Antibiotic Use and Risk of Multiple Sclerosis: A Nested Case-Control Study in Emilia-Romagna Region, Italy.

INTRODUCTION: Known risk factors for multiple sclerosis (MS) include smoking, a low vitamin D status, obesity, and EBV, while the inflammatory feature of the disease strongly suggests the presence of additional infectious agents. The association between use of antibiotics and MS risk that could shed light on these factors is still undetermined. We aimed to evaluate the association between antibiotics and MS risk, in the Emilia-Romagna region (RER), Italy. METHODS: All adult patients with MS seen at any RER MS center (2015-2017) were eligible. For each of the 877 patients included, clinical information was collected and matched to 5 controls (RER residents) (n = 4,205) based on age, sex, place of residence, and index year. Information on antibiotic prescription was obtained through the linkage with the RER drug prescription database. RESULTS: Exposure to any antibiotic 3 years prior to the index year was associated with an increased MS risk (OR = 1.52; 95% CI = 1.29-1.79). Similar results were found for different classes. No dose-response effect was found. DISCUSSION/CONCLUSIONS: Our results suggest an association between the use of antibiotics and MS risk in RER population. However, further epidemiological studies should be done with information on early life and lifestyle factors.

Health-related quality of life in clinically isolated syndrome and risk of conversion to multiple sclerosis.

BACKGROUND AND OBJECTIVES: A few studies have found that low scores on self-rated health and quality of life measures are associated with following worsening disability in multiple sclerosis (MS). We wanted to estimate the association between self-rated quality of life scores among patients with clinically isolated syndrome (CIS) and the risk of subsequent conversion to definite MS. METHODS: One hundred sixty-two patients from the GERONIMUS cohort with a symptom or sign suggestive of MS and without a definite diagnosis of MS at the time of inclusion were asked to evaluate their health-related quality of life according to MSQoL-54 scale. They were clinically assessed and mood and depression scales were applied. The association between the scores of these scales and the risk of converting to definite MS during a 5-year follow-up was estimated using the Cox- proportional hazard regression model. RESULTS: Quality of life at examination was significantly lower compared to those of an age- and sex-adjusted general Italian population. During the follow-up, 116 patients (72%) converted to definite MS. No significant predictive effects were found for the summary scales of MSQol-54 or other scales. The estimates did not change after adjusting for age, sex, BMI, education, MRI findings, Expanded Disability Status Scale (EDSS) score, and treatment at time of examination. CONCLUSION: Persons with CIS in this cohort reported reduced self-rated quality of life compared to the general population, but variation in these scores was not associated with subsequent conversion from CIS to clinical definite MS.

Definitive childlessness in women with multiple sclerosis: a multicenter study.

The frequency of definitive childlessness in women with multiple sclerosis (MS) may be higher than in the general population. MS may also affect decisions on the delivery procedure and on breast-feeding issues. Aim of the study was to assess the frequency of childlessness and its possible causes, the proportion of cesarean deliveries (CD), and the frequency of breast-feeding in patients and controls who have reached the end of their reproductive period. Female MS patients (>43 years) and controls (>45 years) filled out a questionnaire. We enrolled 303 patients and 500 controls. MS was associated with a higher frequency of childlessness (22 vs 13%) and less patients were in a stable relationship (83 vs 89%). There was no difference in the reported rates of infertility and miscarriages, while elective abortions were more frequent in patients (20 vs 12%). MS did not significantly affect the frequency of CD or of breast-feeding. MS-related reasons for childlessness, reported by 16% of childless patients, included disability/fear of future disability, fear of genetically transmitting MS, fear of not starting/discontinuing treatments, and discouragement by physician. Definitive childlessness is more frequent in women with MS compared to controls. A portion of voluntary childlessness may be avoided through correct/tailored information to patients.

Heterogeneity in ALSFRS-R decline and survival: a population-based study in Italy.

Very few studies examined trend over time of the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) and factors influencing it; previous studies, then, included only patients attending tertiary ALS Centres. We studied ALSFRS-R decline, factors influencing this trend and survival in a population-based setting. From 2009 onwards, a prospective registry records all incident ALS cases among residents in Emilia Romagna (population: 4.4 million). For each patient, demographic and clinical details (including ALSFRS-R) are collected by caring physicians at each follow-up. Analysis was performed on 402 incident cases (1279 ALSFRS-R assessments). The average decline of the ALSFRS-R was 0.60 points/month during the first year after diagnosis and 0.34 points/month in the second year. ALSFRS-R decline was heterogeneous among subgroups. Repeated measures mixed model showed that ALSFRS-R score decline was influenced by age at onset (p < 0.01), phenotype (p = 0.01), body mass index (BMI) (p < 0.01), progression rate at diagnosis (ΔFS) (p < 0.01), El Escorial Criteria-Revised (p < 0.01), and FVC% at diagnosis (p < 0.01). Among these factors, at multivariate analysis, only age, site of onset and ΔFS independently influenced survival. In this first population-based study on ALSFRS-R trend, we confirm that ALSFRS-R decline is not homogeneous among ALS patients and during the disease. Factors influencing ALSFRS-R decline may not match with those affecting survival. These disease modifiers should be taken into consideration for trials design and in clinical practice during discussions with patients on prognosis.

Kappa index in the diagnostic work-up of autoimmune encephalitis.

BACKGROUND: The presence of inflammatory changes in the cerebrospinal fluid (CSF), including immunoglobulin intrathecal synthesis (IS), can support the diagnosis of autoimmune encephalitis (AE) and allow prompt treatment. The main aim of our study was to calculate the Kappa index as a marker of IS, in patients with AE. METHODS: Charts of patients undergoing a diagnostic work-up for suspected AE between 2009 and 2023 were reviewed and the Graus criteria applied. CSF and serum kappa free light chains were determined using the Freelite assay (The Binding Site Group) and the turbidimetric Optilite analyzer. RESULTS: We identified 34 patients with "definite" AE (9 anti-NMDAR AE and 25 limbic AE) and nine patients with "possible" AE. Five patients (15%) with definite AE had pleocytosis and twelve (34%) showed CSF-restricted oligoclonal bands (OCB) at isoelectric focusing. The Kappa index was >6 in 29.4% and > 3 in 50% of the definite AE patients. It was elevated (>3) in 36.4% of patients with definite AE who resulted negative to OCB testing and was the only altered parameter suggestive of an ongoing inflammatory process in the CNS in three definite AE patients with otherwise normal CSF findings (i.e. normal cell count and protein levels, no OCBs). In the possible AE group, one patient had a Kappa index >3 in the absence of OCB. CONCLUSIONS: The Kappa index could be useful, as a more sensitive marker of IS and as a supportive marker of neuroinflammation, in the diagnostic work-up of suspected AE.

Insight into Elderly ALS Patients in the Emilia Romagna Region: Epidemiological and Clinical Features of Late-Onset ALS in a Prospective, Population-Based Study.

Few studies have focused on elderly (>80 years) amyotrophic lateral sclerosis (ALS) patients, who represent a fragile subgroup generally not included in clinical trials and often neglected because they are more difficult to diagnose and manage. We analyzed the clinical and genetic features of very late-onset ALS patients through a prospective, population-based study in the Emilia Romagna Region of Italy. From 2009 to 2019, 222 (13.76%) out of 1613 patients in incident cases were over 80 years old at diagnosis, with a female predominance (F:M = 1.18). Elderly ALS patients represented 12.02% of patients before 2015 and 15.91% from 2015 onwards (p = 0.024). This group presented with bulbar onset in 38.29% of cases and had worse clinical conditions at diagnosis compared to younger patients, with a lower average BMI (23.12 vs. 24.57 Kg/m2), a higher progression rate (1.43 vs. 0.95 points/month), and a shorter length of survival (a median of 20.77 vs. 36 months). For this subgroup, genetic analyses have seldom been carried out (25% vs. 39.11%) and are generally negative. Finally, elderly patients underwent less frequent nutritional- and respiratory-supporting procedures, and multidisciplinary teams were less involved at follow-up, except for specialist palliative care. The genotypic and phenotypic features of elderly ALS patients could help identify the different environmental and genetic risk factors that determine the age at which disease onset occurs. Since multidisciplinary management can improve a patient's prognosis, it should be more extensively applied to this fragile group of patients.

Epidemiological, Clinical and Genetic Features of ALS in the Last Decade: A Prospective Population-Based Study in the Emilia Romagna Region of Italy.

Increased incidence rates of amyotrophic lateral sclerosis (ALS) have been recently reported across various Western countries, although geographic and temporal variations in terms of incidence, clinical features and genetics are not fully elucidated. This study aimed to describe demographic, clinical feature and genotype-phenotype correlations of ALS cases over the last decade in the Emilia Romagna Region (ERR). From 2009 to 2019, our prospective population-based registry of ALS in the ERR of Northern Italy recorded 1613 patients receiving a diagnosis of ALS. The age- and sex-adjusted incidence rate was 3.13/100,000 population (M/F ratio: 1.21). The mean age at onset was 67.01 years; women, bulbar and respiratory phenotypes were associated with an older age, while C9orf72-mutated patients were generally younger. After peaking at 70-75 years, incidence rates, among women only, showed a bimodal distribution with a second slight increase after reaching 90 years of age. Familial cases comprised 12%, of which one quarter could be attributed to an ALS-related mutation. More than 70% of C9orf72-expanded patients had a family history of ALS/fronto-temporal dementia (FTD); 22.58% of patients with FTD at diagnosis had C9orf72 expansion (OR 6.34, p = 0.004). In addition to a high ALS incidence suggesting exhaustiveness of case ascertainment, this study highlights interesting phenotype-genotype correlations in the ALS population of ERR.

TeleNeurological evaluation and Support for the Emergency Department (TeleNS-ED): protocol for an open-label clinical trial.

INTRODUCTION: The COVID-19 pandemic compelled health systems to protect patients and medical personnel during transit in hospitals by minimising transfers, prompting the use of telehealth systems. In the field of neurology, telemedicine has been used in emergency settings for acute stroke management between spoke and hub hospital networks, where good outcomes have been achieved. However, data on the use of telemedicine in non-stroke acute neurological conditions accessing the emergency department (ED) are currently missing. METHODS AND ANALYSES: This is an interventional, open-label trial on the use of teleconsultation in the ED for neurological diseases other than stroke. The study aims to develop a remote consultancy system (TeleNeurological Evaluation and Support, TeleNS) for patients with acute neurological symptoms referred to hospital facilities without a 24-hour availability of a neurologist consultant (spoke hospitals). The study population will include 100 ED patients referred to two spoke hospitals in 6 months, who will be asked to perform teleconsultation instead of inperson visits. As a control group, retrospectively available data from patients admitted to the ED of spoke hospitals during the same time period over the last 2 years will be evaluated. The primary objective is to assess whether a TeleNS for the ED guarantees a faster but qualitatively non-inferior diagnostic/therapeutic work-up if compared with inperson examination, assuring the availability of all the necessary examinations and treatments with consistent time-saving. ETHICS AND DISSEMINATION: The trial was designed following the national guidelines on clinical investigation on telemedicine provided by the Italian Ministry of Health and according to the Standard Protocol Items for Randomized Trials statement guidelines. This research protocol was approved by Comitato Etico Area Vasta Emilia Nord in September 2020 (number/identification: 942/2020/DISP/AOUMO SIRER ID 805) and was written without patient involvement. Patients' associations will be involved in the dissemination of study design and results. The results of the study will be presented during scientific symposia or published in scientific journals. TRIAL REGISTRATION NUMBER: NCT04611295.

Kappa Index Versus CSF Oligoclonal Bands in Predicting Multiple Sclerosis and Infectious/Inflammatory CNS Disorders.

BACKGROUND: Cerebrospinal fluid (CSF) kappa free light chains (KFLC) are gaining increasing interest as markers of intrathecal immunoglobulin synthesis. The main aim of this study was to assess the diagnostic accuracy (AUC) of the kappa index (CSF/serum KFLC divided by the CSF/serum albumin ratio) compared to CSF oligoclonal IgG bands (OCB) in predicting Multiple Sclerosis (MS) or a central nervous system infectious/inflammatory disorder (CNSID). METHODS: We enrolled patients who underwent a diagnostic spinal tap throughout two years. KFLC levels were determined using a Freelite assay (Binding Site) and the turbidimetric Optilite analyzer. RESULTS: Of 540 included patients, 223 had a CNSID, and 84 had MS. The kappa index was more sensitive (0.89 versus 0.85) and less specific (0.84 versus 0.89), with the same AUC (0.87) as OCB for MS diagnosis (optimal cut-off: 6.2). Adding patients with a single CSF IgG band to the OCB-positive group slightly increased the AUC (0.88). Likewise, the kappa index (cut-off: 3.9) was more sensitive (0.67 versus 0.50) and less specific (0.81 versus 0.97), with the same AUC (0.74) as OCB, for a CNSID diagnosis. CONCLUSION: The kappa index and CSF OCB have comparable diagnostic accuracies for a MS or CNSID diagnosis and supply the clinician with useful, complementary information.

First-line disease-modifying drugs in relapsing-remitting multiple sclerosis: an Italian real-life multicenter study on persistence.

OBJECTIVE: The introduction of oral disease-modifying drugs (DMDs) in addition to the available, injectable, ones for relapsing-remitting multiple sclerosis (RRMS) could be expected to improve medication persistence due to a greater acceptability of the route of administration. The aim of the study was to compare the proportion of patients discontinuing injectable DMDs (interferon beta 1a/1b, pegylated interferon, glatiramer acetate) with those discontinuing oral DMDs (dimethylfumarate and teriflunomide) during an observation period of at least 12 months. Secondary aims were to compare the time to discontinuation and the reasons for discontinuation between the two groups and to explore the demographic and clinical factors associated with DMD discontinuation. METHODS: In this prospective, multi-center, real-life observational study, patients commencing any first-line DMD between 1 January 2015 and 31 July 2016 were enrolled and followed up for at least 12 months or until the drug was discontinued. RESULTS: Of the 520 included patients, 262 (49.6%) started an injectable and 258 (50.4%) an oral DMD. There was no difference in the proportion of patients on oral (n = 62, 24%) or on injectable (n = 60, 23%) DMDs discontinuing treatment, the most frequent reason being adverse events/side-effects. Higher baseline Expanded Disability Status Scale (EDSS) scores and younger age increased the odds of treatment withdrawal. Time to treatment discontinuation was not different between the two groups and was not influenced by the initiated DMD (oral versus injectable), even after adjustment for baseline differences. CONCLUSION: The route of administration alone (i.e. oral versus injectable) was not a significant predictor of persistence with first-line DMDs in RRMS.

Riluzole and other prognostic factors in ALS: a population-based registry study in Italy.

OBJECTIVE: In this prospective population-based registry study on ALS survival, we investigated the role of riluzole treatment, together with other clinical factors, on the prognosis in incident ALS cases in Emilia Romagna Region (ERR), Italy. METHODS: A registry for ALS has been collecting all incident cases in ERR since 2009. Detailed clinical data from all patients diagnosed with ALS between 1.1.2009 and 31.12.2014 have been analyzed for this study, with last follow up date set at 31.12.2015. RESULTS: During the 6 years of the study, there were 681 incident cases with a median tracheostomy-free survival of 40 months (95% CI 36-44) from onset and of 26 months (95% CI 24-30) from diagnosis; 573 patients (84.14%) were treated with riluzole, 207 (30.39%) patients underwent gastrostomy, 246 (36.12%) non invasive ventilation, and 103 (15.15%) invasive ventilation. Patients who took treatment for ≥ 75% of disease duration from diagnosis had a median survival of 29 months compared to 18 months in patients with < 75% treatment duration. In multivariable analysis, factors independently influencing survival were age at onset (HR 1.04, 95% CI 1.02-1.05, p < 0.001), dementia (HR 1.56, 95% CI 1.05-2.32, p = 0.027), degree of diagnostic certainty (HR 0.88, 95% CI 0.78-0.98, p = 0.021), gastrostomy (HR 1.46, 95% CI 1.14-1.88, p = 0.003), NIV (HR 1.43, 95% CI 1.12-1.82, p = 0.004), and weight loss at diagnosis (HR 1.05, 95% CI 1.03-1.07, p < 0.001), diagnostic delay (HR 0.98, 95% CI 0.97-0.99, p = 0.004), and % treatment duration (HR 0.98, 95% CI 0.98-0.99, p < 0.001). CONCLUSIONS: Independently from other prognostic factors, patients who received riluzole for a longer period of time survived longer, but further population based studies are needed to verify if long-tem use of riluzole prolongs survival.

A multicenter study on the diagnostic significance of a single cerebrospinal fluid IgG band.

The analysis of paired cerebrospinal fluid (CSF) and serum samples with isolectric focusing (IEF) can yield different patterns which can be of aid in the differential diagnosis of central nervous system (CNS) disorders. Rarely, a single CSF-restricted IgG band, which is not included within these patterns, can be detected in association with inflammatory disorders, multiple sclerosis (MS) above all. However, the diagnostic meaning of this abnormality is still uncertain. The main aim of our multicenter study was to establish the frequency and disease associations of single CSF IgG bands. Differences in the CSF profiles between MS and other diseases, and the follow-up patterns were also evaluated. Medical records of patients who underwent CSF analysis, which included IEF, over a 11.5-year period were retrospectively scrutinized at the participating centers, which used similar IEF techniques. One hundred and fifty-one of 9422 CSF reports (1.6%) showed single CSF-restricted IgG bands. Of the 129 patients with a definite diagnosis, 58.2% had CNS inflammatory-demyelinating diseases (the most frequent being MS: 21.7%), 6.2% tumours, 5.4% inflammatory peripheral nervous system diseases and 30.2% miscellaneous diseases. At follow-up, 3 out of the 10 patients with a repeated CSF analysis had developed an oligoclonal band pattern. Our findings indicate that single CSF IgG bands tend to associate with diseases characterized by the involvement of intrathecal humoral immune responses, and strongly support the notion that this abnormality should be regularly reported, thus alerting clinicians of possible inflammatory disorders of the CNS.

Revisiting the Heidenhain Variant of Creutzfeldt-Jakob Disease: Evidence for Prion Type Variability Influencing Clinical Course and Laboratory Findings.

The Heidenhain variant defines a peculiar clinical presentation of sporadic Creutzfeldt-Jakob disease (sCJD) characterized by isolated visual disturbances at disease onset and reflecting the early targeting of prions to the occipital cortex. Molecular and histopathological typing, thus far performed in 23 cases, has linked the Heidenhain variant to the MM1 sCJD type. To contribute a comprehensive characterization of cases with the Heidenhain variant, we reviewed a series of 370 definite sCJD cases. Eighteen patients (4.9%) fulfilled the selection criteria. Fourteen of them belonging to sCJD types MM1 or MM1+2C had a short duration of isolated visual symptoms and overall clinical disease, a high prevalence of periodic sharp-wave complexes in EEG, and a marked increase of cerebrospinal fluid proteins t-tau and 14-3-3 levels. In contrast, three cases of the MM 2C or MM 2+1C types showed a longer duration of isolated visual symptoms and overall clinical disease, non-specific EEG findings, and cerebrospinal fluid concentration below threshold for the diagnosis of "probable" CJD of both 14-3-3 and t-tau. However, a brain DWI-MRI disclosed an occipital cortical hyperintensity in the majority of examined cases of both groups. While confirming the strong linkage with the methionine genotype at the polymorphic codon 129 of the prion protein gene, our results definitely establish that the Heidenhain variant can also be associated with the MM 2C sCJD type in addition to the more common MM1 type. Likewise, our results highlight the significant differences in clinical evolution and laboratory findings between cases according to the dominant PrPSc type (type 1 versus type 2).

[Expression of Lewis carbohydrate antigen in human tumors]. / Espressione dell'antigene carboidratico Lewis nei tumori umani.

In this study we show, by immunoblotting, that Mab B3, a newly isolated monoclonal antibody, reacts with a variety of glycoproteins with different molecular weights expressed in gastric, pancreatic and colorectal cancers. The reactivity pattern differed in cancers arising in different tissues, though no correlation was observed with the histopathological characteristics of the lesions analysed. MAb B3 does not react with liver, brain or kidney cancers and has a limited reactivity with lung cancers but reacts very strongly with metastatic lesions. Because of the limited reactivity of this antibody with normal tissues, MAb B3 genetically fused with toxin in the form of a recombinant immunotoxin may be useful in treating certain kinds of cancer such as metastatic lesions. However, until current trials are completed, we will not know whether this immunotoxin will be helpful in cancer treatment.

Epidemiology of amyotrophic lateral sclerosis in Emilia Romagna Region (Italy): A population based study.

Our objective was to describe incidence and clinical features of ALS from a prospective population-based study in Emilia Romagna Region (ERR). From 2009 onwards, a prospective registry recorded all incident cases of ALS among residents in the ERR (population, 4.4 million inhabitants), involving 17 neurological departments. For each patient, detailed demographic and clinical information was collected by caring physicians. Results showed that from 1 January 2009 to 31 December 2011, 347 patients received a new diagnosis of ALS with a crude incidence rate of 2.63/100,000/year. There was micro-geographic heterogeneity throughout ERR, with higher incidence rates in the low density population (3.27/100,000) (p < 0.01). ALS patients have been more frequently employed in agriculture than the general ERR population (8.64% vs. 4.6%, p < 0.01). Clinical features were similar to those described in previous population based studies. In conclusion, we report incidence rates similar to those reported by European registries, reflecting good accuracy of our prospective study. We confirmed previous studies reporting higher incidence rates in rural areas and among agricultural workers. Although genetics has been gaining increasing importance in ALS aetiology, some epidemiological data are still unexplained. Identifying geographical areas or populations with high incidence rates can be a starting point for identifying environmental risk factors. Further studies having this specific aim can shed light on these topics.

Brain metabolic changes suggestive of axonal damage in radiologically isolated syndrome.

BACKGROUND: The MRI incidental finding in asymptomatic subjects of brain white matter (WM) changes meeting the Barkhof criteria for the diagnosis of multiple sclerosis (MS) has been recently characterized as the radiologically isolated syndrome (RIS). This entity needs to be more specifically defined to allow risk stratification of these subjects. We used brain proton magnetic resonance spectroscopic imaging (1H-MRSI) to assess metabolic changes in an RIS population. METHODS: Twenty-three RIS subjects who were classified according to the Okuda Criteria underwent 1H-MRSI examination with a central brain (CB) volume of interest (VOI) to measure levels of N-acetylaspartate (NAA) and choline (Cho) normalized to creatine (Cr) in the whole CB-VOI, in lesional/perilesional and normal-appearing WM regions, and in the cortical gray matter (CGM). The 1H-MRSI data were compared with those of 20 demographically matched healthy controls (HC). RESULTS: NAA/Cr levels were significantly lower in RIS than in HC in all regions (p < 0.005 for all). No differences in Cho/Cr levels were found in either brain region. A single-subject analysis showed that NAA/Cr levels were at least 2 SDs below the HC mean in the 44% of RIS in the normal-appearing WM and in the 61% of RIS in the CGM. CONCLUSION: Decreased brain NAA/Cr levels in a group of RIS subjects indicates that brain metabolic abnormalities suggestive of axonal damage can be significant even at this early disease stage. This information could be useful for stratifying RIS individuals with a high risk of progression to MS.

Risk of multiple sclerosis following clinically isolated syndrome: a 4-year prospective study.

The aim of the study was to estimate the rate of conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) and to investigate variables predicting conversion in a cohort of patients presenting with symptoms suggestive of MS. Patients with a first symptom suggestive of MS in the preceding 6 months and exclusion of other diseases were enrolled in an observational prospective study from December 2004 through June 2007. Conversion from CIS to MS according to both McDonald and Clinically Defined Multiple Sclerosis (CDMS) criteria was prospectively recorded until March 2010. The multivariate Cox proportional hazard model was used to assess the best predictive factors of conversion from CIS to MS. Among 168 patients included in the analysis, 122 converted to MS according to McDonald criteria whereas 81 converted to MS according to CDMS criteria. The 2-year probability of conversion was 57% for McDonald Criteria and 36% for CDMS criteria. Variables at enrolment significantly associated with conversion according to McDonald criteria were age and positivity for Barkhof criteria, and according to Poser's CDMS criteria, age, positivity for Barkhof criteria and no disease modifying therapy. In this large prospective cohort study the conversion rate from CIS to MS in patients presenting with recent symptoms suggestive of MS was within the range of previous observational studies and lower than that reported in the placebo arm of randomized trials. We confirm the prognostic value of MRI in addition to the previous experimental data on the protective role of disease-modifying therapies.

Improving the characterization of radiologically isolated syndrome suggestive of multiple sclerosis.

OBJECTIVE: To improve the characterization of asymptomatic subjects with brain magnetic resonance imaging (MRI) abnormalities highly suggestive of multiple sclerosis (MS), a condition named as "radiologically isolated syndrome" (RIS). METHODS: Quantitative MRI metrics such as brain volumes and magnetization transfer (MT) were assessed in 19 subjects previously classified as RIS, 20 demographically-matched relapsing-remitting MS (RRMS) patients and 20 healthy controls (HC). Specific measures were: white matter (WM) lesion volumes (LV), total and regional brain volumes, and MT ratio (MTr) in lesions, normal-appearing WM (NAWM) and cortex. RESULTS: LV was similar in RIS and RRMS, without differences in distribution and frequency at lesion mapping. Brain volumes were similarly lower in RRMS and RIS than in HC (p<0.001). Lesional-MTr was lower in RRMS than in RIS (p = 0.048); NAWM-MTr and cortical-MTr were similar in RIS and HC and lower (p<0.01) in RRMS. These values were particularly lower in RRMS than in RIS in the sensorimotor and memory networks. A multivariate logistic regression analysis showed that 13/19 RIS had ≥70% probability of being classified as RRMS on the basis of their brain volume and lesional-MTr values. CONCLUSIONS: Macroscopic brain damage was similar in RIS and RRMS. However, the subtle tissue damage detected by MTr was milder in RIS than in RRMS in clinically relevant brain regions, suggesting an explanation for the lack of clinical manifestations of subjects with RIS. This new approach could be useful for narrowing down the RIS individuals with a high risk of progression to MS.