Diagnostic Criteria For Multiple Sclerosis Research Articles

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.

Parenchymal Neuro-Behçet's disease or Comorbid Behçet's disease with multiple sclerosis: A discriminative analysis of a complex clinical entity

BackgroundPatients with Behçet's disease (BD) may rarely manifest with cerebral white matter lesions resembling multiple sclerosis (MS). This may result in misdiagnosis due to diagnostic difficulties between parenchymal neuro-BD (pNBD) and MS. This study aims to elucidate the distinguishing features of patients with comorbid BD and MS (BD+MS) in comparison to those with pNBD and MS alone by focusing on clinical and laboratory features. We also aimed to identify the distinctive characteristics of BD+MS patients by comparing them to patients with pNBD and MS. MethodsThe methodology of this study involved a retrospective analysis of patient records followed in the Department of Neurology at the Istanbul Faculty of Medicine, Istanbul University. The study population included patients diagnosed with pNBD, MS, and a comorbid condition of BD and MS (BD+MS). We assessed clinical, radiological, and laboratory data, including disease onset, annual relapse rates, Expanded Disability Status Scale (EDSS) progression, and cerebrospinal fluid examination. Several parameters were examined between the pNBD, MS, and BD+MS patient groups to find similarities and differences between subgroups. ResultsOur study included 1,764 patients: 172 with pNBD, 1,574 with MS, and 18 with BD+MS. A predominance of females was noted in the BD+MS (72%, p < 0.001) and MS (69 %, p < 0.001) groups compared to pNBD (30 %). The median age at the onset of neurological symptoms was 35.5 (IQR: 16.8) years for BD+MS, 34.6 (13.6) years for pNBD, and 27.6 (13.3) years for MS (BD+MS vs. MS; p = 0.3, pNBD vs. MS, p = 0.7). Additionally, the number of attacks was notably different, with BD+MS patients experiencing a median of 3.5 (2.0) attacks compared to 3.0 (3.0) for MS patients and only 1.0 (1.0) for pNBD patients, suggesting a more active disease course in the MS and BD+MS groups compared to pNBD (p < 0.001). The median annualized relapse rate for BD+MS was 0.3 (0.2), which was lower than the rate of 0.4 (0.4) in MS (p = 0.048) and equivalent to the rate of 0.2 (0.3) in pNBD (p = 0.2). The time to the first relapse was similar to those with BD+MS and MS, but considerably shorter than in individuals with pNBD (p < 0.0001). The cerebrospinal fluid (CSF) analysis showed no significant differences in neutrophil and lymphocyte counts between BD+MS and MS patients but elevated levels in pNBD patients (p < 0.05). CSF protein levels were consistent across all groups (p = 0.1 and p = 0.7). Oligoclonal bands were detected in all patients with BD+MS, in the majority of MS patients (83.6 %), and a small percentage of pNBD patients (19.7 %), showing a notable distinction between the BD+MS and pNBD groups (p < 0.001). ConclusionOur study underscores the need for a skeptical approach in diagnosing and treating patients with BD who exhibit symptomatic MS-like MRI lesions. Our findings suggest that BD+MS is a distinct clinical entity, warranting specific diagnostic and treatment approaches. Our findings highlight that BD patients with MS-like lesions meeting MS diagnostic criteria should be managed as patients with comorbid MS and BD rather than pNBD.

Exploring Factors Associated with Falls in Multiple Sclerosis: Insights from a Scoping Review.

Multiple sclerosis (MS) is a chronic inflammatory condition that causes demyelination of the central nervous system accompanied by a wide range of symptoms. The high prevalence of falls among patients diagnosed with MS within the initial six months highlights the importance of this issue. The objective of this study is to identify factors associated with falls in MS patients in order to increase awareness and reduce the risk of falls. This scoping review used specific Mesh terms to formulate the literature search around falls and MS using Medline, Google Scholar, Scopus, and Embase search engines. English papers published between 2012 and 2022, studies with a clear definition of falls, McDonald's diagnostic criteria for MS, and those with Expanded Disability Status Scale (EDSS) or Patient Determined Disease Steps (PDDS) scores were included. Critical data from the selected articles were extracted and classified according to the different factors associated with falls in MS patients. Eighteen articles were included in this review. The most important factors associated with falls in MS patients identified were the severity and progression of the disease, mobility and balance problems, bladder dysfunction, fear of falling, fatigue, and cognitive dysfunction. In conclusion, this scoping review yielded the most common factors associated with falls in patients with MS. Study findings can be used to develop future interventions focusing on improving mobility, proprioception, and balance to decrease fall risk and injury amongst MS patients.

Inter-assay diagnostic accuracy of cerebrospinal fluid kappa free light chains for the diagnosis of multiple sclerosis.

Cerebrospinal fluid (CSF) kappa free light chain (κFLC) measures gained increasing interest as diagnostic markers in multiple sclerosis (MS). However, the lack of studies comparing assay-dependent diagnostic cutoff values hinders their use in clinical practice. Additionally, the optimal κFLC parameter for identifying MS remains a subject of ongoing debate. The aim of this study was to compare same-sample diagnostic accuracies of the κFLC index, κIgG index, CSF κFLC/IgG ratio, and isolated CSF κFLC (iCSF-κFLC) between two reference centers using different methods. Paired serum and CSF samples were analyzed for κFLC and albumin concentrations by Freelite®-Optilite (Sint-Jan Bruges hospital) and N Latex®-BNII (Ghent University hospital). Diagnostic performance to differentiate MS from controls was assessed using ROC curve analysis. A total of 263 participants were included (MS, n = 80). Optimal diagnostic cutoff values for the κFLC index (Freelite®-Optilite: 7.7; N Latex®-BNII: 4.71), κIgG index (Freelite®-Optilite: 14.15, N Latex®-BNII: 12.19), and CSF κFLC/IgG ratio (Freelite®-Optilite: 2.27; N Latex®-BNII: 1.44) differed between the two methods. Sensitivities related to optimal cutoff values were 89.9% (Freelite®-Optilite) versus 94.6% (N Latex®-BNII) for the κFLC index, 91% (Freelite®-Optilite) versus 92.2% (N Latex®-BNII) for the κIgG index, and 81.3% (Freelite®-Optilite) versus 91.4% (N Latex®-BNII) for the CSF κFLC/IgG ratio. However, for iCSF-κFLC, optimal diagnostic cutoff values (0.36 mg/L) and related specificities (81.8%) were identical with a related diagnostic sensitivity of 89.9% for Freelite®-Optilite and 90.5% for N Latex®-BNII. The diagnostic performance of the κFLC index [area under the curve (AUC) Freelite®-Optilite: 0.924; N Latex®-BNII: 0.962] and κIgG index (AUC Freelite®-Optilite: 0.929; N Latex®-BNII: 0.961) was superior compared to CSF oligoclonal bands (AUC: 0.898, sensitivity: 83.8%, specificity: 95.9%). The κFLC index and the κIgG index seem to be excellent markers for identifying MS, irrespective of the method used for κFLC quantification. Based on the AUC, they appear to be the measures of choice. For all measures, optimal cutoff values differed between methods except for iCSF-κFLC. iCSF-κFLC might therefore serve as a method-independent, more cost-efficient, initial screening measure for MS. These findings are particularly relevant for clinical practice given the potential future implementation of intrathecal κFLC synthesis in MS diagnostic criteria and for future multicentre studies pooling data on κFLC measures.

Epstein-Barr Virus Strongly Associates With Pediatric Multiple Sclerosis, But Not Myelin Oligodendrocyte Glycoprotein-Antibody-Associated Disease.

Reported rates of Epstein-Barr virus (EBV) seropositivity in children meeting multiple sclerosis (MS) diagnostic criteria are considerably lower than those reported in adult-onset MS, putting in question a requisite role for EBV in MS development. As prior work preceded recognition of myelin oligodendrocyte glycoprotein-associated disease (MOGAD), we assessed viral serologies in 251 children with incident demyelination and prospectively ascertained diagnoses. When MOGAD was serologically accounted for, the prevalence of EBV infection among MS children exceeded 90%, whereas remote EBV infection was not associated with MOGAD risk. Together, these findings substantiate EBV's role across the MS spectrum, and support distinct pathobiological mechanisms in MS versus MOGAD. ANN NEUROL 2024;95:700-705.

Shifting our attention earlier in the multiple sclerosis disease course.

Revisions of multiple sclerosis (MS) diagnostic criteria enable clinicians to diagnose patients earlier in the biologic disease course. Prompt initiation of therapy correlates with improved clinical outcomes. This has led to increased attention on the earliest stages of MS, including the MS prodrome and radiologically isolated syndrome (RIS). Here, we review current understanding and approach to patients with preclinical MS. MS disease biology often begins well before the onset of typical MS symptoms, and we are increasingly able to recognize preclinical and prodromal stages of MS. RIS represents the best characterized aspect of preclinical MS, and its diagnostic criteria were recently revised to better capture patients at highest risk of conversion to clinical MS. The first two randomized control trials evaluating disease modifying therapy use in RIS also found that treatment could delay or prevent onset of clinical disease. Despite progress in our understanding of the earliest stages of the MS disease course, additional research is needed to systematically identify patients with preclinical MS as well as capture those at risk for developing clinical disease. Recent data suggests that preventive immunomodulatory therapies may be beneficial for high-risk patients with RIS; though management remains controversial.

Prognostic factors of first-onset optic neuritis based on diagnostic criteria and antibody status: a multicentre analysis of 427 eyes

BackgroundOptic neuritis (ON) prognosis is influenced by various factors including attack severity, underlying aetiologies, treatments and consequences of previous episodes. This study, conducted on a large cohort of first ON...

Optic nerve topography in multiple sclerosis diagnostic criteria: Existing knowledge and future directions.

Current diagnostic criteria for multiple sclerosis (MS) do not consider the optic nerve as a typical topography for establishing the diagnosis. Recent studies have proved the utility of optic nerve magnetic resonance imaging, optical coherence tomography and visual evoked potentials in detecting optic nerve lesions during the early stages of MS. In addition, emerging evidence supports the inclusion of optic nerve topography as a fifth region to fulfil the dissemination in space criteria. Anticipating a modification in the McDonald criteria, it is crucial for neurologists to familiarize with the diagnostic properties of each test in detecting optic nerve lesions and understand how to incorporate them into the MS diagnostic process. Therefore, the objective of this article is to review the existing evidence supporting the use of these tests in the diagnostic process of MS and provide a practical algorithm that can serve as a valuable guide for clinical practice.

How Early Is Early Multiple Sclerosis?

The development and further optimization of the diagnostic criteria for multiple sclerosis (MS) emphasize the establishment of an early and accurate diagnosis. So far, numerous studies have revealed the significance of early treatment administration for MS and its association with slower disease progression and better late outcomes of the disease with regards to disability accumulation. However, according to current research results, both neuroinflammatory and neurodegenerative processes may exist prior to symptom initiation. Despite the fact that a significant proportion of individuals with radiologically isolated syndrome (RIS) progress to MS, currently, there is no available treatment approved for RIS. Therefore, our idea of "early treatment administration" might be already late in some cases. In order to detect the individuals who will progress to MS, we need accurate biomarkers. In this review, we present notable research results regarding the underlying pathology of MS, as well as several potentially useful laboratory and neuroimaging biomarkers for the identification of high-risk individuals with RIS for developing MS. This review aims to raise clinicians' awareness regarding "subclinical" MS, enrich their understanding of MS pathology, and familiarize them with several potential biomarkers that are currently under investigation and might be used in clinical practice in the future for the identification of individuals with RIS at high risk for conversion to definite MS.

Radiofrequency thermocoagulation for the treatment of trigeminal neuralgia associated with a focal pontine lesion: illustrative case.

Trigeminal neuralgia (TN) associated with a focal pontine lesion is a rare but challenging condition. The origin of the lesion, which does not fulfill the diagnostic criteria for multiple sclerosis, remains disputable. Pain in such conditions is often refractory to treatment, including microvascular decompression. A 36-year-old female presented with a 3.5-year history of shooting pain in the right V2 distribution triggered by talking and chewing. She became less responsive to high-dose carbamazepine over time. Magnetic resonance imaging (MRI) revealed no neurovascular compression but an elongated lesion hyperintense on T2-weighted imaging and T2- fluid-attenuated inversion recovery and hypointense and nonenhancing on T1-magnetization prepared rapid gradient-echo imaging without restricted diffusion, hemorrhage, or supposed malformation along the right pontine trigeminal pathway (PTP). Two other similar lesions were found in the corpus callosum and left thalamus. All lesions were stable compared to MRI data obtained 2 years before. Cerebrospinal fluid contained no oligoclonal bands. Pain attacks ceased with right-sided gasserian radiofrequency thermocoagulation (RFTC), and at the 6-month follow-up, there was no recurrence. In patients with TN, preoperative neuroimaging should assess for brainstem lesions along the PTP. RFTC can be considered a treatment option in medication-refractory TN associated with a focal pontine lesion.

Optic Nerve MRI T2-Hyperintensity: A Nonspecific Marker of Optic Nerve Damage.

MRI abnormalities are common in optic neuropathies, especially on dedicated orbital imaging. In acute optic neuritis, optic nerve T2-hyperintensity associated with optic nerve contrast enhancement is the typical imaging finding. In chronic optic neuropathies, optic nerve T2-hyperintensity and atrophy are regularly seen. Isolated optic nerve T2-hyperintensity is often erroneously presumed to reflect optic neuritis, frequently prompting unnecessary investigations and neuro-ophthalmology consultations. Our goal was to determine the significance of optic nerve/chiasm T2-hyperintensity and/or atrophy on MRI. Retrospective study of consecutive patients who underwent brain/orbital MRI with/without contrast at our institution between July 1, 2019, and June 6, 2022. Patients with optic nerve/chiasm T2-hyperintensity and/or atrophy were included. Medical records were reviewed to determine the etiology of the T2-hyperintensity and/or atrophy. Four hundred seventy-seven patients (698 eyes) were included [mean age 52 years (SD ±18 years); 57% women]. Of the 364 of 698 eyes with optic nerve/chiasm T2-hyperintensity without atrophy, the causes were compressive (104), inflammatory (103), multifactorial (49), glaucoma (21), normal (19), and other (68); of the 219 of 698 eyes with optic nerve/chiasm T2-hyperintensity and atrophy, the causes were compressive (57), multifactorial (40), inflammatory (38), glaucoma (33), normal (7), and other (44); of the 115 of 698 eyes with optic nerve/chiasm atrophy without T2-hyperintensity, the causes were glaucoma (34), multifactorial (21), inflammatory (13), compressive (11), normal (10), and other (26). Thirty-six eyes with optic nerve/chiasm T2-hyperintensity or atrophy did not have evidence of optic neuropathy or retinopathy on ophthalmologic examination, and 17 eyes had clinical evidence of severe retinopathy without primary optic neuropathy. Optic nerve T2-hyperintensity or atrophy can be found with any cause of optic neuropathy and with severe chronic retinopathy. These MRI findings should not automatically prompt optic neuritis diagnosis, workup, and treatment, and caution is advised regarding their use in the diagnostic criteria for multiple sclerosis. Cases of incidentally found MRI optic nerve T2-hyperintensity and/or atrophy without a known underlying optic neuropathy or severe retinopathy are rare. Such patients should receive an ophthalmologic examination before further investigations.

Do we still need OCBs in MS diagnosis and how many?

CSF-specific oligoclonal bands (CSF-OCBs) can be used for dissemination in time (DIT) in the 2017 multiple sclerosis (MS) diagnostic criteria. A cut-off of ≥2 CSF-OCBs was recommended but studies have suggested ≥3 CSF-OCBs may be superior. To assess utility of ≥2 and ≥3 CSF-OCBs as a cut-off for MS diagnosis. Paired serum and CSF-OCBs sent to the Walton Centre, UK between July 2018 and June 2020 were included. CSF-OCBs were assessed using isoelectric focussing and reviewed by two blinded raters. Case records were reviewed. Of 1334 paired serum and CSF-OCB requests, 945 cases had sufficient clinical information. More than 1 CSF-OCB was detected in 268/945(28%) cases. Of these, 252 had ≥2 and 230 had ≥3 CSF-OCBs. The sensitivity and specificity for MS with ≥2 and ≥3 CSF-OCBs were 91.7%, 91.2%, 90.2% and 93.8% respectively. Only 3/22 patients with 2 CSF-OCBs had MS. In 25% of patients, CSF-OCBs reduced time to MS diagnosis (median 437.5 days (28-1332)). Although cut-offs of ≥2 or ≥3 CSF-OCBs performed similarly well, 2 CSF-OCBs were frequently seen with non-inflammatory pathology. Use of ≥3 CSF-OCBs for MS diagnosis should be considered. CSF analysis reduced time to MS diagnosis by approximately 14 months.

Diagnostic Performance of Adding the Optic Nerve Region Assessed by Optical Coherence Tomography to the Diagnostic Criteria for MS.

The optic nerve has been recommended as an additional region for demonstrating dissemination in space (DIS) in diagnostic criteria for multiple sclerosis (MS). To investigate whether adding the optic nerve region as determined by optical coherence tomography (OCT) as part of the DIS criteria improves the 2017 diagnostic criteria. From a prospective observational study, we included patients with a first demyelinating event who had complete information to assess DIS and a spectral-domain OCT scan obtained within 180 days. Modified DIS criteria (DIS+OCT) were constructed by adding the optic nerve to the current DIS regions based on validated thresholds for OCT inter-eye differences. Time to second clinical attack was the primary endpoint. We analyzed 267 MS patients (mean age 31.3 years [SD 8.1], 69% female) during a median observation period of 59 months (range: 13 - 98).Adding the optic nerve as a fifth region improved the diagnostic performance by increasing accuracy (DIS+OCT 81.2% vs. DIS 65.6%,) and sensitivity (DIS+OCT 84.2% vs. DIS 77.9%) without lowering specificity (DIS+OCT 52.2% vs. DIS 52.2%).Fulfilling DIS+OCT criteria (≥2 of 5 DIS+OCT regions involved) indicated a similar risk of a second clinical attack (HR 3.6, CI 1.4 - 14.5) compared to a 2.5-fold increased risk when fulfilling DIS criteria (HR 2.5, CI 1.2 - 11.8).When the analysis was conducted according to topography of the first demyelinating event, DIS+OCT criteria performed similarly in both optic neuritis and non-optic neuritis. Addition of the optic nerve, assessed by OCT, as a fifth region in the current DIS criteria improves diagnostic performance by increasing sensitivity without lowering specificity. This study provides Class II evidence that adding the optic nerve as determined by optical coherence tomography (OCT) as a fifth dissemination in space (DIS) criterion to the 2017 McDonald criteria improves diagnostic accuracy.

West syndrome and multiple sclerosis association

Introduction. West syndrome is a rare and severe infantile epileptic encephalopathy, beginning around the age of six months, characterized by a classic electro-clinical triad. This is a pathology totally different from multiple sclerosis (MS) which is a demyelinating disease of the central nervous system caused, affecting young adults, especially females. The association of these two pathologies has never been described. Observation. We report here an exceptional presentation of MS in a 14-year-old girl with a history of West syndrome. She had normal development until the age of six months, when she began to have flexion spasms. The diagnosis of West syndrome was made with a normal MRI. The infantile spasms disappeared after treatment with vigabatrin and adrenocorticotropic hormone (ACTH). It had generally progressed to Lennox Gastaut encephalopathy, with delayed psychomotor development and epileptic sequelae. At 14, she presented with left hemiparesis within a few days. A cerebral MRI showed multiple nodular hyperintensities of the supra and infratentorial white matter, with the presence of an active lesion, fulfilling the diagnostic criteria for multiple sclerosis. CSF analysis was normal. Anti-AQP4, anti-MOG, anti-NMDA and anti-GABA (AB) antibodies were absent in the blood. Antibodies against HIV and viral hepatitis were. Biotinidase activity and autoimmunity tests were correct. The patient received high doses of methylprednisolone IV (1g/day) for three days with remarkable clinical improvement after 15 days. Discussion. MS is a complex and heterogeneous central nervous system (CNS) demyelinating disease. It is not uncommon for epilepsy to be the first symptom of multiple sclerosis. Seizures, on the other hand, are more common after disease progression. Although the disease is characterized by inflammatory lesions of the white matter, various neuropathological and radiological studies have shown that the disease also affects the grey matter. Several studies have shown that seizures are three to six times more common in MS patients than in the general population. Even though MS can start with epilepsy and a seizure may be the only symptom of a relapse of MS, it is still not known whether the two diseases coexist or whether MS predisposes to seizures. Conclusion. The association of these two totally different pathologies can lead us to say that the mechanism of multiple sclerosis may begin in childhood and that the clinical signs appear in adulthood.

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

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. 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. 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. 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.

Esclerosis múltiple: diagnóstico diferencial y tratamiento

The diagnostic criteria for multiple sclerosis(MS) are based on the identification of a typical syndrome attributable to the central nervous system, the demonstration of dissemination in space and time, and the absence of a better explanation than MS. This article includes some of the demographic, clinical or paraclinical criteria that should prompt consideration of alternative diagnoses. In addition, the usage of the 18 disease-modifying drugs currently employed is reviewed, including the latest additions (diroximel fumarate, siponimod, ozanimod, ponensimod and ofatumumab), the recent indications in clinical courses other than relapsing-remitting and the symptomatic treatment of the disease.

The prevalence and incidence of multiple sclerosis over the past 20 years in northern Japan

The prevalence of multiple sclerosis (MS) in East Asia is thought to be lower than in Western countries. Globally, there is a trend of increasing MS prevalence. We investigated the changes in the prevalence and clinical phenotype of MS in the Tokachi province of Hokkaido in northern Japan, from 2001 to 2021. Data processing sheets were sent to all related institutions inside and outside the Tokachi area of Hokkaido island in Japan and were collected from April to May 2021. The prevalence according to the Poser's diagnostic criteria for MS was determined on March 31, 2021. In 2021, the crude MS prevalence in northern Japan was 22.4/100,000 (95% confidence interval, 17.6-28.0). The prevalences of MS standardized by the Japanese national population in 2001, 2006, 2011, 2016, and 2021 were 6.9, 11.5, 15.3, 18.5, and 23.3, respectively. The female/male ratio was 4.0 in 2021, increased from 2.6 in 2001. We checked the prevalence using the 2017 revised McDonald criteria, and found only additional male patient who had not fulfilled Poser's criteria. The age- and sex-adjusted incidence of MS per 100,000 individuals increased from 0.09 in 1980-1984 to 0.99 in 2005-2009; since then, it has remained stable. The proportions of primary-progressive, relapsing-remitting, and secondary-progressive MS types in 2021 were 3%, 82%, and 15%, respectively. Our results demonstrated a consistent increase in the prevalence of MS among the northern Japanese over 20 years, particularly in females, and consistently lower rates of progressive MS in northern Japan than elsewhere in the world.

Addition of optic nerve involvement to dissemination in space criteria for multiple sclerosis – the value of optical coherence tomography (S46.009)

Addition of optic nerve involvement to dissemination in space criteria for multiple sclerosis – the value of optical coherence tomography (S46.009)

How much of the increased infection risk from higher rituximab doses is mediated by hypogammaglobulinemia in patients with multiple sclerosis? (S46.006)

<h3>Objective:</h3> To estimate to what extent increased infection risk from more rituximab exposure is mediated by hypogammaglobulinemia in multiple sclerosis (MS) patients. <h3>Background:</h3> Prolonged treatment with B-cell depleting therapies increase the risk of hypogammaglobulinemia and infections. These relationships are poorly understood. <h3>Design/Methods:</h3> We conducted a retrospective cohort study utilizing the electronic medical record among Kaiser Permanente Southern California members who met MS diagnostic criteria and were treated with at least two rituximab infusions, 2008–2020. Multivariable Andersen-Gill hazards models were used to assess risk of recurrent outpatient (≥4/year) or serious/hospitalized infections and linear regression to examine correlates of IgG values. <h3>Results:</h3> We identified 2477 MS patients who were treated with rituximab for a median of 2.0 years (IQR=1.0–3.0). 405 patients (16.4%) developed recurrent outpatient infections, 153 (6.2%) serious infections and 249 (10.1%) IgG &lt;700 mg/dL. Higher cumulative rituximab dose (&gt;4g) was correlated with lower IgG levels (Beta=−57.0, p&lt;0.0001, ref≤2g) and, in models mutually adjusted for hypogammaglobulinemia, both were independently associated with an increased risk of serious (&gt;4g, aHR=1.57, 95%CI=1.08–2.28, p=.018; IgG&lt;500, aHR=2.90, 95%CI=1.52–5.54, p=0.001) and outpatient infections (&gt;4g, aHR=2.09, 95%CI=1.64–2.66, p&lt;.0001; IgG&lt;500 aHR=2.48, 95%CI=1.64–3.75, p&lt;.0001; ref=IgG≥700). Mediation analyses showed that hypogammaglobulinemia accounted for 12.6% of serious infection risk associated with higher cumulative rituximab exposure but was not significant for outpatient infections. Other independent modifiable risk factors were advanced physical disability for serious infections (aHR=5.86, p&lt;.0001), obesity (aHR=1.38, p=.0017) and chronic obstructive pulmonary disease (aHR=1.88, p=.0001) for outpatient infections. Black (16.6% of population) or Asian (2.8%) race or Hispanic (31.0%) ethnicity was correlated with significantly higher IgG levels (Betas=260.7, 252.7, 67.3, respectively, p’s&lt;.0001, ref=white) but had no independent influence on infection risks. <h3>Conclusions:</h3> Higher cumulative rituximab doses increase the risk of infections primarily via mechanisms independent of hypogammaglobulinemia. Important factors that influence these relationships include selected comorbidities, race and ethnicity, advanced physical disability, and age. <b>Disclosure:</b> An immediate family member of Dr. Langer-Gould has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Annals of American Thoracic Society. The institution of Dr. Langer-Gould has received research support from PCORI. The institution of an immediate family member of Dr. Langer-Gould has received research support from PCORI, ARQ, NIH. Dr. Langer-Gould has a non-compensated relationship as a Voting Member with ICER CTAF Panel that is relevant to AAN interests or activities. Bonnie Li has nothing to disclose. Ms. Smith has nothing to disclose. Ms. Gonzales has nothing to disclose. Dr. Xu has nothing to disclose.

Incorporating the Central Vein Sign Into the Diagnostic Criteria for Multiple Sclerosis

This Viewpoint discusses incorporating the central vein sign into the diagnostic criteria for multiple sclerosis.