Efficacy of levetiracetam on upper limb movement in multiple sclerosis patients with cerebellar signs: a multicenter double-blind, placebo-controlled, crossover study.

BACKGROUND AND PURPOSE: The literature provides contrasting results on the efficacy of levetiracetam (LEV) in multiple sclerosis (MS) patients with cerebellar signs. It was sought to evaluate the efficacy of LEV on upper limb movement in MS patients. METHODS: In this multicenter double-blind placebo-controlled crossover study, MS patients with prevalently cerebellar signs were randomly allocated into two groups: LEV followed by placebo (group 1) or placebo followed by LEV (group 2). Clinical assessments were performed by a blinded physician at T0 (day 1), T1 (day 22), T2 (2-week wash-out period, day 35) and T3 (day 56). The primary outcome was dexterity in the arm with greater deficit, assessed by the nine-hole peg test (9HPT). Secondary clinical outcomes included responders on the 9HPT (∆9HPT >20%), tremor activity of the daily living questionnaire and self-defined upper limb impairment, through a numeric rating scale. Kinematic evaluation was performed using a digitizing tablet, providing data on normalized jerk, aiming error and centripetal acceleration. RESULTS: Forty-eight subjects (45.2 ± 10.4 years) were randomly allocated into two groups (n = 24 each). 9HPT significantly improved in the LEV phase in both groups (P < 0.001). The LEV treatment phase led to a significant improvement (P < 0.01) of all clinical outcomes in group 1 and in dexterity in group 2. No significant changes were reported during both placebo phases in the two groups. Considering the kinematic analysis, only normalized jerk significantly improved after treatment with LEV (T0-T1) in group 1. CONCLUSIONS: Levetiracetam treatment seems to be effective in improving upper limb dexterity in MS patients with cerebellar signs.

Informing MS patients on treatment options: a consensus on the process of consent taking.

In the last years, change in multiple sclerosis (MS) therapeutic scenario has highlighted the need for an improved doctor-patient communication in advance of treatment initiation in order to allow patient's empowerment in the decision-making process. AIMS: The aims of our project were to review the strategies used by Italian MS specialists to inform patients about treatment options and to design a multicentre shared document that homogenizes the information about disease-modifying treatment (DMTs) and the procedure of taking informed consent in clinical practice. RESULTS: The new resource, obtained by consensus among 31 neurologists from 27 MS Centres in Italy with the supervision of a medico-legal advisor, received the aegis of Italian Neurological Society (SIN) and constitutes a step toward a standardized decision process around DMTs in MS.

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.

Natalizumab discontinuation and disease restart in pregnancy: a case series.

BACKGROUND: The humanized monoclonal alpha4-integrin antibody Natalizumab (NTZ) (Tysabri(©) , Biogen Idec, Cambridge, MA, USA) has shown to be effective in multiple sclerosis (MS) therapy; however, the interruption of the drug has been related to a disease restart. This risk has to be carefully considered in case of accidental or desired pregnancies. AIM OF THE STUDY: To report the risk of disease restart in patients who interrupted NTZ because of pregnancy and discuss the implication of NTZ choice in female childbearing patients with MS. METHODS: Clinical histories and MRI images of four pregnant women with MS who interrupted NTZ. RESULTS: Despite pregnancy is usually related with disease stability, the cases presented here showed an abrupt increase of disability with high number of MRI lesions, some of them with a mass effect. CONCLUSIONS: We recommend that female patients on childbearing age must be informed before starting NTZ treatment of the risk of a return of disease activity when the drug is discontinued. The risk occurs even during pregnancy a condition that is considered as protective for women with MS.

Magnetic resonance imaging correlates of physical disability in relapse onset multiple sclerosis of long disease duration.

BACKGROUND: Understanding long-term disability in multiple sclerosis (MS) is a key goal of research; it is relevant to how we monitor and treat the disease. OBJECTIVES: The Magnetic Imaging in MS (MAGNIMS) collaborative group sought to determine the relationship of brain lesion load, and brain and spinal cord atrophy, with physical disability in patients with long-established MS. METHODS: Patients had a magnetic resonance imaging (MRI) scan of their brain and spinal cord, from which we determined brain grey (GMF) and white matter (WMF) fractional volumes, upper cervical spinal cord cross-sectional area (UCCA) and brain T2-lesion volume (T2LV). We assessed patient disability using the Expanded Disability Status Scale (EDSS). We analysed associations between EDSS and MRI measures, using two regression models (dividing cohort by EDSS into two and four sub-groups). RESULTS: In the binary model, UCCA (p < 0.01) and T2LV (p = 0.02) were independently associated with the requirement of a walking aid. In the four-category model UCCA (p < 0.01), T2LV (p = 0.02) and GMF (p = 0.04) were independently associated with disability. CONCLUSIONS: Long-term physical disability was independently linked with atrophy of the spinal cord and brain T2 lesion load, and less consistently, with brain grey matter atrophy. Combinations of spinal cord and brain MRI measures may be required to capture clinically-relevant information in people with MS of long disease duration.

Natalizumab treatment in multiple sclerosis patients: a multicenter experience in clinical practice in Italy.

We evaluated efficacy of natalizumab in relapsing-remitting multiple sclerosis patients in a clinical practice setting. We report data on the first consecutive 343 patients receiving natalizumab in 12 multiple sclerosis (MS) Italian centers enrolled between April 2007 and November 2010. The main efficacy endpoints were the proportion of patients free from relapses, disease progression, combined clinical activity, defined as presence of relapse or disease progression, from MRI activity, and from any disease activity defined as the absence of any single or combined activity. At the end of follow-up, the cumulative proportion of patients free from relapses was 68%; the proportion of patients free from Expanded Disability Status Scale (EDSS) progression was 93%; the proportion of patients free from combined clinical activity was 65%; the proportion of patients free from MRI activity was 77%; and the proportion of patients free from any disease activity was 53%. Natalizumab was effective in reducing clinical and neuroradiological disease activity. Its effectiveness in clinical practice is higher than that reported in pivotal trials and was maintained over time.

Autologous haematopoietic stem cell transplantation with an intermediate intensity conditioning regimen in multiple sclerosis: the Italian multi-centre experience.

BACKGROUND: Over recent years numerous patients with severe forms of multiple sclerosis (MS) refractory to conventional therapies have been treated with intense immunosuppression followed by autologous haematopoietic stem cell transplantation (AHSCT). The clinical outcome and the toxicity of AHSCT can be diverse, depending on the various types of conditioning protocols and on the disease phase. OBJECTIVES: To report the Italian experience on all the consecutive patients with MS treated with AHSCT with an intermediate intensity conditioning regimen, named BEAM/ATG, in the period from 1996 to 2008. METHODS: Clinical and magnetic resonance imaging outcomes of 74 patients were collected after a median follow-up period of 48.3 (range = 0.8-126) months. RESULTS: Two patients (2.7%) died from transplant-related causes. After 5 years, 66% of patients remained stable or improved. Among patients with a follow-up longer than 1 year, eight out of 25 subjects with a relapsing-remitting course (31%) had a 6-12 months confirmed Expanded Disability Status Scale improvement > 1 point after AHSCT as compared with one out of 36 (3%) patients with a secondary progressive disease course (p = 0.009). Among the 18 cases with a follow-up longer than 7 years, eight (44%) remained stable or had a sustained improvement while 10 (56%), after an initial period of stabilization or improvement with median duration of 3.5 years, showed a slow disability progression. CONCLUSIONS: This study shows that AHSCT with a BEAM/ATG conditioning regimen has a sustained effect in suppressing disease progression in aggressive MS cases unresponsive to conventional therapies. It can also cause a sustained clinical improvement, especially if treated subjects are still in the relapsing-remitting phase of the disease.

Initial oak regeneration responses to experimental warming along microclimatic and macroclimatic gradients.

Quercus spp. are one of the most important tree genera in temperate deciduous forests in terms of biodiversity, economic and cultural perspectives. However, natural regeneration of oaks, depending on specific environmental conditions, is still not sufficiently understood. Oak regeneration dynamics are impacted by climate change, but these climate impacts will depend on local forest management and light and temperature conditions. Here, we studied germination, survival and seedling performance (i.e. aboveground biomass, height, root collar diameter and specific leaf area) of four oak species (Q. cerris, Q. ilex, Q. robur and Q. petraea). Acorns were sown across a wide latitudinal gradient, from Italy to Sweden, and across several microclimatic gradients located within and beyond the species' natural ranges. Microclimatic gradients were applied in terms of forest structure, distance to the forest edge and experimental warming. We found strong interactions between species and latitude, as well as between microclimate and latitude or species. The species thus reacted differently to local and regional changes in light and temperature ; in southern regions the temperate Q. robur and Q. petraea performed best in plots with a complex structure, whereas the Mediterranean Q. ilex and Q. cerris performed better in simply structured forests with a reduced microclimatic buffering capacity. The experimental warming treatment only enhanced height and aboveground biomass of Mediterranean species. Our results show that local microclimatic gradients play a key role in the initial stages of oak regeneration; however, one needs to consider the species-specific responses to forest structure and the macroclimatic context.

Quality of life, depression and fatigue in mildly disabled patients with relapsing-remitting multiple sclerosis receiving subcutaneous interferon beta-1a: 3-year results from the COGIMUS (COGnitive Impairment in MUltiple Sclerosis) study.

BACKGROUND: The precise relationships among quality of life, depression, fatigue and cognitive impairment in multiple sclerosis (MS) are complex and poorly understood. OBJECTIVE: To assess the effects of subcutaneous interferon beta-1a on quality of life, depression and fatigue over 3 years in the COGIMUS study, and to examine the relationship between these outcomes and baseline cognitive status. METHODS: COGIMUS was an observational 3-year trial assessing cognitive function in 459 patients with relapsing-remitting MS treated with subcutaneous interferon beta-1a. RESULTS: In total, 331 patients completed the study (168 received interferon beta-1a, 44 µg subcutaneously three times weekly, and 163 received interferon beta-1a, 22 µg subcutaneously three times weekly). Mean MS Quality of Life-54 (MSQoL-54) composite scores did not change over time. There were no significant differences between groups in MSQoL-54 composite scores when patients were grouped by treatment dose and baseline cognitive status. Mean (standard deviation) Hamilton Depression Rating Scale score decreased from 6.8 (4.9) at baseline to 5.8 (5.9) at year 3. Mean total Fatigue Impact Scale scores were low (<30) at all time points. CONCLUSION: Quality of life, depression and fatigue remained largely stable over 3 years; no effects of treatment dose or baseline cognitive status were found.

Pronounced focal and diffuse brain damage predicts short-term disease evolution in patients with clinically isolated syndrome suggestive of multiple sclerosis.

BACKGROUND: In clinically isolated syndrome (CIS), the role of quantitative magnetic resonance imaging (MRI) in detecting prognostic markers is still debated. OBJECTIVE: To evaluate measures of diffuse brain damage (such as brain atrophy and the ratio of N-acetylaspartate to creatine (NAA/Cr)) in patients with CIS, in addition to focal lesions, as predictors of 1-year disease evolution. METHODS: 49 patients with CIS underwent MRI scans to quantify T2-lesions (T2-L) and gadolinium-enhanced lesion (GEL) number at baseline and after 1 year. Along with 25 healthy volunteers, they also underwent combined MRI/magnetic resonance spectroscopy examination to measure normalized brain volumes (NBVs) and NAA/Cr. Occurrence of relapses and new T2-L was recorded over 1 year to assess disease evolution. RESULTS: Occurrence of relapses and/or new T2-L over 1 year divided patients with CIS into 'active' and 'stable' groups. Active patients had lower baseline NAA/Cr and NBV. Baseline T2-L number, GEL, NAA/Cr and NBV predicted subsequent disease activity. Multivariable logistic regression models showed that both 'focal damage' (based on T2-L number and GEL) and 'diffuse damage' (based on NBV and NAA/Cr) models predicted disease activity at 1 year with great sensitivity, specificity and accuracy. This was best when the four MRI measures were combined (80% sensitivity, 89% specificity, 83% accuracy). CONCLUSIONS: Quantitative MRI measures of diffuse tissue damage such as brain atrophy and NAA/Cr, in addition to measures of focal demyelinating lesions, may predict short-term disease evolution in patients with CIS, particularly when used in combination. If confirmed in larger studies, these findings may have important clinical and therapeutic implications.

A randomized, double-blind, placebo-controlled, parallel-group, enriched-design study of nabiximols* (Sativex(®) ), as add-on therapy, in subjects with refractory spasticity caused by multiple sclerosis.

BACKGROUND: Spasticity is a disabling complication of multiple sclerosis, affecting many patients with the condition. We report the first Phase 3 placebo-controlled study of an oral antispasticity agent to use an enriched study design. METHODS: A 19-week follow-up, multicentre, double-blind, randomized, placebo-controlled, parallel-group study in subjects with multiple sclerosis spasticity not fully relieved with current antispasticity therapy. Subjects were treated with nabiximols, as add-on therapy, in a single-blind manner for 4weeks, after which those achieving an improvement in spasticity of ≥20% progressed to a 12-week randomized, placebo-controlled phase. RESULTS: Of the 572 subjects enrolled, 272 achieved a ≥20% improvement after 4weeks of single-blind treatment, and 241 were randomized. The primary end-point was the difference between treatments in the mean spasticity Numeric Rating Scale (NRS) in the randomized, controlled phase of the study. Intention-to-treat (ITT) analysis showed a highly significant difference in favour of nabiximols (P=0.0002). Secondary end-points of responder analysis, Spasm Frequency Score, Sleep Disturbance NRS Patient, Carer and Clinician Global Impression of Change were all significant in favour of nabiximols. CONCLUSIONS: The enriched study design provides a method of determining the efficacy and safety of nabiximols in a way that more closely reflects proposed clinical practice, by limiting exposure to those patients who are likely to benefit from it. Hence, the difference between active and placebo should be a reflection of efficacy and safety in the population intended for treatment.

Tailored Vessel-Catheter Diameter Ratio in a Direct Aspiration First-Pass Technique: Is It a Matter of Caliber?

BACKGROUND AND PURPOSE: The aspiration technique has gained a prominent role in mechanical thrombectomy. The thrombectomy goal is successful revascularization (modified TICI ≥ 2b) and first-pass effect. The purpose of this study was to evaluate the impact of the vessel-catheter ratio on the modified TICI ≥ 2b and first-pass effect. MATERIALS AND METHODS: This was a retrospective, single-center, cohort study. From January 2018 to April 2020, 111/206 (53.9%) were eligible after applying the exclusion criteria. Culprit vessel diameters were measured by 2 neuroradiologists, and the intraclass correlation coefficient was calculated. The receiver operating characteristic curve was used for assessing the vessel-catheter ratio cutoff for modified TICI ≥ 2b and the first-pass effect. Time to groin puncture and fibrinolysis were weighted using logistic regression. All possible intervals (interval size, 0.1; sliding interval, 0.01) of the vessel-catheter ratio were plotted, and the best and worst intervals were compared using the χ2 test. RESULTS: Modified TICI ≥ 2b outcome was achieved in 75/111 (67.5%), and first-pass effect was achieved in 53/75 (70.6%). The MCA diameter was 2.1 mm with an intraclass correlation coefficient of 0.92. The optimal vessel-catheter ratio cutoffs for modified TICI ≥ 2b were ≤1.51 (accuracy = 0.67; 95% CI, 0.58-0.76; P = 0.001), and for first-pass effect, they were significant (≤1.33; P = .31). The modified TICI ≥ 2b odds ratio and relative risk were 9.2 (95% CI, 2.4-36.2; P = 0.002) and 3.2 (95% CI, 1.2-8.7; P = .024). The odds ratio remained significant after logistic regression (7.4; 95% CI, 1.7-32.5; P = .008). First-pass effect odds ratio and relative risk were not significant (2.1 and 1.5; P > .05, respectively). The modified TICI ≥ 2b best and worst vessel-catheter ratio intervals were not significantly different (55.6% versus 85.7%, P = .12). The first-pass effect best vessel-catheter ratio interval was significantly higher compared with the worst one (78.6% versus 40.0%, P = .03). CONCLUSIONS: The aspiration catheter should be selected according to culprit vessel diameter. The optimal vessel-catheter ratio cutoffs were ≤1.51 for modified TICI ≥ 2b with an odds ratio of 9.2 and a relative risk of 3.2.

A multicenter survey on access to care in Multiple Sclerosis-related trigeminal neuralgia.

The prevalence of trigeminal neuralgia (TN) in patients with Multiple Sclerosis (MS) is higher than in the general population and its management can be particularly challenging due to a number of reasons including high recurrence rates, lack of MS-specific treatment guidelines and uncertainties about pain pathophysiology. Aim of this cross-sectional, multicentre survey was to gather information on the current treatment modalities and options of MS-related TN across 23 Italian MS centres. Initial medical management (carbamazepine or oxcarbazepine) of MS-related TN was fairly homogeneous throughout Italian centres. The most commonly available surgical procedure was microvascular decompression, but the frequency and types of surgical procedures available locally differed considerably throughout MS centers, and were unavailable in one quarter of them. This survey reveals some of the issues that could hamper an optimal patient management and underlines the need for a consensus on MS-related TN to support health-care professionals in their approach to this challenging condition and to facilitate the development of local guidelines aimed at ensuring equity in access to care and treatment optimization.

Validation of the DYMUS questionnaire for the assessment of dysphagia in multiple sclerosis.

Swallowing problems can complicate the course of multiple sclerosis (MS). However, no validated questionnaire for the assessment of dysphagia in MS is currently available. We previously developed a 10-item DYsphagia in Multiple Sclerosis questionnaire (DYMUS). In the present study, this questionnaire was submitted to a validation process. Thirteen Italian MS centres took part in this research in which DYMUS was administered to 1734 consecutive MS patients during routine checkups outside relapse. The questionnaire showed very good internal consistency (Cronbach's alpha = 0.914). It was then subdivided into two subscales, both of which also showed very good internal consistency: Cronbach's alpha was 0.885 for the 'dysphagia for solids' subscale and 0.864 for the 'dysphagia for liquids' subscale. The DYMUS questionnaire was found to be an easy and reliable tool for detecting dysphagia and also for the preliminary selection of patients requiring more specific instrumental analyses, and those suitable for aspiration prevention programmes.

Alexithymia in multiple sclerosis: relationship with fatigue and depression.

OBJECTIVE: The aim of this study was to investigate the prevalence of alexithymia in a sample of patients with multiple sclerosis (MS) and to further evaluate the association between alexithymia and the occurrence of common disabling MS-related symptoms such as fatigue and depression. METHODS: Fifty-eight relapsing-remitting MS patients treated with interferon (IFN)-beta-1a underwent a complete neurological evaluation, including Expanded Disability Status Scale score assessment. Alexithymia, depressive symptoms and fatigue were assessed using the 20-item Toronto Alexithymia Scale, Beck Depression Inventory and Fatigue Severity Scale. RESULTS: Prevalence of alexithymia was 13.8%, with 27.6% of patients presenting borderline alexithymia. Sixty-seven per cent of the patients complained of fatigue while 29.3% of them were depressed. Higher levels of fatigue and depression were found in alexithymic patients when compared with non-alexithymic patients. Results from logistic regressions showed that alexithymia significantly contributes to the severity of fatigue and depression. CONCLUSIONS: Alexithymia was associated with increased severity of fatigue and depression.

FAS-ligand regulates differential activation-induced cell death of human T-helper 1 and 17 cells in healthy donors and multiple sclerosis patients.

Functionally distinct T-helper (Th) subsets orchestrate immune responses. Maintenance of homeostasis through the tight control of inflammatory Th cells is crucial to avoid autoimmune inflammation. Activation-Induced Cell Death (AICD) regulates homeostasis of T cells, and it has never been investigated in human Th cells. We generated stable clones of inflammatory Th subsets involved in autoimmune diseases, such as Th1, Th17 and Th1/17 cells, from healthy donors (HD) and multiple sclerosis (MS) patients and we measured AICD. We find that human Th1 cells are sensitive, whereas Th17 and Th1/17 are resistant, to AICD. In particular, Th1 cells express high level of FAS-ligand (FASL), which interacts with FAS and leads to caspases' cleavage and ultimately to cell death. In contrast, low FASL expression in Th17 and Th1/17 cells blunts caspase 8 activation and thus reduces cell death. Interestingly, Th cells obtained from healthy individuals and MS patients behave similarly, suggesting that this mechanism could explain the persistence of inflammatory IL-17-producing cells in autoimmune diseases, such as MS, where their generation is particularly substantial.

Development of neutralizing antibodies in patients with relapsing-remitting multiple sclerosis treated with IFN-beta1a.

Sixty-eight patients with relapsing-remitting multiple sclerosis (RRMS) were treated with 3 million or 9 million i.u. of recombinant interferon-beta1a (recIFN-beta1a) s.c. three times a week for 2 years. Their sera were tested for antibodies neutralizing the IFN (NAb) in a bioassay. Sera with titers > or = 1:20 were considered positive. We detected NAb in 3.2%, 13.8%, and 15.9% of the patients in sera obtained at 3, 6, and 24 months, respectively. The incidence was not related to the IFN dose. Interestingly, during the 6 month baseline period before the start of the study, relapse rates, baseline disability, and the volume of lesions on T2-weighted images were significantly higher in patients who developed NAb during treatment. Because of interpatient variability, no definitive relationship was observed between NAb formation and loss of clinical or magnetic resonance imaging (MRI) response.

A one-year study on the pharmacodynamic profile of interferon-beta1a in MS.

Interferon (IFN)-beta1a induction of neopterin and beta2-microglobulin (beta2-MG) were evaluated over 1 year in patients with MS. Neopterin and beta2-MG levels peaked 24 to 48 hours after weekly injections of IFNbeta1a over the entire study period. Predose levels of neopterin decreased significantly, consistent with a long-term decrease in IFNgamma expression and macrophage activation during IFNbeta-1a treatment. Predose levels of beta2-MG increased, the significance of which is as yet unclear.

Effect of steroids on Gd-enhancing lesions before and during recombinant beta interferon 1a treatment in relapsing remitting multiple sclerosis.

The aim of this study was to investigate whether a concomitant treatment with recombinant interferon beta 1a (rIFN beta-1a) modifies the effect of steroids on the blood-brain barrier (BBB) in relapsing remitting MS patients, as evaluated by enhanced MRI of the brain. We evaluated 19 patients with a clinical relapse treated only with intravenous methylprednisolone (IVMP; 1 g daily for 6 days), and 10 patients who experienced a clinical relapse and were treated with IVMP (1 g daily for 6 days) during an rIFN beta-1a treatment period. The number and volume of enhancing lesions were analyzed on four serial MR images obtained at monthly intervals (one scan before and three scans after IVMP treatment). A significant reduction in the mean number and volume of enhancing lesions was seen in the first scan after IVMP treatment in all patients. However, while persistently low enhancement was seen in the follow-up scans of patients treated with rIFN beta-1a, a rebound effect (i.e., increase in the number and volume of gadolinium-enhancing lesions) was observed in the other patients during the follow-up. These data suggest that rIFN beta-1a prolongs the beneficial effect of steroids on the BBB.

Effect of training and different measurement strategies on the reproducibility of brain MRI lesion load measurements in multiple sclerosis.

In this study, we evaluated the intra- and interobserver variabilities in measuring lesion load of brain MRI abnormalities present on proton-density scans from patients with MS, using using both manual outlining or a semiautomated local thresholding technique (LTT). We also evaluated how these variabilities were affected by the use of standard rules for lesion load measurements, training, and different measurement strategies. The intraobserver variabilities obtained after establishing rules for lesion load measurements and training were not significantly different from those obtained before any consensus among the observers, both for manual outlining and for the LTT. On the contrary, the interobserver variabilities obtained with manual outlining or the LTT were significantly reduced when rules for lesion load measurements were used. For manual outlining, the intraobserver variability did not significantly change when the measurements were performed after an experienced radiologist identified lesions or when using adjacent slices and the corresponding T2-weighted images as reference for lesion identification. On the contrary, for the LTT, the intraobserver variability was significantly reduced by the use of the radiologic marking. The interobserver variabilities for both manual outlining and the LTT were reduced compared with the free condition when these measurement strategies were used. Our findings demonstrate that both lesion identification and outlining are important sources of variation for MRI lesion load measurements in MS and that there are simple strategies to reduce such variation that might be useful when planning clinical trials.