Multiple sclerosis is a chronic, inflammatory, and neurodegenerative disease of the central nervous system and a major cause of neurological disability in young adults. Its prevalence and incidence are increasing, and it has been estimated at over 2.8 million cases worldwide, in addition to recent trends towards a shift in MS prevalence to older ages, with peak prevalence estimates in the sixth decade of life. Although historically the relapsing and progressive phases of the disease have been considered separate clinical entities, recent evidence of progression independent of relapse activity (PIRA) has led to a reconsideration of multiple sclerosis as a continuum, in which relapsing and progressive features variably coexist from the earliest stages of the disease, challenging the traditional view of the disease course. In this Series article, we provide an overview of how the traditional description of the clinical course of MS and epidemiological trends in Europe have evolved. For this purpose, we focus on the concept of PIRA, discussing its potential as the main mechanism by which patients acquire disability, how its definition varies between studies, and ongoing research in this field. We emphasise the importance of incorporating the assessment of hidden clinical manifestations into patient management to help uncover and quantify the PIRA phenomenon and the possible implications for future changes in the clinical classification of the disease. At the same time, we provide insights into overcoming the challenges of identifying and defining PIRA and adopting a new understanding of the clinical course of MS.

Disability accrual in multiple sclerosis may occur as relapse-associated worsening or progression independent of relapse activity. The role of progression independent of relapse activity in early MS is yet to be established. The objective of this multicentre, observational, retrospective cohort study was to investigate the contribution of relapse-associated worsening and progression independent of relapse activity to confirmed disability accumulation in patients with clinically isolated syndrome and early relapsing-remitting multiple sclerosis, assessed within one year from onset and with follow-up >/= 5 years (n = 5169). Data were extracted from the Italian Multiple Sclerosis Register. Confirmed disability accumulation was defined by an increase in Expanded Disability Status Scale score confirmed at 6 months, and classified per temporal association with relapses. Factors associated with progression independent of relapse activity and relapse-associated worsening were assessed using multivariable Cox regression models. Over a follow-up period of 11.5 ± 5.5 years, progression independent of relapse activity occurred in 1427 (27.6%) and relapse-associated worsening in 922 (17.8%) patients. Progression independent of relapse activity was associated with older age at baseline (HR = 1.19; 95CI 1.13-1.25, p < 0.001), having a relapsing-remitting course at baseline (HR = 1.44; 95CI 1.28-1.61, p < 0.001), longer disease duration at baseline (HR = 1.56; 95%CI 1.28-1.90, p < 0.001), lower Expanded Disability Status Scale at baseline (HR = 0.92; 95CI 0.88-0.96, p < 0.001), lower number of relapses before the event (HR = 0.76; 95CI 0.73-0.80, p < 0.001). Relapse-associated worsening was associated with younger age at baseline (HR = 0.87; 95CI 0.81-0.93, p < 0.001), having a relapsing-remitting course at baseline (HR = 1.55; 95CI 1.35-1.79, p < 0.001), lower Expanded Disability Status Scale at baseline (HR = 0.94; 95CI 0.89-0.99, p = 0.017), higher number of relapses before the event (HR = 1.04; 95CI 1.01-1.07, p < 0.001). Longer exposure to disease modifying drugs was associated with a lower risk of both progression independent of relapse activity and relapse-associated worsening (p < 0.001). This study provides evidence that in early relapsing-onset multiple sclerosis cohort, progression independent of relapse activity was an important contributor to confirmed disability accumulation. Our findings indicate that insidious progression appears even in the earliest phases of the disease, suggesting that inflammation and neurodegeneration can represent a single disease continuum, in which age is one of the main determinants of disease phenomenology.

Objective To assess whether it is feasible to establish specific cut-off values able to discriminate ‘physiological’ or ‘pathological’ brain volume rates in patients with multiple sclerosis (MS). Methods The study was based on the analysis of longitudinal MRI data sets of patients with MS (n=206, 87% relapsing–remitting, 7% secondary progressive and 6% primary progressive) and healthy controls (HC; n=35). Brain atrophy rates were computed over a mean follow-up of 7.5 years (range 1–12) for patients with MS and 6.3 years (range 1–12.5) for HC with the SIENA software and expressed as annualised per cent brain volume change (PBVC/y). A weighted (on the follow-up length) receiver operating characteristic analysis and the area under the curve (AUC) were used for statistics. Results The weighted PBVC/y was −0.51±0.27% in patients with MS and −0.27±0.15% in HC (p<0.0001). There was a significant age-related difference in PBVC/y between HC older and younger than 35 years of age (p=0.02), but not in patients with MS (p=0.8). The cut-off of PBVC/y, as measured by SIENA that could maximise the accuracy in discriminating patients with MS from HC, was −0.37%, with 67% sensitivity and 80% specificity. According to the observed distribution, values of PBVC/y as measured by SIENA that could define a pathological range were above −0.52% with 95% specificity, above −0.46% with 90% specificity and above −0.40% with 80% specificity. Conclusions Our evidence-based criteria provide values able to discriminate the presence or absence of ‘pathological’ brain volume loss in MS with high specificity. Such results could be of great value in a clinical setting, particularly in assessing treatment efficacy in MS.

Significant cognitive impairment has been found in 20—30% of patients with clinically isolated syndromes suggestive of multiple sclerosis. In this study we aimed to assess the prognostic value of the presence of cognitive impairment for the conversion to multiple sclerosis in patients with clinically isolated syndromes. All patients with clinically isolated syndromes consecutively referred to our centre since 2002 and who had been followed-up for at least one year underwent cognitive assessment through the Rao’s Battery and the Stroop test. Possible predictors of conversion to clinically definite multiple sclerosis were evaluated through the Kaplan Meier curves and Cox regression analysis. A total of 56 patients (41 women; age 33.2 ± 8.5 years; expanded disability scale score 1.2 ± 0.7) were recruited. At baseline, 32 patients (57%) fulfilled McDonald’s criteria for dissemination in space. During the follow-up (3.5 ± 2.3 years), 26 patients (46%) converted to a diagnosis of multiple sclerosis. In particular, 64% of patients failing ≥ 2 tests and 88% of patients failing ≥ 3 tests converted to multiple sclerosis. In the Cox regression model, the failure of at least three tests (HR 3.3; 95% CI 1.4—8.1; p = 0.003) and the presence of McDonald’s dissemination in space at baseline (HR 3.8; 95% CI 1.5—9.7; p = 0.005), were found to be predictors for conversion to multiple sclerosis. We conclude that cognitive impairment is detectable in a sizable proportion of patients with clinically isolated syndromes. In these subjects cognitive impairment has a prognostic value in predicting conversion to multiple sclerosis and may therefore play a role in therapeutic decision making.

BICAMS (Brief International Cognitive Assessment for Multiple Sclerosis) has been recently developed as brief, practical and universal assessment tool for cognitive impairment in MS subjects. It includes the Symbol Digit Modalities Test (SDMT), the California Verbal Learning Test-2 (CVLT2) and the Brief Visuospatial Memory Test-Revised (BVMT-R) . In this study we aimed at gathering regression based normative data for the BICAMS battery in the Italian population. Healthy subjects were consecutively recruited among patient friends and relatives. Corrections for demographics were calculated using multivariable linear regression models. Test-retest reliability was assessed using the Pearson correlation coefficient. The BICAMS battery was administered to 273 healthy subjects (180 women, mean age 38.9 ± 13.0 years, mean education 14.9 ± 3.0 years). Test-retest reliability was good for all the tests. The study provided normative data of the BICAMS for the Italian population confirming good test-retest reliability which can facilitate the use of the battery in clinical practice, also for longitudinal patient assessments.

Objective: To assess the relationship between breastfeeding and risk of puerperal relapses in a large cohort of patients with multiple sclerosis (MS). Methods: We prospectively followed-up pregnancies occurring between 2002 and 2008 in women with MS, recruited from 21 Italian MS centers, and gathered data on breastfeeding through a standardized interview. The risk of relapses after delivery was assessed using the Cox regression analysis. Results: A total of 302 out of 423 pregnancies in 298 women resulted in full-term deliveries. Patients were followed up for at least 1 year after delivery. The time-dependent profile of the relapse rate before, during, and after pregnancy did not differ between patients who breastfed and patients who did not. In the multivariate analysis, adjusting for age at onset, age at pregnancy, disease duration, disability level, and relapses in the year prior to pregnancy and during pregnancy, treatment with disease-modifying drugs (DMDs), and exposure to toxics, the only significant predictors of postpartum relapses were relapses in the year before pregnancy (hazard ratio [HR] = 1.5; 95%confidence interval [CI] 1.3–1.9; p < 0.001) and during pregnancy (HR = 2.2; 95% CI 1.5–3.3; p < 0.001). Conclusions: In our sample, postpartum relapses were predicted only by relapses before and during pregnancy. Therefore, the reported association between breastfeeding and a lower risk of postpartum relapses may simply reflect different patient behavior, biased by the disease activity. Our results can assist neurologists facing the breastfeeding issue in mother counseling and shared decision-making. Especially, among patients with high risk of postpartum relapses, breastfeeding may not be feasible and early postpartum treatment should be an option.