A novel eye-movement impairment in multiple sclerosis indicating widespread cortical damage

From progression to progress: The future of multiple sclerosis

Significant advances have been made in the diagnosis and treatment of multiple sclerosis in recent years yet challenges remain. The current classification of MS phenotypes according to disease activity and progression, for example, does not adequately reflect the underlying pathophysiological mechanisms that may be acting in an individual with MS at different time points. Thus, there is a need for clinicians to transition to a management approach based on the underlying pathophysiological mechanisms that drive disability in MS. A Canadian expert panel convened in January 2023 to discuss priorities for clinical discovery and scientific exploration that would help advance the field. Five key areas of focus included: identifying a mechanism-based disease classification system; developing biomarkers (imaging, fluid, digital) to identify pathologic processes; implementing a data-driven approach to integrate genetic/environmental risk factors, clinical findings, imaging and biomarker data, and patient-reported outcomes to better characterize the many factors associated with disability progression; utilizing precision-based treatment strategies to target different disease processes; and potentially preventing disease through Epstein-Barr virus (EBV) vaccination, counselling about environmental risk factors (e.g. obesity, exercise, vitamin D/sun exposure, smoking) and other measures. Many of the tools needed to meet these needs are currently available. Further work is required to validate emerging biomarkers and tailor treatment strategies to the needs of individual patients. The hope is that a more complete view of the individual's pathobiology will enable clinicians to usher in an era of truly personalized medicine, in which more informed treatment decisions throughout the disease course achieve better long-term outcomes.

Abnormal eye movements increase as motor disabilities and cognitive impairments become more evident in Multiple Sclerosis: A novel eye-tracking study

Background

Eye movements can reflect brain alterations and inform on the presence of motor disabilities and cognitive impairments in people with multiple sclerosis (pwMS).

Objective

The aim of the study was to determine the correlation between motor and cognitive measurements and eye movement parameters when performing the n-back task (NBKT).

Methods

This was a cross-sectional study carried out at Ramos Mejía Hospital, a center specialized in demyelinating diseases in Buenos Aires, Argentina. The study population consisted of 66 patients with relapsing-remitting multiple sclerosis (RRMS) and 5 patients with secondary progressive multiple sclerosis (SPMS). pwMS performed the n-back test while using a device head mounted display (HMD) with eyetracking capabilities in order to capture eye movement. Clinical motor and cognitive measures were assessed with Expanded Disability Status Scale (EDSS), Nine Hole Peg Test (NHPT), Timed 25-Foot Walk (T25FW), and Symbol Digit Modalities Test (SDMT).

Results

pwMS showed strong and statistically significant correlations between gaze duration; number of fixations, saccade amplitude and motor disabilities and cognitive impairments as measured by EDSS, NHPT, T25FW, and SDMT.

Conclusion

This study found significant correlations between eye movement behavior and motor and cognitive disability in pwMS. These findings suggest that eye movements have the potential to be used as a surrogate biomarker in MS progression.

Clinical trials for progressive multiple sclerosis: progress, new lessons learned, and remaining challenges

Despite the success of disease-modifying treatments in relapsing multiple sclerosis, for many individuals living with multiple sclerosis, progressive disability continues to accrue. How to interrupt the complex pathological processes underlying progression remains a daunting and ongoing challenge. Since 2014, several immunomodulatory approaches that have modest but clinically meaningful effects have been approved for the management of progressive multiple sclerosis, primarily for people who have active inflammatory disease. The approval of these drugs required large phase 3 trials that were sufficiently powered to detect meaningful effects on disability. New classes of drug, such as Bruton tyrosine-kinase inhibitors, are coming to the end of their trial stages, several candidate neuroprotective compounds have been successful in phase 2 trials, and innovative approaches to remyelination are now also being explored in clinical trials. Work continues to define intermediate outcomes that can provide results in phase 2 trials more quickly than disability measures, and more efficient trial designs, such as multi-arm multi-stage and futility approaches, are increasingly being used. Collaborations between patient organisations, pharmaceutical companies, and academic researchers will be crucial to ensure that future trials maintain this momentum and generate results that are relevant for people living with progressive multiple sclerosis.

Neurovisual rehabilitation in multiple sclerosis: Why a close integration of low-vision rehabilitation and neuropsychological rehabilitation may be effective for visual complaints

OBJECTIVE

The quality of life of people with multiple sclerosis (MS) is often affected by visual complaints. A previous study suggested that visual complaints are not likely to be related to specific visual functions, but by a global decline of cognitive and visual functioning. In this study, we further explore this hypothesis, by investigating the relation between visual functions and global cognitive functioning, aiming to provide recommendations for rehabilitation for visual complaints.

DESIGN

Cross-sectional study.

SETTING

A rehabilitation centre for partially sighted and blind people and a MS centre at a university hospital.

PARTICIPANTS

102 people with MS.

MAIN MEASURE

Correlations between assessments of visual functions (acuity, contrast sensitivity, visual field, smooth pursuit and saccades) and composite scores of a neuropsychological assessment (tests with a visual component and without a visual component).

RESULTS

All composite scores correlated with visual acuity, contrast sensitivity and the sensitivity of the monocular field, but not with smooth pursuit and saccades. Similar patterns were found in various subgroups. Results showed that visual functions that related to visual complaints correlated with a diffuse decline of global cognitive functioning and that visual and cognitive functioning may decline concurrently in people with MS.

CONCLUSIONS

Visual complaints may occur as a result of a diffuse decline of the integrity of a cerebral network involved in vision and cognition. People with MS with visual complaints may benefit from neurovisual rehabilitation, in which low-vision rehabilitation and neuropsychological rehabilitation are closely intertwined.

Visual outcome measures in clinical trials of remyelinating drugs

One of the most promising approaches to delay, prevent or reverse disability progression in multiple sclerosis (MS) is to enhance endogenous remyelination and limit axonal degeneration. In clinical trials of remyelinating drugs, there is a need for reliable, sensitive and clinically relevant outcome measures. The visual pathway, which is frequently affected by MS, provides a unique model system to evaluate remyelination of acute and chronic MS lesions in vivo and non-invasively. In this review, we discuss the different measures that have been used and scrutinise visual outcome measure selection in current and future remyelination trials.

Measuring and predicting the effect of remyelinating therapy in multiple sclerosis: a randomised controlled trial protocol (RESTORE)

INTRODUCTION

Remyelination failure hampers symptomatic recovery in multiple sclerosis (MS), underlining the importance of developing remyelinating therapies. Optic neuritis is currently the most established method of measuring remyelination in MS trials. Complementary more generalisable methods of measuring remyelination are required to confirm treatment efficacy. Measuring internuclear ophthalmoplegia (INO) with infrared oculography provides such a method. Moreover, this method can be expanded with a test for selecting likely treatment responders by using fampridine. The aim of this trial is to investigate the (long-term) remyelinating effects of clemastine fumarate in patients with MS and INO and to evaluate if treatment response can be predicted using fampridine.

METHODS AND ANALYSIS

RESTORE is a single-centre double-blind randomised placebo-controlled trial of clemastine fumarate versus placebo. Prior to clemastine treatment improvement in oculographic features of INO after a single 10 mg dose of fampridine is measured in all participants and used to predict the treatment response to clemastine. Eighty individuals with MS and INO will be 1:1 randomised to 4 mg of clemastine fumarate two times a day for 6 months or equivalent placebo. Our primary outcome is improvement in the Versional Dysconjugacy Index-area under the curve, measured by infrared oculography after 6 months of treatment. Participants are assessed for persistent treatment effects 6, 18 and 30 months after end of treatment. Secondary outcome measures include other oculography parameters including double-step saccades, retinal imaging, visual acuities, physical disability, cognition and patient-reported outcomes.

ETHICS AND DISSEMINATION

Clemastine is a registered and very well-established drug with well-known safety and side effects. The protocol was approved by the medical ethical committee of the Amsterdam UMC, location VUMC and the Dutch Central Committee on Research Involving Human Subject. Written informed consent is obtained from all participants. The results will be published in peer-reviewed medical scientific journals.

TRIAL REGISTRATION NUMBER

EudraCT: 2021-003677-66, ClinicalTrials.gov: NCT05338450.