[Show abstract][Hide abstract] ABSTRACT: To test efficacy and safety of atorvastatin in subjects with clinically isolated syndrome (CIS).
Subjects with CIS were enrolled in a phase II, double-blind, placebo-controlled, 14-center randomized trial testing 80 mg atorvastatin on clinical and brain MRI activity. Brain MRIs were performed quarterly. The primary endpoint (PEP) was development of ≥ 3 new T2 lesions, or one clinical relapse within 12 months. Subjects meeting the PEP were offered additional weekly interferon β-1a (IFNβ-1a).
Due to slow recruitment, enrollment was discontinued after 81 of 152 planned subjects with CIS were randomized and initiated study drug. Median (interquartile range) numbers of T2 and gadolinium-enhancing (Gd) lesions were 15.0 (22.0) and 0.0 (0.0) at baseline. A total of 53.1% of atorvastatin recipients (n = 26/49) met PEP compared to 56.3% of placebo recipients (n = 18/32) (p = 0.82). Eleven atorvastatin subjects (22.4%) and 7 placebo subjects (21.9%) met the PEP by clinical criteria. Proportion of subjects who did not develop new T2 lesions up to month 12 or to starting IFNβ-1a was 55.3% in the atorvastatin and 27.6% in the placebo group (p = 0.03). Likelihood of remaining free of new T2 lesions was significantly greater in the atorvastatin group compared with placebo (odds ratio [OR] = 4.34, p = 0.01). Likelihood of remaining free of Gd lesions tended to be higher in the atorvastatin group (OR = 2.72, p = 0.11). Overall, atorvastatin was well tolerated. No clear antagonistic effect of atorvastatin plus IFNβ-1a was observed on MRI measures.
Atorvastatin treatment significantly decreased development of new brain MRI T2 lesion activity, although it did not achieve the composite clinical and imaging PEP.
This study provided Class II evidence that atorvastatin did not reduce the proportion of patients with CIS meeting imaging and clinical criteria for starting immunomodulating therapy after 12 months, compared to placebo. In an analysis of a secondary endpoint (Class III), atorvastatin was associated with a reduced risk for developing new T2 lesions.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the cost-effectiveness of disease-modifying therapies (DMTs) in the United States compared to basic supportive therapy without DMT for patients with relapsing multiple sclerosis (MS).
Using data from a longitudinal MS survey, we generated 10-year disease progression paths for an MS cohort. We used first-order annual Markov models to estimate transitional probabilities. Costs associated with losses of employment were obtained from the Bureau of Labor Statistics. Medical costs were estimated using the Centers for Medicare and Medicaid Services reimbursement rates and other sources. Outcomes were measured as gains in quality-adjusted life-years (QALY) and relapse-free years. Monte Carlo simulations, resampling methods, and sensitivity analyses were conducted to evaluate model uncertainty.
Using DMT for 10 years resulted in modest health gains for all DMTs compared to treatment without DMT (0.082 QALY or <1 quality-adjusted month gain for glatiramer acetate, and 0.126-0.192 QALY gain for interferons). The cost-effectiveness of all DMTs far exceeded $800,000/QALY. Reducing the cost of DMTs had by far the greatest impact on the cost-effectiveness of these treatments (e.g., cost reduction by 67% would improve the probability of Avonex being cost-effective at $164,000/QALY to 50%). Compared to treating patients with all levels of disease, starting DMT earlier was associated with a lower (more favorable) incremental cost-effectiveness ratio compared to initiating treatment at any disease state.
Use of DMT in MS results in health gains that come at a very high cost.
[Show abstract][Hide abstract] ABSTRACT: The goal of this study was to determine if memory would be improved by donepezil as compared to placebo in a multicenter, double-blind, randomized clinical trial (RCT).
Donepezil 10 mg daily was compared to placebo to treat memory impairment. Eligibility criteria included the following: age 18-59 years, clinically definite multiple sclerosis (MS), and performance ≤ ½ SD below published norms on the Rey Auditory Verbal Learning Test (RAVLT). Neuropsychological assessments were performed at baseline and 24 weeks. Primary outcomes were change on the Selective Reminding Test (SRT) of verbal memory and the participant's impression of memory change. Secondary outcomes included changes on other neuropsychological tests and the evaluating clinician's impression of memory change.
A total of 120 participants were enrolled and randomized to either donepezil or placebo. No significant treatment effects were found between groups on either primary outcome of memory or any secondary cognitive outcomes. A trend was noted for the clinician's impression of memory change in favor of donepezil (37.7%) vs placebo (23.7%) (p = 0.097). No serious or unanticipated adverse events attributed to study medication developed.
Donepezil did not improve memory as compared to placebo on either of the primary outcomes in this study.
This study provides Class I evidence which does not support the hypothesis that 10 mg of donepezil daily for 24 weeks is superior to placebo in improving cognition as measured by the SRT in people with MS whose baseline RAVLT score was 0.5 SD or more below average.
[Show abstract][Hide abstract] ABSTRACT: We performed a placebo-controlled trial of CEP-1347, an inhibitor of neuronal apoptotic cell death, in patients with early Parkinson's disease (PD) to determine whether long-term therapy would slow disability progression. This also provided an opportunity to monitor cancer incidence in a large cohort of PD patients followed prospectively including periods before and after patients developed disability requiring dopaminergic therapy. This was a multicenter study of 806 patients with early PD, without disability requiring dopaminergic therapy, assigned randomly to placebo or one of three doses of CEP-1347. Patients were monitored for an average of 1.8 years (1,467 patient-years) with routine cancer screening evaluations and annual skin examinations by a dermatologist. There was no significant excess of cancers among patients taking CEP-1347 compared with placebo for any cancer type (all P > 0.1). Nonmelanoma skin cancers were the most common cancer type observed. The incidence of melanomas was 20.9 times that predicted in the general population. Most melanomas occurred in patients who had never taken dopaminergic therapy. We found no evidence that CEP-1347 affected cancer incidence within 2 years of follow-up. Melanoma occurrence in our PD patients was greater than predicted compared with the general population and was unrelated to dopaminergic therapy. Clinical surveillance of PD patients for melanoma may be warranted.
No preview · Article · Sep 2010 · Movement Disorders
[Show abstract][Hide abstract] ABSTRACT: Epidermal nerve fiber density (ENFD) is useful in the evaluation of small-fiber neuropathies (SFSNs). A recent evidence-based review highlighted the need to broaden the spectrum of ENFD controls to include lower limb pain states other than polyneuropathy. We studied epidermal innervation in multiple sclerosis (MS) and distal lower limb burning pain (DLLBP). Distal-leg ENFD/morphology in MS DLLBP patients did not differ significantly from that of healthy controls. This study extends the range of ENFD controls and further supports use of ENFD assessment in SFSN.
[Show abstract][Hide abstract] ABSTRACT: We report the results of a single center randomized, double-blind, placebo-controlled, parallel group trial of memantine in adults with multiple sclerosis and spasticity conducted over 12 weeks. Eligible MS patients had to have an Ashworth spasticity rating of 2 or higher in at least one lower extremity muscle group. Subjects were randomized to receive either placebo or memantine 10 mg twice a day. The primary outcome measure for efficacy was the change in Ashworth Spasticity Scale Score. Although well tolerated, memantine treatment did not demonstrate efficacy in treatment of spasticity in this 12-week small exploratory study.
No preview · Article · Dec 2009 · Multiple Sclerosis
[Show abstract][Hide abstract] ABSTRACT: Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) and Parkinson Research Examination of CEP-1347 Trial (PRECEPT) were two clinical trials of potential disease-modifying agents for Parkinson's disease that used the time to reaching disability sufficient to require dopaminergic therapy as the primary endpoint. To compare the thresholds for initiating dopaminergic treatment for Parkinson's disease between the two studies, conducted fifteen years apart. Baseline and 12-month endpoint characteristics for subjects in the placebo arms of the two studies were compared. DATATOP placebo subjects had slightly higher total Unified Parkinson's Disease Rating Scale (UPDRS) scores at baseline than PRECEPT placebo subjects (26.1 vs. 23.6, P = 0.03). Time to endpoint was not significantly different. Mean total UPDRS scores at endpoint among those subjects reaching endpoint by 12 months were 48.4 in DATATOP and 37.5 in PRECEPT (P < 0.0001). Baseline disease severity and time to disability requiring dopaminergic therapy were similar in the DATATOP and PRECEPT trials. The threshold for starting dopaminergic treatment was lower in PRECEPT than in the earlier DATATOP study. This may relate to changes in philosophies with respect to starting treatment for Parkinson's disease, but the factors underlying this change remain to be elucidated.
No preview · Article · Dec 2009 · Movement Disorders
[Show abstract][Hide abstract] ABSTRACT: Objective: To evaluate the cost-effectiveness of disease-modifying therapies (DMTs) in the United States compared to basic supportive therapy without DMT for patients with relapsing multiple sclerosis (MS). Methods: Using data from a longitudinal MS survey, we generated 10-year disease progression paths for an MS cohort. We used first-order annual Markov models to estimate transitional probabilities. Costs associated with losses of employment were obtained from the Bureau of Labor Statistics. Medical costs were estimated using the Centers for Medicare and Medicaid Services reimbursement rates and other sources. Outcomes were measured as gains in quality-adjusted life-years (QALY) and relapse-free years. Monte Carlo simulations, resampling methods, and sensitivity analyses were conducted to evaluate model uncertainty. Results: Using DMT for 10 years resulted in modest health gains for all DMTs compared to treatment without DMT (0.082 QALY or < 1 quality-adjusted month gain for glatiramer acetate, and 0.126-0.192 QALY gain for interferons). The cost-effectiveness of all DMTs far exceeded $800,000/QALY. Reducing the cost of DMTs had by far the greatest impact on the cost-effectiveness of these treatments (e. g., cost reduction by 67% would improve the probability of Avonex being cost-effective at $164,000/QALY to 50%). Compared to treating patients with all levels of disease, starting DMT earlier was associated with a lower (more favorable) incremental cost-effectiveness ratio compared to initiating treatment at any disease state. Conclusion: Use of DMT in MS results in health gains that come at a very high cost. Neurology (R) 2011; 77: 355-363
[Show abstract][Hide abstract] ABSTRACT: Purpose: Cost-effectiveness analysis requires comparison of outcomes in treated and untreated populations. Data from randomized clinical trials (RCT) do not provide progression rates representative of the general population, while treatment effects in observational data may be biased due to non-randomization. We developed a novel approach for estimating untreated progression rates by using data from a population-based longitudinal survey, correcting for the effects of patients’ treatments as reported by pivotal trials.
Method: We used data from the 2000-2005 Sonya Slifka nationally representative MS cohort. Disease progression was characterized by disability-based disease states and relapses. We modeled probabilities of disease state transitions using a first-order annual Markov model that adjusted for demographics, disease duration, recent relapse rates, prior states, and the specific disease-modifying therapy (DMT). To estimate transitional probabilities, we developed an iterative multinomial logistic regression algorithm, constraining the effects of DMT to match those reported by RCTs as follows. We selected initial annual treatment factors and estimated first progression probabilities for controls. For those probabilities, using a numerical algorithm, we found new treatment factors that resulted in the same risk ratios of progression as reported by the trials. The new factors were used in the regression model to adjust for DMT effects and to re-estimate the probabilities for controls. We continued this process iteratively, until the identified factors for the final control probabilities matched published DMT effects from RCTs.
Result: After correcting for the DMT treatment effects and other observable risk factors, the probability of disability progression was greater for estimates based on all MS patients compared to the estimates based on untreated individuals only. The 95% confidence intervals using the entire cohort (including treated and untreated individuals) were narrower than the intervals based on the subsample of untreated patients.
Conclusion: Our results indicate that the untreated patients in our study had lower estimates of disease progression than the treated patients would have had if they remained untreated. This suggests that patients who forgo treatment are likely to have milder, slower progressing forms of MS. Correcting for treatment effects in a more inclusive group of patients likely provides a more realistic estimate of disease progression than simply characterizing progression in an untreated cohort. The use of a population-based cohort also improves the precision of disease progression estimates.
[Show abstract][Hide abstract] ABSTRACT: The risk of Parkinson disease (PD) and its rate of progression may decline with increasing concentration of blood urate, a major antioxidant.
To determine whether serum and cerebrospinal fluid concentrations of urate predict clinical progression in patients with PD.
Eight hundred subjects with early PD enrolled in the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) trial. The pretreatment urate concentration was measured in serum for 774 subjects and in cerebrospinal fluid for 713 subjects.
Treatment-, age-, and sex-adjusted hazard ratios (HRs) for clinical disability requiring levodopa therapy, the prespecified primary end point of the original DATATOP trial.
The HR of progressing to the primary end point decreased with increasing serum urate concentrations (HR for highest vs lowest quintile = 0.64; 95% confidence interval [CI], 0.44-0.94; HR for a 1-SD increase = 0.82; 95% CI, 0.73-0.93). In analyses stratified by alpha-tocopherol treatment (2000 IU/d), a decrease in the HR for the primary end point was seen only among subjects not treated with alpha-tocopherol (HR for a 1-SD increase = 0.75; 95% CI, 0.62-0.89; vs HR for those treated = 0.90; 95% CI, 0.75-1.08). Results were similar for the rate of change in the Unified Parkinson's Disease Rating Scale score. Cerebrospinal fluid urate concentration was also inversely related to both the primary end point (HR for highest vs lowest quintile = 0.65; 95% CI, 0.44-0.96; HR for a 1-SD increase = 0.89; 95% CI, 0.79-1.02) and the rate of change in the Unified Parkinson's Disease Rating Scale score. As with serum urate concentration, these associations were present only among subjects not treated with alpha-tocopherol.
Higher serum and cerebrospinal fluid urate concentrations at baseline were associated with slower rates of clinical decline. The findings strengthen the link between urate concentration and PD and the rationale for considering central nervous system urate concentration elevation as a potential strategy to slow PD progression.
Full-text · Article · Oct 2009 · Archives of neurology
[Show abstract][Hide abstract] ABSTRACT: The initial Multiple Sclerosis Functional Composite (MSFC) proposal was a three-part composite of quantitative measures of ambulation, upper extremity function, and cognitive function expressed as a single composite Z-score. However, the clinical meaning of an MSFC Z-score change is not obvious. This study instead used MSFC component data to define a patient-specific disease progression event.
Evaluate a new method for analyzing disability progression using the MSFC.
MSFC progression was defined as worsening from baseline on scores of at least one MSFC component by 20% (MSFC Progression-20) or 15% (MSFC Progression-15), sustained for >or=3 months. Progression rates were determined using data from natalizumab clinical studies (Natalizumab Safety and Efficacy in Relapsing Remitting Multiple Sclerosis [AFFIRM] and Safety and Efficacy of Natalizumab in Combination With Interferon Beta-1a in Patients With Relapsing Remitting Multiple Sclerosis [SENTINEL]). Correlations between MSFC progression and other clinical measures were determined, as was sensitivity to treatment effects.
Substantial numbers of patients met MSFC progression criteria, with MSFC Progression-15 being more sensitive than MSFC Progression-20, at both 1 and 2 years. MSFC Progression-20 and MSFC Progression-15 were related significantly to Expanded Disability Status Scale (EDSS) score change, relapse rate, and the SF-36 Physical Component Summary (PCS) score change. MSFC Progression-20 and MSFC Progression-15 at 1 year were predictive of EDSS progression at 2 years. Both MSFC progression end points demonstrated treatment effects in AFFIRM, and results were replicated in SENTINEL.
MSFC Progression-20 and MSFC Progression-15 are sensitive measures of disability progression; correlate with EDSS, relapse rates, and SF-36 PCS; and are capable of demonstrating therapeutic effects in randomized, controlled clinical studies.
No preview · Article · Sep 2009 · Multiple Sclerosis
[Show abstract][Hide abstract] ABSTRACT: There is considerable interest in tissue-protective treatments for multiple sclerosis (MS).
We convened a group of MS clinical trialists and related researchers to discuss designs for proof of concept studies utilizing currently available data and assessment methods.
Our favored design was a randomized, double-blind, parallel-group study of active treatment versus placebo focusing on changes in brain volume from a post-baseline scan (3-6 months after starting treatment) to the final visit 1 year later. Study designs aimed at reducing residual deficits following acute exacerbations are less straightforward, depending greatly on the anticipated rapidity of treatment effect onset.
The next step would be to perform one or more studies of potential tissue-protective agents with these designs in mind, creating the longitudinal data necessary to refine endpoint selection, eligibility criteria, and sample size estimates for future trials.
No preview · Article · Jun 2009 · Multiple Sclerosis
[Show abstract][Hide abstract] ABSTRACT: Purpose: Cost-effectiveness analysis requires comparison of outcomes in treated and untreated populations. Data from randomized clinical trials (RCT) do not provide progression rates representative of the general population, while treatment effects in observational data may be biased due to non-randomization. We developed a novel approach for estimating untreated progression rates (controls) by using data from a nationally representative patient cohort, as well as RCT estimates.
Methods: We used data from the Sonya Slifka multiple sclerosis (MS) study. Disease progression was characterized by disability-based disease states and relapses. State transition probabilities were modeled using a first-order Markov model, adjusting for individual characteristics, disease status, and specific disease-modifying therapy (DMT). We developed an iterative multinomial logistic model, constraining the effects of DMT to match those reported by RCTs.
Results: After correcting for DMT treatment effects and risk factors, the probability of disease progression was greater for estimates based on all patients compared to estimates based on untreated individuals only. The 95% confidence intervals using the entire cohort were narrower than the intervals based on untreated patients only.
Conclusions: Untreated patients in our study had lower estimates of disease progression than the treated patients would have had if they remained untreated, suggesting patients forgoing treatment are likely to have milder forms of MS. Correcting for treatment effects in a more inclusive patient group likely provides a more realistic estimate of disease progression than characterizing progression in an untreated cohort. The use of a broader cohort also improves the precision of disease progression estimates.
[Show abstract][Hide abstract] ABSTRACT: Considerable interest has been shown in the potential anti-inflammatory effects of polyunsaturated fatty acids (PUFAs) in multiple sclerosis (MS) and other autoimmune inflammatory disorders. Studies suggest a modest association between consumption of low levels of unsaturated fat and an increased incidence of MS. Moreover, in vitro and in vivo studies have demonstrated that omega-3 and omega-6 PUFA supplementation can reduce immune-cell activation via a number of complex pathways. Noncontrolled and controlled clinical trials of PUFA supplementation in patients with MS have, however, provided mixed results. These studies had important limitations in design and selection of outcome measures, and these factors might partially explain the inconsistent results. We propose that the potential role of PUFAs as disease-modifying, anti-inflammatory treatments for MS should be revisited in proof-of-concept trials that use accepted MRI outcome measures.
No preview · Article · Mar 2009 · Nature Clinical Practice Neurology
[Show abstract][Hide abstract] ABSTRACT: Clinical studies suggested that fampridine (4-aminopyridine) improves motor function in people with multiple sclerosis. This phase III study assessed efficacy and safety of oral, sustained-release fampridine in people with ambulatory deficits due to multiple sclerosis.
We undertook a randomised, multicentre, double-blind, controlled phase III trial. We randomly assigned 301 patients with any type of multiple sclerosis to 14 weeks of treatment with either fampridine (10 mg twice daily; n=229) or placebo (n=72), using a computer-generated sequence stratified by centre. We used consistent improvement on timed 25-foot walk to define response, with proportion of timed walk responders in each treatment group as the primary outcome. We used the 12-item multiple sclerosis walking scale to validate the clinical significance of the response criterion. Efficacy analyses were based on a modified intention-to-treat population (n=296), which included all patients with any post-treatment efficacy data. The study is registered with ClinicalTrials.gov, number NCT00127530.
The proportion of timed walk responders was higher in the fampridine group (78/224 or 35%) than in the placebo group (6/72 or 8%; p<0.0001). Improvement in walking speed in fampridine-treated timed walk responders, which was maintained throughout the treatment period, was 25.2% (95% CI 21.5% to 28.8%) and 4.7% (1.0% to 8.4%) in the placebo group. Timed walk responders showed greater improvement in 12-item multiple sclerosis walking scale scores (-6.84, 95% CI -9.65 to -4.02) than timed walk non-responders (0.05, -1.48 to 1.57; p=0.0002). Safety data were consistent with previous studies.
Fampridine improved walking ability in some people with multiple sclerosis. This improvement was associated with a reduction of patients' reported ambulatory disability, and is a clinically meaningful therapeutic benefit.
[Show abstract][Hide abstract] ABSTRACT: Interferon beta-1a and glatiramer acetate are commonly prescribed for relapsing-remitting multiple sclerosis (RRMS), but no published randomised trials have directly compared these two drugs. Our aim in the REGARD (REbif vs Glatiramer Acetate in Relapsing MS Disease) study was to compare interferon beta-1a with glatiramer acetate in patients with RRMS.
In this multicentre, randomised, comparative, parallel-group, open-label study, patients with RRMS diagnosed with the McDonald criteria who had had at least one relapse within the previous 12 months were randomised to receive 44 mug subcutaneous interferon beta-1a three times per week or 20 mg subcutaneous glatiramer acetate once per day for 96 weeks to assess the time to first relapse. A subpopulation of 460 patients (230 from each group) also had serial MRI scans to assess T2-weighted and gadolinium-enhancing lesion number and volume. Treatments were assigned by a computer-generated randomisation list that was stratified by centre. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00078338.
Between February and December, 2004, 764 patients were randomly assigned: 386 to interferon beta-1a and 378 to glatiramer acetate. After 96 weeks, there was no significant difference between groups in time to first relapse (hazard ratio 0.94, 95% CI 0.74 to 1.21; p=0.64). Relapse rates were lower than expected: 258 patients (126 in the interferon beta-1a group and 132 in the glatiramer acetate group) had one or more relapses (the expected number was 460). For secondary outcomes, there were no significant differences for the number and change in volume of T2 active lesions or for the change in the volume of gadolinium-enhancing lesions, although patients treated with interferon beta-1a had significantly fewer gadolinium-enhancing lesions (0.24 vs 0.41 lesions per patient per scan, 95% CI -0.4 to 0.1; p=0.0002). Safety and tolerability profiles were consistent with the known profiles for both compounds. The overall number and severity of adverse events were similar between the treatments and were not an important cause for discontinuation of the trial during the 96 weeks.
There was no significant difference between interferon beta-1a and glatiramer acetate in the primary outcome. The ability to predict clinical superiority on the basis of results from previous studies might be limited by a trial population with low disease activity, which is an important consideration for ongoing and future trials in patients with RRMS.
No preview · Article · Oct 2008 · The Lancet Neurology
[Show abstract][Hide abstract] ABSTRACT: Monoamine oxidase inhibitors are associated with dietary tyramine interactions that can induce hypertensive crises. Rasagiline mesylate is a novel irreversible selective monoamine oxidase type B inhibitor for Parkinson disease that may have a low risk of interaction with dietary tyramine because of its selectivity. To study interactions of rasagiline with diets unrestricted in tyramine-containing foods, we incorporated transtelephonic, self-monitoring of the blood pressure (BP) into a randomized, placebo-controlled trial of rasagiline 0.5 and 1.0 mg daily in 414 levodopa-treated Parkinson patients with motor fluctuations. The proportion of patients with a systolic BP increase of >30 mm Hg was the primary BP end point. In 13 968 self-measured readings at baseline, the proportion of systolic BP values that increased by >30 mm Hg after a meal ranged from 9.5% to 12.9% in the 3 treatment groups. In 25 733 BPs obtained postrandomization, the proportion of values with a >30-mm Hg systolic postprandial increase was 15% in the placebo group, 15% in the rasagiline 0.5-mg group, and 11% in the rasagiline 1-mg group after 3 weeks of double-blind therapy and 13%, 14%, and 12%, respectively, after 26 weeks of treatment (P value was not significant for all of the comparisons among treatment groups). A postprandial increase in systolic BP to >180 mm Hg at any time after randomization was seen in 3.3%, 2.6%, and 2.9% of the placebo, 0.5-mg, and 1.0-mg rasagiline groups, respectively. These data demonstrate that rasagiline did not induce postprandial hypertension in patients with Parkinson disease who were on an unrestricted diet.
[Show abstract][Hide abstract] ABSTRACT: Pain is common in patients with multiple sclerosis (MS), but estimates of its prevalence have varied widely. The literature describing pain in MS patients spans four decades and has employed a range of different methodologies. We undertook a systematic review in order to summarize current understanding of the association between MS and pain and provide a basis for the design and interpretation of future studies. The point prevalence of pain in patients with MS is nearly 50%, and approximately 75% of patients report having had pain within one month of assessment. Pain adversely affects most aspects of health-related quality of life, including functional domains such as the ability to work. The presence of pain in patients with MS is associated with increased age, duration of illness, depression, degree of functional impairment, and fatigue. Several different types of pain are found in patients with MS, including extremity pain, trigeminal neuralgia, Lhermitte's sign, painful tonic spasms, back pain, and headache. Putative mechanisms of pain in patients with MS are discussed, and a classification of pain in MS is proposed. Few randomized clinical trials of treatments for MS pain have been conducted, and the limitations of current knowledge regarding approaches for treating MS pain are discussed. Suggestions for future studies that would increase understanding of the natural history, mechanisms, and treatment of pain in patients with MS are presented.