"No association between disease modifying treatment and fatigue in multiple sclerosis".

BACKGROUND: Fatigue affects 60-90% of people with multiple sclerosis (MS). It reduces quality of life and the ability to work. The cause of fatigue in MS remains unknown. Several disease-modifying treatments (DMTs) slow the disease process in relapsing MS by suppressing neuroinflammation. We aimed to investigate if treatment with a DMT is associated with lower rates of fatigue. METHODS: In this cross-sectional study of the MS population in three counties in Norway, we used the Fatigue Scale for Motor and Cognitive Functions (FSMC) and the Hospital Anxiety and Depression Scale (HADS) to assess patient-reported fatigue, anxiety and depression. Clinical data were retrieved from the electronic patient record system. We categorized DMTs as high-efficacy therapy or moderate-efficacy therapy. High-efficacy drugs included fingolimod, natalizumab, ocrelizumab, rituximab, alemtuzumab, daclizumab, and autologous hematopoietic stem cell transplantation. Moderate-efficacy drugs included interferons, glatiramer acetate, dimethyl fumarate, and teriflunomide. We included persons with relapsing MS only. RESULTS: Of 1142 patients, 80% had fatigue. Fifty-six percent of the patients were on DMTs (25% on moderate-efficacy treatment and 30% on high-efficacy treatment), 18% had discontinued treatment and 26% had never received any DMT. Sex, level of disability as measured by the Multiple Sclerosis Severity Score, anxiety and depression were independently associated with fatigue. Moderate-efficacy treatment was associated with less fatigue, but not after adjustment for other variables. There was no association between high-efficacy treatment and fatigue. CONCLUSION: We found no independent relationship between the use of disease-modifying treatment and fatigue in MS.

The instrumented single leg stance test detects early balance impairment in people with multiple sclerosis.

Balance impairment is frequent in people with multiple sclerosis (pwMS) and affects risk of falls and quality of life. By using inertial measurement units (IMUs) on the Single Leg Stance Test (SLS) we aimed to discriminate healthy controls (HC) from pwMS and detect differences in balance endurance and quality. Thirdly, we wanted to test the correlation between instrumented SLS parameters and self-reported measures of gait and balance. Fifty-five pwMS with mild (EDSS<4) and moderate disability (EDSS≥4) and 20 HC performed the SLS with 3 IMUs placed on the feet and sacrum and filled the Twelve Item Multiple Sclerosis Walking Scale (MSWS-12) questionnaire. A linear mixed model was used to compare differences in the automated balance measures. Balance duration was significantly longer in HC compared to pwMS (p < 0.001) and between the two disability groups (p < 0.001). Instrumented measures identified that trunk stability (normalized mediolateral and antero-posterior center of mass stability) had the strongest association with disability (R2 marginal 0.30, p < 0.001) and correlated well with MSWS-12 (R = 0.650, p < 0.001). PwMS tended to overestimate own balance compared to measured balance duration. The use of both self-reported and objective assessments from IMUs can secure the follow-up of balance in pwMS.

Humoral immunity to SARS-CoV-2 mRNA vaccination in multiple sclerosis: the relevance of time since last rituximab infusion and first experience from sporadic revaccinations.

INTRODUCTION: The effect of disease-modifying therapies (DMT) on vaccine responses is largely unknown. Understanding the development of protective immunity is of paramount importance to fight the COVID-19 pandemic. OBJECTIVE: To characterise humoral immunity after mRNA-COVID-19 vaccination of people with multiple sclerosis (pwMS). METHODS: All pwMS in Norway fully vaccinated against SARS-CoV-2 were invited to a national screening study. Humoral immunity was assessed by measuring anti-SARS-CoV-2 SPIKE RBD IgG response 3-12 weeks after full vaccination, and compared with healthy subjects. RESULTS: 528 pwMS and 627 healthy subjects were included. Reduced humoral immunity (anti-SARS-CoV-2 IgG <70 arbitrary units) was present in 82% and 80% of all pwMS treated with fingolimod and rituximab, respectively, while patients treated with other DMT showed similar rates as healthy subjects and untreated pwMS. We found a significant correlation between time since the last rituximab dose and the development of humoral immunity. Revaccination in two seronegative patients induced a weak antibody response. CONCLUSIONS: Patients treated with fingolimod or rituximab should be informed about the risk of reduced humoral immunity and vaccinations should be timed carefully in rituximab patients. Our results identify the need for studies regarding the durability of vaccine responses, the role of cellular immunity and revaccinations.

Rebaseline no evidence of disease activity (NEDA-3) as a predictor of long-term disease course in a Norwegian multiple sclerosis population.

Introduction: No evidence of disease activity with three components (NEDA-3) is achieved if the person with MS (pwMS) has no new MRI lesions, no new relapses and no change in Expanded disability status scale (EDSS) over 1 year. Whether NEDA-3 is a good tool in measuring disease activity is up for discussion, but it is superior to the individual parameters separately and user-friendly. There is disagreement on whether NEDA-3 is a good predictor of long-term disability. Methods: This is a retrospective cohort study using real-world data with limited selection bias from the complete MS population at two hospitals in the southeast of Norway. We included pwMS diagnosed between 2006 and 2017 who had enough information to determine time to failure of NEDA-3 after diagnosis. Results: Of 536 pwMS, only 38% achieved NEDA 1 year after diagnosis. PwMS achieving NEDA were more likely to be started on a high efficacy drug as the initial drug, but there were no demographic differences. Mean time to NEDA failure was 3.3 (95% CI 2.9-3.7) years. Starting a high efficiacy therapy was associated with an increased risk of sustaining NEDA as compared to those receiving moderate efficacy therapy. PwMS who achieved NEDA at year one had a mean time to EDSS 6 of 33.8 (95% CI 30.9-36.8) years vs. 30.8 (95% CI 25.0-36.6) years in pwMS who did not achieve NEDA, p < 0.001. When rebaselining NEDA 1 year after diagnosis, 52.2% achieved NEDA in the 1st year after rebaseline, mean time to NEDA failure was 3.4 (95% CI 3.0-3.7) years and mean time to EDSS 6 was 44.5 (95% CI 40.4-48.5) years in pwMS achieving NEDA vs. 29.6 (95% CI 24.2-35.0) years in pwMS not achieving NEDA, p < 0.001. After rebaseline, pwMS with a high efficacy therapy as the initial drug had a mean time from diagnosis to NEDA fail of 4.8 years (95% CI 3.9-5.8) vs. 3.1 years (95% CI 2.7-3.5) in pwMS started on a moderate efficacy therapy, p < 0.001. In pwMS with NEDA failure at year one, 70% failed one, 28% failed two and 2% failed three components. New MRI lesions were the most common cause of NEDA failure (63%), followed by new relapses (50%) and EDSS change (25%). Conclusion: NEDA-3 from rebaseline after 1 year, once treatment is stabilized, can predict the long-term disease course in MS. Starting a high efficacy DMT is associated with longer time to NEDA failure than moderate therapies. Finally, most pwMS only fail one component and new MRI lesions are the most likely cause of NEDA failure.

Fatigue in multiple sclerosis is associated with socioeconomic factors.

OBJECTIVES: Fatigue is one of the leading causes of reduced quality of life and inability to work in people with multiple sclerosis (pwMS). Currently, no treatment effectively ameliorates fatigue. We still know little about what causes fatigue and which factors may contribute to fatigue. Knowledge about socioeconomic factors' role in fatigue might help us recognize strategies for the management of fatigue. Our aim was to explore whether socioeconomic factors are associated with the presence or level of perceived fatigue. METHODS: This is a cross-sectional study of the MS population in three Norwegian counties. We used the Fatigue Scale for Motor and Cognitive Functions to assess self-reported fatigue, and obtained socioeconomic data from Statistics Norway and questionnaires. To assess self-reported anxiety and depression, we employed the Hospital Anxiety and Depression Scale. Clinical data were gathered from the hospital record system. RESULTS: The response rate was 64% (1599/2512). Seventy percent of the respondents were female, and the mean age was 52 years. Higher levels of education were associated with lower levels of fatigue. Receiving a disability pension, being divorced and having children were all factors associated with higher levels of fatigue, as were low parental education, low income, current smoking, and autoimmune comorbidities. We found a higher prevalence of anxiety and depression in pwMS with fatigue compared to those without fatigue CONCLUSION: Female sex, high level of disability, anxiety, depression and socioeconomic factors were independently associated with fatigue in contemporary patients with MS. These factors should be considered when devising management strategies.

Deep neural networks learn general and clinically relevant representations of the ageing brain.

The discrepancy between chronological age and the apparent age of the brain based on neuroimaging data - the brain age delta - has emerged as a reliable marker of brain health. With an increasing wealth of data, approaches to tackle heterogeneity in data acquisition are vital. To this end, we compiled raw structural magnetic resonance images into one of the largest and most diverse datasets assembled (n=53542), and trained convolutional neural networks (CNNs) to predict age. We achieved state-of-the-art performance on unseen data from unknown scanners (n=2553), and showed that higher brain age delta is associated with diabetes, alcohol intake and smoking. Using transfer learning, the intermediate representations learned by our model complemented and partly outperformed brain age delta in predicting common brain disorders. Our work shows we can achieve generalizable and biologically plausible brain age predictions using CNNs trained on heterogeneous datasets, and transfer them to clinical use cases.

Risk of fingolimod rebound after switching to cladribine or rituximab in multiple sclerosis.

BACKGROUND: A sudden onset of extensive disease activity, including severe clinical relapse and extensive brain or spinal magnetic resonance imaging (MRI) lesions, termed "rebound" disease activity has been reported after withdrawal of fingolimod in patients with multiple sclerosis (MS). OBJECTIVE: To compare the risk of rebound after switching from fingolimod to cladribine or rituximab in MS. METHODS: All patients switching from fingolimod to cladribine or rituximab were included in a retrospective cohort study utilizing prospectively collected data from two university hospitals with different treatment strategies. RESULTS: A total of 73 patients with at least 6 months follow-up after switching were identified, 33 patients had switched from fingolimod to cladribine and 40 patients to rituximab. No patients in the rituximab group and seven (21.1%) in the cladribine group qualified for rebound disease activity. Ten (30.3%) of the patients using cladribine and five (12.5%) of the patients using rituximab experienced a relapse. MRI disease activity was seen in 18 (54.5%) and eight (20.0%) of the patients using cladribine and rituximab, respectively. Younger age and previous high relapse rate were associated with increased risk of rebound in the cladribine group. CONCLUSIONS: We identify a lower risk of rebound during the first year after switching from fingolimod to rituximab compared to cladribine, indicating a better initial clinical outcome with the former treatment strategy.

The influence of socioeconomic factors on access to disease modifying treatment in a Norwegian multiple sclerosis cohort.

OBJECTIVE: Several studies report an impact of socioeconomic factors on access to disease modifying treatment (DMT) in multiple sclerosis (MS), with a trend of less access to more deprived persons. We investigated the impact of socioeconomic status (SES) on access to treatment in a well-defined Norwegian MS cohort. METHODS: This is a study of a population-based Norwegian MS cohort. We collected detailed information on disease development, progression, and DMT administered. Socioeconomic data was obtained from Statistics Norway and a questionnaire. RESULTS: We included 1314 persons with relapsing remitting MS at the prevalence date 01/01/2018. The population ever treated with DMTs is younger at onset, has shorter time from onset to diagnosis and lower expanded disability status score (EDSS) at diagnosis. The persons with MS (pwMS) with the highest levels of education, and those who are married are more likely to be ever treated with DMT. In the subgroup treated with a high efficacy DMT as a first drug, the pwMS are younger at prevalence date (39.9 years (SD 12.1)) compared with those who are not treated with a high efficacy DMT as first drug (43.8 years (SD 10.3)). The subgroup treated with a high efficacy DMT as a first drug has a 0.5 point higher EDSS at diagnosis compared to those not treated with a high efficacy DMT as a first drug. The level of education, household income and marital status are inversely related to access to high efficacy DMT as a first drug. None of the above differences persist when analyzing the subgroup diagnosed within the last six years (2012-2017). CONCLUSIONS: Since 2012, the pwMS in this Norwegian cohort are treated equally with DMT in terms of different measures of socioeconomic position.

Sensor-based gait analyses of the six-minute walk test identify qualitative improvement in gait parameters of people with multiple sclerosis after rehabilitation.

The aim of this work was to determine whether wearable inertial measurement units (IMUs) could detect gait improvements across different disability groups of people with Multiple Sclerosis (pwMS) by the six-minute walk test (6MWT) during a rehabilitation stay in a specialized rehabilitation center. Forty-six pwMS and 20 healthy controls (HC) were included in the study. They performed the 6MWT with two inertial measurement units (IMUs) placed on the feet. Thirty-two of the pwMS were retested at the end of the stay. PwMS were divided in a mild-disability and a moderate-disability group. The 6MWT was divided in six sections of 1 min each for technical analysis, and linear mixed models were used for statistical analyses. The comparison between the two disability groups and HC highlighted significant differences for each gait parameter (all p < 0.001). The crossing effect between the test-retest and the two disability groups showed greater improvement for the moderate-disability group. Finally, the gait parameter with the higher effect size, allowing the best differentiation between the disability groups, was the foot flat ratio (R2 = 0.53). Gait analyses from wearable sensors identified different evolutions of gait patterns during the 6MWT in pwMS with different physical disability. The measured effect of a short-time rehabilitation on gait with 6MWT was higher for pwMS with higher degree of disability. Using IMUs in a clinical setting allowed to identify significant changes in inter-stride gait patterns. Wearable sensors and key parameters have the potential as useful clinical tools for focusing on gait in pwMS.

Effect of desire for pregnancy on decisions to escalate treatment in multiple sclerosis care: Differences between MS specialists and non-MS specialists.

BACKGROUND: Therapeutic inertia (TI) is a worldwide phenomenon that affects 60 to 90% of neurologists and up to 25% of daily treatment decisions during management of multiple sclerosis (MS) patients. A large volume of MS patients are women of childbearing age, and desire for pregnancy is a complex variable often affecting MS care. The objective of this study was to determine the effect of desire for pregnancy on decisions to escalate treatment during management of MS patients. METHODS: 300 neurologists with expertise in MS from 20 countries were invited to participate in the study. Participants were presented with 12 pairs of simulated MS patient profiles reflective of case scenarios encountered in clinical practice. Participants were asked to select the ideal candidate for treatment escalation from modest to higher-efficacy therapies. Disaggregated discrete choice experiments were used to estimate the weight of factors and attributes affecting physicians' decisions when considering treatment selection. An excel calculator that provides estimates as the percentage of participants that would escalate treatment for a simulated case-scenario was constructed. RESULTS: 229 (76.3%) completed the study. The mean age (SD) of study participants was 44 (±10) years. The mean (SD) number of MS patients seen per month by each neurologist was 18 (±16). Non-MS specialists were significantly less likely to escalate treatment than MS specialists across mild, moderate, and severe patient cases. These differences were accentuated when case scenarios introduced a desire for pregnancy. The findings were consistent when MRI-lesions, severity of symptoms, and number of relapses were included. CONCLUSIONS: Desire for pregnancy differentially influences decisions to escalate treatment, suggesting knowledge-to-action gaps between MS and non-MS specialists. Our findings indicate the need for educational strategies to overcome these gaps and improve clinical outcomes for MS patients who desire pregnancy.

Early High Efficacy Treatment in Multiple Sclerosis Is the Best Predictor of Future Disease Activity Over 1 and 2 Years in a Norwegian Population-Based Registry.

Background: Moderate and high efficacy disease modifying therapies (DMTs) have a profound effect on disease activity. The current treatment guidelines only recommend high efficacy DMTs for patients with highly active MS. The objective was to examine the impact of initial treatment choice in achieving no evidence of disease activity (NEDA) at year 1 and 2. Methods: Using a real-world population-based registry with limited selection bias from the southeast of Norway, we determined how many patients achieved NEDA on moderate and high efficacy DMTs. Results: 68.0% of patients who started a high efficacy DMT as the first drug achieved NEDA at year 1 and 52.4% at year 2 as compared to 36.0 and 19.4% of patients who started a moderate efficacy DMT as a first drug. The odds ratio (OR) of achieving NEDA on high efficacy drugs compared to moderate efficacy drugs as a first drug at year 1 was 3.9 (95% CI 2.4-6.1, p < 0.001). The OR for high efficacy DMT as the second drug was 2.5 (95% CI 1.7-3.9, p < 0.001), and was not significant for the third drug. Patients with a medium or high risk of disease activity were significantly more likely to achieve NEDA on a high efficacy therapy as a first drug compared to moderate efficacy therapy as a first drug. Conclusions: Achieving NEDA at year 1 and 2 is significantly more likely in patients on high-efficacy disease modifying therapies than on moderate efficacy therapies, and the first choice of treatment is the most important. The immunomodulatory treatment guidelines should be updated to ensure early, high efficacy therapy for the majority of patients diagnosed with MS.

No significant differences in absenteeism or academic achievements in a Norwegian multiple sclerosis case control study.

BACKGROUND: The duration and features of the multiple sclerosis (MS) prodrome are not well defined. We aimed to ascertain whether people with a future MS diagnosis have more days of absence and perform worse in upper secondary school than age, gender and county-matched controls. METHODS: Using registry data from the southeast of Norway, we identified people with MS born ≥1978. Statistics Norway provided information on grades and days of absence in cases and matched controls. We looked at absence in the three years of upper secondary school and grades in the compulsory subjects Norwegian, English, mathematics and physical education. RESULTS: We identified 107 cases with disease onset one year or more after graduation and 626 controls. There were no significant differences in absence or grades achieved in the population as a whole or in those with disease onset within four years of diagnosis, and no association between time to disease onset and days of absence or grades. CONCLUSION: There was no difference in days of absence or grades achieved in upper secondary school in the four years leading up to disease onset in cases compared to controls. A potential prodrome may not affect cognition enough to impact school achievements.

Maternal education has significant influence on progression in multiple sclerosis.

OBJECTIVE: The identification of potential risk factors for disease severity is of great importance in the treatment of multiple sclerosis. The influence of socioeconomic status on progression in multiple sclerosis (MS) is sparsely investigated. Our aim was to investigate how socioeconomic status in adolescence influences disease progression in later life. METHODS: A total of 1598 patients with multiple sclerosis from a well-defined population in Norway were included. Detailed information on disease progression, measured by expanded disability status scale (EDSS) and multiple sclerosis severity score (MSSS), were combined with data on socioeconomic factors. We used residency and parental level of education at patients' age 16 and exposure to second-hand smoking as a measure of socioeconomic status in adolescence, adjusting for the same variables as well as use of disease modifying treatments at prevalence date 01.01.18. RESULTS: High maternal level of education at patients' age 16 was significantly associated with less pronounced disease progression measured by MSSS (ß-coefficient -0.58, p = 0.015), younger age and lower EDSS at disease onset, and shorter time from onset to diagnosis. No significant associations were found for paternal education level and MSSS. The use of any disease modifying treatment before prevalence date was significantly associated with disease progression (ß-coefficient -0.49, p=0.004), while residence, current and second-hand smoking were not. CONCLUSION: This study on a population-based, real-world cohort shows that the parental level of education has a significant impact on a timely diagnosis of MS. In addition to disease modifying treatment, maternal level of education also had an impact on disease progression in later life.

High prevalence of fatigue in contemporary patients with multiple sclerosis.

OBJECTIVE: The prevalence of multiple sclerosis (MS)-related fatigue may have changed due to new diagnostic criteria and new disease modifying drugs. We aimed to assess the prevalence of fatigue in a contemporary MS cohort, and to explore associations between fatigue and clinical and demographic factors. METHODS: This is a cross-sectional study of the MS population in three Norwegian counties. Fatigue was assessed with the Fatigue Scale for Motor and Cognitive Functions (FSMC). We also assessed self-reported anxiety, depression and daytime sleepiness. RESULTS: The response rate was 64% (1599/2512). The mean age of the participants was 52 ± 13 years, median EDSS was 2.5 (IQR 1.5-3.0) and median disease duration from onset was 16 years (IQR 8-25). We found a prevalence of fatigue of 81%. Women had a higher prevalence of fatigue than men (83% vs 78%, p = 0.02). The prevalence increased with age (p < 0.001) and with increasing disease severity (p < 0.001), but in multivariate analyses, only sex and disease severity remained independent determinants of fatigue. Anxiety, depression, and daytime sleepiness were more prevalent in patients with fatigue than in those without fatigue (all p-values < 0.001). CONCLUSION: The prevalence of fatigue is high in contemporary patients with MS. Fatigue is associated with female sex and level of disability, as well as with anxiety, depression and excessive daytime sleepiness.

The course of multiple sclerosis rewritten: a Norwegian population-based study on disease demographics and progression.

OBJECTIVES: Over the past few decades, there has been an improvement in the rate of disability progression in multiple sclerosis (MS) patients, and most studies relate this evolvement to the introduction of disease-modifying therapies. However, several other factors have changed over this period, including access to MRI and newer diagnostic criteria. The aim of this study is to investigate changes in the natural course of MS over time in a near-complete and geographically well-defined population from the south-east of Norway. METHODS: We examined disease progression and demographics over two decades and assessed the effect of disease-modifying therapies using linear mixed-effect models. RESULTS: In a cohort of 2097 patients, we found a significant improvement in disability as measured by the Expanded Disability Status Scale (EDSS) stratified by age, and the improvement remained significant after adjusting for time on disease-modifying medications, gender and progressive MS at onset. The time from disease onset to EDSS 6 in the total cohort was 29.8 years (95% CI 28.5-31.1) and was significantly longer in patients diagnosed after 2006 compared to patients diagnosed before. There are significant differences between patient demographics, as well as time to EDSS 6, in the near-complete, geographically well-defined population compared to an additional cohort from the capital Oslo and its suburbs. CONCLUSION: The natural course of MS is improving, but the improvement seen in disease progression has multifaceted explanations. Our study underlines the importance of completeness of data, relevant timeframes and demographics when comparing different MS populations. Studies on incomplete populations should be interpreted with caution.

The genetic architecture of human brainstem structures and their involvement in common brain disorders.

Brainstem regions support vital bodily functions, yet their genetic architectures and involvement in common brain disorders remain understudied. Here, using imaging-genetics data from a discovery sample of 27,034 individuals, we identify 45 brainstem-associated genetic loci, including the first linked to midbrain, pons, and medulla oblongata volumes, and map them to 305 genes. In a replication sample of 7432 participants most of the loci show the same effect direction and are significant at a nominal threshold. We detect genetic overlap between brainstem volumes and eight psychiatric and neurological disorders. In additional clinical data from 5062 individuals with common brain disorders and 11,257 healthy controls, we observe differential volume alterations in schizophrenia, bipolar disorder, multiple sclerosis, mild cognitive impairment, dementia, and Parkinson's disease, supporting the relevance of brainstem regions and their genetic architectures in common brain disorders.

State of the Art and Future Challenges in Multiple Sclerosis Research and Medical Management: An Insight into the 5th International Porto Congress of Multiple Sclerosis.

The 5th International Porto Congress of Multiple Sclerosis took place between the 14th and 16th of February 2019 in Porto, Portugal. Its intensive programme covered a wide-range of themes-including many of the hot topics, challenges, pitfalls and yet unmet needs in the field of multiple sclerosis (MS)-led by a number of well-acknowledged world experts. This meeting review summarizes the talks that took place during the congress, which focussed on issues in MS as diverse as the development and challenges of progressive MS, epidemiology, differential diagnosis, medical management, molecular research and imaging tools.

Prevalence of multiple sclerosis in rural and urban districts in Telemark county, Norway.

OBJECTIVE: To explore the trends in prevalence and incidence of multiple sclerosis (MS) in Telemark, Norway (latitude 58.7-60.3˚N), over the past two decades, with focus on differences between rural and urban areas. METHODS: Data from all patients with a confirmed diagnosis of MS in Telemark since 1993 were prospectively recorded and collected in a retrospective chart review. Prevalence estimates on January 1st 1999, 2009 and 2019, and incidence rates at five-year intervals between 1999 and 2018 were calculated and all results were adjusted to the European Standard Population. The study population was divided into urban and rural residency using a Norwegian governmental index. RESULTS: We registered 579 patients with MS in Telemark between 1999 and 2019. The adjusted prevalence estimates for January 1st 1999, 2009 and 2019 were 105.8/105, 177.1/105 and 260.6/105, respectively. In 2019, the prevalence estimates were 250.4/105 in urban and 316.2 /105 in rural areas. Between 1999 and 2018, the yearly incidence increased from 8.4/105 to 14.4/105. CONCLUSIONS: The prevalence of MS in Telemark is among the highest ever reported in Norway, consistent with an increasing incidence in the county over the past twenty years. The even higher prevalence in the rural areas is unlikely to be explained by possible risk factors like latitude, exposure to sunlight and diet. Further studies on differences between urban and rural areas are required to reveal possible new risk factors.

The diagnostic value of IgG index versus oligoclonal bands in cerebrospinal fluid of patients with multiple sclerosis.

BACKGROUND: Diagnostic criteria for multiple sclerosis have been developed to guide the diagnostic process. In the latest revision of the McDonald criteria, the presence of oligoclonal bands may replace the need for dissemination in time. The aim of this study is to investigate if the less time-consuming analysis of immunoglobulin G index in cerebrospinal fluid can safely predict the findings of oligoclonal bands. METHODS: This is a retrospective study of patients with multiple sclerosis at three hospitals in South-East Norway where lumbar puncture is performed routinely. We included patients diagnosed with multiple sclerosis after 2005 with known oligoclonal band status and an immunoglobulin G index score. RESULTS: Of 1295 patients diagnosed during or after 2005, 93.8% were oligoclonal band positive at diagnosis. Of 842 multiple sclerosis patients with known immunoglobulin G index and oligoclonal band status, 93.3% were oligoclonal band positive and 76.7% had an elevated immunoglobulin G index. The positive predictive value of a high immunoglobulin G index when oligoclonal bands are positive was 99.4% (95% confidence interval 98.4-99.8%). The negative predictive value of a normal immunoglobulin G index when oligoclonal bands are negative was 26.5% (95% confidence interval 23.5-29.9%). CONCLUSION: An immunoglobulin G index >0.7 has a positive predictive value >99% for oligoclonal bands. An elevated immunoglobulin G index adds diagnostic value versus oligoclonal bands and saves time in the diagnostic process.