Lebrun‐Frénay, Christine

ABSTRACT Objectives We aimed to determine the frequency of subclinical optic nerve (ON) lesions using MRI, optical coherence tomography (OCT), and visual evoked potentials (VEP) in radiologically isolated syndrome (RIS), and to assess their diagnostic and prognostic significance. Methods We conducted a retrospective, multicenter study of 179 RIS individuals followed in clinical practice who met the 2023 RISC criteria. The diagnostic performance of the 2024 McDonald criteria, with and without optic nerve assessment, was evaluated and compared with that of the 2017 criteria. Associations with clinical conversion, comorbidities, and MRI disease activity were analyzed using multivariate models. Results Silent ON lesions appeared in 107/179 (59.8%) individuals, mainly detected by VEP (100/164; 61.0%) and OCT (69/118; 58.5%), with routine MRI identifying 31/166 (18.7%). During follow‐up, 71 (39.7%) had a first clinical event. The presence, laterality, or number of silent ON lesions did not correlate with clinical conversion, event type, or MRI activity. Younger age and the absence of comorbidities associated with other MRI lesions, rather than with ON lesions, were associated with clinical conversion. Including ON in the 2024 McDonald criteria increased sensitivity but decreased specificity, with 17/179 (9.5%) meeting dissemination‐in‐space criteria solely due to ON lesions. Interpretation Subclinical ON lesions are common in RIS and are mainly found by OCT and VEP, not routine MRI. Including ON increases sensitivity but does not predict clinical conversion and may lower specificity. These findings suggest cautious interpretation of ON and support a multimodal assessment approach in RIS.

Background: Previous studies have shown that people with multiple sclerosis (MS) had frequent healthcare visits up to 10 years before being diagnosed but with no information from magnetic resonance imaging (MRI) scans of the connection with the radiologically isolated syndrome (RIS). Objective: To analyze healthcare use 3 years before the RIS diagnosis. Methods: We examined healthcare usage before the first scan in RIS cases from 2010 to 2019. RIS subjects were identified from the French National MS observatory and compared to the general population (matched 10:1) and MS patients (matched 4:1). Results: Among 482 RIS individuals, 223 (46.3%) were not linked to the healthcare resources database. The remaining RIS individuals (53.7%) had higher healthcare usage before their RIS diagnosis for issues related to neurology visits, headaches (odds ratio (OR): 3.34, confidence interval (CI): [2.00–5.57], p < 0.0001), and the use of anti-migraine drugs (OR: 2.61, CI: [1.37–4.99], p = 0.004) compared to MS. Conclusion: Only about half of RIS patients had MS-selected healthcare resources, which allowed for data linkage. Those who did seek care before their RIS diagnosis were most commonly known for other neurological comorbidities. These findings do not support the idea of a systemic prodrome before RIS diagnosis.

AbstractObjectiveThe radiologically isolated syndrome (RIS) represents the earliest detectable preclinical phase of multiple sclerosis (MS). Increasing evidence suggests that the central vein sign (CVS) enhances lesion specificity, allowing for greater MS diagnostic accuracy. This study evaluated the diagnostic performance of the CVS in RIS.MethodsPatients were prospectively recruited in a single tertiary center for MS care. Participants with RIS were included and compared to a control group of sex and age‐matched subjects. All participants underwent 3 Tesla magnetic resonance imaging, including postcontrast susceptibility‐based sequences, and the presence of CVS was analyzed. Sensitivity and specificity were assessed for different CVS lesion criteria, defined by proportions of lesions positive for CVS (CVS+) or by the absolute number of CVS+ lesions.Results180 participants (45 RIS, 45 MS, 90 non‐MS) were included, representing 5285 white matter lesions. Among them, 4608 were eligible for the CVS assessment (970 in RIS, 1378 in MS, and 2260 in non‐MS). According to independent ROC comparisons, the proportion of CVS+ lesions performed similarly in diagnosing RIS from non‐MS than MS from non‐MS (p = 0.837). When a 6‐lesion CVS+ threshold was applied, RIS lesions could be diagnosed with an accuracy of 87%. MS could be diagnosed with a sensitivity of 98% and a specificity of 83%. Adding OCBs or Kappa index to CVS biomarker increased the specificity to 100% for RIS diagnosis.InterpretationThis study shows evidence that CVS is an effective imaging biomarker in differentiating RIS from non‐MS, with similar performances to those in MS.

Abstract The radiologically isolated syndrome (RIS) was defined in 2009 as the presence of asymptomatic, incidentally identified demyelinating-appearing white matter lesions in the CNS within individuals lacking symptoms typical of multiple sclerosis (MS). The RIS criteria have been validated and predict the transition to symptomatic MS reliably. The performance of RIS criteria that require fewer MRI lesions is unknown. 2009-RIS subjects, by definition, fulfil three to four of four criteria for 2005 dissemination in space (DIS) and subjects fulfilling only one or two lesions in at least one 2017 DIS location were identified within 37 prospective databases. Univariate and multivariate Cox regression models were used to identify predictors of a first clinical event. Performances of different groups were calculated. Seven hundred and forty-seven subjects (72.2% female, mean age 37.7 ± 12.3 years at the index MRI) were included. The mean clinical follow-up time was 46.8 ± 45.4 months. All subjects had focal T2 hyperintensities suggestive of inflammatory demyelination on MRI; 251 (33.6%) fulfilled one or two 2017 DIS criteria (designated as Groups 1 and 2, respectively), and 496 (66.4%) fulfilled three or four 2005 DIS criteria representing 2009-RIS subjects. Group 1 and 2 subjects were younger than the 2009-RIS group and were more likely to develop new T2 lesions over time (P &lt; 0.001). Groups 1 and 2 were similar regarding survival distribution and risk factors for transition to MS. At 5 years, the cumulative probability for a clinical event was 29.0% for Groups 1 and 2 compared to 38.7% for 2009-RIS (P = 0.0241). The presence of spinal cord lesions on the index scan and CSF-restricted oligoclonal bands in Groups 1–2 increased the risk of symptomatic MS evolution at 5 years to 38%, comparable to the risk of development in the 2009-RIS group. The presence of new T2 or gadolinium-enhancing lesions on follow-up scans independently increased the risk of presenting with a clinical event (P &lt; 0.001). The 2009-RIS subjects or Groups 1 and 2 with at least two of the risk factors for a clinical event demonstrated better sensitivity (86.0%), negative predictive value (73.1%), accuracy (59.8%) and area under the curve (60.7%) compared to other criteria studied. This large prospective cohort brings Class I evidence that subjects with fewer lesions than required in the 2009 RIS criteria evolve directly to a first clinical event at a similar rate when additional risk factors are present. Our results provide a rationale for revisions to existing RIS diagnostic criteria.

Objective We have previously identified male sex, younger age, and the presence of spinal cord lesions as independent factors that increase the 5‐year risk for evolution from radiologically isolated syndrome (RIS) to multiple sclerosis. Here, we investigate risk factors for the development of a clinical event using a 10‐year, multinational, retrospectively identified RIS dataset. Methods RIS subjects were identified according to 2009 RIS criteria and followed longitudinally as part of a worldwide cohort study. We analyzed data from 21 individual databases from 5 different countries. Associations between clinical and magnetic resonance imaging (MRI) characteristics and the risk of developing a first clinical event were determined using multivariate Cox regression models. Results Additional follow‐up data were available in 277 of 451 RIS subjects (86% female). The mean age at RIS diagnosis was 37.2 years (range, 11–74 years), with a median clinical follow‐up of 6.7 years. The cumulative probability of a first clinical event at 10 years was 51.2%. Age, positive cerebrospinal fluid for oligoclonal bands, infratentorial lesions on MRI, and spinal cord lesions, were baseline independent predictors associated with a subsequent clinical event. The presence of gadolinium‐enhanced lesions during follow‐up was also associated with the risk of a seminal event. The reason for MRI and gadolinium‐enhancing lesions at baseline did not influence the risk of a subsequent clinical event. Interpretation Approximately half of all individuals with RIS experience a first clinical event within 10 years of the index MRI. The identification of independent predictors of risk for symptom onset may guide education and clinical management of individuals with RIS. ANN NEUROL 2020;88:407–417.

Background: Younger age, male sex and presence of spinal cord lesion(s) increase the risk of conversion from radiologically isolated syndrome (RIS) to relapsing-remitting multiple sclerosis (RRMS). Elevated cerebrospinal fluid (CSF) chitinase-3-like protein 1 (CHI3L1) levels predict conversion from clinically isolated syndrome (CIS) to RRMS. Objective: To evaluate the prognostic value of CSF CHI3L1 in RIS patients for conversion to RRMS. Methods: We compared CSF CHI3L1 concentrations in RIS, CIS, RRMS and symptomatic controls (SCs). We analysed the influence of epidemiological, radiological and CSF parameters on the risk of clinical event. Results: A total of 211 patients (71 RIS, 48 CIS, 50 RRMS and 42 SC) were included. CSF CHI3L1 levels were lower in RIS than in RRMS and higher in RIS with positive CSF versus negative CSF and SC. The presence of at least one spinal cord lesion was the only independent predictor of faster conversion to RRMS. Association of high CSF CHI3L1 levels, positive CSF (presence of oligoclonal bands and/or an elevated IgG index) or four Barkhof criteria with any spinal cord lesion showed a tendency for reduced mean conversion time. Conclusion: CSF CHI3L1 correlates with positive CSF but is not an independent predictor of the risk of conversion from RIS to RRMS.

ObjectiveThe aim of this work was to evaluate the preprogressive phase in subjects with radiologically isolated syndrome (RIS) who evolve to primary progressive multiple sclerosis (PPMS).MethodsA multicenter RIS cohort was previously established. Demographic, clinical, and radiological characteristics of subjects with RIS that evolved directly to PPMS were compared to those that developed a relapsing disease course from onset (clinically isolated syndrome [CIS] or relapsing‐remitting MS) and were also compared to two other population‐ and clinic‐based PPMS cohorts.ResultsOf the 453 subjects with RIS, 128 evolved to symptomatic MS during the follow‐up (113 developed a first acute clinical event consistent with CIS/MS, 15 evolved to PPMS). PPMS prevalence (11.7%) and onset age (mean ± standard deviation; 49.1 ± 12.1) in the RIS group were comparable to other PPMS populations (p > 0.05). Median time to PPMS was 3.5 years (range, 1.6–5.4). RIS evolved to PPMS more commonly in men (p = 0.005) and at an older age (p < 0.001) when compared to CIS/MS, independent of follow‐up duration. Subjects who evolved to PPMS had more spinal cord lesions (100%) before symptomatic evolution than those that developed CIS/MS (64%) and those that remained asymptomatic (23%) within the follow‐up period (P = 0.005). Other MRI characteristics in the preprogressive phase of PPMS were indistinguishable from CIS/MS.InterpretationSubjects with RIS evolve to PPMS at the same frequency as expected from general MS populations in an age‐dependent manner. Besides age, unequivocal presence of spinal cord lesions and being male predicted evolution to PPMS. Our findings further suggest that RIS is biologically part of the MS spectrum. Ann Neurol 2016;79:288–294