Sphingosine 1-phosphate receptor modulators in multiple sclerosis treatment: A practical review

Four sphingosine 1-phosphate (S1P) receptor modulators (fingolimod, ozanimod, ponesimod, and siponimod) are approved by the US Food and Drug Administration for the treatment of multiple sclerosis. This review summarizes efficacy and safety data on these S1P receptor modulators, with an emphasis on similarities and differences. Efficacy data from the pivotal clinical trials are generally similar for the four agents. However, because no head-to-head clinical studies were conducted, direct efficacy comparisons cannot be made. Based on the adverse event profile of S1P receptor modulators, continued and regular monitoring of patients during treatment will be instructive. Notably, the authors recommend paying attention to the cardiac monitoring guidelines for these drugs, and when indicated screening for macular edema and cutaneous malignancies before starting treatment. To obtain the best outcome, clinicians should choose the drug based on disease type, history, and concomitant medications for each patient. Real-world data should help to determine whether there are meaningful differences in efficacy or side effects between these agents.

Mapping the Relationship of White Matter Lesions to Depression in Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated neurological disorder, and up to 50% of patients experience depression. We investigated how white matter network disruption is related to depression in MS.

METHODS

Using electronic health records, 380 participants with MS were identified. Depressed individuals (MS+Depression group; n = 232) included persons who had an ICD-10 depression diagnosis, had a prescription for antidepressant medication, or screened positive via Patient Health Questionnaire (PHQ)-2 or PHQ-9. Age- and sex-matched nondepressed individuals with MS (MS-Depression group; n = 148) included persons who had no prior depression diagnosis, had no psychiatric medication prescriptions, and were asymptomatic on PHQ-2 or PHQ-9. Research-quality 3T structural magnetic resonance imaging was obtained as part of routine care. We first evaluated whether lesions were preferentially located within the depression network compared with other brain regions. Next, we examined if MS+Depression patients had greater lesion burden and if this was driven by lesions in the depression network. Primary outcome measures were the burden of lesions (e.g., impacted fascicles) within a network and across the brain.

RESULTS

MS lesions preferentially affected fascicles within versus outside the depression network (β = 0.09, 95% CI = 0.08 to 0.10, p < .001). MS+Depression patients had more lesion burden (β = 0.06, 95% CI = 0.01 to 0.10, p = .015); this was driven by lesions within the depression network (β = 0.02, 95% CI = 0.003 to 0.040, p = .020).

CONCLUSIONS

We demonstrated that lesion location and burden may contribute to depression comorbidity in MS. MS lesions disproportionately impacted fascicles in the depression network. MS+Depression patients had more disease than MS-Depression patients, which was driven by disease within the depression network. Future studies relating lesion location to personalized depression interventions are warranted.

Mapping the relationship of white matter lesions to depression in multiple sclerosis

Importance

Multiple sclerosis (MS) is an immune-mediated neurological disorder that affects nearly one million people in the United States. Up to 50% of patients with MS experience depression.

Objective

To investigate how white matter network disruption is related to depression in MS.

Design

Retrospective case-control study of participants who received research-quality 3-tesla neuroimaging as part of MS clinical care from 2010-2018. Analyses were performed from May 1 to September 30, 2022.

Setting

Single-center academic medical specialty MS clinic.

Participants

Participants with MS were identified via the electronic health record (EHR). All participants were diagnosed by an MS specialist and completed research-quality MRI at 3T. After excluding participants with poor image quality, 783 were included. Inclusion in the depression group (MS+Depression) required either: 1) ICD-10 depression diagnosis (F32-F34.*); 2) prescription of antidepressant medication; or 3) screening positive via Patient Health Questionnaire-2 (PHQ-2) or -9 (PHQ-9). Age- and sex-matched nondepressed comparators (MS-Depression) included persons with no depression diagnosis, no psychiatric medications, and were asymptomatic on PHQ-2/9.

Exposure

Depression diagnosis.

Main Outcomes and Measures

We first evaluated if lesions were preferentially located within the depression network compared to other brain regions. Next, we examined if MS+Depression patients had greater lesion burden, and if this was driven by lesions specifically in the depression network. Outcome measures were the burden of lesions (e.g., impacted fascicles) within a network and across the brain. Secondary measures included between-diagnosis lesion burden, stratified by brain network. Linear mixed-effects models were employed.

Results

Three hundred-eighty participants met inclusion criteria, (232 MS+Depression: age[SD]=49[12], %females=86; 148 MS-Depression: age[SD]=47[13], %females=79). MS lesions preferentially affected fascicles within versus outside the depression network (β=0.09, 95% CI=0.08-0.10, P<0.001). MS+Depression had more white matter lesion burden (β=0.06, 95% CI=0.01-0.10, P=0.015); this was driven by lesions within the depression network (β=0.02, 95% CI 0.003-0.040, P=0.020).

Conclusions and Relevance

We provide new evidence supporting a relationship between white matter lesions and depression in MS. MS lesions disproportionately impacted fascicles in the depression network. MS+Depression had more disease than MS-Depression, which was driven by disease within the depression network. Future studies relating lesion location to personalized depression interventions are warranted.

Cellular and humoral immune responses following SARS-CoV-2 mRNA vaccination in patients with multiple sclerosis on anti-CD20 therapy

SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (TFH) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (TH1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating TFH responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.

Limbic pathway lesions in patients with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a well-known demyelinating disease to cause cognitive dysfunction. The limbic system, relevant to memory, can be easily overlooked in conventional magnetic resonance imaging (MRI).

PURPOSE

To investigate the distribution and frequency of demyelinating lesions affecting white matter connections of the limbic system based on localization with diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) color maps compared to three-dimensional T2-weighted (T2W) and FLAIR volumes in MS patients.

MATERIAL AND METHODS

One hundred and fifty patients with a known diagnosis of MS were identified for this Health Insurance Portability and Accountability (HIPAA)-compliant retrospective cross-sectional study. DTI-derived FA color maps, co-registered to T2W and FLAIR images, were analyzed for lesions affecting the three white matter tracts of the limbic system including cingulum, fornix, and mammilothalamic tracts by two investigators. The approximate location of the lesions on FLAIR was always confirmed on the co-registered DTI-derived FA color maps.

RESULTS

Of the 150 patients analyzed, 14.6% had cingulum lesions, 2.6% had fornix lesions, and 2.6% had mammilothalamic tract lesions; 21.3% of patients had at least one of the three tracts affected.

CONCLUSION

A relatively high frequency of lesions involving the limbic tracts may explain memory deficits and emotional dysfunction commonly experienced by patients with MS. The combined information from T2W, FLAIR, and DTI-derived FA color map allowed for more accurate localization of lesions affecting the major white matter tracts of the limbic system.

Re-evaluating the treatment of acute optic neuritis

Clinical case reports and prospective trials have demonstrated a reproducible benefit of hypothalamic-pituitary-adrenal (HPA) axis modulation on the rate of recovery from acute inflammatory central nervous system (CNS) demyelination. As a result, corticosteroid preparations and adrenocorticotrophic hormones are the current mainstays of therapy for the treatment of acute optic neuritis (AON) and acute demyelination in multiple sclerosis.Despite facilitating the pace of recovery, HPA axis modulation and corticosteroids have failed to demonstrate long-term benefit on functional recovery. After AON, patients frequently report visual problems, motion perception difficulties and abnormal depth perception despite 'normal' (20/20) vision. In light of this disparity, the efficacy of these and other therapies for acute demyelination require re-evaluation using modern, high-precision paraclinical tools capable of monitoring tissue injury.In no arena is this more amenable than AON, where a new array of tools in retinal imaging and electrophysiology has advanced our ability to measure the anatomic and functional consequences of optic nerve injury. As a result, AON provides a unique clinical model for evaluating the treatment response of the derivative elements of acute inflammatory CNS injury: demyelination, axonal injury and neuronal degeneration.In this article, we examine current thinking on the mechanisms of immune injury in AON, discuss novel technologies for the assessment of optic nerve structure and function, and assess current and future treatment modalities. The primary aim is to develop a framework for rigorously evaluating interventions in AON and to assess their ability to preserve tissue architecture, re-establish normal physiology and restore optimal neurological function.

Identifying and addressing unmet therapeutic needs in MS

Current disease-modifying treatments in multiple sclerosis (MS) are partially effective in reducing relapses and slowing disease progression, but these treatments do not restore function and are effective mainly in relapsing forms of MS. Unmet needs in MS include treatments for progressive forms of MS, agents with improved efficacy and safety profiles and that comprehensively manage MS symptoms, and medications with neuroprotective or remyelinating properties. Some adverse effects of disease-modifying agents could be reduced if medications are developed with more specific treatment targets, and research into the pathogenesis of MS may lead to agents that could restore myelin or protect nerves from inflammation.

Multiple sclerosis update

Multiple sclerosis (MS) is a chronic but incurable disease of the central nervous system (CNS) that is often diagnosed in the second or third decade of life. It is more common among women than men, significantly impairs patient quality of life, and is associated with substantial costs to patients, healthcare systems, and society. Of the approximately 2.3 million individuals worldwide that have MS, more than 400,000 reside in the United States. Although the etiology of MS is not completely understood, a great deal of evidence suggests a complex relationship between environmental and genetic factors. The pathophysiology of MS involves an aberrant attack by the host immune system on oligodendrocytes, which synthesize and maintain myelin sheaths in the CNS. There are 4 identified disease courses in MS, and approximately 85% of people with MS present with relapsing-remitting MS, which is characterized by discrete acute attacks followed by periods of remission. Signs and symptoms of MS are dependent on the demyelinated area(s) of the CNS and often involve sensory disturbances, limb weakness, fatigue, and increased body temperature. The criteria for a diagnosis of MS include evidence of damage in at least 2 separate areas of the CNS, evidence that the damage occurred at different time points, and the ruling out of other possible diagnoses. Diseasemodifying drugs (DMDs) that reduce the frequency of relapses, development of brain lesions, and progression of disability are the standard of care for relapsing forms of MS, and the use of DMDs should be initiated as early as possible.

Constructing an adaptive care model for the management of disease-related symptoms throughout the course of multiple sclerosis—performance improvement CME

Background:

Symptom management remains a challenging clinical aspect of MS.

Objective:

To design a performance improvement continuing medical education (PI CME) activity for better clinical management of multiple sclerosis (MS)-related depression, fatigue, mobility impairment/falls, and spasticity.

Methods:

Ten volunteer MS centers participated in a three-stage PI CME model: A) baseline assessment; B) practice improvement CME intervention; C) reassessment. Expert faculty developed performance measures and activity intervention tools. Designated MS center champions reviewed patient charts and entered data into an online database. Stage C data were collected eight weeks after implementation of the intervention and compared with Stage A baseline data to measure change in performance.

Results:

Aggregate data from the 10 participating MS centers (405 patient charts) revealed performance improvements in the assessment of all four MS-related symptoms. Statistically significant improvements were found in the documented assessment of mobility impairment/falls ( p=0.003) and spasticity ( p<0.001). For documentation of care plans, statistically significant improvements were reported for fatigue ( p=0.007) and mobility impairment/falls ( p=0.040); non-significant changes were noted for depression and spasticity.

Conclusions:

Our PI CME interventions demonstrated performance improvement in the management of MS-related symptoms. This PI CME model (available at www.achlpicme.org/ms/toolkit ) offers a new perspective on enhancing symptom management in patients with MS.

Direct visualization of short transverse relaxation time component (ViSTa)

White matter of the brain has been demonstrated to have multiple relaxation components. Among them, the short transverse relaxation time component (T2<40 ms; T2⁎<25 ms at 3 T) has been suggested to originate from myelin water whereas long transverse relaxation time components have been associated with axonal and/or interstitial water. In myelin water imaging, T2 or T2⁎ signal decay is measured to estimate myelin water fraction based on T2 or T2⁎ differences among the water components. This method has been demonstrated to be sensitive to demyelination in the brain but suffers from low SNR and image artifacts originating from ill-conditioned multi-exponential fitting. In this study, a novel approach that selectively acquires short transverse relaxation time signal is proposed. The method utilizes a double inversion RF pair to suppress a range of long T1 signal. This suppression leaves short T2⁎ signal, which has been suggested to have short T1, as the primary source of the image. The experimental results confirm that after suppression of long T1 signals, the image is dominated by short T2⁎ in the range of myelin water, allowing us to directly visualize the short transverse relaxation time component in the brain. Compared to conventional myelin water imaging, this new method of direct visualization of short relaxation time component (ViSTa) provides high quality images. When applied to multiple sclerosis patients, chronic lesions show significantly reduced signal intensity in ViSTa images suggesting sensitivity to demyelination.

Exposure to CYP3A4-inducing and CYP3A4-non-inducing antiepileptic agents and the risk of fractures

PURPOSE

To evaluate whether exposure to Cytochrome P450, family 3, subfamily A, polypeptide 4 (CYP3A4)-inducing antiepileptics increases fracture risk compared to CYP3A4-non-inducing antiepileptics.

METHODS

We performed a retrospective cohort study of initiators of antiepileptic agents using a UK medical record database (The Health Improvement Network) from 1995 to 2007. We considered an antiepileptic user an initiator if he or she had not received a prescription for an antiepileptic agent within the first year after entry in the database. Proportional hazards regression was used to calculate hazard ratios for fracture during long-term (≥ 6 months) exposure to CYP3A4 inducing versus CYP3A4 non-inducing antiepileptics.

RESULTS

We identified 4077 initiators of CYP3A4-inducing antiepileptics and 6433 initiators of CYP3A4-non-inducing antiepileptics with at least 6 months of antiepileptic exposure. During 6006 person-years exposed to CYP3A4-inducing antiepileptics, 118 fractures were identified for an incidence rate of 1.96 (95% confidence interval (CI): 1.63-2.35) fractures per 100 person-years. During 7184 person-years exposed to CYP3A4-non-inducing antiepileptics, 127 fractures were identified, for an incidence rate of 1.77 (95% CI: 1.47-2.10) fractures per 100 person-years. The adjusted hazard ratio for CYP3A4-inducing antiepileptic versus CYP3A4-non-inducing antiepileptic was 1.21 (95% CI: 0.93-1.56). No duration-response relationship was evident.

CONCLUSIONS

Our results do not support the hypothesis that CYP3A4 induction by antiepileptic agents increases the fracture risk. Further research will be needed to evaluate whether mechanisms other than CYP3A4 induction might explain some of the elevated risk of fractures associated with long-term use of antiepileptic agents.

Stratus OCT Quality Control in Two Multi-Centre Multiple Sclerosis Clinical Trials

The University of California (UC) Davis Reading Center evaluated 19,961 scans from 981 subjects in two multiple sclerosis therapeutic trials with the aim of determining the influence of optical coherence tomography quality control procedures on error rates. There was no optical coherence tomography technician certification in Trial 1, and technicians had very limited monitoring and feedback during the trial in view of the fact that data were received retrospectively. However, technicians were certified in Trial 2 and submitted data in accordance with the protocol. Trial 2 scans had higher signal strengths, fewer errors, and more useable data than the scans in Trial 1. Thus, certified technicians and prompt transmission of data for ongoing quality control monitoring provided higher quality data in multiple sclerosis trials.

Fingolimod for the treatment of relapsing multiple sclerosis

Fingolimod is the first oral agent approved in the USA for the treatment of relapsing forms of multiple sclerosis. Fingolimod is a sphingosine 1-phosphate receptor modulator that binds to sphingosine 1-phosphate receptors on lymphocytes, resulting in a downregulation of the receptor and a reversible sequestration of lymphocytes in lymphoid tissue. Effector memory T cells are not sequestered so that immune surveillance may be minimally affected. Two large-scale Phase III clinical trials have demonstrated the efficacy of fingolimod compared with placebo and intramuscular interferon β-1a in relapsing-remitting multiple sclerosis. Due to its mechanism of action, fingolimod administration may be associated with first-dose bradycardia and macular edema. Therefore, patients should be observed for 6 h at the time of their first dose and undergo ophthalmologic evaluation prior to treatment initiation and at 3-4 months after initiation.

The current landscape and unmet needs in multiple sclerosis

When introduced in the early and middle 1990s, current first-line pharmacologic therapies for multiple sclerosis (MS)--interferon beta-1a, interferon beta-1b, and glatiramer acetate--constituted a major advancement in MS treatment. Nevertheless, disease progression, although typically delayed with these agents, remains inevitable in most patients and constitutes a significant limitation of the currently available treatments. Moreover, the first-line therapies all require frequent subcutaneous or intramuscular injections, delivery modalities that are associated with subpar treatment adherence. The demand for more effective agents has produced a new generation of MS therapies with impressive efficacy profiles--although their long-term safety and tolerability remain largely unknown. Some of the new agents have been formulated for oral administration, which will likely have a positive impact on treatment adherence. These new agents are appearing during a time of major change in MS research. As the old expectation of inevitable disease progression is being reconsidered, the notion of sustained disease inactivity has become a credible, still somewhat elusive, goal. Neuroprotection may also be possible with new and existing treatments. At the same time, new imaging techniques, such as measuring disease progression via T1-hypointense lesions ("black holes"), and a better understanding of pathophysiologic factors in MS--such as the role of neurotrophic growth factors and oxidative stress--are changing the ways that efficacy is measured and how new agents are developed.

Longitudinal study of vision and retinal nerve fiber layer thickness in multiple sclerosis

OBJECTIVE

Cross-sectional studies of optical coherence tomography (OCT) show that retinal nerve fiber layer (RNFL) thickness is reduced in multiple sclerosis (MS) and correlates with visual function. We determined how longitudinal changes in RNFL thickness relate to visual loss. We also examined patterns of RNFL thinning over time in MS eyes with and without a prior history of acute optic neuritis (ON).

METHODS

Patients underwent OCT measurement of RNFL thickness at baseline and at 6-month intervals during a mean follow-up of 18 months at 3 centers. Low-contrast letter acuity (2.5%, 1.25% contrast) and visual acuity (VA) were assessed.

RESULTS

Among 299 patients (593 eyes) with >or=6 months follow-up, eyes with visual loss showed greater RNFL thinning compared to eyes with stable vision (low-contrast acuity, 2.5%: p < 0.001; VA: p = 0.005). RNFL thinning increased over time, with average losses of 2.9microm at 2 to 3 years and 6.1microm at 3 to 4.5 years (p < 0.001 vs 0.5-1-year follow-up interval). These patterns were observed for eyes with or without prior history of ON. Proportions of eyes with RNFL loss greater than test-retest variability (>or=6.6microm) increased from 11% at 0 to 1 year to 44% at 3 to 4.5 years (p < 0.001).

INTERPRETATION

Progressive RNFL thinning occurs as a function of time in some patients with MS, even in the absence of ON, and is associated with clinically significant visual loss. These findings are consistent with subclinical axonal loss in the anterior visual pathway in MS, and support the use of OCT and low-contrast acuity as methods to evaluate the effectiveness of putative neuroprotection protocols.

An approach to comparing accuracies of two FLAIR MR sequences in the detection of multiple sclerosis lesions in the brain in the absence of gold standard

RATIONALE AND OBJECTIVES

The purpose of this study was to present a new methodology to compare accuracies of two imaging fluid attenuated inversion recovery (FLAIR) magnetic resonance sequences in detection of multiple sclerosis (MS) lesions in the brain in the absence of ground truth, and to determine whether the two sequences, which differed only in echo time (TE), have the same accuracy.

MATERIALS AND METHODS

We acquired FLAIR images at TE(1) = 90 ms and TE(2) = 155 ms from 46 patients with MS (24-69 years old, mean 45.8, 15 males) and 11 healthy volunteers (23-54 years old, mean 37.1, 6 males). Seven experienced neuroradiologists segmented lesions manually on randomly presented corresponding TE(1) and TE(2) images. For every image pair, a "surrogate ground truth" for each TE was generated by applying probability thresholds, ranging from 0.3 to 0.5, to the weighted average of experts' segmentations. Jackknife alternative free-response receiver operating characteristic analysis was used to compare experts' performance on TE(1) and TE(2) images, using successively the TE(1)- and TE(2)-based ground truths.

RESULTS

Supratentorially, there were significant differences in relative accuracy between the two sequences, ranging from 8.4% to 12.1%. In addition, we found a higher ratio of false positives to true positives for the TE(2) sequence using the TE(2) ground truth, compared to the TE(1) equivalent. Infratentorially, differences in the relative accuracy did not reach statistical significance.

CONCLUSION

The presented methodology may be useful in assessing the value of new clinical imaging protocols or techniques in the context of replacing existing ones, when the absolute ground truth is not available, and in determining changes in disease progression in follow-up studies. Our results suggest that the sequence with shorter TE should be preferred because it generates relatively fewer false positives. The finding is consistent with results of previous computer simulation studies.

Macular volume determined by optical coherence tomography as a measure of neuronal loss in multiple sclerosis

BACKGROUND

Inner (area adjacent to the fovea) and outer regions of the macula differ with respect to relative thicknesses of the ganglion cell layer (neurons) vs retinal nerve fiber layer (RNFL; axons).

OBJECTIVE

To determine how inner vs outer macular volumes relate to peripapillary RNFL thickness and visual function in multiple sclerosis (MS) and to examine how these patterns differ among eyes with vs without a history of acute optic neuritis (ON).

DESIGN

Study using cross-sectional optical coherence tomography.

SETTING

Three academic tertiary care MS centers.

PARTICIPANTS

Patients with MS, diagnosed by standard criteria, and disease-free control participants.

MAIN OUTCOME MEASURES

Optical coherence tomography was used to measure macular volumes and RNFL thickness. Visual function was assessed using low-contrast letter acuity and high-contrast visual acuity (Early Treatment Diabetic Retinopathy Study charts).

RESULTS

Among eyes of patients with MS (n = 1058 eyes of 530 patients), reduced macular volumes were associated with peripapillary RNFL thinning; 10-microm differences in RNFL thickness (9.6% of thickness in control participants without disease) corresponded to 0.20-mm(3) reductions in total macular volume (2.9% of volume in control participants without disease, P < .001). This relation was similar for eyes of MS patients with and without a history of ON. Although peripapillary RNFL thinning was more strongly associated with decrements in outer compared with inner macular volumes, correlations with inner macular volume were significant (r = 0.58, P < .001) and of slightly greater magnitude for eyes of MS patients with a history of ON vs eyes of MS patients without a history of ON (r = 0.61 vs r = 0.50). Lower (worse) visual function scores were associated with reduced total, inner, and outer macular volumes. However, accounting for peripapillary RNFL thickness, the relation between vision and inner macular volume remained significant and unchanged in magnitude, suggesting that this region contains retinal structures separate from RNFL axons that are important to vision.

CONCLUSIONS

Analogous to studies of gray matter in MS, these data provide evidence that reductions of volume in the macula (approximately 34% neuronal cells by average thickness) accompany RNFL axonal loss. Peripapillary RNFL thinning and inner macular volume loss are less strongly linked in eyes of MS patients without a history of ON than in eyes of MS patients with a history of ON, suggesting alternative mechanisms for neuronal cell loss. Longitudinal studies with segmentation of retinal layers will further explore the relation and timing of ganglion cell degeneration and RNFL thinning in MS.

Modulation of serum uric acid levels by inosine in patients with multiple sclerosis does not affect blood pressure

The role of uric acid (UA) in human physiology is subject to controversy. Either it is an important radical scavenger, a mostly neutral, waste metabolic product that may cause gout and kidney stones if elevated, or it is involved in the causation of hypertension, vascular and renal diseases. Recently we conducted a clinical trial to determine whether raising the serum UA levels through the oral administration of inosine is well tolerated and may benefit patients with multiple sclerosis. An important aspect of the safety profile is whether raising the serum UA levels elevates blood pressure. During the 1-year trial, blood pressure and serum UA levels were monitored in 16 patients. Both parameters were recorded throughout the trial that included 69 visits by patients at baseline and during the placebo phase as well as 138 visits while receiving inosine treatment. We have observed that although the serum UA levels increased significantly during the inosine treatment phase of the trial, from 4.2+/-0.8 to 7.1+/-1.7 mg per 100 ml, blood pressure remained unchanged, averaging 123+/-15/78+/-9. Our findings indicate that raising the serum UA levels to upper normal physiological levels for a period of up to 1-year does not influence blood pressure significantly.

The treatment of multiple sclerosis with inosine

OBJECTIVE

The objective of this study is to evaluate the safety and tolerability of inosine in patients with relapsing-remitting multiple sclerosis (RRMS). The secondary objectives are to assess the effects of inosine administration on serum urate (UA) levels, the progression of neurologic disability, the cumulative number of new, active lesions on magnetic resonance imaging (MRI), and changes in serum levels for markers of inflammation.

DESIGN

Oral administration of inosine was used to raise serum levels of the natural peroxynitrite scavenger UA in 16 patients with RRMS during a 1-year randomized, double-blind trial.

OUTCOME MEASURES

The endpoints studied were relapse rate, disability assessed by the Kurtzke Expanded Disability Status Scale (EDSS), MRI, and analysis of serum levels of nitrotyrosine, and oxidative and pro-inflammatory makers.

RESULTS

Increased serum UA levels correlated with a significant decrease in the number of gadolinium-enhanced lesions and improved EDSS. A number of MRI intensity-based parameters were altered by inosine treatment, in certain cases correlating with changes in serum UA levels. In a patient with low serum UA and high lesion activity, raising UA levels by inosine treatment decreased serum nitrotyrosine while increasing the ratio of Th2 to Th1 cytokines in circulating cells. The only side-effect correlated with inosine treatment was kidney stone formation in 4/16 subjects.

CONCLUSIONS

These data suggest that the use of inosine to raise serum UA levels may have benefits for at least some MS patients. The effect of this treatment is likely to be a consequence of inactivation of peroxynitrite-dependent free radicals. Close monitoring of serum UA levels as well as other measures are required to avoid the potential development of kidney stones.

Vision related quality of life in multiple sclerosis: correlation with new measures of low and high contrast letter acuity

OBJECTIVE

To examine the relation between low contrast letter acuity, a new visual function test for multiple sclerosis (MS) trials, and vision targeted health related quality of life (HRQOL).

METHODS

Patients in this cross sectional study were part of an ongoing investigation of visual function in MS. Patients were tested binocularly using low contrast letter acuity and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) charts. The 25 Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), 10 Item Neuro-Ophthalmic Supplement to the NEI-VFQ-25, Impact of Visual Impairment Scale and Short Form 36 Health Survey (SF-36) were administered.

RESULTS

Among 167 patients, mean age was 48 (10) years, with median Expanded Disability Status Scale (EDSS) 2.0 (range 1.0-7.5), and median binocular Snellen acuity equivalent (ETDRS charts) 20/16 (range 20/12.5 to 20/100). Reductions in vision specific HRQOL were associated with lower (worse) scores for low contrast letter acuity and VA (p<0.001, linear regression, accounting for age). Two line differences in visual function were associated, on average, with >4 point (6.7-10.9 point) worsening in the NEI-VFQ-25 composite score, reductions that are considered clinically meaningful. Scores for the 10 Item Neuro-Ophthalmic Supplement to the NEI-VFQ-25 also correlated well with visual function. Associations between reduced low contrast acuity and worse vision targeted HRQOL remained significant in models accounting for high contrast VA, EDSS and history of acute optic neuritis.

CONCLUSIONS

Low contrast letter acuity scores correlate well with HRQOL in MS. Two line differences in scores for low contrast acuity and VA reflect clinically meaningful differences in vision targeted HRQOL. Low contrast acuity testing provides information on patient reported aspects of vision, supporting use of these measures in MS clinical trials.

Expanded Disability Status Scale Calculator for Handheld Personal Digital Assistant: Reliability Study

Through a standard neurological examination, the Expanded Disability Status Scale (EDSS) score is traditionally determined by a pen-and-paper method. The objectives of this study were to compare the interrater/method reliability of EDSS scores obtained through the pen-and-paper method with those obtained with the EDSS Calculator, evaluate test-retest reliability of the EDSS Calculator, and examine the validity of EDSS Calculator scores through correlation with the Ambulation Index (AI). During a single office visit, 62 subjects with multiple sclerosis (MS) from six study centers had disability levels evaluated by separate raters using the EDSS calculator and pen-and-paper methods in random order. Seven days later, subjects returned for reevaluation with the EDSS Calculator; AI was also evaluated. Mean EDSS scores for the sample were 3.5 ± 2.2 with the calculator and 3.4 ± 2.0 (range 0–8) with the traditional method. Interrater reliability between scores with the two methods was high (κ = 0.84; confidence interval [CI], 0.74–0.94). Test-retest reliability with the calculator was also high (κ = 0.93; CI, 0.86–0.996). Correlation between disability scores from the EDSS Calculator and AI was 0.73 (P &lt;.001). Relative to the pen-and paper method, the EDSS Calculator was found to be highly reliable and provide valid results when measuring disability in MS patients.

Palliative care in amyotrophic lateral sclerosis, Parkinson's disease, and multiple sclerosis

BACKGROUND

Amyotrophic lateral sclerosis, Parkinson's disease, atypical parkinsonian syndromes, and multiple sclerosis are progressive neurologic disorders that cumulatively afflict a large number of people. Effective end-of-life palliative care depends upon an understanding of the clinical aspects of each of these disorders.

OBJECTIVES

The authors review the unique and overlapping aspects of each of these disorders with an emphasis upon the clinical management of symptoms.

DESIGN

The authors review current management and the supporting literature.

CONCLUSIONS

Clinicians have many effective therapeutic options to choose from when managing the symptoms produced by these disorders.

Relation of vision to global and regional brain MRI in multiple sclerosis

OBJECTIVE

To examine the relation between low-contrast letter acuity, an emerging visual outcome for multiple sclerosis (MS) clinical trials, and brain MRI abnormalities in an MS cohort.

METHODS

T2 lesion volume and brain parenchymal fraction were determined for whole brain and within visual pathway regions of interest. Magnetization transfer ratio histograms were examined. Vision testing was performed binocularly using low-contrast letter acuity (2.5%, 1.25% contrast) and high-contrast visual acuity (VA). Linear regression, accounting for age and disease duration, was used to assess the relation between vision and MRI measures.

RESULTS

Patients (n = 45) were aged 44 +/- 11 years, with disease duration of 5 years (range <1 to 21), Expanded Disability Status Scale score of 2.0 (0 to 6.0), and binocular Snellen acuity of 20/16 (20/12.5 to 20/25). The average T2 lesion volume was 18.5 mm(3). Patients with lower (worse) low-contrast letter acuity and high-contrast VA scores had greater T2 lesion volumes in whole brain (2.5% contrast: p = 0.004; 1.25%: p = 0.002; VA: p = 0.04), Area 17 white matter (2.5%: p < 0.001; 1.25%: p = 0.02; VA: p = 0.01), and optic radiations (2.5%: p = 0.001; 1.25%: p = 0.02; VA: p = 0.007). Within whole brain, a 3-mm(3) increase in lesion volume corresponded, on average, to a 1-line worsening of low-contrast acuity, whereas 1-line worsening of high-contrast acuity corresponded to a 5.5-mm(3) increase.

CONCLUSIONS

Low-contrast letter acuity scores correlate well with brain MRI lesion burden in multiple sclerosis (MS), supporting validity for this vision test as a candidate for clinical trials. Disease in the postgeniculate white matter is a likely contributor to visual dysfunction in MS that may be independent of acute optic neuritis history.

Interferon-beta: Mechanism of action and dosing issues

In patients with multiple sclerosis (MS), activation of immune cells and breakdown of the blood-brain barrier (BBB) lead to demyelination and axon injury. Although repairing damage to neurons is not possible, immunomodulating therapies can reduce the inflammatory processes that lead to demyelination. Interferon-beta (IFN-beta) is a polypeptide, normally produced by fibroblasts, that has antiviral and antiproliferative effects. Binding of IFN-beta to its receptor induces a complex transcriptional response. In immune cells (the most likely target of IFN-beta's therapeutic effect in MS), IFN-beta reduces antigen presentation and T-cell proliferation, alters cytokine and matrix metalloproteinase (MMP) expression, and restores suppressor function. Therapeutic forms of IFN-beta can be produced in bacterial expression systems (IFN-beta1b) or in mammalian cells (IFN-beta1a). These forms have some differences in their amino acid sequence and posttranslational modifications, but the transcriptional response to IFN- beta1b and IFN-beta1a appears to be similar, if not indistinguishable. However, the biological response and the clinical effect do vary with changes in the dosing frequency of IFN-beta. In clinical trials, IFN-beta1a IM administered weekly elicits a transient biological response compared to IFN-beta1b administered SC every other day or IFN-beta1a (administered SC three times per week). Comparative clinical trials suggest that the differences in the biological response are clinically meaningful: more frequent IFN-beta administration produces superior clinical responses.

Validation and test characteristics of a 10-item neuro-ophthalmic supplement to the NEI-VFQ-25

PURPOSE

To determine whether a 10-Item Neuro-Ophthalmic Supplement increases the capacity of the 25-Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) to capture self-reported visual dysfunction in patients with neuro-ophthalmologic disorders.

DESIGN

A cross-sectional survey to examine the characteristics of a 10-Item Neuro-Ophthalmic Supplement to the 25-Item NEI-VFQ-25 in a cohort of patients with neuro-ophthalmologic disorders.

METHODS

The 10-Item Neuro-Ophthalmic Supplement was designed previously by our research group by survey and focus-group methods. In the present study, the NEI-VFQ-25 and 10-Item Supplement were administered concurrently to patients and disease-free control subjects. High-contrast visual acuities with patient usual distance correction were measured with the use of Early Treatment Diabetic Retinopathy Study (ETDRS) charts.

RESULTS

Diagnoses for patients (n = 215) included optic neuritis, multiple sclerosis, idiopathic intracranial hypertension, ischemic optic neuropathy, stroke, ocular myasthenia gravis, ocular motor palsies, and thyroid eye disease. Scores for the 10-Item Supplement had a significant capacity to distinguish patients vs disease-free control subjects that was independent of the NEI-VFQ-25 composite score (odds ratio in favor of patient vs control status for 10-point worsening in Supplement scores: 2.7 [95% confidence interval [CI], 1.6, 4.6]; P < .001, logistic regression models that account for NEI-VFQ-25 composite score, age, and gender). Patients with visual dysfunction (binocular Snellen equivalents worse than 20/20) had significantly lower mean scores (9-21 points lower); these differences remained significant after accounting for age and gender (P >or= .001, linear regression). Supplement items and composite scores demonstrated appropriate degrees of internal consistency reliability.

CONCLUSION

The 10-Item Neuro-Ophthalmic Supplement demonstrates a capacity to capture self-reported visual dysfunction beyond that of the NEI-VFQ-25 alone, which supports validity for this new scale. The use of the 10-Item Supplement in clinical trials and epidemiologic studies will examine its capacity to demonstrate treatment effects in longitudinal cohorts.

Treatment of Susac syndrome with gamma globulin and corticosteroids

Susac syndrome is a rare vasculopathy characterized by visual, hearing, and cognitive dysfunction. Optimal treatment is unknown, but many patients require chemotherapy to control disease activity. We describe two patients with Susac syndrome and their response to intravenous immune globulin (IVIg) and corticosteroids. Both patients improved following acute treatment with IVIg and intravenous methylprednisolone (IVMP), and no further relapses were observed. One patient showed significant improvement in hearing and MRI lesions shortly following acute treatment. Treatment with IVIg and corticosteroids provides a therapeutic option that avoids the toxicities of chemotherapy and suggests the possible importance of pathologic antibodies in the pathogenesis of Susac syndrome.

Relation of visual function to retinal nerve fiber layer thickness in multiple sclerosis

PURPOSE

To examine the relation of visual function to retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in multiple sclerosis (MS), and to compare RNFL thickness among MS eyes with a history of acute optic neuritis (MS ON eyes), MS eyes without an optic neuritis history (MS non-ON eyes), and disease-free control eyes.

DESIGN

Cross-sectional study.

PARTICIPANTS

Patients with MS (n = 90; 180 eyes) and disease-free controls (n = 36; 72 eyes).

METHODS

Retinal never fiber layer thickness was measured using optical coherence tomography (OCT; fast RNFL thickness software protocol). Vision testing was performed for each eye and binocularly before OCT scanning using measures previously shown to capture dysfunction in MS patients: (1) low-contrast letter acuity (Sloan charts, 2.5% and 1.25% contrast levels at 2 m) and (2) contrast sensitivity (Pelli-Robson chart at 1 m). Visual acuity (retroilluminated Early Treatment Diabetic Retinopathy charts at 3.2 m) was also measured, and protocol refractions were performed.

MAIN OUTCOME MEASURES

Retinal nerve fiber layer thickness measured by OCT, and visual function test results.

RESULTS

Although median Snellen acuity equivalents were better than 20/20 in both groups, RNFL thickness was reduced significantly among eyes of MS patients (92 mum) versus controls (105 mum) (P<0.001) and particularly was reduced in MS ON eyes (85 mum; P<0.001; accounting for age and adjusting for within-patient intereye correlations). Lower visual function scores were associated with reduced average overall RNFL thickness in MS eyes; for every 1-line decrease in low-contrast letter acuity or contrast sensitivity score, the mean RNFL thickness decreased by 4 mum.

CONCLUSIONS

Scores for low-contrast letter acuity and contrast sensitivity correlate well with RNFL thickness as a structural biomarker, supporting validity for these visual function tests as secondary clinical outcome measures for MS trials. These results also suggest a role for ocular imaging techniques such as OCT in trials that examine neuroprotective and other disease-modifying therapies. Although eyes with a history of acute optic neuritis demonstrate the greatest reductions in RNFL thickness, MS non-ON eyes have less RNFL thickness than controls, suggesting the occurrence of chronic axonal loss separate from acute attacks in MS patients.

Neuronal cell injury precedes brain atrophy in multiple sclerosis

Global brain atrophy estimated using MRI and whole brain N-acetylaspartate (WBNAA) concentration measured with proton MR spectroscopy were obtained in 42 patients with relapsing-remitting multiple sclerosis and 41 matched control subjects. Patients exhibited cross-sectional atrophy (0.5%; p = 0.033) and WBNAA decline (1.8%/y; p = 0.005) vs disease duration. The 3.6-fold rate disparity between the two processes suggests that neuronal/axonal dysfunction (N-acetylaspartate decline) precedes parenchyma loss, not its consequence (i.e., is an earlier, more sensitive specific metric of the ongoing disease activity).

Contrast letter acuity as a visual component for the Multiple Sclerosis Functional Composite

BACKGROUND

Visual dysfunction is one of the most common causes of disability in multiple sclerosis (MS). The Multiple Sclerosis Functional Composite (MSFC), a new clinical trial outcome measure, does not currently include a test of visual function.

OBJECTIVE

To examine contrast letter acuity as a candidate visual function test for the MSFC.

METHODS

Binocular contrast letter acuity testing (Sloan charts) was performed in a subgroup of participants from the International Multiple Sclerosis Secondary Progressive Avonex Controlled Trial (IMPACT Substudy) and in MS patients and disease-free control subjects from a cross-sectional study of visual outcome measures (Multiple Sclerosis Vision Prospective cohort [MVP cohort]). High-contrast visual acuity was measured in both studies; MVP cohort participants underwent additional binocular testing for contrast sensitivity (Pelli-Robson chart), color vision (D-15 desaturated test), and visual field (Esterman test, Humphrey Field Analyzer II).

RESULTS

Contrast letter acuity (Sloan charts, p < 0.0001, receiver operating characteristic curve analysis) and contrast sensitivity (Pelli-Robson chart, p = 0.003) best distinguished MS patients from disease-free control subjects in the MVP cohort. Correlations of Sloan chart scores with MSFC and Expanded Disability Statue Scale (EDSS) scores in both studies were significant and moderate in magnitude, demonstrating that Sloan chart scores reflect visual and neurologic dysfunction not entirely captured by the EDSS or MSFC.

CONCLUSIONS

Among clinical measures, contrast letter acuity (Sloan charts) and contrast sensitivity (Pelli-Robson chart) demonstrate the greatest capacity to identify binocular visual dysfunction in MS. Sloan chart testing also captures unique aspects of neurologic dysfunction not captured by current EDSS or MSFC components, making it a strong candidate visual function test for the MSFC.

Relapsing-remitting multiple sclerosis and whole-brain N-acetylaspartate measurement: evidence for different clinical cohorts initial observations

PURPOSE

To quantify the rate of concentration decline of neuronal marker N-acetylaspartate (NAA) in the entire brain of patients with relapsing-remitting multiple sclerosis (MS) in relation to healthy age-matched control subjects.

MATERIALS AND METHODS

Whole-brain NAA (WBNAA) concentration was quantified in 49 patients with relapsing-remitting MS by using magnetic resonance (MR) imaging and proton MR spectroscopy. It was statistically analyzed by using Spearman rank correlation coefficients to test the intragroup relationship between WBNAA and Expanded Disability Status Scale (EDSS) score and Mann-Whitney analyses to test for differences between subgroups' EDSS scores versus previously published WBNAA values for healthy subjects, disease duration, and age.

RESULTS

Analyses indicated three subgroups of WBNAA dynamics: Ten patients' conditions were "stable," exhibiting an insignificant change of about 0% (0.02/14.37) per year of clinically definite disease duration (P =.54); 27 patients showed "moderate" decline, -2.8% (-0.34/12.18) per year (P <.01); and 12 patients experienced "rapid" decline, -27.9% (-3.39/12.14) per year (P <.01). No correlation was found between WBNAA deficit, EDSS score, and age.

CONCLUSION

Ascertaining an individual's NAA concentration dynamics might enable early forecast of disease course, reflect disease severity and thus influence treatment decisions, and improve clinical trial efficiency by allowing selection of candidates on the basis of WBNAA dynamics in addition to clinical status.

Self-reported visual dysfunction in multiple sclerosis: new data from the VFQ-25 and development of an MS-specific vision questionnaire

PURPOSE

To examine vision-specific health-related quality of life in a cohort of patients with multiple sclerosis (MS) using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25), and to identify content areas for a brief MS-specific vision questionnaire.

DESIGN

Cross-sectional survey.

METHODS

The VFQ-25 and a modified version of the Optic Neuritis Treatment Trial (ONTT) Patient Questionnaire were administered by in-person interview to 80 patients at the University of Pennsylvania MS Center. Binocular visual acuities were obtained following a standard protocol using retroilluminated Early Treatment Diabetic Retinopathy Study charts.

RESULTS

Despite a median binocular visual acuity of 20/16 (20/12.5-20/250), VFQ-25 subscale scores in the MS cohort were significantly lower (worse) compared with those of a published reference group of eye disease-free patients (P =.0001-0.009, two-tailed t tests). Rank-correlations of VFQ-25 composite (overall) scores with visual acuity were modest, but significant (r(s) = 0.33, P =.003), supporting construct validity for VFQ-25 scores in MS populations. Seven additional aspects of self-reported visual dysfunction in MS were also identified.

CONCLUSIONS

Patients with MS have a high degree of self-reported visual dysfunction that is not entirely captured by visual acuity. The VFQ-25 is an effective measure of self-reported visual loss in MS. A brief MS-specific vision questionnaire may provide additional useful information when administered concurrently with the VFQ-25 in future investigations of MS and other neuroophthalmologic disorders.

Antagonism of beta-endorphin-induced prolactin release by alpha-melanocyte-stimulating hormone and corticotropin-like intermediate lobe peptide

The ability of two proopiomelanocortin-derived peptides, alpha MSH and corticotropin-like intermediate lobe peptide (CLIP) [ACTH (18-39)] to antagonize the stimulation of PRL secretion by beta-endorphin (beta EP) was studied in the rat. When 50 ng beta EP were injected into the lateral cerebral ventricle, plasma PRL rose from a mean baseline of 1.87 +/- 0.43 ng/ml (+/- SEM) to a peak of 23.0 +/- 3.67 ng/ml 10 min after the injection. When the same animals received 500 ng alpha MSH together with 50 ng beta EP, the peak concentration of PRL was reduced by 74% to 6.05 +/- 1.43 ng/ml (P less than 0.005). After the injection of 500 ng CLIP together with 500 ng beta EP, the peak concentration of PRL was reduced by 47% to 12.8 +/- 3.09 ng/ml (P less than 0.01). Total PRL release, determined by calculating the areas under the plasma PRL concentration curves, was also significantly reduced by the injection of alpha MSH or CLIP. A dose of 100 ng alpha-MSH or CLIP also antagonized the stimulation of PRL secretion by 50 ng beta EP. PRL release was reduced by 62% after administration of 100 ng alpha MSH (P less than 0.001) and by 43% after 100 ng CLIP (P less than 0.05). When 100 ng alpha MSH and 100 ng CLIP were injected together, there was an additive effect in blocking the stimulation of PRL release by beta EP, and the peak plasma PRL concentration was reduced by 81%. Des-acetyl alpha MSH, the predominant form of alpha MSH in the hypothalamus, was also very effective in antagonizing beta EP-induced PRL release. The peak PRL concentration was reduced by 52% after administration of 100 ng des-acetyl alpha MSH plus 50 ng beta EP compared with that after beta EP alone (P less than 0.005). We conclude that relatively low doses of both alpha MSH and CLIP can effectively antagonize the actions of beta EP on pituitary PRL release. These findings suggest the possibility that differential posttranslational processing of proopiomelanocortin may serve as a regulator of anterior pituitary function.