Temporal visual resolution and disease severity in MS

Optic neuritis in Asian type opticospinal multiple sclerosis (OSMS-ON) in a non-Asian population: A functional-structural paradox

BACKGROUND

Biomarkers have improved the classification of autoimmune inflammatory disorders, including optic neuritis (ON) as a frequent presentation of multiple sclerosis, neuromyelitis spectrum disorders, MOG antibody-related disease (MOGAD), and opticospinal multiple sclerosis (OSMS). The phenotype of OSMS in non-Asian populations is less well known.

OBJECTIVE

We investigated the clinical features and prognosis of OSMS-ON in a Brazilian cohort.

METHODS

This was a single-center cohort study of patients from Rio de Janeiro (Brazil) with OSMS. All individuals were MOG- and AQP4-seronegative, clinically diagnosed with ON, and had magnetic resonance imaging-confirmed transverse myelitis (TM). Subjects and healthy controls (HCs) were assessed for visual acuity (logMAR VA), automated perimetry mean deviation (MD), intraocular pressure, and spectral-domain optical coherence tomography (OCT), followed by automated retinal layer segmentation of the peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell and inner plexiform layer (mGCIPL). Receiver operator characteristic curves were plotted and the area under the curve (AUC) was calculated for group comparisons of retinal asymmetry of the pRNFL and mGCIPL.

RESULTS

The 30 patients with OSMS were predominantly female and white. The mean age was 48 years (range 20-70 years). Unilateral ON was the index event in 83.3% of patients. Over the average 18-year follow-up period, there were 89 relapses of ON. In individuals with OSMS, the average VA was 0.07±0.14 in the right eye (RE) and 0.13±0.30 in the left eye (LE). The MD was -5.37±5.88 dB and -5.23±3.34 dB for the RE and LE, respectively. There was a significant cumulative loss of VA (p = 0.0003) and MD (p = 0.0001) with a higher number of recurrent episodes. Atrophy of the pRNFL thickness was significant in OSMS (RE, 78.62 ± 16.01 µm; LE, 79.86 ± 13.79 µm) relative to the HC group (RE, 98.87 ± 10.68 µm; LE, 97.87 ± 10.85 µm, p = 0.0001). Likewise, there was significant mGCIPL atrophy in patients with OSMS (RE, 74.96 ± 14.46 µm; LE, 73.88 ± 13.79 µm) relative to the HC group (RE, 90.50 ± 6.74 µm; LE, 90.41± 6.89 µm; p = 0.0001). Retinal asymmetry, inter-eye percentage, and absolute differences accurately separated patients with unilateral ON from HCs (AUC=0.89 and AUC=0.85, respectively).

CONCLUSION

A structural-functional paradox was found in OSMS with a high diagnostic value for a novel metric based on retinal asymmetry. The functional visual outcome are excellent despite significant structural damage to the inner retinal layers in patients with a high ON relapse rate and long-term bilateral sequential involvement.

Impaired motion perception is associated with functional and structural visual pathway damage in multiple sclerosis and neuromyelitis optica spectrum disorders

Background:

Decreased motion perception has been suggested as a marker for visual pathway demyelination in optic neuritis (ON) and/or multiple sclerosis (MS).

Objectives:

To examine the influence of neuro-axonal damage on motion perception in MS and neuromyelitis optica spectrum disorders (NMOSD).

Methods:

We analysed motion perception with numbers-from-motion (NFM), visual acuity, (multifocal (mf)) VEP, optical coherence tomography in patients with MS (n = 38, confirmatory cohort n = 43), NMOSD (n = 13) and healthy controls (n = 33).

Results:

NFM was lower compared with controls in MS (B = −12.37, p < 0.001) and NMOSD (B = −34.5, p < 0.001). NFM was lower in ON than in non-ON eyes (B = −30.95, p = 0.041) in NMOSD, but not MS. In MS and NMOSD, lower NFM was associated with worse visual acuity (B = −139.4, p < 0.001/B = −77.2, p < 0.001) and low contrast letter acuity (B = 0.99, p = 0.002/B = 1.6, p < 0.001), thinner peripapillary retinal nerve fibre layer (B = 1.0, p < 0.001/ B = 0.92, p = 0.016) and ganglion cell/inner plexiform layer (B = 64.8, p < 0.001/B = 79.5, p = 0.006), but not with VEP P100 latencies. In the confirmatory MS cohort, lower NFM was associated with thinner retinal nerve fibre layer (B = 1.351, p < 0.001) and increased mfVEP P100 latencies (B = −1.159, p < 0.001).

Conclusions:

Structural neuro-axonal visual pathway damage is an important driver of motion perception impairment in MS and NMOSD.

Imaging correlates of visual function in multiple sclerosis

No single neuroimaging technique or sequence is capable of reflecting the functional deficits manifest in MS. Given the interest in imaging biomarkers for short- to medium-term studies, we aimed to assess which imaging metrics might best represent functional impairment for monitoring in clinical trials. Given the complexity of functional impairment in MS, however, it is useful to isolate a particular functionally relevant pathway to understand the relationship between imaging and neurological function. We therefore analyzed existing data, combining multiparametric MRI and OCT to describe MS associated visual impairment. We assessed baseline data from fifty MS patients enrolled in ReBUILD, a prospective trial assessing the effect of a remyelinating drug (clemastine). Subjects underwent 3T MRI imaging, including Neurite Orientation Dispersion and Density Imaging (NODDI), myelin content quantification, and retinal imaging, using OCT. Visual function was assessed, using low-contrast letter acuity. MRI and OCT data were studied to model visual function in MS, using a partial, least-squares, regression analysis. Measures of neurodegeneration along the entire visual pathway, described most of the observed variance in visual disability, measured by low contrast letter acuity. In those patients with an identified history of ON, however, putative myelin measures also showed correlation with visual performance. In the absence of clinically identifiable inflammatory episodes, residual disability correlates with neurodegeneration, whereas after an identifiable exacerbation, putative measures of myelin content are additionally informative.

Visualizing the Central Nervous System: Imaging Tools for Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) are autoimmune central nervous system conditions with increasing incidence and prevalence. While MS is the most frequent inflammatory CNS disorder in young adults, NMOSD is a rare disease, that is pathogenetically distinct from MS, and accounts for approximately 1% of demyelinating disorders, with the relative proportion within the demyelinating CNS diseases varying widely among different races and regions. Most immunomodulatory drugs used in MS are inefficacious or even harmful in NMOSD, emphasizing the need for a timely and accurate diagnosis and distinction from MS. Despite distinct immunopathology and differences in disease course and severity there might be considerable overlap in clinical and imaging findings, posing a diagnostic challenge for managing neurologists. Differential diagnosis is facilitated by positive serology for AQP4-antibodies (AQP4-ab) in NMOSD, but might be difficult in seronegative cases. Imaging of the brain, optic nerve, retina and spinal cord is of paramount importance when managing patients with autoimmune CNS conditions. Once a diagnosis has been established, imaging techniques are often deployed at regular intervals over the disease course as surrogate measures for disease activity and progression and to surveil treatment effects. While the application of some imaging modalities for monitoring of disease course was established decades ago in MS, the situation is unclear in NMOSD where work on longitudinal imaging findings and their association with clinical disability is scant. Moreover, as long-term disability is mostly attack-related in NMOSD and does not stem from insidious progression as in MS, regular follow-up imaging might not be useful in the absence of clinical events. However, with accumulating evidence for covert tissue alteration in NMOSD and with the advent of approved immunotherapies the role of imaging in the management of NMOSD may be reconsidered. By contrast, MS management still faces the challenge of implementing imaging techniques that are capable of monitoring progressive tissue loss in clinical trials and cohort studies into treatment algorithms for individual patients. This article reviews the current status of imaging research in MS and NMOSD with an emphasis on emerging modalities that have the potential to be implemented in clinical practice.

Optic chiasm measurements may be useful markers of anterior optic pathway degeneration in neuromyelitis optica spectrum disorders

OBJECTIVES

We aimed to evaluate optic chiasm (OC) measures as potential imaging marker for anterior optic pathway damage assessment in the context of neuromyelitis optica spectrum disorders (NMOSD).

MATERIALS AND METHOD

This cross-sectional study included 39 patients exclusively with aquaporin 4-IgG seropositive NMOSD of which 25 patients had a history of optic neuritis (NMOSD-ON) and 37 age- and sex-matched healthy controls (HC). OC heights, width, and area were measured using standard 3D T1-weighted MRI. Sensitivity of these measures to detect neurodegeneration in the anterior optic pathway was assessed in receiver operating characteristics analyses. Correlation coefficients were used to assess associations with structural measures of the anterior optic pathway (optic nerve dimensions, retinal ganglion cell loss) and clinical measures (visual function and disease duration).

RESULTS

OC heights and area were significantly smaller in NMOSD-ON compared to HC (NMOSD-ON vs. HC p < 0.0001). An OC area smaller than 22.5 mm² yielded a sensitivity of 0.92 and a specificity of 0.92 in separating chiasms of NMOSD-ON from HC. OC area correlated well with structural and clinical measures in NMOSD-ON: optic nerve diameter (r = 0.4, p = 0.047), peripapillary retinal nerve fiber layer thickness (r = 0.59, p = 0.003), global visual acuity (r = - 0.57, p = 0.013), and diseases duration (r = - 0.5, p = 0.012).

CONCLUSION

Our results suggest that OC measures are promising and easily accessible imaging markers for the assessment of anterior optic pathway damage.

KEY POINTS

• Optic chiasm dimensions were smaller in neuromyelitis optica spectrum disorder patients compared to healthy controls. • Optic chiasm dimensions are associated with retinal measures and visual dysfunction. • The optic chiasm might be used as an easily accessible imaging marker of neurodegeneration in the anterior optic pathway with potential functional relevance.

The immediate effect of stroboscopic visual training on information-processing time in people with multiple sclerosis: an exploratory study

Stroboscopic visual training (SVT) is a form of training aimed at improving visual and perceptual performance by having individuals perform activities under conditions of intermittent vision. The efficacy of SVT has never been examined in people with multiple sclerosis (PwMS), therefore, our aim was to examine the immediate effect of SVT on cognitive function, gait and static balance performance in PwMS. This assessor-blinded, randomized crossover study included 26 PwMS, 16 females, mean age 47.9 and median EDSS score 4.5. Participants attended two sessions: SVT and control training. Exercises for both the SVT and control sessions were based on ball-catching tasks. Training sessions were identical in length (40-50 min) and type of exercise drills. The difference between the two practice regimes was that the SVT session was performed wearing stroboscopic glasses and the control training was performed with similar glasses without lenses. Cognition was evaluated by a computerized software (Mindstreams^®, NeuroTrax Corp., NY). Gait and balance were evaluated via wearable accelerometers (APDM, Oregon, USA). Outcome measures were collected twice during a single session, prior to training and immediately afterward. Information processing speed (p = 0.003) increased at the post-evaluation compared with baseline, solely in the SVT session. No differences between pre-post evaluations were observed for other cognitive scores following the SVT session. No differences between pre-post measurements were noted for gait and balance following the SVT session. The present study's results justify performing future RCT studies to examine the effects of a longer SVT program on cognition in PwMS.

Fingolimod after a first unilateral episode of acute optic neuritis (MOVING) - preliminary results from a randomized, rater-blind, active-controlled, phase 2 trial

Background

Neuroprotection and promotion of remyelination represent important therapeutic gaps in multiple sclerosis (MS). Acute optic neuritis (ON) is a frequent MS manifestation. Based on the presence and properties of sphingosine-1-phosphate receptors (S1PR) on astrocytes and oligodendrocytes, we hypothesized that remyelination can be enhanced by treatment with fingolimod, a S1PR modulator currently licensed for relapsing-remitting MS.

Methods

MOVING was an investigator-driven, rater-blind, randomized clinical trial. Patients with acute unilateral ON, occurring as a clinically isolated syndrome or MS relapse, were randomized to 6 months of treatment with 0.5 mg oral fingolimod or subcutaneous IFN-β 1b 250 μg every other day. The change in multifocal visual evoked potential (mfVEP) latency of the qualifying eye was examined as the primary (month 6 vs. baseline) and secondary (months 3, 6 and 12 vs. baseline) outcome. In addition, full field visual evoked potentials, visual acuity, optical coherence tomography as well as clinical relapses and measures of disability, cerebral MRI, and self-reported visual quality of life were obtained for follow-up. The study was halted due to insufficient recruitment (n = 15), and available results are reported.

Results

Per protocol analysis of the primary endpoint revealed a significantly larger reduction of mfVEP latency at 6 months compared to baseline with fingolimod treatment (n = 5; median decrease, 15.7 ms) than with IFN-β 1b treatment (n = 4; median increase, 8.15 ms) (p <  0.001 for interaction). Statistical significance was maintained in the secondary endpoint analysis. Descriptive results are reported for other endpoints.

Conclusion

Preliminary results of the MOVING trial argue in support of a beneficial effect of fingolimod on optic nerve remyelination when compared to IFN-β treatment. Interpretation is limited by the small number of complete observations, an unexpected deterioration of the control group and a difference in baseline mfVEP latencies. The findings need to be confirmed in larger studies.

Trial registration

The trial was registered as EUDRA-CT 2011–004787-30 on October 26, 2012 and as NCT01647880 on July 24, 2012.

Assessments of vessel density and foveal avascular zone metrics in multiple sclerosis: an optical coherence tomography angiography study

BACKGROUND/OBJECTIVES

To investigate optical coherence tomography angiography (OCT-A) findings of foveal avascular zone (FAZ) metrics and macular & peripapillary vessel densities (VD) in subjects with multiple sclerosis (MS).

METHODS

The study design was prospective and cross-sectional. FAZ metrics and VDs of the superficial capillary plexus (SCP), deep capillary plexus (DCP), retinal peripapillary capillary plexus (RPCP) along with the structural OCT measurements were scanned by using the Nidek's RS-3000 Advance in MS patients and healthy controls. All subject also underwent an assessment of visual evoked potentials (VEPs). The relationships between the OCT-A parameters with other clinical findings were analysed.

RESULTS

Forty-seven MS patients (94 eyes) and 61 healthy volunteers (122 eyes) were included in this study. Thirty-five eyes of the MS patients had an ON history. The structural OCT measurements were significantly differed between the groups (P < 0.001). All FAZ metrics were inversely correlated with central foveal thickness (CFT) (P < 0.001). The FAZ area and perimeter were inversely correlated with the VD of both SCP and DCP (P < 0.05). The VDs of SCP and DCP were significantly differed between the study groups (P < 0.001). The VEP latency was inversely correlated with the retinal nerve fibre layer, macular and ganglion cell layer thicknesses, the VD of SCP, and the VD of the DCP (P < 0.001).

CONCLUSIONS

Based on OCT angiography, VDs of macular and peripapillary area may be useful in detecting damage from ON in patients with MS.

Suggestions for improving the design of clinical trials in multiple sclerosis-results of a systematic analysis of completed phase III trials

This manuscript reviews the primary and secondary endpoints of pivotal phase III trials with immunomodulatory drugs in multiple sclerosis (MS). Considering the limitations of previous trial designs, we propose new standards for the planning of clinical trials, taking into account latest insights into MS pathophysiology and patient-relevant aspects. Using a systematic overview of published phase III (pivotal) trials performed as part of application for drug market approval, we evaluate the following characteristics: trial duration, number of trial participants, comparators, and endpoints (primary, secondary, magnetic resonance imaging outcome, and patient-reported outcomes). From a patient perspective, the primary and secondary endpoints of clinical trials are only partially relevant. High-quality trial data pertaining to efficacy and safety that stretch beyond the time frame of pivotal trials are almost non-existent. Understanding of long-term benefits and risks of disease-modifying MS therapy is largely lacking. Concrete proposals for the trial designs of relapsing (remitting) multiple sclerosis/clinically isolated syndrome, primary progressive multiple sclerosis, and secondary progressive multiple sclerosis (e.g., study duration, mechanism of action, and choice of endpoints) are presented based on the results of the systematic overview. Given the increasing number of available immunotherapies, the therapeutic strategy in MS has shifted from a mere "relapse-prevention" approach to a personalized provision of medical care as to the choice of the appropriate drugs and their sequential application over the course of the disease. This personalized provision takes patient preferences as well as disease-related factors into consideration such as objective clinical and radiographic findings but also very burdensome symptoms such as fatigue, depression, and cognitive impairment. Future trial designs in MS will have to assign higher relevance to these patient-reported outcomes and will also have to implement surrogate measures that can serve as predictive markers for individual treatment response to new and investigational immunotherapies. This is an indispensable prerequisite to maximize the benefit of individual patients when participating in clinical trials. Moreover, such appropriate trial designs and suitable enrolment criteria that correspond to the mode of action of the study drug will facilitate targeted prevention of adverse events, thus mitigating risks for individual study participants.

Transcranial Magnetic Stimulation as a Potential Biomarker in Multiple Sclerosis: A Systematic Review with Recommendations for Future Research

Multiple sclerosis (MS) is a demyelinating disorder of the central nervous system. Disease progression is variable and unpredictable, warranting the development of biomarkers of disease status. Transcranial magnetic stimulation (TMS) is a noninvasive method used to study the human motor system, which has shown potential in MS research. However, few reviews have summarized the use of TMS combined with clinical measures of MS and no work has comprehensively assessed study quality. This review explored the viability of TMS as a biomarker in studies of MS examining disease severity, cognitive impairment, motor impairment, or fatigue. Methodological quality and risk of bias were evaluated in studies meeting selection criteria. After screening 1603 records, 30 were included for review. All studies showed high risk of bias, attributed largely to issues surrounding sample size justification, experimenter blinding, and failure to account for key potential confounding variables. Central motor conduction time and motor-evoked potentials were the most commonly used TMS techniques and showed relationships with disease severity, motor impairment, and fatigue. Short-latency afferent inhibition was the only outcome related to cognitive impairment. Although there is insufficient evidence for TMS in clinical assessments of MS, this review serves as a template to inform future research.

Ozanimod for the treatment of relapsing remitting multiple sclerosis

INTRODUCTION

Ozanimod is a selective sphingosine 1-phosphate receptor 1 and 5 modulator under development by Celgene, for the treatment of relapsing remitting multiple sclerosis. Extensive clinical experience has become available for the related compound fingolimod, favoring the sphingosine 1-phosphate therapeutic concept. Off-target effects have been attributed to its low receptor specificity and have prompted the development of next generation sphingosine 1-phosphate receptor modulators. Areas covered: The authors evaluate the literature of ozanimod, using the PubMed database as well as repositories of the European Committee for Treatment and Research in Multiple Sclerosis and the American and European Academy of Neurology. Specifically, the authors cover and discuss the preclinical data on ozanimod, pharmacokinetics and dynamics, and data on efficacy and safety from the pivotal trials. Expert opinion: Superiority of ozanimod over intramuscular interferon β-1a with regard to reduction in annualized relapse rate and magnetic resonance imaging outcomes has been shown in two phase III trials. The beneficial effect on brain volume and gray matter loss are encouraging and in line with data on other newer immunomodulators. Ozanimod is a valuable contribution to the therapeutic armamentarium in MS, although the effect on disability progression is unclear and requires further investigations.

Diagnosis and Treatment of NMO Spectrum Disorder and MOG-Encephalomyelitis

Neuromyelitis optica spectrum disorders (NMOSD) are autoantibody mediated chronic inflammatory diseases. Serum antibodies (Abs) against the aquaporin-4 water channel lead to recurrent attacks of optic neuritis, myelitis and/or brainstem syndromes. In some patients with symptoms of NMOSD, no AQP4-Abs but Abs against myelin-oligodendrocyte-glycoprotein (MOG) are detectable. These clinical syndromes are now frequently referred to as "MOG-encephalomyelitis" (MOG-EM). Here we give an overview on current recommendations concerning diagnosis of NMOSD and MOG-EM. These include antibody and further laboratory testing, MR imaging and optical coherence tomography. We discuss therapeutic options of acute attacks as well as longterm immunosuppressive treatment, including azathioprine, rituximab, and immunoglobulins.