Jiwon Oh

• MD, FRCPC
• Johns Hopkins Medicine

Morphometric measures derived from spinal cord segmentations can serve as diagnostic and prognostic biomarkers in neurological diseases and injuries affecting the spinal cord. While robust, automatic segmentation methods to a wide variety of contrasts and pathologies have been developed over the past few years, whether their predictions are stable...

Importance Progression independent of relapse activity (PIRA) is a significant contributor to long-term disability accumulation in relapsing-remitting multiple sclerosis (MS). Prior studies have used varying PIRA definitions, hampering the comparability of study results. Objective To compare various definitions of PIRA. Design, Setting, and Parti...

Background: Tolebrutinib is an oral, brain-penetrant, and bioactive Bruton's tyrosine kinase inhibitor that modulates peripheral inflammation and persistent immune activation within the central nervous system, including disease-associated microglia and B cells. More data are needed on its efficacy and safety in treating relapsing multiple sclerosi...

Accurate segmentation and labeling of spinal structures are essential for diagnosing and managing spinal pathologies. However, variations in imaging contrast, resolution, and anatomical landmarks complicate automated MRI analysis. Manual methods are time-consuming and error-prone, highlighting the need for robust automation. We introduce TotalSpine...

Introduction Long-term population-based safety studies, applying advanced causal inference techniques, including an active comparator with new-user design, are needed to investigate skin cancer outcomes among individuals with multiple sclerosis (MS) treated with fingolimod. This study aims to describe a protocol for investigating the relationship b...

Background and Purpose The central vein sign (CVS) is a diagnostic imaging biomarker for multiple sclerosis (MS). FLAIR* is a combined MRI contrast that provides high conspicuity for CVS at 3 Tesla (3T), enabling its sensitive and accurate detection in clinical settings. This study evaluated whether CVS conspicuity of 3T FLAIR* is reliable across i...

Trigeminal neuralgia (TN) is commonly associated with multiple sclerosis (MS). Whether TN should be considered a clinical relapse or evidence of active disease lacks consensus. TN was diagnosed in 0.9%–1.9% ( n = 171) of people with multiple sclerosis (pwMS) at three international sites. In 9.9%, TN was their first potential demyelinating symptom....

The development of disease-modifying therapies (DMTs) for the treatment of multiple sclerosis (MS) has been highly successful in recent decades. It is now widely accepted that early initiation of DMTs after disease onset is associated with a better long-term prognosis. However, the question of when and how to de-escalate or discontinue DMTs remains...

In multiple sclerosis (MS), increasing disability is considered to occur due to persistent, chronic inflammation trapped within the central nervous system (CNS). This condition, known as smoldering neuroinflammation, is present across the clinical spectrum of MS and is currently understood to be relatively resistant to treatment with existing disea...

Spinal cord disease is important in most people with multiple sclerosis, but assessment remains less emphasized in patient care, basic and clinical research and therapeutic trials. The North American Imaging in Multiple Sclerosis Spinal Cord Interest Group was formed to determine and present the contemporary landscape of multiple sclerosis spinal c...

Background and Objectives Women with multiple sclerosis (MS) are at risk of disease reactivation in the early postpartum period. Ocrelizumab (OCR) is an anti-CD20 therapy highly effective at reducing MS disease activity. Data remain limited regarding use of disease-modifying therapies (DMTs), including OCR, and disease activity during peripregnancy...

Background and Purpose Paramagnetic rim lesions (PRLs) are an MRI biomarker of chronic inflammation in people with multiple sclerosis (MS). PRLs may aid in the diagnosis and prognosis of MS. However, manual identification of PRLs is time‐consuming and prone to poor interrater reliability. To address these challenges, the Automated Paramagnetic Rim...

The development of disease-modifying therapies (DMTs) for neurological disorders is an important goal in modern neurology, and the associated challenges are similar in many chronic neurological conditions. Major advances have been made in the multiple sclerosis (MS) field, with a range of DMTs being approved for relapsing MS and the introduction of...

Background and purpose: The central vein sign (CVS) is a proposed diagnostic imaging biomarker for multiple sclerosis (MS). The proportion of white matter lesions exhibiting the CVS (CVS+) is higher in patients with MS compared to its radiological mimics. Evaluation for CVS+ lesions in prior studies have been performed by manual rating, an approac...

Background Disease progression is observed across the spectrum of people with multiple sclerosis (MS) and identification of effective treatment strategies to halt progression remains one of the greatest unmet clinical needs. Objectives The Canadian Prospective Cohort Study to Understand Progression in MS (CanProCo) was designed to evaluate a wide...

Background Cerebrospinal fluid (CSF) oligoclonal bands (OCB) are a diagnostic biomarker in multiple sclerosis (MS). The central vein sign (CVS) is an imaging biomarker for MS that may improve diagnostic accuracy. Objectives The objective of the study is to examine the diagnostic performance of simplified CVS methods in comparison to OCB in partici...

Background/Objectives The COVID-19 pandemic raised concern amongst clinicians that disease-modifying therapy (DMT), particularly anti-CD20 monoclonal antibodies (mAB) and fingolimod, could worsen COVID-19 in people with multiple sclerosis (pwMS). This study aimed to examine DMT prescribing trends pre- and post-pandemic. Methods A multi-centre long...

Background Comparisons between cladribine and other potent immunotherapies for multiple sclerosis (MS) are lacking. Objectives To compare the effectiveness of cladribine against fingolimod, natalizumab, ocrelizumab and alemtuzumab in relapsing-remitting MS. Methods Patients with relapsing-remitting MS treated with cladribine, fingolimod, natalizu...

Background Disability progression is a key milestone in the disease evolution of people with multiple sclerosis (PwMS). Prediction models of the probability of disability progression have not yet reached the level of trust needed to be adopted in the clinic. A common benchmark to assess model development in multiple sclerosis is also currently lack...

Despite therapeutic suppression of relapses, multiple sclerosis (MS) patients often experience subtle deterioration, which extends beyond the definition of “progression independent of relapsing activity.” We propose the concept of smouldering‐associated‐worsening (SAW), encompassing physical and cognitive symptoms, resulting from smouldering pathol...

B cells are critical to the pathogenesis of multiple sclerosis (MS), an autoimmune disease of the central nervous system. B cell depletion using anti-CD20 monoclonal antibodies (mAbs) has proven to be an extremely successful treatment strategy, with profound suppression of both clinical and radiological evidence of focal inflammatory disease. Sever...

Background The COVID-19 pandemic raised concern amongst clinicians that disease-modifying therapies (DMT), particularly anti-CD20 monoclonal antibodies (mAb) and fingolimod, could worsen COVID-19 in people with multiple sclerosis (pwMS). This study aimed to examine DMT prescribing trends pre- and post-pandemic onset. Methods A multi-centre longitu...

Background and purpose: Low-field 64mT portable brain MRI (pMRI) has recently shown diagnostic promise for MS. This study aimed to evaluate the utility of pMRI in assessing dissemination in space (DIS) in patients presenting with optic neuritis and determine whether deploying pMRI in the MS clinic can shorten the time from symptom onset to MRI. M...

This study aimed to determine whether choroid plexus volume (CPV) could differentiate multiple sclerosis (MS) from its mimics. A secondary analysis of two previously enrolled studies, 50 participants with MS and 64 with alternative diagnoses were included. CPV was automatically segmented from 3T magnetic resonance imaging (MRI), followed by manual...

Background Performing routine brain magnetic resonance imaging (MRI) is widely accepted as the standard of care for disease monitoring in multiple sclerosis (MS), but the utility of performing routine spinal cord (SC) MRI for this purpose is still debatable. Objective This study aimed to measure the frequency of new isolated cervical spinal cord l...

Chronic active lesions (CAL) are an important manifestation of chronic inflammation in multiple sclerosis and have implications for non-relapsing biological progression. In recent years, the discovery of innovative MRI and PET-derived biomarkers has made it possible to detect CAL, and to some extent quantify them, in the brain of persons with multi...

Background There are no specific, evidence-based recommendations for the management of individuals with radiologically isolated syndrome. Imaging and blood biomarkers may have prognostic utility. Objective To determine whether plasma neurofilament light protein (NfL) or glial fibrillary acidic protein (GFAP) levels in people with radiologically is...

Background The central vein sign (CVS) is a proposed magnetic resonance imaging (MRI) biomarker for multiple sclerosis (MS); the optimal method for abbreviated CVS scoring is not yet established. Objective The aim of this study was to evaluate the performance of a simplified approach to CVS assessment in a multicenter study of patients being evalu...

Objectives: To investigate the incidence of demyelinating disease (DD) among spondyloarthritis (SpA) patients and identify risk factors that predict DD in this patient population. Methods: Axial SpA (axSpA) and psoriatic arthritis (PsA) patients were identified from a longitudinal cohort database. Each group was analysed according to the presence...

Geographical variations in the incidence and prevalence of multiple sclerosis have been reported globally. Latitude as a surrogate for exposure to ultraviolet radiation but also other lifestyle and environmental factors are regarded as drivers of this variation. No previous studies evaluated geographical variation in the risk of secondary progressi...

What is this summary about?: Patient registries contain anonymous data from people who share the same medical condition. The MSBase registry contains information from over 80,000 people living with multiple sclerosis (MS) across 41 countries. Using information from the MSBase registry, the GLIMPSE (Generating Learnings In MultiPle SclErosis) study...

Importance Autologous hematopoietic stem cell transplant (AHSCT) is available for treatment of highly active multiple sclerosis (MS). Objective To compare the effectiveness of AHSCT vs fingolimod, natalizumab, and ocrelizumab in relapsing-remitting MS by emulating pairwise trials. Design, Setting, and Participants This comparative treatment effec...

Background Some studies comparing primary and secondary progressive multiple sclerosis (PPMS, SPMS) report similar ages at onset of the progressive phase and similar rates of subsequent disability accrual. Others report later onset and/or faster accrual in SPMS. Comparisons have been complicated by regional cohort effects, phenotypic differences in...

Background Multiple Sclerosis (MS) affects people in their most productive years of life. Consequently, MS can substantially affect employment and work-related outcomes. Objectives This study characterizes productivity loss and employment status of people with multiple sclerosis (pwMS) and investigates associated factors. Methods We used baseline...

Background and Objectives Multiple sclerosis (MS), a leading cause of non-traumatic neurologic disability in young adults, exerts a substantial economic burden on the healthcare system. The objective of this study was to quantify the excess healthcare costs of MS in British Columbia (BC), Canada. Methods A retrospective matched-cohort study of MS...

Traditionally, multiple sclerosis has been categorised by distinct clinical descriptors—relapsing-remitting, secondary progressive, and primary progressive—for patient care, research, and regulatory approval of medications. Accumulating evidence suggests that the clinical course of multiple sclerosis is better considered as a continuum, with contri...

Background Sexual dysfunction (SD) is frequently reported in multiple sclerosis (MS) and is likely related to MS-related damage to the spinal cord (SC). Objective To assess associations between SD and quantitative MRI measures in people with MS (pwMS). Methods This pilot study included 17 pwMS with SD who completed questionnaires assessing SD, mo...

Background: The central vein sign (CVS) is a proposed MRI biomarker of multiple sclerosis (MS). The impact of gadolinium-based contrast agent (GBCA) administration on CVS evaluation remains poorly investigated. Objective: To assess the effect of GBCA use on CVS detection and on the diagnostic performance of the CVS for MS, using a 3-T FLAIR* sequen...

Objective Little work has evaluated integrated models of care in multiple sclerosis (MS) and the composition of MS care teams across Canada is largely unknown. We aimed to gather information regarding existing models of MS care across Canada, and to assess the perceptions of health care providers (HCPs) regarding the models of care required to full...

Background and purpose: The North American Imaging in Multiple Sclerosis (NAIMS) multisite project identified interscanner reproducibility issues with T1-based whole brain volume (WBV). Lateral ventricular volume (LVV) acquired on T2-fluid-attenuated inverse recovery (FLAIR) scans has been proposed as a robust proxy measure. Therefore, we sought t...

Objectives To analyze work productivity loss and costs, including absenteeism (time missed from work), presenteeism (reduced productivity while working), and unpaid work loss, among a sample of employed people with multiple sclerosis (pwMS) in Canada, as well as its association with clinical, sociodemographic, and work-related factors. Methods We...

Objective : To report clinical characteristics and outcomes of people with multiple sclerosis (PwMS) who developed COVID-19 infection in Toronto, Canada. Methods : Descriptive, retrospective, single-center study that included all known PwMS at the St. Michael's Hospital MS Clinic who had PCR-confirmed COVID-19 infection between March 2020 and May...

Background Neurological disability progression occurs across the spectrum of people living with multiple sclerosis (MS). Although there are a handful of disease-modifying treatments approved for use in progressive phenotypes of MS, there are no treatments that substantially modify the course of clinical progression in MS. Characterizing the determi...

The 2015 Magnetic Resonance Imaging in Multiple Sclerosis and 2016 Consortium of Multiple Sclerosis Centres guidelines on the use of MRI in diagnosis and monitoring of multiple sclerosis made an important step towards appropriate use of MRI in routine clinical practice. Since their promulgation, there have been substantial relevant advances in know...

Although multiple sclerosis (MS) has traditionally been considered a white matter disease, extensive research documents the presence and importance of gray matter injury including cortical and deep regions. The deep gray matter (DGM) exhibits a broad range of pathology and is uniquely suited to study the mechanisms and clinical relevance of tissue...

Objective The central vein sign (CVS) and “paramagnetic rim lesions” (PRL) are emerging imaging biomarkers in multiple sclerosis (MS) reflecting perivenular demyelination and chronic, smoldering inflammation. The objective of this study was to assess relationships between cognitive impairment (CI) and the CVS and PRL in radiologically isolated synd...

Accurate interpretation and quantification of magnetic resonance imaging (MRI) is vital to medical research and clinical practice. However, lack of MRI standardization and differences in acquisition protocols often lead to measurement inconsistencies across sites. Image harmonization techniques have been shown to improve qualitative and quantitativ...

Standardized magnetic resonance imaging (MRI) protocols are important for the diagnosis and monitoring of patients with multiple sclerosis (MS). The Consortium of Multiple Sclerosis Centers (CMSC) convened an international panel of MRI experts to review and update the current guidelines. The objective was to update the standardized MRI protocol and...

Background Multiple sclerosis (MS) incidence is rising in traditionally low-burden regions, including the Middle East and North Africa (MENA). Objectives Our objective was to evaluate disease characteristics in MS patients of MENA descent (MENA-MS). Methods MENA-MS patients and age- and sex-matched MS patients of European descent (EUR-MS) were id...

Background The spinal cord (SC) is highly relevant to disability in multiple sclerosis (MS), but few studies have evaluated longitudinal changes in quantitative spinal cord magnetic resonance imaging (SC-MRI). Objectives The aim of this study was to characterize the relationships between 5-year changes in SC-MRI with disability in MS. Methods In...

Clinicians involved with different aspects of the care of persons with multiple sclerosis (MS) and scientists with expertise on clinical and imaging techniques convened in Dallas, TX, USA on February 27, 2019 at a North American Imaging in Multiple Sclerosis Cooperative workshop meeting. The aim of the workshop was to discuss cardinal pathobiologic...

Individuals with radiologically isolated syndrome (RIS) have incidental magnetic resonance imaging (MRI) abnormalities suggestive of multiple sclerosis (MS).¹ Recent studies using susceptibility-based imaging have shown that a subgroup of chronic MS white matter lesions (WMLs) have a rim of paramagnetic susceptibility-associated signal loss at the...

Magnetic resonance imaging (MRI) has revolutionized the diagnosis and management of people living with multiple sclerosis (MS). However, conventional MRI sequences and measures currently used in clinical practice have limitations in the appropriate diagnosis, prediction of future disability, and monitoring of disease activity in MS. A specific chal...

Magnetic resonance imaging (MRI) is a flexible medical imaging modality that often lacks reproducibility between protocols and scanners. It has been shown that even when care is taken to standardize acquisitions, any changes in hardware, software, or protocol design can lead to differences in quantitative results. This greatly impacts the quantitat...

Objective: To summarize current and emerging imaging techniques that can be used to assess neuroprotection and repair in multiple sclerosis (MS), and to provide a consensus opinion on the potential utility of each technique in clinical trial settings. Methods: Clinicians and scientists with expertise in the use of MRI in MS convened in Toronto,...

Background MRI is the imaging modality of choice for diagnosis and intervention assessment in neurological disease. Its full potential has not been realized due in part to challenges in harmonizing advanced techniques across multiple sites. Purpose To develop a method for the assessment of reliability and repeatability of advanced multisite‐multis...

On average, African Americans with multiple sclerosis demonstrate higher inflammatory disease activity, faster disability accumulation, greater visual dysfunction, more pronounced brain tissue damage and higher lesion volume loads compared to Caucasian Americans with multiple sclerosis. Neurodegeneration is an important component of multiple sclero...

Magnetic resonance image analysis is often hampered by inconsistent data due to upgrades or changes to the scanner platform or modification of scanning protocols. These changes can manifest in three main sources of image inconsistency: contrast, resolution, and noise. Modern analysis techniques that use supervised machine learning can be especially...

High resolution magnetic resonance (MR) images are desired in many clinical applications, yet acquiring such data with an adequate signal-to-noise ratio requires a long time, making them costly and susceptible to motion artifacts. A common way to partly achieve this goal is to acquire MR images with good in-plane resolution and poor through-plane r...

The North American Imaging in Multiple Sclerosis (NAIMS) Cooperative represents a network of 27 academic centers focused on accelerating the pace of magnetic resonance imaging (MRI) research in multiple sclerosis (MS) through idea exchange and collaboration. Recently, NAIMS completed its first project evaluating the feasibility of implementation an...

Background: Lesion load is a common biomarker in multiple sclerosis, yet it has historically shown modest associations with clinical outcomes. Lesion count, which encapsulates the natural history of lesion formation and is thought to provide complementary information, is difficult to assess in patients with confluent (i.e. spatially overlapping) le...

Purpose: To explore (i) the variability of upper cervical cord area (UCCA) measurements from volumetric brain 3D T1 -weighted scans related to gradient nonlinearity (GNL) and subject positioning; (ii) the effect of vendor-implemented GNL corrections; and (iii) easily applicable methods that can be used to retrospectively correct data. Methods: A...