Background

Neuromyelitis optica spectrum disorders (NMOSD) encompasses a group of rare inflammatory diseases which primarily target the optic nerves, spinal cord, and brain. Typically, magnetic resonance imaging (MRI) data from single-center studies comprise 20-50 patients, limiting statistical power for outcomes research. Using retrospective data from the PArallel MRI in NmOsd (PAMRINO) study, a novel prospective NMOSD image repository (NMOsDIR) representing multiple international sites was coordinated by Charité-Universitätsmedizin Berlin and the Medical Image Analysis Center (Basel).

Objectives

The PAMRINO study aimed to investigate and analyze retrospective MRIs collected from NMOSD-specialized centers, potentially for the evaluation of disease-related brain and spinal cord changes. NMOsDIR serves as an international imaging research resource (comprising standardized retinal optical coherence tomography and MRI scans) and clinical data hub for prospective studies in NMOSD. Linking imaging and clinical data, as well as enabling analysis pipelines for each modality, will facilitate multi-centered studies using sufficient data and statistical power to advance outcomes research in this rare disease.

Methods

For clinical data collection in PAMRINO, a Research Electronic Data Capture (REDCap) platform was used, where participating centers entered data relevant for NMOSD patient monitoring. An image database (XNAT) was established for image uploads. This large collection of MRI data is currently being analyzed in a joint international effort of NMOSD clinical neuroradiologists and scientists.

Results

Brain, spinal cord, and optic nerve MRI scans with associated clinical data were collected from 514 NMOSD patients and 56 healthy controls from 17 international centers. Roughly 20,000 individual MRI scans from patients and healthy controls were collected. Of these, 78% had T1-weighted cerebral MRIs (55% with 3D scans), 80% had T2-weighted cerebral MRIs (54% with 3D scans), 86% had T2-weighted spinal cord MRIs (55% with 3D scans), and 35% had optic nerve MRIs.

Conclusions

We successfully established PAMRINO, an international collaborative retrospective MRI and clinical data repository. The knowledge gained during this process provided important new insights, where the initial analysis of the dataset has underscored the large degree of heterogeneity in image and clinical data collection in NMOSD-specialized centers. Thus, calling for more standardized methods of data acquisition and imaging analysis, as not to limit research opportunities. The new longitudinal, prospective NMOsDIR will help us to answer many pressing - yet open - questions regarding patients seropositive for aquaporin-4-IgG+, myelin oligodendrocyte glycoprotein-IgG+ and other autoimmune-related diseases. In turn, such a strategy will strengthen future capabilities in research, diagnosis, monitoring and improving NMOSD patient care.

Background

Over 2 years in the CARE-MS trials (NCT00530348; NCT00548405), alemtuzumab (12 mg/day; baseline (BL): 5 days; 12 months later: 3 days) significantly improved clinical and MRI outcomes versus subcutaneous interferon beta-1a (SC IFNB-1a) in relapsing-remitting multiple sclerosis patients. Alemtuzumab efficacy was maintained through a 4-year extension study (NCT00930553), wherein patients could receive additional 3-day courses (≥12 months apart, as needed for disease activity) or receive other disease-modifying therapy per investigator’s discretion.

Objectives

To evaluate post hoc the effects of alemtuzumab on brain atrophy over 6 years in CARE-MS patients without relapses and MRI disease activity.

Methods

Analysis included pooled CARE-MS patients with or without disease activity between BL and Year 1 or BL and Year 2. Absence of disease activity was defined as no BL gadolinium (Gd)-enhancing T1 lesions and no clinical relapses or MRI disease activity (new Gd-enhancing or new/enlarging T2 lesions) from Years 0-1 or Years 0-2 (Definition 1). A second definition had the additional criterion of no relapse within 60 days before BL (Definition 2). Brain atrophy was measured by brain parenchymal fraction (BPF); differences in the median annualized percent change in BPF were assessed using ranked ANCOVA adjusted for region and BL BPF.

Results

Compared with SC IFNB-1a, alemtuzumab reduced median annualized percent change in BPF in patients free of disease activity during Years 0-1 (Definition 1: -0.37% vs -0.61%, P=0.006; Definition 2: -0.36% vs -0.54%, P=0.024) or Years 0-2 (Definition 1: -0.27% vs -0.44%, P=0.014; Definition 2: -0.28% vs -0.41%, P=0.045). Median annualized percent change in BPF was reduced with alemtuzumab versus SC IFNB-1a in patients with disease activity in Years 0-1 (-0.61% vs -0.79%, P=0.005) or Years 0-2 (-0.40% vs -0.56%, P<0.0001). Over 6 years, brain volume loss (BVL) was slower in patients without disease activity who initiated alemtuzumab at core study BL (-1.66%) than in those who received SC IFNB-1a in the core studies and initiated alemtuzumab in the extension (-2.05%).

Conclusions

Brain atrophy was reduced with alemtuzumab compared with SC IFNB-1a in patients without disease activity over 2 years. A slower rate of BVL was maintained through Year 6 in patients without disease activity who received alemtuzumab in the core study compared with SC IFNB-1a, suggesting alemtuzumab may slow neurodegeneration associated with BVL.

STUDY SUPPORT: Sanofi.

Background

Slowly expanding lesions (SELs) can be detected on conventional in vivo brain magnetic resonance imaging (MRI). Previous studies suggest that SELs reflect chronic tissue loss in the absence of ongoing acute inflammation. Histopathological characterization of SELs are still not fully investigated.

Objectives

To characterize SEL regions using in vivo MRIs and postmortem brain tissue, and compare the difference between SEL and non-SEL regions.

Methods

We identified an autopsy case with secondary progressive MS (male, age=51 years, disease duration=23 years), who had standardized in vivo MRIs. The interval between the last in vivo MRI and death was 7 weeks. From the last two years of in vivo MRIs, T2 lesions were segmented, and the Jacobian determinants of nonlinear registration between baseline and follow-up scans were calculated. SELs were identified as regions with small local constant and concentric expansion from baseline lesions. We identified 11 regions-of-interest (ROI): 10 T2 lesions (3 SELs and 7 non-SEL) and 1 normal-appearing white matter (NAWM). Using a custom brain cutting box with MRI-visible markers, the in vivo ROIs were localized on the corresponding brain slice. The ROIs were blocked and stained for proteolipid protein, SMI-31/32, and MHC class II. We then evaluated myelin status, axonal diameter, axonal loss, and inflammatory activity in ROIs.

Results

The NAWM region was myelinated, the axonal diameter was 0.74 um, and axonal density was 23.4%. In the SEL regions, the mean axonal diameter was 1.11 um, and mean axonal density was 17.5%. In non-SEL regions, the mean axonal diameter was 0.84 um, and mean axonal density was 15.7%.

Two SEL and 4 non-SEL regions were demyelinated. The demyelinated SEL regions had activated microglia at the lesion edge and were compatible with chronic active lesions. Three demyelinated non-SEL regions also had activated microglia at the edge. One demyelinated non-SEL region was a chronic inactive lesion. No microglia activity was observed in any of the myelinated non-SEL regions. In the myelinated SEL region, the density of activated microglia was higher compared to NAWM.

Conclusions

Not all SEL regions in T2 lesions were demyelinated. SEL also had greater axonal diameters suggesting of axonal swelling. In this case report, all of the demyelinated SEL regions had activated microglia at the lesion edge.

Background

Quantitative MRI measures are proposed as biomarkers of disease course and therapeutic response. Understanding the evolution of these metrics is key for interpretation of change in clinical practice.

Objectives

To describe longitudinal changes in T2 lesion volume (T2LV), whole brain (WBF) and gray matter (GMF) fraction, and thalamic volume (TV) over the disease course in a large multiple sclerosis (MS) cohort.

Methods

Demographics, disease history, and MRI were collected from MS patients at a single site. Patients with ≥2 MRI assessments were included. T2LV, WBF, GMF, and TV annualized rate of change and raw values compared to the first available scan were analyzed. Multivariate mixed-effects models were used to evaluate longitudinal MRI changes, adjusting for age at disease onset, sex, and patient-determined disease steps category (PDDS) with a random intercept for patient and an autoregressive covariance structure. For each outcome, three models were generated: a linear model, a second-order B-spline model, and a third-order B-spline model were tested for nonlinearity in the relationship between MRI outcome and disease duration and were compared based on Akaike Information Criterion.

Results

1012 patients were included (69.2% female, 72.9% relapsing-remitting MS, mean ± SD age at disease onset 34.4±10.3, age at baseline MRI 43.8±11.1, disease duration 9.4±5.8 years, mean number of MRIs 3.1±1.2, median [IQR] PDDS 1.0 [0.0-3.0]). Male sex (B=4.9) and PDDS>3 (B=7.0) were associated with greater T2LV accumulation over the disease course (best fit: linear model). T2LV annualized rate of change peaked at 5-6 years of disease duration (rate 9%/year) (best fit: third-order B spline). Male sex, older age, and PDDS>3 were associated with lower WBF, TV (best fit: linear model), and GMF (best fit: second-order B spline), all p<0.05. No non-linear effect of disease duration on WBF, TV, and GMF were observed. There was no statistically significant change in the annualized rate of change of WBF, TV, and GMF over the disease course.

Conclusions

The dynamics of T2LV accumulation are variable throughout the disease course, whereas the rate of change of WBF, TV, and GMF were more stable. These results suggest T2LV accumulation reflecting focal lesion activity predominates early in the disease while WBF, TV, and GMF loss reflecting underlying neurodegeneration is present at disease onset and continues throughout the course.

Background

Cognitive dysfunction is common in multiple sclerosis (MS) and can impair processing speed, episodic memory, and executive function. Magnetic resonance imaging (MRI) studies have demonstrated associations between several MRI metrics and cognitive functioning in MS, including thalamic volume and brain parenchymal fraction. Fingolimod is an MS therapy that demonstrated reduced brain volume loss across several clinical trials.

Objectives

Determine the relationship between cognitive function in fingolimod-treated relapsing-remitting MS patients and 7 tesla (7T) MRI measures.

Methods

We recruited fingolimod-treated MS patients and healthy controls to be followed for 12 months. Participants underwent 7T brain MRI and cognitive testing including the symbol digit modalities test (SDMT), selective reminding test (SRT), and the trail making, color, and verbal subtests of the Delis-Kaplan Executive Function System (DKEFS) at baseline, 6 months, and 12 months. Mixed effects linear regression models were used to determine the relationship between MRI metrics and neurometric test performance, fitting values from all 3 time points. Rates of change in MRI metrics and neurometric test performance were compared between patients and controls using two-sample t-tests.

Results

We enrolled 15 MS patients with mean age 42.4 years (SD=5.6), mean disease duration 8.5 years (SD=4.1), and median expanded disability status scale 3 (IQR=1.5-3.5). Five controls were enrolled with mean age 41.5 (SD=6.6) years. Controls performed better than patients on all psychometric tests, but this was only significant for tests of orthographic knowledge (DKEFS letter fluency) and long-term storage (SRT). When MRI metrics were used to predict neuropsychological test performance over time in patients, thalamic volume was a significant predictor of visuospatial memory (BVMTR), long-term storage (SRT), and inhibitory control (DKEFS Color Inhibition). Thalamic myelin density was a significant predictor of visuospatial memory (BVMTR), long-term storage (SRT), and semantic knowledge (DKEFS Verbal Category Fluency). When changes in neuropsychological testing performance and MRI metrics were compared for patients and controls from 0-6 months, and from 0-12 months, none of the differences between patients and controls were significant.

Conclusions

Thalamic volume and myelin density are associated with measures of cognitive function. 7T MRI of the thalamus may be useful as a clinical trial measure to predict cognitive effects.