Robert A. Bermel

The measurement and clinical relevance of brain atrophy in multiple sclerosis

Brain atrophy has emerged as a clinically relevant component of disease progression in multiple sclerosis. Progressive loss of brain tissue bulk can be detected in vivo in a sensitive and reproducible manner by MRI. Clinical studies have shown that brain atrophy begins early in the disease course. The increasing amount of data linking brain atrophy to clinical impairments suggest that irreversible tissue destruction is an important determinant of disease progression to a greater extent than can be explained by conventional lesion assessments. In this review, we will summarise the proposed mechanisms contributing to brain atrophy in patients with multiple sclerosis. We will critically discuss the wide range of MRI-based methods used to quantify regional and whole-brain-volume loss. Based on a review of current information, we will summarise the rate of atrophy among phenotypes for multiple sclerosis, the clinical relevance of brain atrophy, and the effect of disease-modifying treatments on its progression.

Predictors of long‐term outcome in multiple sclerosis patients treated with interferon beta

To identify early predictors of long‐term outcomes in patients with relapsing–remitting multiple sclerosis (RRMS) treated with intramuscular (IM) interferon beta‐1a (IFNβ‐1a).

A semiautomated measure of whole-brain atrophy in multiple sclerosis

Brain atrophy is a proposed MRI marker of irreversible pathologic damage in multiple sclerosis (MS). The brain parenchymal fraction (BPF) is the ratio of brain parenchymal volume to the total volume within the surface contour. We developed a semiautomated measure of BPF using commercially available edge-finding and thresholding software (30-min analysis time per patient). We measured BPF in 78 patients with MS and 17 healthy controls. BPF was lower in a cohort of patients with MS (n=50) (0.843+/-0.042, range 0.743-0.906) age-matched to controls (0.877+/-0.020, range 0.835-0.901) (p<0.001). BPF correlated inversely with third ventricular width (r=-0.785, p<0.001), and total T1 hypointense lesion volume (r=-0.347, p=0.011), but not with total T2 hyperintense lesion volume (r=-0.213, p=0.13). BPF correlated negatively with expanded disability status scale (EDSS) score (r=-0.391, p=0.0006) and disease duration (r=-0.281, p=0.01). Stepwise regression compared the relative abilities of MRI variables to predict clinical data. By regression of age, BPF, third ventricular width, T2 lesions, and T1 lesions, BPF was the best predictor of disability score (R(2)=0.204, p<0.001). Third ventricular width was the best predictor of disease duration (R(2)=0.316, p<0.001). None of the MRI variables differed between relapsing-remitting (RR) (n=60) and secondary progressive (SP) (n=18) disease course (p>0.05). The intrarater, interrater, and scan-rescan BPF variability (COV) was 0.31%, 0.34%, and 0.41% and the accuracy against a phantom was 99.1%. We conclude that whole-brain atrophy in MS can be reliably and readily quantified by a semiautomated approach. Longitudinal studies are warranted to determine if this method provides a sensitive biologic marker of the MS disease process.

Measurement of brain and spinal cord atrophy by magnetic resonance imaging as a tool to monitor multiple sclerosis.

Evaluation of brain and spinal cord atrophy by magnetic resonance imaging (MRI) has become an increasingly important component of understanding the multiple sclerosis (MS) disease process. These destructive aspects of the disease develop early in the disease course. A growing body of data links brain and spinal cord atrophy to clinical impairment more closely than can be linked with conventional measures of overt lesions. Thus, irreversible tissue damage may be a key factor leading to disease progression. In this review, the authors present the proposed mechanisms leading to central nervous system (CNS) atrophy. They describe the available MRI‐based techniques to measure regional and global atrophy of the brain and spinal cord. They compare the rate of atrophy among MS phenotypes and summarize the emerging data linking atrophy to neurological and neuropsychological impairment. Finally, they discuss the effect of disease‐modifying immunotherapies on the rate of CNS atrophy in patients with MS. Future research to clarify the etiology and pathophysiology of brain and spinal cord atrophy should provide new targets for therapeutic development.

Regional Brain Atrophy Is Associated With Physical Disability in Multiple Sclerosis: Semiquantitative Magnetic Resonance Imaging and Relationship to Clinical Findings

Objectibe. Brain atrophy may occur early in the course of multiple sclerosis (MS) and may be associated with disability. Brain magnetic resonance imaging (MRI) of 114 MS patients (group A) were analyzed for regional atrophy (vs age‐/gender‐matched controls) and T1 and T2 lesions using 4‐point rating systems. Thirty‐five separate patients (group B) were analyzed for cortical atrophy (ordinal scale), third ventricular width, and total T2 hyperintense lesion volume (computer assisted). In group A, regression modeling indicated that inferior frontal atrophy (P= .0003) and T2 lesions in the pons (P= .02) predicted physical disability (Expanded Disability Status Scale [EDSS] score). Secondary progressive (SP) versus relapsing patients were predicted by inferior parietal (P= .002), superior parietal (P= .006), temporal (P= .008), inferior frontal (P= .01), superior frontal (P= .01), cerebellum (P= .01), occipital (P= .01), and midbrain (P= .02) atrophy. SP patients were also predicted by total atrophy (P= .01) and third ventricular enlargement (P= .03) but not T1 or T2 lesions. In group B, the regression model predicting EDSS score included only superior frontal atrophy (r= 0.515, P= .002). Mean kappa coefficients of ordinal ratings were 0.9 (intraobserver) and 0.8 (interobserver). Ordinal ratings correlated well with quantitative assessments. The authors conclude that brain atrophy is closely associated with physical disability and clinical course in MS patients and can be appreciated using a semiquantitative MRI regional rating system.

Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study

BACKGROUND Most patients with multiple sclerosis without previous optic neuritis have thinner retinal layers than healthy controls. We assessed the role of peripapillary retinal nerve fibre layer (pRNFL) thickness and macular volume in eyes with no history of optic neuritis as a biomarker of disability worsening in a cohort of patients with multiple sclerosis who had at least one eye without optic neuritis available. METHODS In this multicentre, cohort study, we collected data about patients (age ≥16 years old) with clinically isolated syndrome, relapsing-remitting multiple sclerosis, and progressive multiple sclerosis. Patients were recruited from centres in Spain, Italy, France, Germany, Czech Republic, Netherlands, Canada, and the USA, with the first cohort starting in 2008 and the latest cohort starting in 2013. We assessed disability worsening using the Expanded Disability Status Scale (EDSS). The pRNFL thickness and macular volume were assessed once at study entry (baseline) by optical coherence tomography (OCT) and was calculated as the mean value of both eyes without optic neuritis for patients without a history of optic neuritis or the value of the non-optic neuritis eye for patients with previous unilateral optic neuritis. Researchers who did the OCT at baseline were masked to EDSS results and the researchers assessing disability with EDSS were masked to OCT results. We estimated the association of pRNFL thickness or macular volume at baseline in eyes without optic neuritis with the risk of subsequent disability worsening by use of proportional hazards models that included OCT metrics and age, disease duration, disability, presence of previous unilateral optic neuritis, and use of disease-modifying therapies as covariates. FINDINGS 879 patients with clinically isolated syndrome (n=74), relapsing-remitting multiple sclerosis (n=664), or progressive multiple sclerosis (n=141) were included in the primary analyses. Disability worsening occurred in 252 (29%) of 879 patients with multiple sclerosis after a median follow-up of 2·0 years (range 0·5-5 years). Patients with a pRNFL of less than or equal to 87 μm or less than or equal to 88 μm (measured with Spectralis or Cirrus OCT devices) had double the risk of disability worsening at any time after the first and up to the third years of follow-up (hazard ratio 2·06, 95% CI 1·36-3·11; p=0·001), and the risk was increased by nearly four times after the third and up to the fifth years of follow-up (3·81, 1·63-8·91; p=0·002). We did not identify meaningful associations for macular volume. INTERPRETATION Our results provide evidence of the usefulness of monitoring pRNFL thickness by OCT for prediction of the risk of disability worsening with time in patients with multiple sclerosis. FUNDING Instituto de Salud Carlos III.

Intramuscular interferon beta-1a therapy in patients with relapsing-remitting multiple sclerosis: a 15-year follow-up study

Disease-modifying drugs are initiated early and continued for years in patients with multiple sclerosis. Long-term tolerability and impact are not known. The objective of this study was to evaluate long-term tolerability of intramuscular interferon beta-1a and effects on disability and quality of life. Patients were evaluated an average of 15 years after randomization into a placebo-controlled, double-blind trial of intramuscular interferon beta-1a for relapsing multiple sclerosis. Patient-reported Expanded Disability Status Scale, the Short Form-36, a visual analog scale of self-care independence, and a living situation questionnaire were administered. Status was ascertained in 79% (136/172) of eligible patients. Analysis focused on 122 living patients. Despite open-label, non-standardized treatment after the 2-year clinical trial, 46% (n= 56) of the patients remained on intramuscular interferon beta-1a. Expanded Disability Status Scale scores were correlated highly with Short Form-36 subcategories and visual analog scale scores. Patients currently using intramuscular interferon beta-1a had a significantly lower mean Expanded Disability Status Scale score (p= 0.011), less progression to Expanded Disability Status Scale milestones, significantly better scores on the physical component of the Short Form-36 (p< 0.0001), and reported better general health and greater independence. We conclude that patients continuing to use intramuscular interferon beta-1a had less disability and better quality of life compared with patients not currently using intramuscular interferon beta-1a 15 years after randomization into a clinical trial.

Early tolerability and safety of fingolimod in clinical practice

BACKGROUND Fingolimod is approved by the U.S. Food and Drug Administration to reduce relapses and disability progression in relapsing forms of MS. Several screening studies and a first-dose observation (FDO) period are recommended due to adverse effects observed in clinical trials. OBJECTIVE The objective of this study is to describe the early experience with fingolimod, including startup, tolerability and safety in a large academic multiple sclerosis (MS) center. METHODS Patients prescribed fingolimod from September 2010 to July 2011 were identified through electronic medical records. Demographics, MS disease history, pre-treatment screening studies, FDO experience during shared medical visits and three month follow-up data were analyzed. RESULTS Three hundred ninety-one patients were prescribed fingolimod of whom 317 started the medication and were included in the analysis. Fingolimod was most frequently used in relapsing remitting MS (n=256, 80.8%) and was prescribed as a first-line agent in 11 cases (3.5%). FDO was uneventful in 308 patients (96.8%). Adverse events during FDO were self limited and included symptomatic bradycardia (n=3), chest tightness (n=2) and hypertension (n=1). Fingolimod was discontinued in 30 patients (9.5%) at three months. Adverse effects leading to discontinuation by more than one patient included headache (n=4), macular edema (n=3), nausea (n=3) and hypertension (n=2). CONCLUSIONS Fingolimod was well tolerated during FDO and adverse events were self limited. The shared medical visit is an appropriate setting for FDO. Adverse effects were similar to those described in clinical trials but the discontinuation rate was higher.

Hippocampal volume is related to cognitive decline and fornicial diffusion measures in multiple sclerosis.

PURPOSE To assess for associations between hippocampal atrophy and measures of cognitive function, hippocampal magnetization transfer ratio (MTR), and diffusion measures of the fornix, the largest efferent white matter tract from the hippocampus, in patients with multiple sclerosis (MS) and controls. MATERIALS AND METHODS A total of 53 patients with MS and 20 age- and sex-matched healthy controls participated in cognitive testing and scanning including high spatial-resolution diffusion imaging and a T1-MPRAGE scan. Hippocampal volume and fornicial thickness measures were calculated and compared to mean values of fornicial transverse diffusivity, mean diffusivity, longitudinal diffusivity, fractional anisotropy, mean hippocampal MTR, and scores on measures of episodic memory, processing speed, and working memory tasks. RESULTS In patients with MS, hippocampal volume was significantly related to fornicial diffusion measures (P<7×10(-4)) and to measures of verbal (P=0.030) and visual spatial (P=0.004) episodic memory and a measure of information processing speed (P<0.037). DISCUSSION These results highlight the role of the hippocampus in cognitive dysfunction in patients with MS and suggest that measures of hippocampal atrophy could be used to capture aspects of disease progression.

Interferon-beta treatment for multiple sclerosis.

SummaryMultiple sclerosis (MS) is the leading nontraumatic cause of neurologic disability in young adults. Interferon-β, approved for use in 1993, was the first treatment to modify the course and prognosis of the disease and remains a mainstay of MS treatment. Numerous large-scale clinical trials in early, active patient populations have established the clinical efficacy of interferon-β in reducing relapses and delaying disability progression. Although its mechanism of action remains incompletely understood, a reduction in active lesions seen on magnetic resonance imaging implies primary anti-inflammatory properties, a mechanism supported by basic immunologic research. Variation in individual patient responsiveness to interferon-β may be due to disease variability or differential induction of interferon-stimulated genes. The magnitude of the therapeutic effect appears to be similar among products, but the optimal dose, route, and frequency of administration of the drug remain uncertain.