Primary Outcomes

Description: Quantification of CSF levels of miR-142-3p by qPCR analysis. Relative quantification will be performed by 2^(-ddCt) method.

Measure: CSF concentration of miR-142-3p

Time: T0 (enrollment); MS patients vs Control subjects

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Description: Quantification of CSF inflammatory molecules (TNF, IL-1β, IL-6, IL-17, IFN-γ, IL1ra, IL-22, IL-2, IL-2ra, IL-10, IL-4, IL-5, IL-13, IL-12p40, IL-8) by Luminex multiplex assays; neurofilaments, beta amyloid, tau proteins and growth factors (like NGF, PDGF and BDNF) by Luminex multiplex assays. Data will be expressed as pg/ml.

Measure: CSF concentration of soluble molecules

Time: T0 (enrollment); MS patients vs Control subjects

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Description: Clinical disability will be certified by a qualified neurologist through the Progression Index (PI) calculated as EDSS combined with disease duration (EDSS/disease duration). Disease duration is estimated as the number of years from onset to the most recent assessment of disability and EDSS scale ranging from 0 to 10 in 0.5 unit increments that represent higher levels of disability.

Measure: Clinical disability assessment by Progression Index calculation for correlation analysis with CSF-miR-142-3p levels

Time: Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up

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Description: The Multiple Sclerosis Functional Composite (MSFC) is a three-part composite clinical measure. Three variables were recommended as primary measures: Timed 25-Foot walk; 9-Hole Peg Test; and Paced Auditory Serial Addition Test (PASAT- 3"). The results from each of these three tests are transformed into Z-scores and averaged to yield a composite score for each patient at each time point. There are 3 components: the average scores from the four trials on the 9-HPT; the average scores of two 25-Foot Timed Walk trials; the number correct from the PASAT-3. The scores for these three dimensions are combined to create a single score that can be used to detect change over time. This is done by creating Z-scores for each component. MSFC Score = {Zarm, average + Zleg, average + Zcognitive} / 3.0 (Where Zxxx =Z-score) Increased scores represent deterioration in the 9-HPT and the 25-Foot Timed Walk, whereas decreased scores represent deterioration in the PASAT-3.

Measure: Clinical disability assessment by MSFC calculation for correlation analysis with CSF-miR-142-3p levels

Time: Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up

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Description: By conventional MRI (1.5 Tesla) the following parameters will be evaluated: dual-echo proton density, FLAIR, T1-WI, T2-WI, and contrast-enhanced T1-WI after intravenous gadolinium (Gd) infusion (0.2 ml/kg). A new Gd+ lesion is defined as a typical area of hyperintense signal on postcontrast T1-WI. A new or newly enlarging lesion on T2-WI is defined as a rounded or oval lesion arising from an area previously considered as normal appearing brain tissue and/or showing an identifiable increase in size from a previously stable-appearing lesion. An active scan is defined as showing any new, enlarging or recurrent lesion(s) on postcontrast T1- and T2-WI.

Measure: Neuroradiological assessment for correlation analysis with CSF-miR-142-3p levels

Time: Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up

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Description: To assess synaptic excitability by SICI, ICF and LICI, motor thresholds will be calculated at rest as the lowest stimulus intensity able to evoke MEPs of about 50uV in 5 out of 10 consecutive trials (cts), and during a slight voluntary contraction of the target muscle (20-30% of the max voluntary contraction) as the lowest intensity able to evoke MEPs > 100uV in 5 out of 10 cts. The mean peak-to-peak amplitude of the conditioned MEP (cMEP), at each interstimulus interval (ISI), will be expressed as a percentage of the mean peak-to-peak amplitude of the test MEP (tMEP). PAS-induced LTP-like plasticity will be expressed as changes of the average MEPs size at each time point after PAS compared to the average baseline MEPs size. Before PAS, 25 MEPs, evoked by single TMS pulses over the APB motor hot spot set at an intensity to obtain MEPs size of about 1mV peak-to-peak, will be collected. The same stimulus intensity will be used to obtain 25 MEPs 0', 30' and 60' after PAS.

Measure: Neurophysiological assessments for correlation analysis with CSF-miR-142-3p levels

Time: Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up

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Description: To investigate miR-142-3p association with synaptopathy-driven disease progression (measured in terms of clinical or radiological changes and TMS variables), multivariable generalized linear models (GLM) will be applied considering miR level in the CSF as an independent variable adjusting for demographical, clinical, neuroradiological, neurophysiological, biochemical factors and treatments. In the case of unsuccessful identification, Principal Component Analysis (PCA) will be performed to evaluate the miR contribution with other molecules in the CSF (as cytokines, chemokines, growth factors, neurofilaments, beta amyloid and tau protein) to synaptopathy-driven disease progression to reduce the number of variable examined and increase the power of multivariate analysis. Statistical correlations will be repeated on the identified PCA components including miR-142-3p as part of the component. The significance level is established at p<0.05.

Measure: Statistical correlation of miR-142-3p levels in MS CSF with disease and neurophysiological parameters

Time: T0 (enrollment), T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months).

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Secondary Outcomes

Description: miR-142-3p levels in the CSF will be assessed at T0, as reported above. The responsiveness to the DMT, who MS patients underwent as part of their clinical routine, will be evaluated according to clinical and neuroradiological parameters considered in the primary outcomes. Changes in such parameters will be evaluated at different time points during a six-year follow-up (T12-T0; T24-T0, T24-T12, etc). Both univariable and multivariable approaches and stratification of patients based on DMT treatment will be performed.The significance level is established at p<0.05.

Measure: Statistical correlation of miR-142-3p levels in MS CSF with patient's responsiveness to disease modifying therapies (DMTs).

Time: Time Frame: T0 (enrollment); Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up

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Description: Genetic screening will be performed on peripheral blood withdrawn from MS patients at T0. The following SNPs in MIR142 gene coding for miR-142-3p: rs550842646, rs377637047, rs562696473, rs529802001, rs547987105, rs573562920, rs544684689 and rs549927573, and in SLC1A3 gene coding for GLAST/EAAT1: rs137852620, rs2032892, rs2562582, rs4869675, rs4869676, rs2269272, rs2269273, rs1049522, rs1049524 and rs2731886, will be analyzed. Univariable and multivariable correlations of minor allele presence of each screened SNP with clinical, neuroradiological and neurophysiological parameters, detected in the primary outcomes (T0, T12, T24, T36, T48, T60, T72), will allow the identification of SNPs relevant to disease progression. The significance level is established at p<0.05.

Measure: Genotyping of SNPs in SLC1A3 and MIR-142 genes for correlation analysis with disease parameters

Time: Time Frame: T0 (enrollment); Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up

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Description: Lower limb spasticity will be evaluated in all recruited MS patients at T0 and during 6-year-follow-up. A subgroup of MS patients with lower-limb spastic symptoms and carrying SNPs in in SLC1A3 and MIR-142 genes relevant to disease progression will undergo therapeutic iTBS protocol daily for two weeks (interventional substudy) and spasticity will be assessed also immediately before the beginning (W0) and after 2 weeks at the end of the protocol (W2). The H/M amplitude ratio of the Soleus H reflex will be evaluated by EMG recordings as an index of spinal excitability. Compound motor action potentials (cMAPs) and H reflex will be evoked by electrical stimulation of the tibial nerve. The maximum amplitudes of the H reflex (H) and CMAP (M) potentials will be measured from peak to peak and H/M ratio was calculated by dividing the maximal amplitude of H wave by that of M wave.

Measure: Lower limb spasticity assessment by H/M amplitude ratio for the therapeutic TMS substudy

Time: Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up; Changes from the starting day (W0) to the end of the 2-week iTBS protocol (W2).

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Description: Lower limb spasticity will be evaluated in all recruited MS patients at T0 and during 6-year-follow-up. A subgroup of MS patients with lower-limb spastic symptoms and carrying SNPs in in SLC1A3 and MIR-142 genes relevant to disease progression will undergo therapeutic iTBS protocol daily for two weeks (interventional substudy) and spasticity will be assessed also immediately before the beginning (W0) and after 2 weeks at the end of the protocol (W2). The Modified Ashworth Scale (MAS) assesses resistance during passive soft-tissue stretching ranging from 0 to 4 score.

Measure: Lower limb spasticity assessment by MAS score for the therapeutic TMS substudy

Time: Changes from T0 (enrollment) to T12 (12 months), T24 (24 months), T36 (36 months), T48 (48 months), T60 (60 months) and T72 (72 months) of follow-up; Changes from the starting day (W0) to the end of the 2-week iTBS protocol (W2).

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Description: Minor allele presence of each screened SNP in SLC1A3 and MIR-142, identified at T0 as relevant to disease progression (see above), will be correlated with changes in spasticity parameters (the H/M amplitude ratio of the Soleus H reflex and MAS score) upon the iTBS treatment (W2-W0). The significance level is established at p<0.05.

Measure: Statistical correlation of response to iTBS treatment with MS-significant SNPs of both SLC1A3 and MIR-142.

Time: T0 (enrollment); Changes from the starting day (W0) to the end of the 2-week iTBS protocol (W2).

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