Cognitive impairment among patients with multiple sclerosis: associations with employment and quality of life.

OBJECTIVES: To explore the relationship between cognitive impairment and conventional measures of disability in multiple sclerosis (MS), quality of life (QOL) and employment status using the brief international cognitive assessment for multiple sclerosis (BICAMS) in the routine outpatient clinic. METHODS: 62 patients with MS were assessed on the BICAMS test battery for cognitive impairment. Data were obtained on employment status and a number of questionnaires completed including fatigue severity score, multiple sclerosis neuropsychological questionnaire, hospital anxiety and depression scale, the functional assessment of multiple sclerosis (FAMS) as well as on the EuroQOL five dimension questionnaire (EQ-5D). Other assessments include the patient activation measure and unidimensional self-efficacy scale for multiple sclerosis. RESULTS: Cognitive assessment revealed 44 subjects (65%) had evidence of cognitive impairment on formal testing. In comparison with patients without evidence of cognitive impairment, cognitively impaired patients exhibited significantly higher rates of unemployment (p=0.009). The symbol digits modalities test was the most significant predictor of unemployment. Cognitive impairment was associated with lower QOL scores on the FAMS (p=0.001) and EQ-5D (p<0.001). CONCLUSIONS: BICAMS provides a sensitive and easy to administer screening test for cognitive impairment within the outpatient setting. Cognitive impairment is common in our cohort of patients with MS attending outpatients and appears to be associated with increased rates of unemployment and lower measures of QOL.

A Randomised Controlled Trial of Efficacy of Cognitive Rehabilitation in Multiple Sclerosis: A Cognitive, Behavioural, and MRI Study.

Aim. To explore the efficacy of home-based, computerised, cognitive rehabilitation in patients with multiple sclerosis using neuropsychological assessment and advanced structural and functional magnetic resonance imaging (fMRI). Methods. 38 patients with MS and cognitive impairment on the Brief International Cognitive Assessment for MS (BICAMS) were enrolled. Patients were randomised to undergo 45 minutes of computerised cognitive rehabilitation using RehaCom software (n = 19) three times weekly for six weeks or to a control condition (n = 19). Neuropsychological and MRI data were obtained at baseline (time 1), following the 6-week intervention (time 2), and after a further twelve weeks (time 3). Cortical activations were explored using fMRI and microstructural changes were explored using quantitative magnetisation transfer (QMT) imaging. Results. The treatment group showed a greater improvement in SDMT gain scores between baseline and time 2 compared to the control group (p = 0.005). The treatment group exhibited increased activation in the bilateral prefrontal cortex and right temporoparietal regions relative to control group at time 3 (p < 0.05FWE corrected). No significant changes were observed on QMT. Conclusion. This study supports the hypothesis that home-based, computerised, cognitive rehabilitation may be effective in improving cognitive performance in patients with MS. Clinical trials registration is ISRCTN54901925.

Reports of patients and relatives from the CogniCIS study about cognition in clinically isolated syndrome: what are our patients telling us?

OBJECTIVE: To assess the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) in patients with clinically isolated syndrome (CIS). METHODS: 130 European CIS patients and 60 relatives completed the MSNQ. RESULTS: The mean (SD) MSNQ score for CIS patients was 15.5 (10.8) and for their informants 11.3 (9.6). Neither the CIS patient nor relative MSNQ report scores correlated with any of the cognitive test scores in the Brief Repeatable Battery of Neuropsychological Tests, but they were significantly related to psychosocial scales including depression. CONCLUSIONS: In CIS, patient and relative MSNQ scores are influenced by psychosocial variables rather than actual objective cognitive status. Formal cognitive test assessment is recommended for CIS patients.

Recommendations for a Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS).

BACKGROUND: Cognitive impairment in MS impacts negatively on many patients at all disease stages and in all subtypes. Full clinical cognitive assessment is expensive, requiring expert staff and special equipment. Test versions and normative data are not available for all languages and cultures. OBJECTIVE: To recommend a brief cognitive assessment for multiple sclerosis (MS) that is optimized for small centers, with one or few staff members, who may not have neuropsychological training and constructed to maximize international use. METHODS: An expert committee of twelve members representing the main cultural groups that have so far contributed considerable data about MS cognitive dysfunction was convened. Following exhaustive literature review, peer-reviewed articles were selected to cover a broad spectrum of cultures and scales that targeted cognitive domains vulnerable to MS. Each was rated by two committee members and candidates scales were rated on psychometric qualities (reliability, validity, and sensitivity), international application, ease of administration, feasibility in the specified context, and acceptability to patients. RESULTS: The committee recommended the Symbol Digit Modalities Test, if only 5 minutes was available, with the addition of the California Verbal Learning Test - Second Edition and the Brief Visuospatial Memory Test - Revised learning trials if a further 10 minutes could be allocated for testing. CONCLUSIONS: A brief cognitive assessment for MS has been recommended. A validation protocol has been prepared for language groups and validation studies have commenced.

Analysis of clinical outcomes according to original treatment groups 16 years after the pivotal IFNB-1b trial.

BACKGROUND: Evidence for efficacy of disease-modifying drugs in multiple sclerosis (MS) comes from trials of short duration. We report results from a 16 y, retrospective follow-up of the pivotal interferon beta-1b (IFNB-1b) study. METHODS: The 372 trial patients were randomly assigned to placebo (n=123), IFNB-1b 50 microg (n=125) or IFNB-1b 250 microg (n=124) subcutaneously every other day for at least 2 y. Some remained randomised for up to 5 y but, subsequently, patients received treatment according to physicians' discretion. Patients were re-contacted and asked to participate. Efficacy related measures included MRI parameters, relapse rate, the Expanded Disability Status Scale, the Multiple Sclerosis Functional Composite Measure and conversion to secondary progressive MS. RESULTS: Of the 88.2% (328/372) of patients who were identified, 69.9% (260/372) had available case report forms. No differences in outcome between original randomisation groups could be discerned using standard disability and MRI measures. However, mortality rates among patients originally treated with IFNB-1b were lower than in the original placebo group (18.3% (20/109) for placebo versus 8.3% (9/108) for IFNB-1b 50 microg and 5.4% (6/111) for IFNB-1b 250 microg). CONCLUSIONS: The original treatment assignment could not be shown to influence standard assessments of long-term efficacy. On-study behaviour of patients was influenced by factors that could not be controlled with the sacrifice of randomisation and blinding. Mortality was higher in patients originally assigned to placebo than those who had received IFNB-1b 50 microg or 250 microg. The dataset provides important resources to explore early predictors of long-term outcome.

Should whole body cryotherapy sessions be differentiated between women and men? A preliminary study on the role of the body thermal resistance.

The aim of this study was to investigate how body thermal resistance between sexes evolves over time in the recovery period after a WBC session and to show how this parameter should be considered as a key parameter in WBC protocols. Eighteen healthy participants volunteered for the study (10 males and 8 females). Temperature (core and skin) were recorded pre- and post (immediately and every 5 min until 35 min post) exposure to a single bout of WBC (30 s at -60 °C, 150 s at -110 °C). From both core and skin temperatures a bio-heat transfer model was applied which led to the analytical formulation of the body thermal resistance. An unsteady behavior presenting a similar time-evolution trend in the body insulative response is shown for both females and males, possibly due to the vasodilatation process following an intense peripheral vasoconstriction during the extreme cold. Females present a 37% higher inner thermal resistance than males when reaching an asymptotical thermal state at rest due to a higher concentration of body fat percentage. Adiposity of tissues inherent in fat mass percentage appears to be a key parameter in the body thermal resistance to be taken into account in the definition of appropriate protocols for males and females. The conclusions of this preliminary study suggest that in order to achieve the same skin effects on temperature and consequently to cool efficiency tissues in the same way, the duration of cryotherapy protocols should be shorter when considering female compared to male.

Long-term effects of prolonged-release fampridine in cognitive function, fatigue, mood and quality of life of MS patients: The IGNITE study.

BACKGROUND: Studies have reported conflicting results regarding the potential benefit of prolonged release (PR) fampridine in other domains besides walking. Moreover, only a small number of studies have explored long- term effects of PR fampridine. The aim of this study was to assess cognitive function, quality of life, mood and fatigue in MS patients treated with fampridine after 6 and 12 months of treatment. METHODS: IGNITE was an observational, open label study. Subjects were examined with the timed 25-ft walk (T25FW) and the BICAMS battery and were asked to complete the Multiple Sclerosis Impact Scale (MSIS-29), Modified Fatigue Impact Scale (MFIS), Beck Depression Inventory-II (BDI-II) and MS International Quality-of-Life questionnaire (MUSIQOL) at baseline and at weeks 24 and 48. Patients were sub-grouped into responders (n:40) and non-responders (n:20) according to T25FW performance after 2 weeks on treatment. RESULTS: After 6 months, statistically significant improvement was observed on T25FW (p < .001), SDMT (p < .001) and MSIS29 (p < .001), for responders. After 1 year on treatment, statistically significant improvement was observed in T25FW (p < .001), MSIS29 (p = .004), SDMT (p < .001) and MUSIQOL (p = .03) for responders. There were no statistically significant improvements for the non-responders. CONCLUSIONS: PR Fampridine may have a beneficial effect on information processing speed though not on memory. Study data provide some evidence that fampridine treatment may reduce the impact of MS on daily activities and improve quality of life but has no effect on subjective fatigue and mood.

A longitudinal study of cognition in primary progressive multiple sclerosis.

There are few longitudinal studies of cognition in patients with multiple sclerosis, and the results of these studies remain inconclusive. No serial neuropsychological data of an exclusively primary progressive series are available. Cross-sectional analyses have revealed significant correlations between cognition and magnetic resonance imaging (MRI) parameters in primary progressive multiple sclerosis (PPMS). This study investigated cognitive and MRI change in 99 PPMS patients from five European centres for 2 years. They were assessed at 12 month intervals using the Brief Repeatable Battery, a reasoning test, and a measure of depression. The MRI parameters of T1 hypointensity load, T2 lesion load, and partial brain volume were also calculated at each time point. There were no significant differences between the mean cognitive scores of the patients at year 0 and year 2. However, one-third of the patients demonstrated absolute cognitive decline on individual test scores. Results indicated that initial cognitive status on entry into the study was a good predictor of cognitive ability at 2 years. There was only a small number of significant correlations between changes in cognition and changes on MRI, notably T1 hypointensity load with the two attentional tasks (r = -0.266, P = 0.017; r = -0.303, P = 0.012). It is probable that multiple factors underlie this weak relation between the cognitive and MRI measures.

Validation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in Greek population with multiple sclerosis.

BACKGROUND: Cognitive impairment is experienced by about 50% of patients with Multiple Sclerosis (MS) worldwide and affects their employment, disease management and quality of life in general. The Brief International Cognitive assessment for MS (BICAMS) is a brief, practical and potentially universal battery for cognitive impairment in MS patients. It consists of three tests: the Symbol Digit Modalities Test (SDMT), the California Verbal Learning Test-2 (CVLT-2) and the Brief Visuospatial Memory Test-Revised (BVMT-R). OBJECTIVE: The objective of this study was to validate the BICAMS in Greek MS patients and controls. METHODS: Forty four MS patients and seventy nine healthy control (HC) participants were recruited and tested. They were group matched for age, education, gender and also premorbid cognitive reserve. All of them completed the three tests of the BICAMS battery. Instead of CVLT-2, the Greek validated form (Greek Verbal Learning Test, GVLT), was used. In addition, cognitive reserve was assessed using the Cognitive Reserve Index questionnaire (CRIq) standardized for the Greek population. RESULTS: Significant difference was found in the performance of the two groups in all tests (p<0.0001, p<0.02, p<0.009 for SDMT, GVLT and BVMT-R respectively). Test-retest reliability was good for all the tests. Based on the criterion of 1 or more tests below the 5th percentile of healthy controls performance, 47% of patients were found impaired. CONCLUSIONS: The study provides validation of BICAMS in Greek population and therefore facilitates the use of this battery in clinical practice and in future studies of MS patients in Greece.

Impaired glycogenic substrate activation of glycogen synthase is associated with depressed synthase phosphatase activity in diabetic rat liver.

Glucose and gluconeogenic substrates promote the activation of hepatic glycogen synthase in vivo and in vitro; activation occurs as inactive glycogen synthase D is dephosphorylated to active glycogen synthase I by glycogen synthase phosphatase. Impairments of glycogen accumulation and glycogen synthase activation in diabetes have been attributed to decreased glycogen synthase phosphatase activity. To determine the role of glycogen synthase phosphatases associated with cytosol and smooth endoplasmic reticulum in the impairment of glycogen synthase activation, livers of normal and streptozotocin-diabetic fed rats were sampled by freeze-clamping before and after perfusion with a mixture of 25 mM glucose, 10 mM glutamine, 4 mM lactate, and 1 mM pyruvate. Perfusion induced activation of glycogen synthase in normal rats, but activation was reduced in the diabetic rats in proportion to the severity of insulin deficiency (r = 0.72, P less than 0.0001). There was also a close correlation between insulin levels and glycogen synthase phosphatase activities of both cytosol (r = 0.76, P less than 0.0001) and SER (r = 0.71, P less than 0.0001) fractions. In contrast, glycogen phosphorylase phosphatase activity and inactivation of glycogen phosphorylase during perfusion were normal in the diabetic livers. This is the first demonstration that glycogen synthase phosphatase activities in both soluble and SER fractions of liver cells are closely related to circulating insulin levels, and that the impairment of glycogen synthesis in diabetes may result from deficient glycogen synthase phosphatase activity in both cell compartments.

A preliminary validation of the brief international cognitive assessment for multiple sclerosis (BICAMS) tool in an Irish population with multiple sclerosis (MS).

BACKGROUND: Cognitive impairment is common in multiple sclerosis (MS) irrespective of disease stage or subtype. It is typically underreported and neuropsychological testing can be required to detect more subtle evidence of cognitive impairment. The Brief International Cognitive Assessment in Multiple Sclerosis (BICAMS) was an initiative undertaken by a panel of experts with the primary objective of identifying a brief cognitive assessment tool that could be administered by healthcare professionals without formal neuropsychological training to identify early or subtle cognitive impairment among MS patients. OBJECTIVES: To validate BICAMS in Irish patients with MS and healthy controls. METHODS: Consecutive patients attending the MS outpatient department from January to April 2014 were recruited. Age, gender, education, handedness, MS subtype, expanded disability status scale (EDSS) and disease duration were recorded. They were administered BICAMS composed of Symbol Digit Modalities Test (SDMT), California Verbal Learning Test (CVLT-II) and Brief Visuospatial Memory Test (BVMT-R). Depression and anxiety were assessed using the Hospital Anxiety and Depression Scale (HADS). Control participants were composed of unaffected relatives, spouses or carers attending the clinic with a patient and were matched by age, gender and years of education. Impairment on individual tests was defined as -1.5 SD below reference group means. RESULTS: 67 patients [73% women; mean age: 43.9 yrs (12.1); mean years of education: 13.6 yrs (2.7)] and 66 controls [68% women; mean age 42.7 yrs (12.7); mean years of education: 14.1 yrs (3.2)] were recruited. Of the MS patient group: 70% were classified as having relapsing remitting MS, 28% secondary progressive MS and 2% primary progressive MS (PPMS). Mean EDSS scores were 1.8 (SD: 0.9), 5.7 (SD: 1.4) and 7.0 in each group respectively with mean disease duration of 10.2 (SD: 8.4) years, 20.6 (10.2) and 17 years. Mean scores and standard deviations for patients and control participants respectively were 46 (12.9) and 55.9 (10.9), p < 0.001; d = 0.83 for SDMT; 45.3 (10.2) and 52.8 (8.8), p < 0.001; d = 0.79 for CVLT-II and 17.9 (7.1) and 20.7 (6.6), p = 0.02; d = 0.41 for BVMT-R. Using regression based norms derived from the control sample only 43% of patients compared to 83% of control participants' results were within the normal range on all three tests. As expected higher rates of unemployment was seen amongst the patient population compared to control participants. Using the HADS 11 patients were classified as depressed and 13 as suffering from anxiety. Neither, these measures or the level of fatigue as measured by the MFIS was significantly associated with any of the three outcome measures (Pearson r < ± 0.3). CONCLUSIONS: This study demonstrates that BICAMS is an easy test to administer and should be used as a basic tool to identify patients with cognitive impairment who may benefit from further neuropsychological assessment. Cognitive impairment can put patients at risk of poor self-management of disease including poor mediation adherence, and negatively impact on employment. Once identified appropriate support and monitoring can be put in place. BICAMS may also be used to help guide treatment decisions and rehabilitation. Further studies will be needed to assess its reliability over time and ability to detect meaningful changes.

Effects of NBm lesions on T-maze performance and thalamic biochemistry.

Fisher 344 rats underwent bilateral nucleus basalis magnocellularis (NBm) lesioning followed by testing in a delayed nonmatching-to-sample T-maze task. Both lesion and control animals acquired the task although the NBm animals were mildly impaired on acquisition and on trials to criterion. Increasing the delay reduced accuracy of performance equally in both groups. The NBm lesion did not alter the level of several thalamic amino acids. These data indicate that NBm lesioning does not produce a significant impairment in working or reference memory in this task and supports the hypothesis that NBm lesioning impairs attention.

Inpatient rehabilitation in multiple sclerosis: do the benefits carry over into the community?

OBJECTIVE: To determine the duration and pattern of carry-over of benefits gained after a short period of multidisciplinary inpatient rehabilitation. BACKGROUND: Few studies have evaluated the outcome of rehabilitation after discharge. Long-term follow-up is required to establish whether gains made during the inpatient stay are sustained over time and in the patient's own environment. METHODS: Prospective single-group longitudinal study. Fifty consecutive patients with progressive MS undergoing inpatient rehabilitation were followed for 12 months after discharge. Assessments were undertaken on admission (A), at discharge, and subsequently at 3-month intervals for 1 year (1Y) with a battery of measures addressing neurologic status, disability, handicap, quality of life, and emotional well-being. The time taken to return to baseline level was calculated using summary measures, and trends in performance levels were plotted. RESULTS: Twelve-month data were collected for 92% of patients. Although neurologic status declined (median Expanded Disability Status Scale scores: A = 6.8, 1Y = 8.0), improvements were maintained in disability and handicap for 6 months, emotional well-being for 7 months, and health-related quality of life (physical component) for 10 months. CONCLUSIONS: The benefits gained from rehabilitation were partly maintained after discharge despite worsening neurologic status. Carry-over of benefits, however, declined over time, reinforcing the need for continuity of care between the inpatient setting and the community.

Evidence-based measurement: which disability scale for neurologic rehabilitation?

OBJECTIVE: To compare the 10-item Barthel Index (BI), 18-item Functional Independence Measure (FIM), and 30-item Functional Independence Measure + Functional Assessment Measure (FIM+FAM) as measures of disability outcomes for neurologic rehabilitation. METHODS: A total of 149 inpatients from two rehabilitation units in South England specializing in neurologic disorders were studied. Traditional psychometric methods were used to evaluate and compare acceptability (score distributions), reliability (internal consistency, intrarater reproducibility), validity (concurrent, convergent and discriminant construct), and responsiveness (standardized response mean). RESULTS: All three rating scales satisfied recommended criteria for reliable and valid measurement of disability, and are acceptable and responsive in this study sample. The FIM and FIM+FAM total scales are psychometrically similar measures of global disability. The BI, FIM, and FIM+FAM motor scales are psychometrically similar measures of physical disability. The FIM and FIM+FAM cognitive scales are psychometrically similar measures of physical disability. CONCLUSIONS: In the sample studied, the BI, FIM, FIM+FAM have similar measurement properties, when examined using traditional psychometric analyses. Although instruments with more items and item response categories generate more qualitative information about an outcome, they may not improve its measurement. Results highlight the importance of using recognized techniques of scale construction to develop health outcome measures.

Involvement of the thyroid gland in histiocytosis X.

A 27 month old white male infant clinically suspected of having histiocytosis X had an enlarged hard hypofunctioning thyroid. A needle biopsy of the thyroid showed disruption of the thyroid architecture by an infiltrate consisting of large histiocytes admixed with eosinophils, neutrophils, and lymphocytes, confirming the clinical diagnosis of histiocytosis X.

NGF increases cortical acetylcholine release in rats with lesions of the nucleus basalis.

Rats received a unilateral lesion of the nucleus basalis by infusion of ibotenic acid. Two weeks after the lesion, osmotic minipumps were implanted, that infused 1 microgram human recombinant nerve growth factor (NGF) or cytochrome-C per day into the lateral ventricle. After four weeks of treatment, release of acetylcholine was measured in the frontal neocortex by means of in-vivo microdialysis. Release was decreased by 75% on the lesioned side; perfusion with 100 mM KCl increased release on the intact side by 130% and on the lesioned side by 80%. Treatment with NGF increased release on the lesioned side twofold, but had no effect on release on the intact side.

Rehabilitation of incomplete spinal cord pathology: factors affecting prognosis and outcome.

To determine the factors affecting the outcome of patients with incomplete spinal cord lesions, a retrospective study was performed of all such patients (n = 49) admitted to the neurorehabilitation unit of the National Hospital for Neurology and Neurosurgery, London, over a 2-year period. Disability on admission and discharge as measured by the Functional Independence Measure (FIM), change in disability, presence or absence of neurological recovery, patient age, level of the lesion and length of inpatient stay were the main outcome measures. Data were complete on 39 patients. There were 20 patients with cervical myelopathy, 15 with intrinsic cord abnormalities including syrinxes, 7 with spinal cord infarcts and 7 with other conditions such as tropical spastic paraparesis and hereditary paraparesis. Age ranged from 17 to 88 years (mean 53). Mean duration of stay was 40 days and the duration was related to the diagnosis. Nineteen of the patients made some neurological improvement, while all but one improved on the FIM. This functional gain did not correlate with the patients' age, initial disability or level of the lesion, but was related to the length of stay in the unit, and neurological improvement. We conclude that the needs of patients with progressive incomplete spinal cord lesions due to neurological disease differ from those of patients with acute traumatic spinal cord lesions and are best managed in a neurological rehabilitation unit. Efficacy appears to be related to neurological recovery and the duration of rehabilitation. This study underlines the value of combined neurological and rehabilitation expertise in the management of this patient group and the need to incorporate both disciplines in planning service provision.

The role of the left hemisphere in verbal and spatial reasoning tasks.

Laterality of reasoning processes have long been a source of investigation. Differing formats of verbal and spatial reasoning tasks have meant it has not been possible to extricate true performance level from artefacts of input and output modalities. The Verbal and Spatial Reasoning Test (VESPAR) offers this opportunity, by virtue of matched sets of verbal and spatial inductive reasoning problems. Two series of 40 patients with unilateral left and right hemisphere lesions were tested on two verbal and two spatial subtests of the VESPAR, together with a battery of baseline tests. The performance of the left and right hemisphere lesion cases was compared with a normal standardisation sample. Whereas only the left hemisphere group failed the verbal sections, both left and right hemisphere groups failed the spatial sections. The influence of aphasia on spatial reasoning was considered to be an incomplete explanation for the failure of the left hemisphere group on the spatial sections. It is concluded that this investigation provides firmer evidence of a crucial role for the left hemisphere in both verbal and spatial abstract reasoning processes.

Discrepantly poor verbal skills in poor readers: a failure of learning or ability?

Poor verbal skills in poor readers have long been reported in the literature. There have been many attempts to understand the interaction between poor verbal ability and poor verbal achievement. The methodological problems are considerable, including the measurement of verbal ability, which has been confounded by previous learning. A new reasoning test, the VESPAR, has been designed to measure novel problem solving and thus to be less reliant on acquired verbal skills. One hundred and seventy 14-year-olds completed the VESPAR, the Cognitive Abilities Test (CAT) and a single-word reading test. Overall, verbal scores were weaker than spatial scores. A subgroup of 38 pupils with particularly marked discrepancies between verbal and non-verbal CAT was identified. The especially discrepant pupils were matched with other non-discrepant pupils from the year group for either verbal or non-verbal CAT. The discrepant group's reading was at the same level as the matched verbal CAT group. However, the primary verbal ability of the discrepancy group, as measured on the VESPAR, was greater than the matched verbal CAT group. This raises the possibility that CAT- but not VESPAR-discrepant pupils may be at particular risk of under-achievement in the verbal domain.

Survival in MS: a randomized cohort study 21 years after the start of the pivotal IFNß-1b trial.

OBJECTIVE: To examine the effects of interferon beta (IFNß)-1b on all-cause mortality over 21 years in the cohort of 372 patients who participated in the pivotal randomized clinical trial (RCT), retaining (in the analysis) the original randomized treatment-assignments. METHODS: For this randomized long-term cohort study, the primary outcome, defined before data collection, was the comparison of all-cause mortality between the IFNß-1b 250 µg and placebo groups from the time of randomization through the entire 21-year follow-up interval (intention-to-treat, log-rank test for Kaplan-Meier survival curves). All other survival outcomes were secondary. RESULTS: After a median of 21.1 years from RCT enrollment, 98.4%(366 of 372) of patients were identified, and, of these, 81 deaths were recorded (22.1% [81 of 366]). Patients originally randomly assigned to IFNß-1b 250 µg showed a significant reduction in all-cause mortality over the 21-year period compared with placebo (p = 0.0173), with a hazard ratio of 0.532 (95% confidence interval 0.314-0.902). The hazard rate of death at long-term follow-up by Kaplan-Meier estimates was reduced by 46.8% among IFNß-1b 250 µg-treated patients (46.0% among IFNß-1b 50 µg-treated patients) compared with placebo. Baseline variables did not influence the observed treatment effect. CONCLUSIONS: There was a significant survival advantage in this cohort of patients receiving early IFNß-1b treatment at either dose compared with placebo. Near-complete ascertainment, together with confirmatory findings from both active treatment groups, strengthens the evidence for an IFNß-1b benefit on all-cause mortality. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that early treatment with IFNß-1b is associated with prolonged survival in initially treatment-naive patients with relapsing-remitting multiple sclerosis.