increasing women-to-men ratio in later birth cohorts of patients with multiple sclerosis (MS) has been observed in several populations and has been hypothesised to be due to one or several environmental factors of importance for disease aetiology. However, in a study based on data from the Swedish MS registry (SMSreg) this ratio was recently reported to be rather stable during the 20(th) century. OBJECTIVE: The purpose of this study was to reinvestigate the women-to-men ratio in Sweden based on data from all available data sources, including deceased patients. METHOD: We combined data from the SMSreg with data from national patient registers. RESULTS: In total we obtained information on 19,510 MS patients born 1931-1985, 13,321 women and 6189 men. The women-to-men ratio increased from 1.70 for patients born in the 1930s to 2.67 for patients born in the 1980s. When comparing the coverage of SMSreg to the full data set, a significantly higher proportion of women born 1931-1935 compared to men born in the same period were found in SMSreg, resulting in a sampling bias hiding the increasing sex ratio in the full material. CONCLUSION: The women-to-men ratio in MS has increased in Sweden during the 20(th) century similarly to observations in other western countries.

Sex ratio of multiple sclerosis in the National Swedish MS Register (SMSreg).

BACKGROUND: Sex ratio in multiple sclerosis has been reported from several geographical areas. The disease is more common in women. In Europe the female-to-male ratio varies from 1.1 to 3.4. A recent study from Canada has reported a significant increase, with time, in female-to-male ratio in multiple sclerosis over the last 100 years. OBJECTIVE: The aim of this study was to analyse any change in sex ratio in multiple sclerosis in the Swedish population. METHODS: Data from the Swedish MS Register and data from the Swedish National Statistics Office were used to estimate sex ratio by year of birth and year of onset. RESULTS: In the analysis of sex ratio by year of birth there were 8834 patients (6271 women and 2563 men) born between 1931 and 1985. The mean women-to-men ratio was 2.62. No clear trend was noted for the women-to-men ratio by year of birth (Spearman's rho = 0.345, p = 0.298, n = 11). The number of patients analysed by year of onset was 9098 during the time period 1946 until 2005. The mean women-to-men ratio was 2.57. No significant change in women-to-men ratio (Spearman's rho = -0.007, p = 0.983, n = 12) with time was observed. CONCLUSION: There is no evidence for an increasing women-to-men ratio with time amongst Swedish multiple sclerosis patients.

A longitudinal observational study of brain atrophy rate reflecting four decades of multiple sclerosis: a comparison of serial 1D, 2D, and volumetric measurements from MRI images.

INTRODUCTION: Multiple sclerosis (MS) has a variable progression with an early onset of atrophy. Individual longitudinal radiological evaluations (over decades) are difficult to perform due to the limited availability of magnetic resonance imaging (MRI) in the past, patients lost in follow-up, and the continuous updating of scanners. We studied a cohort with widespread disease duration at baseline. The observed individual atrophy rates over time of 10 years represented four decades of disease span. METHODS: Thirty-seven MS patients (age range 24-65 years with disease duration 1-33 years) were consecutively selected and evaluated with MRI at baseline 1995 and in 1996. They were followed up for a decade (mean of 9.25 years, range 7.3-10 years) up to 2003-2005. Brain parenchymal volume and volumes of the supratentorial ventricles were analyzed with semi-automated volumetric measurements at three time points (1995, 1996, and 2003-2005). RESULTS: Volumetric differences were found over shorter periods of time (1-7 months); however, differences vanished by the end of follow-up. A uniform longitudinal decrease in brain volume and increase in ventricle volumes were found. Frontal horn width (1D) correlated strongest to 3D measures. No statistical differences of atrophy rates between MS courses were found. Supratentorial ventricular volumes were associated with disability and this association persisted during follow-up. CONCLUSION: Despite variable clinical courses, the degenerative effects of MS progression expressed in brain atrophy seem to uniformly progress over longer periods of time. These volumetric changes can be detected using 1D and 2D measurements performed on a routine PACS workstation.

Progression of non-age-related callosal brain atrophy in multiple sclerosis: a 9-year longitudinal MRI study representing four decades of disease development.

BACKGROUND: In multiple sclerosis (MS), multiple periventricular lesions are commonly the first findings on MRI. However, most of these MS lesions are clinically silent. The brain atrophy rate has shown better correlation to physical disability, but it is not clear how atrophy develops over decades. Corpus callosum forms the roof of the third and lateral ventricles. The corpus callosum area (CCA) in a midsagittal image is age independent in a normal adult population up to the seventh decade; therefore it can be used as a marker for non-age-related, pathological brain atrophy. OBJECTIVES: To investigate whether and how CCA decreases in size over time in patients with MS. METHODS: In a clinical observational study, 37 patients with MS with a wide range of disease duration at baseline (1-33 years) were followed. Three different MS courses were represented. The mean of individual MRI follow-up was 9 years. Multiple sclerosis severity score (MSSS) was also applied to evaluate disability at baseline and after 9 years of follow-up. RESULTS: A significant decrease in CCA over 9 years (p<0.001) and a persisting association between CCA and the disability status were found. The atrophy rate was similar ever four decades of MS for all MS courses. The mean annual CCA decrease was 9.25 mm2 (1.8%). Surprisingly, atrophy rate did not correlate with sex, disease duration, age at MS onset or MS course. CONCLUSIONS: Serial evaluations of CCA might be a robust method in monitoring a non-age-related decrease in CCA, reflecting progression of irreversible destructive changes in MS.