Misdiagnosis and underdiagnosis of multiple sclerosis: A systematic review and meta-analysis.

BACKGROUND: Diagnostic errors in multiple sclerosis (MS) impact patients and healthcare systems. OBJECTIVES: This study aimed to determine the prevalence of MS misdiagnosis and underdiagnosis, time delay in reaching a correct diagnosis and potential impact of sex. METHODS: Systematic review and meta-analysis on MS diagnostic errors. RESULTS: Out of 3910 studies, we included 62 for a qualitative synthesis and 24 for meta-analyses. Frequency of misdiagnosis (incorrect assignment of an MS diagnosis) ranged from 5% to 41%, with a pooled proportion based on six studies of 15% (95% CI: 9%-26%, n = 1621). The delay to rectify a misdiagnosis ranged from 0.3 to 15.9 years. Conversely, underdiagnosis (unrecognized diagnosis of MS) ranged from 3% to 58%, with a pooled proportion in four studies of 36% (95% CI: 20%-55%, n = 728). Pooling seven studies comprising 2851 individuals suggested a diagnostic delay to establish a correct MS diagnosis of 17.3 months (95% CI: 11.9-22.7) in patients underdiagnosed. In a meta-analysis of five studies, women were 2.1 times more likely to be misdiagnosed with MS compared to men (odds ratio, 95% CI: 1.53-2.86). CONCLUSION: This study provides summary-level evidence for the high prevalence of MS misdiagnosis and underdiagnosis. Future studies are needed to understand the causes of these diagnostic challenges in MS care.

Differential Diagnosis of Suspected Multiple Sclerosis in Pediatric and Late-Onset Populations: A Review.

Importance: While the typical onset of multiple sclerosis (MS) occurs in early adulthood, 2% to 10% of cases initially present prior to age 18 years, and approximately 5% after age 50 years. Guidance on approaches to differential diagnosis in suspected MS specific to these 2 age groups is needed. Observations: There are unique biological factors in children younger than 18 years and in adults older than age 50 years compared to typical adult-onset MS. These biological differences, particularly immunological and hormonal, may influence the clinical presentation of MS, resilience to neuronal injury, and differential diagnosis. While mimics of MS at the typical age at onset have been described, a comprehensive approach focused on the younger and older ends of the age spectrum has not been previously published. Conclusions and Relevance: An international committee of MS experts in pediatric and adult MS was formed to provide consensus guidance on diagnostic approaches and key clinical and paraclinical red flags for non-MS diagnosis in children and older adults.

Multicenter automated central vein sign detection performs as well as manual assessment for the diagnosis of multiple sclerosis.

BACKGROUND AND PURPOSE: The central vein sign (CVS) is a proposed diagnostic imaging biomarker for multiple sclerosis (MS). The proportion of white matter lesions exhibiting the CVS (CVS+) is higher in patients with MS compared to its radiological mimics. Evaluation for CVS+ lesions in prior studies have been performed by manual rating, an approach that is time-consuming and has variable inter-rater reliability. Accurate automated methods would facilitate efficient assessment for CVS. The objective of this study was to compare the performance of an automated CVS detection method with manual rating for the diagnosis of MS. MATERIALS AND METHODS: 3T MRI was acquired in 86 participants undergoing evaluation for MS in a 9-site multicenter study. Participants presented with either typical or atypical clinical syndromes for MS. An automated CVS detection method was employed and compared to manual rating, including total CVS+ proportion and a simplified counting method in which experts visually identified up to 6 CVS+ lesions using FLAIR* contrast (a voxel-wise product of T2 FLAIR and post-contrast T2*-EPI images). RESULTS: Automated CVS processing was completed in 79 of 86 participants (91%), of whom 28 (35%) fulfilled the 2017 McDonald criteria at the time of imaging. The area under the receiver-operator characteristic curve (AUC) for discrimination between participants with and without MS for the automated CVS approach was 0.78 (95% confidence interval: [0.67,0.88]). This was not significantly different from simplified manual counting methods (select6*) (0.80 [0.69,0.91]) or manual assessment of total CVS+ proportion (0.89 [0.82,0.96]). In a sensitivity analysis excluding 11 participants whose MRI exhibited motion artifact, the AUC for the automated method was 0.81 [0.70,0.91], which was not statistically different from that for select6* (0.79 [0.68,0.92]) or manual assessment of total CVS+ proportion (0.89 [0.81,0.97]). CONCLUSIONS: Automated CVS assessment was comparable to manual CVS scoring for differentiating patients with MS from those with other diagnoses. Large, prospective, multicenter studies utilizing automated methods and enrolling the breadth of disorders referred for suspicion of MS are needed to determine optimal approaches for clinical implementation of an automated CVS detection method. ABBREVIATIONS: CVS= central vein sign; CVS+ = white matter lesions exhibiting the CVS; MRI = magnetic resonance imaging; MS = multiple sclerosis; T2 FLAIR = T2 fluid-attenuated inversion recovery; T2*-EPI = T2*-weighted 3D echo planar imaging; FLAIR* = a voxel-wise product of T2 FLAIR and post-contrast T2*-EPI images; select6* = simplified counting method in which experts visually identified up to 6 CVS+ lesions on FLAIR* imaging.

Misdiagnosis of Multiple Sclerosis: Past, Present, and Future.

PURPOSE OF REVIEW: Misdiagnosis of multiple sclerosis (MS) is a prevalent worldwide problem. This review discusses how MS misdiagnosis has evolved over time and focuses on contemporary challenges and potential strategies for its prevention. RECENT FINDINGS: Recent studies report cohorts with a range of misdiagnosis between 5 and 18%. Common disorders are frequently misdiagnosed as MS. Overreliance on MRI findings and misapplication of MS diagnostic criteria are often associated with misdiagnosis. Emerging imaging biomarkers, including the central vein sign and paramagnetic rim lesions, may aid diagnostic accuracy when evaluating patients for suspected MS. MS misdiagnosis can have harmful consequences for patients and healthcare systems. Further research is needed to better understand its causes. Concerted and novel educational efforts to ensure accurate and widespread implementation of MS diagnostic criteria remain an unmet need. The incorporation of diagnostic biomarkers highly specific for MS in the future may prevent misdiagnosis.

Differential diagnosis of suspected multiple sclerosis: global health considerations.

The differential diagnosis of multiple sclerosis can present specific challenges in patients from Latin America, Africa, the Middle East, eastern Europe, southeast Asia, and the Western Pacific. In these areas, environmental factors, genetic background, and access to medical care can differ substantially from those in North America and western Europe, where multiple sclerosis is most common. Furthermore, multiple sclerosis diagnostic criteria have been developed primarily using data from North America and western Europe. Although some diagnoses mistaken for multiple sclerosis are common regardless of location, a comprehensive approach to the differential diagnosis of multiple sclerosis in Latin America, Africa, the Middle East, eastern Europe, southeast Asia, and the Western Pacific regions requires special consideration of diseases that are prevalent in those locations. A collaborative effort has therefore assessed global differences in multiple sclerosis differential diagnoses and proposed recommendations for evaluating patients with suspected multiple sclerosis in regions beyond North America and western Europe.

Diagnostic performance of central vein sign versus oligoclonal bands for multiple sclerosis.

BACKGROUND: Cerebrospinal fluid (CSF) oligoclonal bands (OCB) are a diagnostic biomarker in multiple sclerosis (MS). The central vein sign (CVS) is an imaging biomarker for MS that may improve diagnostic accuracy. OBJECTIVES: The objective of the study is to examine the diagnostic performance of simplified CVS methods in comparison to OCB in participants with clinical or radiological suspicion for MS. METHODS: Participants from the CentrAl Vein Sign in MS (CAVS-MS) pilot study with CSF testing were included. Select-3 and Select-6 (counting up to three or six CVS+ lesions per scan) were rated on post-gadolinium FLAIR* images. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value for Select-3, Select-6, OCB, and combinations thereof were calculated for MS diagnosis at baseline and at 12 months. RESULTS: Of 53 participants, 25 were OCB+. At baseline, sensitivity for MS diagnosis was 0.75 for OCB, 0.83 for Select-3, and 0.71 for Select-6. Specificity for MS diagnosis was 0.76 for OCB, 0.48 for Select-3, and 0.86 for Select-6. At 12 months, PPV for MS diagnosis was 0.95 for Select-6 and 1.00 for Select-6 with OCB+ status. DISCUSSION: Results suggest similar diagnostic performance of simplified CVS methods and OCB. Ongoing studies will refine whether CVS could be used in replacement or in conjunction with OCB.

Differential diagnosis of suspected multiple sclerosis: considerations in people from minority ethnic and racial backgrounds in North America, northern Europe, and Australasia.

The differential diagnosis of suspected multiple sclerosis has been developed using data from North America, northern Europe, and Australasia, with a focus on White populations. People from minority ethnic and racial backgrounds in regions where prevalence of multiple sclerosis is high are more often negatively affected by social determinants of health, compared with White people in these regions. A better understanding of changing demographics, the clinical characteristics of people from minority ethnic or racial backgrounds, and the social challenges they face might facilitate equitable clinical approaches when considering a diagnosis of multiple sclerosis. Neuromyelitis optica, systemic lupus erythematous, neurosarcoidosis, infections, and cerebrovascular conditions (eg, hypertension) should be considered in the differential diagnosis of multiple sclerosis for people from minority ethnic and racial backgrounds in North America, northern Europe, and Australasia. The diagnosis of multiple sclerosis in people from a minority ethnic or racial background in these regions requires a comprehensive approach that considers the complex interplay of immigration, diagnostic inequity, and social determinants of health.

Multiple sclerosis presenting with paroxysmal symptoms: Patients at the limitations of current diagnostic criteria.

Paroxysmal neurological symptoms in patients with multiple sclerosis (MS) have long been acknowledged. However, consideration of whether such symptoms are a clinical attack and sufficient for fulfillment of MS diagnostic criteria has varied as criteria have evolved over time. Previous studies and anecdotal reports indicate that some patients with MS first present with syndromes such as trigeminal neuralgia, Lhermitte's phenomenon, tonic spasm, and seizure years before an attack typical of MS such as optic neuritis or myelitis. We discuss four patients with presumed MS who initially presented with these syndromes with evidence of a corresponding central nervous system (CNS) lesion who, were these symptoms considered an attack, could have been diagnosed with relapsing remitting MS or clinically isolated syndrome. This case series aims to highlight the unmet need for data for such patient presentations and for clinical guidance from future MS diagnostic criteria to optimize care.

Diagnosis concealment behaviors and disclosure beliefs are associated with health and quality of life in people with multiple sclerosis.

BACKGROUND: People with multiple sclerosis (pwMS) struggle with whether, how, and how much to disclose their diagnosis. They often expend resources to conceal their diagnosis, and hold beliefs that it may negatively affect their personal relationships and/or professional opportunities. To better understand these effects, we developed a measure to quantify concealment behaviors and disclosure beliefs. Our main objective is to evaluate relationships of DISCO-MS responses to health and quality of life in a multinational cohort. METHODS: Survey responses were obtained for DISCO-MS and PROMIS-MS scales: global health, communication, social roles participation, anxiety, depression, emotional / behavioral dyscontrol, fatigue, lower extremity function, positive affect / well-being, social roles satisfaction, sleep, stigma, upper extremity function, cognitive function, bladder control, bowel control, visual function. Simple linear regression assessed associations. RESULTS: 263 pwMS were include. Higher concealment was associated with higher anxiety (beta= 0.15 [0.07, 0.23]), depression (beta = 0.13 [0.05, 0.21]), emotional dyscontrol (beta = 0.12 [0.04, 0.20]), lower affect / well-being (beta = -0.13 [-0.21, - 0.05]). Higher anticipation of negative consequences of disclosure was associated with lower self-reported physical (beta = -0.15) and mental health (beta = -0.14), lower positive affect / well-being, social roles satisfaction, higher anxiety, depression, emotional dyscontrol, sleep disturbance, and higher perceived stigma. DISCUSSION: These results reveal potential consequences of diagnosis concealment for physical and mental health and quality of life. Raising awareness and implementing interventions may mitigate negative repercussions of concealment.

Choroid plexus volume differentiates MS from its mimics.

This study aimed to determine whether choroid plexus volume (CPV) could differentiate multiple sclerosis (MS) from its mimics. A secondary analysis of two previously enrolled studies, 50 participants with MS and 64 with alternative diagnoses were included. CPV was automatically segmented from 3T magnetic resonance imaging (MRI), followed by manual review to remove misclassified tissue. Mean normalized choroid plexus volume (nCPV) to intracranial volume demonstrated relatively high specificity for MS participants in each cohort (0.80 and 0.76) with an area under the receiver-operator characteristic curve of 0.71 (95% confidence interval (CI) = 0.55-0.87) and 0.65 (95% CI = 0.52-0.77). In this preliminary study, nCPV differentiated MS from its mimics.

Assessing Free-Living Postural Sway in Persons With Multiple Sclerosis.

Postural instability is associated with disease status and fall risk in Persons with Multiple Sclerosis (PwMS). However, assessments of postural instability, known as postural sway, leverage force platforms or wearable accelerometers, and are most often conducted in laboratory environments and are thus not broadly accessible. Remote measures of postural sway captured during daily life may provide a more accessible alterative, but their ability to capture disease status and fall risk has not yet been established. We explored the utility of remote measures of postural sway in a sample of 33 PwMS. Remote measures of sway differed significantly from lab-based measures, but still demonstrated moderately strong associations with patient-reported measures of balance and mobility impairment. Machine learning models for predicting fall risk trained on lab data provided an Area Under Curve (AUC) of 0.79, while remote data only achieved an AUC of 0.51. Remote model performance improved to an AUC of 0.74 after a new, subject-specific k-means clustering approach was applied for identifying the remote data most appropriate for modelling. This cluster-based approach for analyzing remote data also strengthened associations with patient-reported measures, increasing their strength above those observed in the lab. This work introduces a new framework for analyzing data from remote patient monitoring technologies and demonstrates the promise of remote postural sway assessment for assessing fall risk and characterizing balance impairment in PwMS.

A multicenter pilot study evaluating simplified central vein assessment for the diagnosis of multiple sclerosis.

BACKGROUND: The central vein sign (CVS) is a proposed magnetic resonance imaging (MRI) biomarker for multiple sclerosis (MS); the optimal method for abbreviated CVS scoring is not yet established. OBJECTIVE: The aim of this study was to evaluate the performance of a simplified approach to CVS assessment in a multicenter study of patients being evaluated for suspected MS. METHODS: Adults referred for possible MS to 10 sites were recruited. A post-Gd 3D T2*-weighted MRI sequence (FLAIR*) was obtained in each subject. Trained raters at each site identified up to six CVS-positive lesions per FLAIR* scan. Diagnostic performance of CVS was evaluated for a diagnosis of MS which had been confirmed using the 2017 McDonald criteria at thresholds including three positive lesions (Select-3*) and six positive lesions (Select-6*). Inter-rater reliability assessments were performed. RESULTS: Overall, 78 participants were analyzed; 37 (47%) were diagnosed with MS, and 41 (53%) were not. The mean age of participants was 45 (range: 19-64) years, and most were female (n = 55, 71%). The area under the receiver operating characteristic curve (AUROC) for the simplified counting method was 0.83 (95% CI: 0.73-0.93). Select-3* and Select-6* had sensitivity of 81% and 65% and specificity of 68% and 98%, respectively. Inter-rater agreement was 78% for Select-3* and 83% for Select-6*. CONCLUSION: A simplified method for CVS assessment in patients referred for suspected MS demonstrated good diagnostic performance and inter-rater agreement.

Implementing Shared Decision-Making for Multiple Sclerosis: The MS-SUPPORT Tool.

BACKGROUND: Disease modifying therapies (DMTs) offer opportunities to improve the course of multiple sclerosis (MS), but decisions about treatment are difficult. People with multiple sclerosis (pwMS) want more involvement in decisions about DMTs, but new approaches are needed to support shared decision-making (SDM) because of the number of treatment options and the range of outcomes affected by treatment. We designed a patient-centered tool, MS-SUPPORT, to facilitate SDM for pwMS. We sought to evaluate the feasibility and impact of MS-SUPPORT on decisions about disease modifying treatments (DMTs), SDM processes, and quality-of-life. METHODS: This multisite randomized controlled trial compared the SDM intervention (MS-SUPPORT) to control (usual care) over a 12-month period. English-speaking adults with relapsing MS were eligible if they had an upcoming MS appointment and an email address. To evaluate clinician perspectives, participants' MS clinicians were invited to participate. Patients were referred between November 11, 2019 and October 23, 2020 by their MS clinician or a patient advocacy organization (the Multiple Sclerosis Association of America). MS-SUPPORT is an online, interactive, evidence-based decision aid that was co-created with pwMS. It clarifies patient treatment goals and values and provides tailored information about MS, DMTs, and adherence. Viewed by patients before their clinic appointment, MS-SUPPORT generates a personalized summary of the patient's treatment goals and preferences, adherence, DMT use, and clinical situation to share with their MS clinician. Outcomes (DMT utilization, adherence, quality-of-life, and SDM) were assessed at enrollment, post-MS-SUPPORT, post-appointment, and quarterly for 1 year. RESULTS: Participants included 501 adults with MS from across the USA (84.6% female, 83% white) and 34 of their MS clinicians (47% neurologists, 41% Nurse Practitioners, 12% Physician Assistants). Among the 203 patients who completed MS-SUPPORT, most (88.2%) reported they would recommend it to others and that it helped them talk to their doctor (85.2%), understand their options (82.3%) and the importance of taking DMTs as prescribed (82.3%). Among non-users of DMTs at baseline, the probability ratio of current DMT use consistently trended higher over one-year follow-up in the MS-SUPPORT group (1.30 [0.86-1.96]), as did the cumulative probability of starting a DMT within 6-months, with shorter time-to-start (46 vs 90 days, p=0.24). Among the 222 responses from 34 participating clinicians, more clinicians in the MS-SUPPORT group (vs control) trended towards recommending their patient start a DMT (9 of 108 (8%) vs 5 of 109 (5%), respectively, p=0.26). Adherence (no missed doses) to daily-dosed DMTs was higher in the MS-SUPPORT group (81.25% vs 56.41%, p=.026). Fewer patients forgot their doses (p=.046). The MS-SUPPORT group (vs control) reported 1.7 fewer days/month of poor mental health (p=0.02). CONCLUSIONS: MS-SUPPORT was strongly endorsed by patients and is feasible to use in clinical settings. MS-SUPPORT increased the short-term probability of taking and adhering to a DMT, and improved long-term mental health. Study limitations include selection bias, response bias, social desirability bias, and recall bias. Exploring approaches to reinforcement and monitoring its implementation in real-world settings should provide further insights into the value and utility of this new SDM tool.

Clinical and radiologic characteristics associated with multiple sclerosis misdiagnosis at a tertiary referral center in the United States.

BACKGROUND: Misdiagnosis of multiple sclerosis (MS) is common and can have harmful effects on patients and healthcare systems. Identification of factors associated with misdiagnosis may aid development of prevention strategies. OBJECTIVE: To identify clinical and radiological predictors of MS misdiagnosis. METHODS: We retrospectively reviewed medical records of all patients who were referred to Johns Hopkins MS Center from January 2018 to June 2019. Patients who carried a diagnosis of MS were classified as correctly diagnosed or misdiagnosed with MS by the Johns Hopkins clinician. Demographics, clinical, laboratory, and radiologic data were collected. Differences between the two groups were evaluated, and a regression model was constructed to identify predictors of misdiagnosis. RESULTS: Out of 338 patients who were previously diagnosed with MS, 41 (12%) had been misdiagnosed. An alternative diagnosis was confirmed in 28 (68%) of the misdiagnosed patients; cerebrovascular disease was the most common alternate diagnosis. Characteristics associated with misdiagnosis were female sex (odds ratio (OR): 5.81 (95% confidence interval (CI): 1.60, 21.05)) and non-specific brain magnetic resonance imaging (MRI) lesions (OR: 7.66 (3.42, 17.16)). CONCLUSION: Misdiagnosis is a frequent problem in MS care. Non-specific brain lesions were the most significant predictor of misdiagnosis. Interventions aimed to reduce over-reliance on imaging findings and misapplication of the McDonald criteria may prevent MS misdiagnosis.

Laboratory evaluation for the differential diagnosis of possible multiple sclerosis in the United States: A physician survey.

BACKGROUND: There is limited evidence and lack of guidelines for diagnostic laboratory evaluation of patients with possible multiple sclerosis (MS). OBJECTIVE: To survey neurologists on their practice of laboratory testing in patients with possible MS. METHODS: An online survey was developed to query the frequency of serum and cerebrospinal fluid (CSF) studies ordered in the routine evaluation of patients with possible MS, and in three hypothetical clinical cases. Non-MS specialist neurologists who evaluate patients for MS in their practice were invited to participate by MedSurvey (a medical market research company). RESULTS: The survey was completed by 190 neurologists. A mean of 17.2 (SD: 17.0) tests in serum and CSF were reported "always" ordered in the evaluation of patients with possible MS. CSF oligoclonal bands was the most frequently selected ("always" among 73.7% of participants). Antinuclear antibody (43.2%), erythrocyte sedimentation rate (34.2%), and thyroid stimulating hormone (31.6%) were also among the most frequently ordered. DISCUSSION: Extensive laboratory evaluations are often completed in the evaluation of possible MS. However, many of these tests have poor specificity and false positive results could yield unnecessary increased costs, diagnostic delay, and potentially misdiagnosis. Further research is needed to identify optimal laboratory approaches for possible MS.

Differential diagnosis of suspected multiple sclerosis: an updated consensus approach.

Accurate diagnosis of multiple sclerosis requires careful attention to its differential diagnosis-many disorders can mimic the clinical manifestations and paraclinical findings of this disease. A collaborative effort, organised by The International Advisory Committee on Clinical Trials in Multiple Sclerosis in 2008, provided diagnostic approaches to multiple sclerosis and identified clinical and paraclinical findings (so-called red flags) suggestive of alternative diagnoses. Since then, knowledge of disorders in the differential diagnosis of multiple sclerosis has expanded substantially. For example, CNS inflammatory disorders that present with syndromes overlapping with multiple sclerosis can increasingly be distinguished from multiple sclerosis with the aid of specific clinical, MRI, and laboratory findings; studies of people misdiagnosed with multiple sclerosis have also provided insights into clinical presentations for which extra caution is warranted. Considering these data, an update to the recommended diagnostic approaches to common clinical presentations and key clinical and paraclinical red flags is warranted to inform the contemporary clinical evaluation of patients with suspected multiple sclerosis.

Processing speed and memory test performance are associated with different brain region volumes in Veterans and others with progressive multiple sclerosis.

Background: Cognitive dysfunction and brain atrophy are both common in progressive multiple sclerosis (MS) but are seldom examined comprehensively in clinical trials. Antioxidant treatment may affect the neurodegeneration characteristic of progressive MS and slow its symptomatic and radiographic correlates. Objectives: This study aims to evaluate cross-sectional associations between cognitive battery components of the Brief International Cognitive Assessment for Multiple Sclerosis with whole and segmented brain volumes and to determine if associations differ between secondary progressive (SPMS) and primary progressive (PPMS) MS subtypes. Design: The study was based on a baseline analysis from a multi-site randomized controlled trial of the antioxidant lipoic acid in veterans and other people with progressive MS (NCT03161028). Methods: Cognitive batteries were conducted by trained research personnel. MRIs were processed at a central processing site for maximum harmonization. Semi-partial Pearson's adjustments evaluated associations between cognitive tests and MRI volumes. Regression analyses evaluated differences in association patterns between SPMS and PPMS cohorts. Results: Of the 114 participants, 70% had SPMS. Veterans with MS made up 26% (n = 30) of the total sample and 73% had SPMS. Participants had a mean age of 59.2 and sd 8.5 years, and 54% of them were women, had a disease duration of 22.4 (sd 11.3) years, and had a median Expanded Disability Status Scale of 6.0 (with an interquartile range of 4.0-6.0, moderate disability). The Symbol Digit Modalities Test (processing speed) correlated with whole brain volume (R = 0.29, p = 0.01) and total white matter volume (R = 0.33, p < 0.01). Both the California Verbal Learning Test (verbal memory) and Brief Visuospatial Memory Test-Revised (visual memory) correlated with mean cortical thickness (R = 0.27, p = 0.02 and R = 0.35, p < 0.01, respectively). Correlation patterns were similar in subgroup analyses. Conclusion: Brain volumes showed differing patterns of correlation across cognitive tasks in progressive MS. Similar results between SPMS and PPMS cohorts suggest combining progressive MS subtypes in studies involving cognition and brain atrophy in these populations. Longitudinal assessment will determine the therapeutic effects of lipoic acid on cognitive tasks, brain atrophy, and their associations.

Global Barriers to the Diagnosis of Multiple Sclerosis: Data From the Multiple Sclerosis International Federation Atlas of MS, Third Edition.

BACKGROUND AND OBJECTIVES: Recent data suggest increasing global prevalence of multiple sclerosis (MS). Early diagnosis of MS reduces the burden of disability-adjusted life years and associated health care costs. Yet diagnostic delays persist in MS care and even within national health care systems with robust resources, comprehensive registries, and MS subspecialist referral networks. The global prevalence and characteristics of barriers to expedited MS diagnosis, particularly in resource-restricted regions, have not been extensively studied. Recent revisions to MS diagnostic criteria demonstrate potential to facilitate earlier diagnosis, but global implementation remains largely unknown. METHODS: The Multiple Sclerosis International Federation third edition of the Atlas of MS was a survey that assessed the current global state of diagnosis including adoption of MS diagnostic criteria; barriers to diagnosis with respect to the patient, health care provider, and health system; and existence of national guidelines or national standards for speed of MS diagnosis. RESULTS: Coordinators from 107 countries (representing approximately 82% of the world population), participated. Eighty-three percent reported at least 1 "major barrier" to early MS diagnosis. The most frequently reported barriers included the following: "lack of awareness of MS symptoms among general public" (68%), "lack of awareness of MS symptoms among health care professionals" (59%), and "lack of availability of health care professionals with knowledge to diagnose MS" (44%). One-third reported lack of "specialist medical equipment or diagnostic tests." Thirty-four percent reported the use of only 2017 McDonald criteria (McD-C) for diagnosis, and 79% reported 2017 McD-C as the "most commonly used criteria." Sixty-six percent reported at least 1 barrier to the adoption of 2017 McD-C, including "neurologists lack awareness or training" by 45%. There was no significant association between national guidelines pertaining to MS diagnosis or practice standards addressing the speed of diagnosis and presence of barriers to early MS diagnosis and implementation of 2017 McD-C. DISCUSSION: This study finds pervasive consistent global barriers to early diagnosis of MS. While these barriers reflected a lack of resources in many countries, data also suggest that interventions designed to develop and implement accessible education and training can provide cost-effective opportunities to improve access to early MS diagnosis.