Prevention of irreversible disability is currently the most important goal of disease modifying therapy for multiple sclerosis. The disability outcomes used in most clinical trials rely on progression of Expanded Disability Status Scale score confirmed over 3 or 6 months. However, sensitivity and stability of this metric has not been extensively evaluated. Using the global MSBase cohort study, we evaluated 48 criteria of disability progression, testing three definitions of baseline disability, two definitions of progression magnitude, two definitions of long-term irreversibility and four definitions of event confirmation period. The study outcomes comprised the rates of detected progression events per 10 years and the proportions of the recorded events persistent at later time points. To evaluate the ratio of progression frequency and stability for each criterion, we calculated the proportion of events persistent over the five subsequent years once progression was achieved. Finally, we evaluated the clinical and demographic determinants characterising progression events and, for those that regressed back to baseline, determinants of their subsequent regression. The study population consisted of 16 636 patients with the minimum of three recorded disability scores, totalling 112 584 patient-years. The progression rates varied between 0.41 and 1.14 events per 10 years, with the length of required confirmation interval as the most important determinant of the observed variance. The concordance among all tested progression criteria was only 17.3%. Regression of disability occurred in 11-34% of the progression events over the five subsequent years. The most important determinant of progression stability was the length of the confirmation period. For the most accurate set of the progression criteria, the proportions of 3-, 6-, 12- or 24-month confirmed events persistent over 5 years reached 70%, 74%, 80% and 89%, respectively. Regression post progression was more common in younger patients, relapsing-remitting disease course, and after a smaller change in disability, and was inflated by higher visit frequency. These results suggest that the disability outcomes based on 3-6-month confirmed disability progression overestimate the accumulation of permanent disability by up to 30%. This could lead to spurious results in short-term clinical trials, and the issue may be magnified further in cohorts consisting predominantly of younger patients and patients with relapsing-remitting disease. Extension of the required confirmation period increases the persistence of progression events.

Results confirm a favourable effect on relapses as pregnancy proceeds, and an early postpartum peak. Pre-conception DMT exposure and low ARR were independently protective against postpartum relapse. This novel finding could provide clinicians with a strategy to minimise postpartum relapse risk in women with MS planning pregnancy.

This Cuban multiethnic population had a prevalence of NMO of 0.52 per 100,000 and an estimated average annual incidence rate of 0.053 per 100,000 with no differences by ethnicity. Black patients were older, with more relapses and motor impairment.

Objective: To asses the presence of cortical demyelination in brains of patients with neuromyelitis optica (NMO). NMO is an autoimmune inflammatory demyelinating disease that specifically targets aquaporin-4-rich regions of the CNS. Since aquaporin-4 is highly expressed in normal cortex, we anticipated that cortical demyelination may occur in NMO.Methods: This is a cross-sectional neuropathologic study performed on archival forebrain and cerebellar tissue sections from 19 autopsied patients with a clinically and/or pathologically confirmed NMO spectrum disorder.Results: Detailed immunohistochemical analyses of 19 archival NMO cases revealed preservation of aquaporin-4 in a normal distribution within cerebral and cerebellar cortices, and no evidence of cortical demyelination. Conclusions:This study provides a plausible explanation for the absence of a secondary progressive clinical course in NMO and shows that cognitive and cortical neuroimaging abnormalities previously reported in NMO cannot be attributed to cortical demyelination. Lack of cortical demyelination is another characteristic that further distinguishes NMO from MS. Neurology Neuromyelitis optica (NMO) is an autoimmune inflammatory demyelinating relapsing disease of the CNS in which a disease-specific circulating autoantibody (NMO-immunoglobulin G [IgG]) binds to the aquaporin-4 (AQP4) water channel that is concentrated in the astrocytic foot processes.1-3 Increasing evidence supports a primary pathogenic role for this IgG. 4-6 Clinical, laboratory, neuroimaging, and pathologic features distinguish NMO from classic multiple sclerosis (MS). 7,8 Cognitive deficits and neuroimaging abnormalities have been described in normalappearing gray matter in NMO.9,10 Since AQP4 is heavily expressed in normal human cortex, 7,11 we anticipated finding cortical pathology in NMO. This study describes our findings from a systematic examination of NMO patients' brains for evidence of cortical demyelination.METHODS This cross-sectional neuropathologic study was performed on archival forebrain and cerebellar tissue obtained from 19 autopsied patients with a clinically and/or pathologically confirmed NMO spectrum disorder (NMOSD) 8 : NMO (n ϭ 16) or NMOSD (n ϭ 3; 2 relapsing longitudinally extensive transverse myelitis, 1 relapsing optic neuritis). Autopsies were performed at Mayo Clinic, Rochester, MN, or sent in from other institutions for diagnostic purposes between 1958 and 2009. The study was approved by the Institutional Review Board of Mayo Clinic, Rochester, MN. Clinical follow-up was obtained via review of medical records. Descriptive statistics were used to characterize the population demographics and number of blocks analyzed (table). Median age was 45 years at symptom onset (range 12-80) and 50 years at death (range 16 -80). Median disease duration was 36 months (range 8 -180). NMO-IgG serostatus was known in 6 cases (positive in 5, including all 3 NMOSD cases). Causes of death were

The aim of this work was to evaluate sex differences in the incidence of multiple sclerosis relapses; assess the relationship between sex and primary progressive disease course; and compare effects of age and disease duration on relapse incidence. Annualized relapse rates were calculated using the MSBase registry. Patients with incomplete data or <1 year of follow-up were excluded. Patients with primary progressive multiple sclerosis were only included in the sex ratio analysis. Relapse incidences over 40 years of multiple sclerosis or 70 years of age were compared between females and males with Andersen-Gill and Tweedie models. Female-to-male ratios stratified by annual relapse count were evaluated across disease duration and patient age and compared between relapse-onset and primary progressive multiple sclerosis. The study cohort consisted of 11 570 eligible patients with relapse-onset and 881 patients with primary progressive multiple sclerosis. Among the relapse-onset patients (82 552 patient-years), 48,362 relapses were recorded. Relapse frequency was 17.7% higher in females compared with males. Within the initial 5 years, the female-to-male ratio increased from 2.3:1 to 3.3:1 in patients with 0 versus ≥4 relapses per year, respectively. The magnitude of this sex effect increased at longer disease duration and older age (P < 10(-12)). However, the female-to-male ratio in patients with relapse-onset multiple sclerosis and zero relapses in any given year was double that of the patients with primary progressive multiple sclerosis. Patient age was a more important determinant of decline in relapse incidence than disease duration (P < 10(-12)). Females are predisposed to higher relapse activity than males. However, this difference does not explain the markedly lower female-to-male sex ratio in primary progressive multiple sclerosis. Decline in relapse activity over time is more closely related to patient age than disease duration.

BackgroundMultiple Sclerosis is more common in women than men and females have more relapses than men. In a large international cohort we have evaluated the effect of gender on disability accumulation and disease progression to determine if male MS patients have a worse clinical outcome than females.MethodsUsing the MSBase Registry, data from 15,826 MS patients from 25 countries was analysed. Changes in the severity of MS (EDSS) were compared between sexes using a repeated measures analysis in generalised linear mixed models. Kaplan-Meier analysis was used to test for sex difference in the time to reach EDSS milestones 3 and 6 and the secondary progressive MS.ResultsIn relapse onset MS patients (n = 14,453), males progressed significantly faster in their EDSS than females (0.133 vs 0.112 per year, P<0.001,). Females had a reduced risk of secondary progressive MS (HR (95% CI) = 0.77 (0.67 to 0.90) P = 0.001). In primary progressive MS (n = 1,373), there was a significant increase in EDSS over time in males and females (P<0.001) but there was no significant sex effect on the annualized rate of EDSS change.ConclusionAmong registrants of MSBase, male relapse-onset patients accumulate disability faster than female patients. In contrast, the rate of disability accumulation between male and female patients with primary progressive MS is similar.

Objectives:The aim was to analyse risk of relapse phenotype recurrence in multiple sclerosis and to characterise the effect of demographic and clinical features on this phenotype. Methods: Information about relapses was collected using MSBase, an international observational registry. Associations between relapse phenotypes and history of similar relapses or patient characteristics were tested with multivariable logistic regression models. Tendency of relapse phenotypes to recur sequentially was assessed with principal component analysis. Results: Among 14,969 eligible patients (89,949 patient-years), 49,279 phenotypically characterised relapses were recorded. Visual and brainstem relapses occurred more frequently in early disease and in younger patients. Sensory relapses were more frequent in early or non-progressive disease. Pyramidal, sphincter and cerebellar relapses were more common in older patients and in progressive disease. Women presented more often with sensory or visual symptoms. Men were more prone to pyramidal, brainstem and cerebellar relapses. Importantly, relapse phenotype was predicted by the phenotypes of previous relapses. ( . Sensory, visual and brainstem relapses showed better recovery than other relapse phenotypes. Relapse severity increased and the ability to recover decreased with age or more advanced disease. Conclusion: Relapse phenotype was associated with demographic and clinical characteristics, with phenotypic recurrence significantly more common than expected by chance.

This study, based on a Cuban patient population, with long duration of disease, good sample size and detailed characterization by MRI, demonstrated the brain MRI pattern of R-NMO patients, which is different from MS.