Patient and family views on research priorities and design of clinical trials and research studies in pediatric multiple sclerosis.

BACKGROUND AND OBJECTIVES: This survey study aimed to (1) identify patient/family research priorities in pediatric-onset multiple sclerosis (POMS), and (2) delineate optimized methods for research study/clinical trials design, engagement, and implementation. METHODS: Participants were as follows: (1) parents of a child (<18 years) with POMS enrolled in a national registry, (2) adolescents (13-17 years) with POMS in the registry, and (3) adults (18-40 years) with POMS receiving care at a registry affiliated clinic. Of 293 eligible participants, 192 completed surveys. RESULTS: Experiences with health care and medications were generally positive but there remain areas of priority improvement. Incentives to participate in clinical trials included medications previously tested and in pill form, bloodwork/study visits required ⩾ every 3 months, cognitive testing ⩽1 hour, compensation for travel and time, ability to continue current multiple sclerosis (MS) medication, option to take study medication if on placebo, and individualized study feedback. Priorities for clinical research were (1) psychosocial impact, (2) cognitive/academic impact, (3) environmental risk, and (4) nutrition. CONCLUSIONS: Results highlighted the importance of a holistic approach to study design and a focus on the impact of disease on daily life to best engage patients and families in POMS clinical trials and research.

Distinct plasma lipids predict axonal injury and multiple sclerosis activity.

BACKGROUND: Lipids are of particular interest for the study of neuroinjury and neuroinflammation as structural lipids are major components of myelin, and a variety of lipid species modulate inflammation. In this study, we performed an in-depth lipidomics analysis to identify lipids associated with injury and disease activity. METHODS: Plasma samples were collected from paediatric-onset multiple sclerosis (MS) cases within 4 years of disease onset from 17 sites. The lipidome was measured using untargeted and targeted mass spectrometry. For cross-sectional analyses, the agreement between multiple machine learning models was used to predict neurofilament light chain (NfL) levels. In longitudinal analyses, the association between clinical (relapse count) and imaging (MRI count with ≥1 enhancing or new T2 lesion) outcomes with each metabolite was estimated using adjusted negative binomial regression. RESULTS: At sample collection, 68% of the 435 included individuals were treatment-naive, with a median disease duration of 0.8 years (IQR 0.3-1.7). For longitudinal analyses, 381 and 335 subjects had at least 1 year of clinical and imaging follow-up, respectively. In cross-sectional analyses, NfL chain levels identified structural lipids (phosphatidylcholines and phosphatidylethanolamines) as the highest-performing predictors, including external validation. In contrast, longitudinal analyses found polyunsaturated fatty acids (PUFAs) and their derivatives to be protective from subsequent disease activity (q<0.001, multiple outcomes). CONCLUSION: There are two categories of lipids associated with MS processes. First, structural lipids strongly associated with NfL levels may result from cell lysis secondary to acute inflammation. In contrast, PUFAs, especially ω-3, had a protective effect on subsequent disease activity.

Early Adversity and Socioeconomic Factors in Pediatric Multiple Sclerosis: A Case-Control Study.

BACKGROUND AND OBJECTIVES: Psychosocial adversity and stress, known to predispose adults to neurodegenerative and inflammatory immune disorders, are widespread among children who experience socioeconomic disadvantage, and the associated neurotoxicity and proinflammatory profile may predispose these children to multiple sclerosis (MS). We sought to determine associations of socioeconomic disadvantage and psychosocial adversity with odds of pediatric-onset MS (POMS), age at POMS onset, and POMS disease activity. METHODS: This case-control study used data collected across 17 sites in the United States by the Environmental and Genetic Risk Factors for Pediatric Multiple Sclerosis Study. Cases (n = 381) were youth aged 3-21 years diagnosed with POMS or a clinically isolated demyelinating syndrome indicating high risk of MS. Frequency-matched controls (n = 611) aged 3-21 years were recruited from the same institutions. Prenatal and postnatal adversity and postnatal socioeconomic factors were assessed using retrospective questionnaires and zip code data. The primary outcome was MS diagnosis. Secondary outcomes were age at onset, relapse rate, and Expanded Disability Status Scale (EDSS). Predictors were maternal education, maternal prenatal stress events, child separation from caregivers during infancy and childhood, parental death during childhood, and childhood neighborhood disadvantage. RESULTS: MS cases (64% female, mean age 15.4 years, SD 2.8) were demographically similar to controls (60% female, mean age 14.9 years, SD 3.9). Cases were less likely to have a mother with a bachelor's degree or higher (OR 0.42, 95% CI 0.22-0.80, p = 0.009) and were more likely to experience childhood neighborhood disadvantage (OR 1.04 for each additional point on the neighborhood socioeconomic disadvantage score, 95% CI 1.00-1.07; p = 0.025). There were no associations of the socioeconomic variables with age at onset, relapse rate, or EDSS, or of prenatal or postnatal adverse events with risk of POMS, age at onset, relapse rate, or EDSS. DISCUSSION: Low socioeconomic status at the neighborhood level may increase the risk of POMS while high parental education may be protective against POMS. Although we did not find associations of other evaluated prenatal or postnatal adversities with POMS, future research should explore such associations further by assessing a broader range of stressful childhood experiences.

Multiple sclerosis in Somali Americans: Nature or nurture?

BACKGROUND: Differences in the MS course between White and Black populations is well accepted. The existence of a large Somali immigrant population in Minnesota facilitates a study of MS characteristics in this immigrant native African population. The objective of this study was to compare Somali American (SA), African American (AA), and White American (WA) persons with MS (pwMS) regarding clinical features and disease modifying therapy (DMT) use. METHODS: This single center (Mayo Clinic) geographically-restricted retrospective cohort study (residing within 250 miles of Rochester, MN, USA) included participants seen before May 2023. Age at immigration to the USA; age at MS onset; DMT use/type; MS phase/phenotype; age at progressive MS (PMS) onset; and proportion with severe MS (expanded disability status scale-EDSS ≥6) were examined. RESULTS: 18 SApwMS, 92 AApwMS, and 94 WApwMS were included. Of the 15 SApwMS not born in USA, 3/15 immigrated pre-puberty, 3/15 peri­puberty, 8/15 post-puberty, and 1/15 at an unknown date. SApwMS were younger at MS onset (median years, interquartile range (IQR)=25, 22-33 vs. AApwMS: 31, 25-38; p = 0.049 vs. WApwMS: 35, 27-41; p = 0.022). DMT use frequencies were 13/19 SApwMS, 69/92 AApwMS, 80/94 WApwMS (p > 0.05). SApwMS were treated with DMT earlier than AApwMS (HR 2.16, p = 0.012) and WApwMS (HR 1.86, p = 0.041). SApwMS were less commonly treated with natalizumab (SApwMS 0 %, AApwMS 13 %, WApwMS 25 %; p = 0.035) and anti-CD20 therapies (SApwMS 23 %, AApwMS 23 %, WApwMS 48 %; p = 0.005). PMS occurred in 3/19 SApwMS, 28/92 AApwMS and 29/94 WApwMS (p > 0.05). Age of PMS onset in SApwMS (47 years, 34-57) was similar to WApwMS (47 years, 31-71; p > 0.05) but older than AApwMS (41 years, 18-7; p = 0.008). CONCLUSIONS: SApwMS that recently immigrated to the USA have similar disease course to WApwMS, and better than AApwMS from the same geographical region.

Association of nutritional intake with clinical and imaging activity in pediatric multiple sclerosis.

BACKGROUND: Understanding nutrition's role in multiple sclerosis (MS) can guide recommendations and intervention-based studies. OBJECTIVE: Evaluate the association between nutrition and pediatric-onset MS outcomes. METHODS: Prospective longitudinal multicenter study conducted as part of the US Network of Pediatric MS centers. Predictors were collected using a food screener estimating intake of various dietary food groups (e.g. dairy and fruits) and additional calculated indices (e.g. Healthy Eating Index (HEI)). Outcomes included time-from-enrollment to clinical relapse, new magnetic resonance imaging (MRI) T2 lesions, and Expanded Disability Status Scale (EDSS) increase. RESULTS: 353 children with MS were enrolled (mean ± SD age 15.4 ± 2.9, follow-up 3.9 ± 2.6 years). Multivariable analysis demonstrated that increased dairy by 50% of recommended intake was associated with increased relapse risk by 41% (adjusted hazard ratio (HR) 1.41, 95% CI 1.07-1.86), and risk of T2 progression by 40% (1.40, 1.12-1.74). Increased intake of fruit or vegetable above recommended, and every five-point HEI increase decreased relapse risk by 25% (0.75, 0.60-0.95), 45% (0.55, 0.32-0.96), and 15% (0.84, 0.74-0.96), respectively. No associations were found with EDSS. CONCLUSION: This work supports the influence of dietary intake on MS course, particularly with dairy intake. Future prospective study is required to establish causation.

Predictors of a relapsing course in myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described demyelinating disorder, and children represent about 50% of all cases. Almost half of the patients experience relapses, but very few studies have evaluated predictors of relapse risk, challenging clinical management. The study aimed to identify predictors at MOGAD onset that are associated with a relapsing course. METHODS: Prospectively collected data from paediatric patients with MOGAD seen by the US Network of Paediatric MS Centres were leveraged. Univariable and adjusted multivariable models were used to predict recurrent disease. RESULTS: We identified 326 MOGAD cases (mean age at first event 8.9 years [SD 4.3], 57% female, 77% white and 74% non-Hispanic) and 46% relapsed during a mean follow-up of 3.9 years (SD 4.1). In the adjusted multivariable model, female sex (HR 1.66, 95% CI 1.17 to 2.36, p=0.004) and Hispanic/Latino ethnicity (HR 1.77, 95% CI 1.19 to 2.64, p=0.005) were associated with a higher risk of relapsing MOGAD. Maintenance treatment initiated before a second event with rituximab (HR 0.25, 95% CI 0.07 to 0.92, p=0.037) or intravenous immunoglobulin (IVIG) (HR 0.35, 95% CI 0.14 to 0.88, p=0.026) was associated with lower risk of a second event in multivariable analyses. Conversely, maintenance steroids were associated with a higher estimated relapse risk (HR 1.76, 95% CI 0.90 to 3.45, p=0.097). CONCLUSION: Sex and ethnicity are associated with relapsing MOGAD. Use of rituximab or IVIG therapy shortly after onset is associated with a lower risk of the second event. Preventive treatment after a first event could be considered for those with a higher relapse risk.

Radiologic Lag and Brain MRI Lesion Dynamics During Attacks in MOG Antibody-Associated Disease.

BACKGROUND AND OBJECTIVES: Knowledge of the evolution of CNS demyelinating lesions within attacks could assist diagnosis. We evaluated intra-attack lesion dynamics in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) vs multiple sclerosis (MS) and aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD). METHODS: This retrospective observational multicenter study included consecutive patients from Mayo Clinic (USA) and Great Ormond Street Hospital for Children (UK). Inclusion criteria were as follows: (1) MOGAD, MS, or AQP4+NMOSD diagnosis; (2) availability of ≥2 brain MRIs (within 30 days of attack onset); and (3) brain involvement (i.e., ≥1 T2 lesion) on ≥1 brain MRI. The initial and subsequent brain MRIs within a single attack were evaluated for the following: new T2 lesions(s); resolved T2 lesion(s); both; or no change. This was compared between MOGAD, MS, and AQP4+NMOSD attacks. We used the Mann-Whitney U test and χ2/Fisher exact test for statistical analysis. RESULTS: Our cohort included 55 patients with MOGAD (median age, 14 years; interquartile range [IQR] 5-34; female sex, 29 [53%]) for a total of 58 attacks. The comparison groups included 38 patients with MS, and 19 with AQP4+NMOSD. In MOGAD, the initial brain MRI (median of 5 days from onset [IQR 3-9]) was normal in 6/58 (10%) attacks despite cerebral symptoms (i.e., radiologic lag). The commonest reason for repeat MRI was clinical worsening or no improvement (33/56 [59%] attacks with details available). When compared with the first MRI, the second intra-attack MRI (median of 8 days from initial scan [IQR 5-13]) showed the following: new T2 lesion(s) 27/58 (47%); stability 24/58 (41%); resolution of T2 lesion(s) 4/58 (7%); or both new and resolved T2 lesions 3/58 (5%). Findings were similar between children and adults. Steroid treatment was associated with resolution of ≥1 T2 lesion (6/28 [21%] vs 1/30 [3%], p = 0.048) and reduced the likelihood of new T2 lesions (9/28 vs 18/30, p = 0.03). Intra-attack MRI changes favored MOGAD (34/58 [59%]) over MS (10/38 [26%], p = 0.002) and AQP4+NMOSD (4/19 [21%], p = 0.007). Resolution of ≥1 T2 lesions was exclusive to MOGAD (7/58 [12%]). DISCUSSION: Radiologic lag is common within MOGAD attacks. Dynamic imaging with frequent appearance and occasional disappearance of lesions within a single attack suggest MOGAD diagnosis over MS and AQP4+NMOSD. These findings have implications for clinical practice, clinical trial attack adjudication, and understanding of MOGAD pathogenesis.

Diagnostic Utility of MOG Antibody Testing in Cerebrospinal Fluid.

OBJECTIVE: The aim of this study was to assess the diagnostic utility of cerebrospinal fluid (CSF) myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) testing. METHODS: We retrospectively identified patients for CSF MOG-IgG testing from January 1, 1996, to May 1, 2023, at Mayo Clinic and other medical centers that sent CSF MOG-IgG for testing including: controls, 282; serum MOG-IgG positive MOG antibody-associated disease (MOGAD), 74; serum MOG-IgG negative high-risk phenotypes, 73; serum false positive MOG-IgG with alternative diagnoses, 18. A live cell-based assay assessed CSF MOG-IgG positivity (IgG-binding-index [IBI], ≥2.5) using multiple anti-human secondary antibodies and end-titers were calculated if sufficient sample volume. Correlation of CSF MOG-IgG IBI and titer was assessed. RESULTS: The pan-IgG Fc-specific secondary was optimal, yielding CSF MOG-IgG sensitivity of 90% and specificity of 98% (Youden's index 0.88). CSF MOG-IgG was positive in: 4/282 (1.4%) controls; 66/74 (89%) serum MOG-IgG positive MOGAD patients; and 9/73 (12%) serum MOG-IgG negative patients with high-risk phenotypes. Serum negative but CSF positive MOG-IgG accounted for 9/83 (11%) MOGAD patients, and all fulfilled 2023 MOGAD diagnostic criteria. Subgroup analysis of serum MOG-IgG low-positives revealed CSF MOG-IgG positivity more in MOGAD (13/16[81%]) than other diseases with false positive serum MOG-IgG (3/15[20%]) (p = 0.01). CSF MOG-IgG IBI and CSF MOG-IgG titer (both available in 29 samples) were correlated (Spearman's r = 0.64, p < 0.001). INTERPRETATION: CSF MOG-IgG testing has diagnostic utility in patients with a suspicious phenotype but negative serum MOG-IgG, and those with low positive serum MOG-IgG results and diagnostic uncertainty. These findings support a role for CSF MOG-IgG testing in the appropriate clinical setting. ANN NEUROL 2024;96:34-45.

Defining the natural history of tumefactive demyelination: A retrospective cohort of 257 patients.

OBJECTIVE: To describe demographic, clinical, and radiographic features of tumefactive demyelination (TD) and identify factors associated with severe attacks and poor outcomes. METHODS: Retrospective review of TD cases seen at Mayo Clinic, 1990-2021. RESULTS: Of 257 patients with TD, 183/257 (71%) fulfilled the 2017 multiple sclerosis (MS) McDonald criteria at the last follow-up, 12/257 (5%) had myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), 0 had aquaporin-4-IgG seropositive neuromyelitis optic spectrum disorders (AQP4+ NMOSD), and 62/257 (24%) were cryptogenic. Onset before age 18 was present in 18/257 (7%). Female to male ratio was 1.3:1. Cerebrospinal fluid oligoclonal (CSF) bands were present in 95/153 (62%). TD was the first demyelinating attack in 176/257 (69%). At presentation, 59/126 (47%) fulfilled Barkhof criteria for dissemination in space, 59/100 (59%) had apparent diffusion coefficient (ADC) restriction, and 57/126 (45%) had mass effect. Despite aggressive clinical presentation at onset, 181/257 (70%) of patients remained fully ambulatory (Expanded Disability Status Scale [EDSS] ≤4) after a 3.0-year median follow-up duration. Severe initial attack-related disability (EDSS ≥4) was more common in patients with motor symptoms (81/143 vs. 35/106, p < 0.0001), encephalopathy (20/143 vs. 2/106, p < 0.0001) and ADC restriction on initial MRI (42/63 vs. 15/33, p = 0.04). Poor long-term outcome (EDSS ≥4) was more common in patients with older onset age (41.9 ± 15 vs. 36.8 ± 15.6, p = 0.02) and motor symptoms at onset (49/76 vs. 66/171, p < 0.0001). INTERPRETATION: Most TD patients should be considered part of the MS spectrum after excluding MOGAD and NMOSD. Motor symptoms and older age at presentation portend a poor outcome.

Timing and Predictors of T2-Lesion Resolution in Patients With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

OBJECTIVES: To determine the timing and predictors of T2-lesion resolution in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). METHODS: This retrospective observational study using standard-of-care data had inclusion criteria of MOGAD diagnosis, ≥2 MRIs 12 months apart, and ≥1 brain/spinal cord T2-lesion. The median (interquartile range [IQR]) number of MRIs (82% at disease onset) per-patient were: brain, 5 (2-8); spine, 4 (2-8). Predictors of T2-lesion resolution were assessed with age- and sex-adjusted generalized estimating equations and stratified by T2-lesion size (small <1 cm; large ≥1 cm). RESULTS: We studied 583 T2-lesions (brain, 512 [88%]; spinal cord, 71 [12%]) from 55 patients. At last MRI (median follow-up 54 months [IQR 7-74]) 455 T2-lesions (78%) resolved. The median (IQR) time to resolution was 3 months (1.4-7.0). Small T2-lesions resolved more frequently and faster than large T2-lesions. Acute T1-hypointensity decreased the likelihood (odds ratio [95% CI]) of T2-lesion resolution independent of size (small: 0.23 [0.09-0.60], p = 0.002; large: 0.30 [0.16-0.55], p < 0.001), whereas acute steroids favored resolution of large T2-lesions (1.75 [1.01-3.03], p = 0.046). Notably, 32/55 (58%) T2-lesions resolved without treatment. DISCUSSION: The high frequency of spontaneous T2-lesion resolution suggests that this represents MOGAD's natural history. The speed of T2-lesion resolution and influence of size, corticosteroids, and T1-hypointensity on this phenomenon gives insight into MOGAD pathogenesis.

Demographic Features and Clinical Course of Patients With Pediatric-Onset Multiple Sclerosis on Newer Disease-Modifying Treatments.

BACKGROUND: Treatment of pediatric-onset multiple sclerosis (POMS) is challenging given the lack of safety and efficacy data in the pediatric population for many of the disease-modifying treatments (DMTs) approved for use in adults with MS. Our objective was to describe the demographic features and clinical and radiologic course of patients with POMS treated with the commonly used newer DMTs within the US Network of Pediatric MS Centers (NPMSC). METHODS: This is an analysis of prospectively collected data from patients who initiated treatment before age 18 with the DMTs listed below at the 12 regional pediatric MS referral centers participating in the NPMSC. RESULTS: One hundred sixty-eight patients on dimethyl fumarate, 96 on fingolimod, 151 on natalizumab, 166 on rituximab, and 37 on ocrelizumab met criteria for analysis. Mean age at DMT initiation ranged from 15.2 to 16.5 years. Disease duration at the time of initiation of index DMT ranged from 1.1 to 1.6 years with treatment duration of 0.9-2.0 years. Mean annualized relapse rate (ARR) in the year prior to initiating index DMT ranged from 0.4 to 1.0. Mean ARR while on index DMT ranged from 0.05 to 0.20. New T2 and enhancing lesions occurred in 75%-88% and 55%-73% of the patients, respectively, during the year prior to initiating index DMT. After initiating index DMT, new T2 and enhancing lesions occurred in 0%-46% and 11%-34% patients, respectively. Rates of NEDA-2 (no evidence of disease activity) ranged from 76% to 91% at 6 months of treatment with index DMTs and 66% to 84% at 12 months of treatment with index DMTs. CONCLUSIONS: Though limited by relatively short treatment duration with the index DMTs, our data suggest clinical and MRI benefit, as well as high rates of NEDA-2, in a large number of POMS patients, which can be used to guide future studies in this population.

Cerebral enhancement in MOG antibody-associated disease.

INTRODUCTION: Limited data exist on brain MRI enhancement in myelin-oligodendrocyte-glycoprotein (MOG) antibody-associated disease (MOGAD) and differences from aquaporin-4-IgG-positive-neuromyelitis-optica-spectrum-disorder (AQP4+NMOSD), and multiple sclerosis (MS). METHODS: In this retrospective observational study, we identified 122 Mayo Clinic MOGAD patients (1 January 1996-1 July 2020) with cerebral attacks. We explored enhancement patterns using a discovery set (n=41). We assessed enhancement frequency and Expanded Disability Status Scale scores at nadir and follow-up in the remainder (n=81). Two raters assessed T1-weighted-postgadolinium MRIs (1.5T/3T) for enhancement patterns in MOGAD, AQP4+NMOSD (n=14) and MS (n=26). Inter-rater agreement was assessed. Leptomeningeal enhancement clinical correlates were analysed. RESULTS: Enhancement occurred in 59/81 (73%) MOGAD cerebral attacks but did not influence outcome. Enhancement was often patchy/heterogeneous in MOGAD (33/59 (56%)), AQP4+NMOSD (9/14 (64%); p=0.57) and MS (16/26 (62%); p=0.63). Leptomeningeal enhancement favoured MOGAD (27/59 (46%)) over AQP4+NMOSD (1/14 (7%); p=0.01) and MS (1/26 (4%); p<0.001) with headache, fever and seizures frequent clinical correlates. Ring enhancement favoured MS (8/26 (31%); p=0.006) over MOGAD (4/59 (7%)). Linear ependymal enhancement was unique to AQP4+NMOSD (2/14 (14%)) and persistent enhancement (>3 months) was rare (0%-8%) across all groups. Inter-rater agreement for enhancement patterns was moderate. CONCLUSIONS: Enhancement is common with MOGAD cerebral attacks and often has a non-specific patchy appearance and rarely persists beyond 3 months. Leptomeningeal enhancement favours MOGAD over AQP4+NMOSD and MS.

Comparison of MRI T2-lesion evolution in pediatric MOGAD, NMOSD, and MS.

BACKGROUND: Magnetic resonance imaging (MRI) T2-lesions resolve more often in myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) than aquaporin-4 IgG-positive neuromyelitis optica spectrum disorder (AQP4 + NMOSD) and multiple sclerosis (MS) in adults but few studies analyzed children. OBJECTIVE: The main objective of this study is to investigate MRI T2-lesion evolution in pediatric MOGAD, AQP4 + NMOSD, and MS. METHODS: Inclusion criteria were as follows: (1) first clinical attack; (2) abnormal MRI (⩽6 weeks); (3) follow-up MRI beyond 6 months without relapses in that region; and (4) age < 18 years. An index T2-lesion (symptomatic/largest) was identified, and T2-lesion resolution or persistence on follow-up MRI was determined. RESULTS: We included 56 patients (MOGAD, 21; AQP4 + NMOSD, 8; MS, 27) with 69 attacks. Index T2-lesion resolution was more frequent in MOGAD (brain 9 of 15 [60%]; spine 8 of 12 [67%]) than AQP4 + NMOSD (brain 1 of 4 [25%]; spine 0 of 7 [0%]) and MS (brain 0 of 18 [0%]; spine 1 of 13 [8%]), p < 0.01. Resolution of all T2-lesions occurred more often in MOGAD (brain 6 of 15 [40%]; spine 7 of 12 [58%]) than AQP4 + NMOSD (brain 1 of 4 [25%]; spine 0 of 7 [0%]), and MS (brain 0 of 18 [0%]; spine 1 of 13 [8%]), p < 0.01. Reductions in median index T2-lesion area were greater in MOGAD (brain, 305 mm; spine, 23 mm) than MS (brain, 42 mm [p<0.001]; spine, 10 mm [p<0.001]) without differing from AQP4 + NMOSD (brain, 133 mm [p=0.42]; spine, 19.5 mm [p=0.69]). CONCLUSION: In children, MRI T2-lesions resolved more often in MOGAD than AQP4 + NMOSD and MS which is similar to adults suggesting these differences are related to pathogenesis rather than age.

ADC restriction is not associated with clinical response to plasma exchange following a cerebral attack of multiple sclerosis.

BACKGROUND: MS is the most common CNS inflammatory demyelinating disease. Plasma exchange (PLEX) has well-demonstrated efficacy in acute corticosteroid-refractory attacks of demyelination but identifying the factors that predict favorable PLEX response remains elusive. We aimed to determine if apparent diffusion coefficient (ADC) restriction on brain MRI predicts clinical response to PLEX in individuals with an acute cerebral attack of MS. METHODS: Retrospective chart review of individuals with a cerebral attack of MS who underwent PLEX at Mayo Clinic. RESULTS: We identified 34 individuals who fulfilled the inclusion criteria. Twenty-seven (79%) responded to plasma exchange, with 16/34 (47%) having moderate and 11/34 (32%) marked improvement. Twenty-three (68%) people had ADC restriction on brain MRI prior to PLEX.  ADC restriction did not predict response (p = 0.51). Several other pre-PLEX factors, including sex, Expanded Disability Status Scale (EDSS) at initial attack, time to PLEX, and concurrent spinal cord attack, also failed to predict response. Plasma-exchange responders had less disability at 6-month follow-up compared to non-responders (median EDSS 2.5 (range 1.0-10.0) vs. 7.5 (5.5-10.0), p<0.001). CONCLUSION: Acute cerebral attacks of MS have a high rate of plasma exchange response resulting in a lower EDSS at 6-months. ADC restriction does not predict response to plasma exchange.

Gene-environment interactions increase the risk of paediatric-onset multiple sclerosis associated with household chemical exposures.

BACKGROUND: We previously reported an association between household chemical exposures and an increased risk of paediatric-onset multiple sclerosis. METHODS: Using a case-control paediatric multiple sclerosis study, gene-environment interaction between exposure to household chemicals and genotypes for risk of paediatric-onset multiple sclerosis was estimated.Genetic risk factors of interest included the two major HLA multiple sclerosis risk factors, the presence of DRB1*15 and the absence of A*02, and multiple sclerosis risk variants within the metabolic pathways of common household toxic chemicals, including IL-6 (rs2069852), BCL-2 (rs2187163) and NFKB1 (rs7665090). RESULTS: 490 paediatric-onset multiple sclerosis cases and 716 controls were included in the analyses. Exposures to insect repellent for ticks or mosquitos (OR 1.47, 95% CI 1.06 to 2.04, p=0.019), weed control products (OR 2.15, 95% CI 1.51 to 3.07, p<0.001) and plant/tree insect or disease control products (OR 3.25, 95% CI 1.92 to 5.49, p<0.001) were associated with increased odds of paediatric-onset multiple sclerosis. There was significant additive interaction between exposure to weed control products and NFKB1 SNP GG (attributable proportions (AP) 0.48, 95% CI 0.10 to 0.87), and exposure to plant or disease control products and absence of HLA-A*02 (AP 0.56; 95% CI 0.03 to 1.08). There was a multiplicative interaction between exposure to weed control products and NFKB1 SNP GG genotype (OR 2.30, 95% CI 1.00 to 5.30) but not for other exposures and risk variants. No interactions were found with IL-6 and BCL-2 SNP GG genotypes. CONCLUSIONS: The presence of gene-environment interactions with household toxins supports their possible causal role in paediatric-onset multiple sclerosis.

Long-term clinical, imaging and cognitive outcomes association with MS immunopathology.

OBJECTIVE: In this observational study on a cohort of biopsy-proven central nervous system demyelinating disease consistent with MS, we examined the relationship between early-active demyelinating lesion immunopattern (IP) with subsequent clinical course, radiographic progression, and cognitive function. METHODS: Seventy-five patients had at least one early-active lesion on biopsy and were pathologically classified into three immunopatterns based on published criteria. The median time from biopsy at follow-up was 11 years, median age at biopsy - 41, EDSS - 4.0. At last follow-up, the median age was 50, EDSS - 3.0. Clinical examination, cognitive assessment (CogState battery), and 3-Tesla-MRI (MPRAGE/FLAIR/T2/DIR/PSIR/DTI) were obtained. RESULTS: IP-I was identified in 14/75 (19%), IP-II was identified in 41/75 (56%), and IP-III was identified in 18/75 (25%) patients. Patients did not differ significantly by immunopattern in clinical measures at onset or last follow-up. The proportions of disease courses after a median of 11 years were similar across immunopatterns, relapsing-remitting being most common (63%), followed by monophasic (32%). No differences in volumetric or DTI measures were found. CogState performance was similar for most tasks. A slight yet statistically significant difference was identified for episodic memory scores, with IP-III patients recalling one word less on average. INTERPRETATION: In this study, immunopathological heterogeneity of early-active MS lesions identified at biopsy does not correlate with different long-term clinical, neuroimaging or cognitive outcomes. This could be explained by the fact that while active white matter lesions are pathological substrates for relapses, MS progression is driven by mechanisms converging across immunopatterns, regardless of pathogenic mechanisms driving the acute demyelinated plaque.

Rare and low-frequency coding genetic variants contribute to pediatric-onset multiple sclerosis.

BACKGROUND: Rare genetic variants are emerging as important contributors to the heritability of multiple sclerosis (MS). Whether rare variants also contribute to pediatric-onset multiple sclerosis (POMS) is unknown. OBJECTIVE: To test whether genes harboring rare variants associated with adult-onset MS risk (PRF1, PRKRA, NLRP8, and HDAC7) and 52 major histocompatibility complex (MHC) genes are associated with POMS. METHODS: We analyzed DNA samples from 330 POMS cases and 306 controls from the US Network of Pediatric MS Centers and Kaiser Permanente Northern California for which Illumina ExomeChip genotypes were available. Using the gene-based method "SKAT-O," we tested the association between candidate genes and POMS risk. RESULTS: After correction for multiple comparisons, one adult-onset MS gene (PRF1, p = 2.70 × 10-3) and two MHC genes (BRD2, p = 5.89 × 10-5 and AGER, p = 7.96 × 10-5) were significantly associated with POMS. Results suggest these are independent of HLA-DRB1*1501. CONCLUSION: Findings support a role for rare coding variants in POMS susceptibility. In particular, rare minor alleles within PRF1 were more common among individuals with POMS compared to controls while the opposite was true for rare variants within significant MHC genes, BRD2 and AGER. These genes would not have been identified by common variant studies, emphasizing the merits of investigating rare genetic variation in complex diseases.

Imaging of Central Nervous System Demyelinating Disorders.

OBJECTIVE: This article summarizes neuroimaging findings in demyelinating disease, the most common being multiple sclerosis. Revisions to criteria and treatment options have been ongoing, and MRI plays a pivotal role in diagnosis and disease monitoring. The common antibody-mediated demyelinating disorders with their respective classic imaging features are reviewed, as well as the differential diagnostic considerations on imaging. LATEST DEVELOPMENTS: The clinical criteria of demyelinating disease rely heavily on imaging with MRI. With novel antibody detection, the range of clinical demyelinating syndromes has expanded, most recently with myelin oligodendrocyte glycoprotein-IgG antibodies. Imaging has improved our understanding of the pathophysiology of multiple sclerosis and disease progression, and further research is underway. The importance of increased detection of pathology outside of the classic lesions will have an important role as therapeutic options are expanding. ESSENTIAL POINTS: MRI has a crucial role in the diagnostic criteria and differentiation among common demyelinating disorders and syndromes. This article reviews the typical imaging features and clinical scenarios that assist in accurate diagnosis, differentiation between demyelinating diseases and other white matter diseases, the importance of standardized MRI protocols in clinical practice, and novel imaging techniques.

Tumefactive Demyelination in MOG Ab-Associated Disease, Multiple Sclerosis, and AQP-4-IgG-Positive Neuromyelitis Optica Spectrum Disorder.

BACKGROUND AND OBJECTIVES: Studies on tumefactive brain lesions in myelin oligodendrocyte glycoprotein-immunoglobulin G (IgG)-associated disease (MOGAD) are lacking. We sought to characterize the frequency clinical, laboratory, and MRI features of these lesions in MOGAD and compare them with those in multiple sclerosis (MS) and aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD). METHODS: We retrospectively searched 194 patients with MOGAD and 359 patients with AQP4+NMOSD with clinical/MRI details available from the Mayo Clinic databases and included those with ≥1 tumefactive brain lesion (maximum transverse diameter ≥2 cm) on MRI. Patients with tumefactive MS were identified using the Mayo Clinic medical record linkage system. Binary multivariable stepwise logistic regression identified independent predictors of MOGAD diagnosis; Cox proportional regression models were used to assess the risk of relapsing disease and gait aid in patients with tumefactive MOGAD vs those with nontumefactive MOGAD. RESULTS: We included 108 patients with tumefactive demyelination (MOGAD = 43; AQP4+NMOSD = 16; and MS = 49). Tumefactive lesions were more frequent among those with MOGAD (43/194 [22%]) than among those with AQP4+NMOSD (16/359 [5%], p < 0.001). Risk of relapse and need for gait aid were similar in tumefactive and nontumefactive MOGAD. Clinical features more frequent in MOGAD than in MS included headache (18/43 [42%] vs 10/49 [20%]; p = 0.03) and somnolence (12/43 [28%] vs 2/49 [4%]; p = 0.003), the latter also more frequent than in AQP4+NMOSD (0/16 [0%]; p = 0.02). The presence of peripheral T2-hypointense rim, T1-hypointensity, diffusion restriction (particularly an arc pattern), ring enhancement, and Baló-like or cystic appearance favored MS over MOGAD (p ≤ 0.001). MRI features were broadly similar in MOGAD and AQP4+NMOSD, except for more frequent diffusion restriction in AQP4+NMOSD (10/15 [67%]) than in MOGAD (11/42 [26%], p = 0.005). CSF analysis revealed less frequent positive oligoclonal bands in MOGAD (2/37 [5%]) than in MS (30/43 [70%], p < 0.001) and higher median white cell count in MOGAD than in MS (33 vs 6 cells/µL, p < 0.001). At baseline, independent predictors of MOGAD diagnosis were the presence of somnolence/headache, absence of T2-hypointense rim, lack of T1-hypointensity, and no diffusion restriction (Nagelkerke R 2 = 0.67). Tumefactive lesion resolution was more common in MOGAD than in MS or AQP4+NMOSD and improved model performance. DISCUSSION: Tumefactive lesions are frequent in MOGAD but not associated with a worse prognosis. The clinical, MRI, and CSF attributes of tumefactive MOGAD differ from those of tumefactive MS and are more similar to those of tumefactive AQP4+NMOSD with the exception of lesion resolution, which favors MOGAD.

Cerebral Cortical Encephalitis in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

Cerebral cortical encephalitis (CCE) is a recently described myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) phenotype. In this observational retrospective study, we characterized 19 CCE patients (6.7% of our MOGAD cohort). Headache (n = 15, 79%), seizures (n = 13, 68%), and encephalopathy (n = 12, 63%) were frequent. Magnetic resonance imaging revealed unilateral (n = 12, 63%) or bilateral (n = 7, 37%) cortical T2 hyperintensity and leptomeningeal enhancement (n = 17, 89%). N-Methyl-D-aspartate receptor autoantibodies coexisted in 2 of 15 tested (13%). CCE pathology (n = 2) showed extensive subpial cortical demyelination (n = 2), microglial reactivity (n = 2), and inflammatory infiltrates (perivascular, n = 1; meningeal, n = 1). Most received high-dose steroids (n = 17, 89%), and all improved, but 3 had CCE relapses. This study highlights the CCE spectrum and provides insight into its pathogenesis. ANN NEUROL 2023;93:297-302.