Profiling cognitive-motor interference in a large sample of persons with progressive multiple sclerosis and impaired processing speed: results from the CogEx study.

BACKGROUND: Performing cognitive-motor dual tasks (DTs) may result in reduced walking speed and cognitive performance. The effect in persons with progressive multiple sclerosis (pwPMS) having cognitive dysfunction is unknown. OBJECTIVE: To profile DT-performance during walking in cognitively impaired pwPMS and examine DT-performance by disability level. METHODS: Secondary analyses were conducted on baseline data from the CogEx-study. Participants, enrolled with Symbol Digit Modalities Test 1.282 standard deviations below normative value, performed a cognitive single task ([ST], alternating alphabet), motor ST (walking) and DT (both). Outcomes were number of correct answers on the alternating alphabet task, walking speed, and DT-cost (DTC: decline in performance relative to the ST). Outcomes were compared between EDSS subgroups (≤ 4, 4.5-5.5, ≥ 6). Spearman correlations were conducted between the DTCmotor with clinical measures. Adjusted significance level was 0.01. RESULTS: Overall, participants (n = 307) walked slower and had fewer correct answers on the DT versus ST (both p < 0.001), with a DTCmotor of 15.8% and DTCcognitive of 2.7%. All three subgroups walked slower during the DT versus ST, with DTCmotor different from zero (p's < 0.001). Only the EDSS ≥ 6 group had fewer correct answers on the DT versus ST (p < 0.001), but the DTCcognitive did not differ from zero for any of the groups (p ≥ 0.039). CONCLUSION: Dual tasking substantially affects walking performance in cognitively impaired pwPMS, to a similar degree for EDSS subgroups.

Do patients' and referral centers' characteristics influence multiple sclerosis phenotypes? Results from the Italian multiple sclerosis and related disorders register.

BACKGROUND: Multiple sclerosis (MS) is characterized by phenotypical heterogeneity, partly resulting from demographic and environmental risk factors. Socio-economic factors and the characteristics of local MS facilities might also play a part. METHODS: This study included patients with a confirmed MS diagnosis enrolled in the Italian MS and Related Disorders Register in 2000-2021. Patients at first visit were classified as having a clinically isolated syndrome (CIS), relapsing-remitting (RR), primary progressive (PP), progressive-relapsing (PR), or secondary progressive MS (SP). Demographic and clinical characteristics were analyzed, with centers' characteristics, geographic macro-areas, and Deprivation Index. We computed the odds ratios (OR) for CIS, PP/PR, and SP phenotypes, compared to the RR, using multivariate, multinomial, mixed effects logistic regression models. RESULTS: In all 35,243 patients from 106 centers were included. The OR of presenting more advanced MS phenotypes than the RR phenotype at first visit significantly diminished in relation to calendar period. Females were at a significantly lower risk of a PP/PR or SP phenotype. Older age was associated with CIS, PP/PR, and SP. The risk of a longer interval between disease onset and first visit was lower for the CIS phenotype, but higher for PP/PR and SP. The probability of SP at first visit was greater in the South of Italy. DISCUSSION: Differences in the phenotype of MS patients first seen in Italian centers can be only partly explained by differences in the centers' characteristics. The demographic and socio-economic characteristics of MS patients seem to be the main determinants of the phenotypes at first referral.

Factors associated with treatment escalation among MS specialists and general neurologists: Results from an International cojoint study.

BACKGROUND: Previous studies in multiple sclerosis (MS) showed that therapeutic inertia (TI) affects 60-90% of neurologists and up to 25% of daily treatment decisions. The objective of this study was to determine the most common factors and attribute levels associated with decisions to treatment escalation in an international study in MS care. METHODS: 300 neurologists with MS expertise from 20 countries were invited to participate. Participants were presented with 12 pairs of simulated MS patient profiles described by 13 clinically relevant factors. We used disaggregated discrete choice experiments to estimate the weight of factors and attributes affecting physicians' decisions when considering treatment selection. Participants were asked to select the ideal candidate for treatment escalation from modest to higher-efficacy therapies. RESULTS: Overall, 229 neurologists completed the study (completion rate: 76.3%). The top 3 weighted factors associated with treatment escalation were: previous relapses (20%), baseline expanded disability status scale [EDSS] (18%), and MRI activity (13%). Patient demographics and desire for pregnancy had a modest influence (≤ 3%). We observed differences in the weight of factors associated with treatment escalation between MS specialists and non-MS specialists. CONCLUSIONS: Our results provide critical information on factors influencing neurologists' treatment decisions and should be applied to continuing medical education strategies.

Peak width of skeletonized mean diffusivity (PSMD) and cognitive functions in relapsing-remitting multiple sclerosis.

Peak width of skeletonized mean diffusivity (PSMD) is a new MRI marker, which has shown clinical relevance in some neurological conditions and, in preliminary data, in multiple sclerosis (MS). We aimed here to investigate, in a group of relapsing-remitting MS (RRMS) patients, the relationship between PSMD and cognitive performances, in comparison with other MRI measures. RRMS patients (n = 60) and normal controls (n = 15) underwent a 3 T MRI examination. MRI-based white matter (WM) lesion volume, microstructural integrity (assessed with Tract-Based Spatial Statistics of diffusion tensor imaging [DTI] images) and brain volumes (i.e., total brain, grey matter [GM] and WM) were computed. In addition, PSMD was calculated through "skeletonization" of WM tracts and diffusion histograms. Cognition was evaluated with Rao's Brief Repeatable Battery (BRB), which incorporated tests of verbal and visual memory, attention, concentration, information processing speed and verbal fluency. PSMD closely correlated with symbol digit modalities test (SDMT) (r = -0.70, p < 0.001) and, to a lesser extent, with verbal and visual memory tests. Multiple regression analysis showed that PSMD explained SDMT variance (R2 = 0.54, p < 0.001) more than other MRI measures. Results point out the relevance of microstructural damage, as assessed by PSMD, as a reliable marker of cognition in MS, especially in explaining dysfunction in information processing speed.

Treatment of MOG antibody associated disorders: results of an international survey.

INTRODUCTION: While monophasic and relapsing forms of myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are increasingly diagnosed world-wide, consensus on management is yet to be developed. OBJECTIVE: To survey the current global clinical practice of clinicians treating MOGAD. METHOD: Neurologists worldwide with expertise in treating MOGAD participated in an online survey (February-April 2019). RESULTS: Fifty-two responses were received (response rate 60.5%) from 86 invited experts, comprising adult (78.8%, 41/52) and paediatric (21.2%, 11/52) neurologists in 22 countries. All treat acute attacks with high dose corticosteroids. If recovery is incomplete, 71.2% (37/52) proceed next to plasma exchange (PE). 45.5% (5/11) of paediatric neurologists use IV immunoglobulin (IVIg) in preference to PE. Following an acute attack, 55.8% (29/52) of respondents typically continue corticosteroids for ≥ 3 months; though less commonly when treating children. After an index event, 60% (31/51) usually start steroid-sparing maintenance therapy (MT); after ≥ 2 attacks 92.3% (48/52) would start MT. Repeat MOG antibody status is used by 52.9% (27/51) to help decide on MT initiation. Commonly used first line MTs in adults are azathioprine (30.8%, 16/52), mycophenolate mofetil (25.0%, 13/52) and rituximab (17.3%, 9/52). In children, IVIg is the preferred first line MT (54.5%; 6/11). Treatment response is monitored by MRI (53.8%; 28/52), optical coherence tomography (23.1%; 12/52) and MOG antibody titres (36.5%; 19/52). Regardless of monitoring results, 25.0% (13/52) would not stop MT. CONCLUSION: Current treatment of MOGAD is highly variable, indicating a need for consensus-based treatment guidelines, while awaiting definitive clinical trials.

The clinical spectrum of anti-MOG associated acquired demyelinating disorders: Three case-reports.

BACKGROUND: The spectrum of differential diagnosis of acquired demyelinating disorders of the central nervous system has been recently broadened. There is now growing evidence that supports anti-myelin oligodendrocyte antibodies associated demyelination as a distinct disease entity, with some clinical characteristics that somehow overlap those of Multiple Sclerosis (MS) and anti-AQP4+ Neuromyelitis Optica Spectrum Disorders (AQP4+NMOSD) but different pathogenesis and treatment strategies. SUMMARY: We hereby present 3 cases of anti-MOG+ patients with different disease courses - ranging from mild to severe - all presenting with Optic neuritis (ON) at the onset. Optic neuritis (ON) is a common manifestation of different central nervous system (CNS) inflammatory disorders and can represent the first clinical event of MS and NMOSD. ON is also the most common presentation of antiMOG demyelinating disorders, followed by - and sometimes associated with - myelitis, most commonly extended over more than 2 spinal cord segments and defined as longitudinally extended transverse myelitis (LETM). All the three patients tested negative for oligoclonal bands in CSF and anti-AQP4 Ab in serum, had a relapsing disease course characterized by prominent involvement of the optic nerve and spinal cord, with good recovery after treatment with high-dose corticosteroids. However, they had a different disease course at follow-up and underwent different treatment approaches. CONCLUSIONS: Since anti-MOG+ patients can have a multiphasic disease course and accumulate disability over time, a high degree of suspicion and early diagnosis are of critical importance for treatment decision-making in clinical practice. AIM: The aim of this case report is to enhance focus on an emerging disease spectrum among acquired CNS demyelinating disorders.

Subclinical motor impairment assessed with an engineered glove correlates with magnetic resonance imaging tissue damage in radiologically isolated syndrome.

BACKGROUND: An engineered glove measuring finger motor performance previously showed ability to discriminate early-stage multiple sclerosis (MS) patients from healthy controls (HCs). Radiologically isolated syndrome (RIS) classifies asymptomatic subjects with brain magnetic resonance imaging (MRI) abnormalities suggestive of multiple sclerosis. METHODS: Seventeen asymptomatic subjects with RIS and 17 HCs were assessed. They performed finger-to-thumb opposition sequences at their maximal velocity, metronome-paced bimanual movements and conventional and diffusion tensor MRI. RESULTS: Subjects with RIS showed lower (P = 0.005) maximal velocity and higher (P = 0.006) bimanual coordination impairment than HCs. In RIS, bimanual coordination correlated with T2-lesion volume, fractional anisotropy and radial diffusivity in the white matter. CONCLUSIONS: These findings point out the relevance of fine hand measures as a robust marker of subclinical disability.

ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosis.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a complex disease of the central nervous system. As new drugs are becoming available, knowledge on diagnosis and treatment must continuously evolve. There is therefore a need for a reference tool compiling current data on benefit and safety, to aid professionals in treatment decisions and use of resources across Europe. The European Committee of Treatment and Research in Multiple Sclerosis (ECTRIMS) and the European Academy of Neurology (EAN) have joined forces to meet this need. The objective was to develop an evidence-based clinical practice guideline for the pharmacological treatment of people with MS to guide healthcare professionals in the decision-making process. METHODS: This guideline has been developed using the GRADE methodology and following the recently updated EAN recommendations for guideline development. Clinical questions were formulated in PICO format (patient, intervention, comparator, outcome) and outcomes were prioritized according to their relevance to clinical practice. An exhaustive literature search up to December 2016 was performed for each question and the evidence is presented narratively and, when possible, combined in a meta-analysis using a random-effects model. The quality of evidence for each outcome was rated into four categories - very high, high, low and very low - according to the risk of bias. GRADE evidence profiles were created using GRADEprofiler (GRADEpro) software (Version 3.6). The recommendations with assigned strength (strong, weak) were formulated based on the quality of evidence and the risk-benefit balance. Consensus between the panellists was reached by use of the modified nominal group technique. RESULTS: A total of 10 questions have been agreed, encompassing treatment efficacy, response criteria, strategies to address suboptimal response and safety concerns and treatment strategies in MS and pregnancy. The guideline takes into account all disease-modifying drugs approved by the European Medicine Agency at the time of publication. A total of 20 recommendations were agreed by the guideline working group members after three rounds of consensus.

Effect of organizational features on patient satisfaction with care in Italian multiple sclerosis centres.

BACKGROUND AND PURPOSE: Receiving clear, complete and up-to-date information and having a satisfying relationship with the health professional (HP) are of primary importance for MS patients. Healthcare organization plays a key role in promoting an effective relationship and communication between patients and HPs. The present study aims to explore which care organization and service characteristics provided by Italian MS centres best predict patients' satisfaction with healthcare. METHODS: Eighty-one centres and 707 patients (502 women, mean age 40.5 years, SD 10.2; mean education 12.2 years, SD 3.6; time since diagnosis 5.9 years, SD 1.5) were included in the analysis. The care organization and service provided by each centre were evaluated in comparison with the National Institute for Health and Care Excellence (NICE) guidelines on management of MS. Patients' satisfaction with care was measured using the patient self-assessed questionnaire 'Comunicazione medico-paziente nella Sclerosi Multipla, revised' section 2 (COSM-R section 2). RESULTS: The clinical characteristics of patients significantly affected their satisfaction. A multivariate regression model showed that higher patients' satisfaction (COSM-R score) was inversely associated with hospital size (number of patients under care) (ß = -0.21, 95% confidence interval -0.35; -0.07) and directly associated with psychological interventions (ß = 2.44, 95% confidence interval 0.29; 4.59). CONCLUSIONS: Multiple sclerosis patients from larger hospitals are less satisfied with the information received and the relationship with HPs. Building an individualized relationship between patients and HPs and tailoring the communication of information improve patients' satisfaction. Such a goal is probably less likely to be accomplished in larger centres with many incoming patients. Moreover, when the centres also provide structured psychological interventions, the patients are more satisfied.

Efficacy and safety of cannabinoid oromucosal spray for multiple sclerosis spasticity.

BACKGROUND: The approval of 9-δ-tetrahydocannabinol and cannabidiol (THC:CBD) oromucosal spray (Sativex) for the management of treatment-resistant multiple sclerosis (MS) spasticity opened a new opportunity for many patients. The aim of our study was to describe Sativex effectiveness and adverse events profile in a large population of Italian patients with MS in the daily practice setting. METHODS: We collected data of all patients starting Sativex between January 2014 and February 2015 from the mandatory Italian medicines agency (AIFA) e-registry. Spasticity assessment by the 0-10 numerical rating scale (NRS) scale is available at baseline, after 1 month of treatment (trial period), and at 3 and 6 months. RESULTS: A total of 1615 patients were recruited from 30 MS centres across Italy. After one treatment month (trial period), we found 70.5% of patients reaching a ≥20% improvement (initial response, IR) and 28.2% who had already reached a ≥30% improvement (clinically relevant response, CRR), with a mean NRS score reduction of 22.6% (from 7.5 to 5.8). After a multivariate analysis, we found an increased probability to reach IR at the first month among patients with primary and secondary progressive MS, (n=1169, OR 1.4 95% CI 1.04 to 1.9, p=0.025) and among patients with >8 NRS score at baseline (OR 1.8 95% CI 1.3-2.4 p<0.001). During the 6 months observation period, 631(39.5%) patients discontinued treatment. The main reasons for discontinuation were lack of effectiveness (n=375, 26.2%) and/or adverse events (n=268, 18.7%). CONCLUSIONS: Sativex can be a useful and safe option for patients with MS with moderate to severe spasticity resistant to common antispastic drugs.

A 10-year follow-up of the European multicenter trial of interferon ß-1b in secondary-progressive multiple sclerosis.

OBJECTIVES: To explore long-term effects of treatment and prognostic relevance of variables assessed at baseline and during the European secondary progressive multiple sclerosis (SPMS) trial of interferon beta 1b (IFNB-1b). METHODS: We assessed 362 patients (60% female; median age 41 years; Expanded Disability Status Scale (EDSS): 5.5; 51% randomized to IFNB-1b) for their EDSS and treatment history after 10 years. Non-parametric analysis of covariance (ANCOVA) and multivariate linear regression models were applied. RESULTS: Median EDSS was 6.0 at the end of the randomized controlled trial (RCT), in the IFNB-1b and placebo groups, and 7.0 in long-term follow-up patients (those receiving IFNB-1b in the RCT were 6.5 and those receiving placebo in the RCT were 7.0; p = 0.086). 24 patients (6.6%) were deceased. The EDSS at baseline and the EDSS change during the RCT were the most important predictors of the EDSS 10 years later (partial R(2): 0.47). The ability to predict changes in EDSS 10 years after the RCT was limited (R(2): 0.12). Magnetic resonance imaging (MRI) measures remained in the predictive models, but explained < 5% of the variability. CONCLUSIONS: The results from this analysis did not provide convincing evidence to support a favorable long-term outcome in those patients allocated IFNB-1b during the RCT, in our SPMS cohort. The progressive stage of the disease remains largely unpredictable by clinical and conventional MRI measures, so better prognostic markers are needed.

BREMSO: a simple score to predict early the natural course of multiple sclerosis.

BACKGROUND AND PURPOSE: Early prediction of long-term disease evolution is a major challenge in the management of multiple sclerosis (MS). Our aim was to predict the natural course of MS using the Bayesian Risk Estimate for MS at Onset (BREMSO), which gives an individual risk score calculated from demographic and clinical variables collected at disease onset. METHODS: An observational study was carried out collecting data from MS patients included in MSBase, an international registry. Disease impact was studied using the Multiple Sclerosis Severity Score (MSSS) and time to secondary progression (SP). To evaluate the natural history of the disease, patients were analysed only if they did not receive immune therapies or only up to the time of starting these therapies. RESULTS: Data from 14 211 patients were analysed. The median BREMSO score was significantly higher in the subgroups of patients whose disease had a major clinical impact (MSSS≥ third quartile vs. ≤ first quartile, P < 0.00001) and who reached SP (P < 0.00001). The BREMSO showed good specificity (79%) as a tool for predicting the clinical impact of MS. CONCLUSIONS: BREMSO is a simple tool which can be used in the early stages of MS to predict its evolution, supporting therapeutic decisions in an observational setting.

Anxiety state affects information processing speed in patients with multiple sclerosis.

The aim of this study was to investigate the impact of anxiety on the cognitive performance of a clinical sample of relapsing-remitting (RR) MS patients. One hundred ninety patients (140 females) were included in the study and assessed through the beck depression inventory, the state-trait anxiety inventory and the Rao's brief repeatable battery which assesses cognitive domains most frequently impaired in MS. As for neuropsychological performance, a total of 76 (40%) subjects fulfilled our criterion for cognitive impairment. Tests most frequently failed by cognitive impairment (CI) patients were those assessing complex attention and information processing speed [Simbol Digit Modalities Test (SDMT), Paced Auditory Serial Auditory Test (PASAT) 3 and 2] and verbal memory. In the univariate analysis, state anxiety was related to failure on the SDMT (p = 0.042), and marginally, to failure on the PASAT-3 (p = 0.068), and to the presence of CI (p = 0.082). Moderate/severe depression was detected in 38 (20%) patients and fatigue in 109 (57%). Higher depression scores were related to impairment on the ST (OR = 1.05; 95% CI 1.01-1.10; p = 0.029).

Computer-assisted rehabilitation of attention in patients with multiple sclerosis: results of a randomized, double-blind trial.

BACKGROUND: There is controversial information on the efficacy of cognitive rehabilitation in multiple sclerosis (MS). OBJECTIVE: The objective of this paper is to test a home-based computerized program for retraining attention dysfunction in MS. METHODS: Relapsing-remitting patients who failed > 2 tests of attention on an extensive neuropsychological battery were randomized to specific or nonspecific computerized training (ST, n-ST), in one-hour sessions, twice a week for three months. Outcome measures included neuropsychological assessment, depression, fatigue, everyday activities and a visual analogue scale assessing attentive performance (VAS). Assessments were repeated after the interventions and after a further three months. Statistical analysis included the analysis of variance (ANOVA) for repeated measures. RESULTS: Eighty-eight out of 102 randomized patients completed the study (69 women, age 40.9 ± 11.5 years, disease duration 13.0 ± 8.7 years, Expanded Disability Status Scale score 2.7 ± 1.5). Fifty-five patients were randomized to ST, 33 to n-ST. A benefit of the ST was observed on the Paced Auditory Serial Addition Test (p < 0.002). However, patient self-report did not reveal differences between ST and n-ST patient groups. CONCLUSION: Although our program trained different attention components, we could detect some improvements exclusively on tasks of sustained attention. Moreover, patient self-perceived results may be independent of the training program.

The Rao's Brief Repeatable Battery version B: normative values with age, education and gender corrections in an Italian population.

The Brief Repeatable Battery (BRB) of Neuropsychological Tests is one of the most widely used instruments to assess cognitive functioning in multiple sclerosis patients. However, to date, normative data for the Italian population are available only for the version A, which limits the use of the battery in longitudinal evaluations. We administered the BRB version B to 132 healthy subjects to obtain normative values taking into account the influences of demographic factors on the test scores and calculating corrections for these relevant factors (age, gender and education). Higher age and educational level were associated with better performance on all the tests. The World List Generation was also influenced by gender, since women performed better than men. Moreover, some tests of the version B seem to be easier than those of version A. Our data can improve the applicability of the BRB for both clinical and research purposes in longitudinal assessments.

Prevalence of patient-reported dysphagia in multiple sclerosis patients: an Italian multicenter study (using the DYMUS questionnaire).

OBJECTIVE: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) with a chronic course. Dysphagia represents one of the current challenges in clinical practice for the management of MS patients. Dysphagia starts to appear in mildly impaired MS subjects (EDSS 2-3) and becomes increasingly common in the most severely disabled subjects (EDSS 8-9). The aim of the present study was to evaluate the frequency and characteristics of patient-reported dysphagia in MS patients with a multicenter study using the recently developed DYMUS (DYsphagia in MUltiple Sclerosis) questionnaire. DESIGN: Data were collected in a multi-centre, cross-sectional study using a face-to-face structured questionnaire for clinical characteristics and the DYMUS questionnaire. RESULTS: 1875 patients were interviewed. The current study has shown a correlation between patient-reported dysphagia and EDSS and disease course but not with age, gender and disease duration. Questionnaires were divided into "patient-reported dysphagia-yes" (587, 31.3%) and "patient-reported dysphagia-no" (1288, 68.7%). Compared with the patient-reported dysphagia-no group, patients in patient-reported dysphagia-yes group had higher EDSS score (mean EDSS 4.6 vs. 2.8; p<0.001) and had a longer disease duration (mean duration 13 years vs. 11 years; p<0.001), while there was no significant difference in gender (32.7% vs. 30.5% male and 67.3% vs. 69.5% female) and in age composition (46.18 vs. 42.05). CONCLUSIONS: This study represents the largest, multi-centre sample of MS patients evaluated for patient-reported dysphagia utilizing an ad-hoc questionnaire for this condition.

Adverse events after endovascular treatment of chronic cerebro-spinal venous insufficiency (CCSVI) in patients with multiple sclerosis.

Although it is debated whether chronic cerebro-spinal venous insufficiency (CCSVI) plays a role in multiple sclerosis (MS) development, many patients undergo endovascular treatment (ET) of CCSVI. A study is ongoing in Italy to evaluate the clinical outcome of ET. Severe adverse events (AEs) occurred in 15/462 subjects at a variable interval after ET: jugular thrombosis in seven patients, tetraventricular hydrocephalus, stroke, paroxysmal atrial fibrillation, status epilepticus, aspiration pneumonia, hypertension with tachicardia, or bleeding of bedsore in the remaining seven cases. One patient died because of myocardial infarction 10 weeks after ET. The risk of severe AEs related to ET for CCSVI must be carefully considered.

Endovascular treatment of CCSVI in patients with multiple sclerosis: clinical outcome of 462 cases.

Although it is still debated whether chronic cerebro-spinal venous insufficiency (CCSVI) plays a role in multiple sclerosis (MS) development, many patients underwent endovascular treatment (ET) of CCSVI. The objective of the study is to evaluate the outcome and safety of ET in Italian MS patients. Italian MS centers that are part of the Italian MS Study Group were all invited to participate to this retrospective study. A structured questionnaire was used to collect detailed clinical data before and after the ET. Data from 462 patients were collected in 33 centers. ET consisted of balloon dilatation (93 % of cases) or stent application. The mean follow-up duration after ET was 31 weeks. Mean EDSS remained unchanged after ET (5.2 vs. 4.9), 144 relapses occurred in 98/462 cases (21 %), mainly in RR-MS patients. Fifteen severe adverse events were recorded in 3.2 % of cases. Given the risk of severe adverse events and the lack of objective beneficial effects, our findings confirm that at present ET should not be recommended to patients with MS.

Fluctuations of MS births and UV-light exposure.

BACKGROUND: Patients with multiple sclerosis (MS) are more frequently born in spring when compared to autumn. Fluctuation of UV-light has been hypothesized to drive this phenomenon. AIM: To assess the correlation between fluctuation of sunlight and birth season in persons with MS. METHODS: For this record-linkage study, we collected from the international MSBase and the Italian MS iMed-web databases the dates of birth of 11,415 patients with MS from 36 centres from 15 countries worldwide and compared these to dates of live-births from national registries. From all participating sites, we collected data on UV-light fluctuation and assessed its correlation with seasonal fluctuation in MS births. RESULTS: Compared with the reference cohort, an increased proportion of persons with MS were born in spring and a decreased proportion in autumn (odds ratio (OR) to be born in spring versus autumn = 1.158, χ² = 36.347, P < 0.001). There was no significantly increased fluctuation of MS births with increased quartile of ambient UV-light fluctuation (Ptrend = 0.086). CONCLUSION: Seasonal fluctuation of MS births as found in this worldwide cohort of patients with MS did not correlate with variation in seasonal fluctuation of UV-light. Most likely, it results from a complex interplay between fluctuation of sunlight, behavioural factors, other environmental factors and (epi)genetic factors.