Optic chiasm involvement in multiple sclerosis, aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein-associated disease.

BACKGROUND: Optic neuritis (ON) is a common feature of inflammatory demyelinating diseases (IDDs) such as multiple sclerosis (MS), aquaporin 4-antibody neuromyelitis optica spectrum disorder (AQP4 + NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). However, the involvement of the optic chiasm (OC) in IDD has not been fully investigated. AIMS: To examine OC differences in non-acute IDD patients with (ON+) and without ON (ON-) using magnetisation transfer ratio (MTR), to compare differences between MS, AQP4 + NMOSD and MOGAD and understand their associations with other neuro-ophthalmological markers. METHODS: Twenty-eight relapsing-remitting multiple sclerosis (RRMS), 24 AQP4 + NMOSD, 28 MOGAD patients and 32 healthy controls (HCs) underwent clinical evaluation, MRI and optical coherence tomography (OCT) scan. Multivariable linear regression models were applied. RESULTS: ON + IDD patients showed lower OC MTR than HCs (28.87 ± 4.58 vs 31.65 ± 4.93; p = 0.004). When compared with HCs, lower OC MTR was found in ON + AQP4 + NMOSD (28.55 ± 4.18 vs 31.65 ± 4.93; p = 0.020) and MOGAD (28.73 ± 4.99 vs 31.65 ± 4.93; p = 0.007) and in ON- AQP4 + NMOSD (28.37 ± 7.27 vs 31.65 ± 4.93; p = 0.035). ON+ RRMS had lower MTR than ON- RRMS (28.87 ± 4.58 vs 30.99 ± 4.76; p = 0.038). Lower OC MTR was associated with higher number of ON (regression coefficient (RC) = -1.15, 95% confidence interval (CI) = -1.819 to -0.490, p = 0.001), worse visual acuity (RC = -0.026, 95% CI = -0.041 to -0.011, p = 0.001) and lower peripapillary retinal nerve fibre layer (pRNFL) thickness (RC = 1.129, 95% CI = 0.199 to 2.059, p = 0.018) when considering the whole IDD group. CONCLUSION: OC microstructural damage indicates prior ON in IDD and is linked to reduced vision and thinner pRNFL.

Pediatric Autoimmune Neurologic Disorders.

OBJECTIVE: This article discusses common principles in diagnosing and managing autoimmune neurologic conditions in children. LATEST DEVELOPMENTS: The key to improving outcomes in all patients with autoimmune neurologic diseases is making an early diagnosis, promptly initiating treatment, and identifying patients who will benefit from long-term maintenance treatment. Some neuroinflammatory syndromes can be diagnosed with an antibody biomarker (eg, aquaporin-4 antibodies, N-methyl-d-aspartate [NMDA] receptor antibodies), whereas others require clinical diagnostic criteria (eg, multiple sclerosis, opsoclonus-myoclonus syndrome). A proportion of children will be labeled as seronegative, and further investigations for other inflammatory or monogenetic etiologies need to be carried out in parallel with treating the central nervous system inflammation. Time to treatment and treatment escalation were shown to correlate with outcomes in many patients with these disorders. The choice and duration of treatment should be evaluated considering side effects and risks in the short and long terms. The presence of a highly inflammatory disease process in children supports the use of highly effective disease-modifying therapies in pediatrics. ESSENTIAL POINTS: The phenotypes of pediatric autoimmune neurologic conditions may change across different age groups, as the brain is still actively developing. In general, the presentation in children is more inflammatory, but overall disability is lower, likely because of better neuroplasticity and repair. Convincing evidence has increasingly emerged to support the biological rationale that effective immunosuppressive therapies used in adult neuroimmunology are equally effective in children.

Validation of the 2023 international diagnostic criteria for MOGAD in a pediatric cohort.

OBJECTIVE: To validate the recently published diagnostic criteria for Myelin Oligodendrocyte Glycoprotein-antibody associated disease (MOGAD) in real-world cohort of children with acquired demyelinating syndromes. METHODS: Patients <18yrs presenting with demyelinating disease to Pediatric neuroimmunology clinics at two Israeli tertiary centers who had MOG antibodies (MOG-Abs) tested between 01/07/2017 and 15/08/2023 were included. Diagnostic criteria for MOGAD were applied and sensitivity and specificities were calculated. RESULTS: MOG-Abs were detected in 28/63 (44 %). Median age at onset for all patients was 11.4 yrs (range 1.1-17.6 yrs) and 41 (65 %) were female. Of the patients testing negative, ADEM was the most common diagnosis (n = 11) followed by MS (n = 8). No patients without MOG-Abs were diagnosed with MOGAD. All patients with a clinical diagnosis of MOGAD had positive MOG-Abs and fulfilled the 2023 international diagnostic criteria for MOGAD. Sensitivity, specificity, positive predictive value, and negative predictive value were 100 %. We found no difference between younger (<10yrs old) and older (>10 yrs old) children in the number of supportive criteria fulfilled at onset (median 2 vs. 2.5, p = 0.4) The number of supporting features was higher in patients with relapsing (n = 5) vs. monophasic (n = 23) disease course at onset (median 3 vs. 2, p = 0.03) and at final follow-up (median 5 vs. 2, p = 0.004). CONCLUSION: Recent MOGAD diagnostic criteria had excellent performance in this pediatric cohort but did not add to the diagnostic accuracy of the antibody test alone.

One- and Two-Year Multidisciplinary Follow-Up of MIS-C at a Tertiary Hospital: A Retrospective Cohort Study.

BACKGROUND: Although 6-month follow-up of patients with multisystem inflammatory syndrome in children (MIS-C) was reassuring, there is scant data on long-term sequelae, including whether changing variants affect clinical severity and outcomes. METHODS: Children (<18 years of age) admitted to Great Ormond Street Hospital between April 4, 2020, and January 2023, meeting diagnostic criteria for MIS-C were included. Admission and follow-up data were categorized by the predominant SARS-CoV-2 circulating variant in the United Kingdom. RESULTS: One hundred and sixty children [median age, 10.1 (interquartile range, 7.9-12.6) years] were included. There was no difference in the time of symptom onset to diagnosis between waves (P=0.23) or hospitalization days across all waves (P=0.32). Inflammatory markers were normal for up to 2 years in all patients except one. Eleven patients (6.9%) remain in follow-up: cardiology (n=5), gastroenterology (n=5) and nephrology (n=1). The main self-reported symptoms at 2 years were abdominal pain (n=5) and myalgia (n=2). Fatigue was present in approximately a quarter of patients at admission; this reduced to 14 (9%), (2%) and 1 (2%) at 6-month, 1-year and 2-year follow-ups, respectively. Chronic fatigue or long-COVID symptomatology was rare (n=1) even with high rates of concurrent Epstein-Barr virus positivity (49/134). All patients had sustained neurological recovery with no new neurological pathology observed. CONCLUSIONS: Patients with MIS-C have a sustained recovery, which is reassuring for positive long-term outcomes. Across waves, time from symptom onset to diagnosis and treatment, symptomatology and length of stay were similar. Sustained recovery is reassuring for clinicians and parents alike. Differentiating long-COVID symptomatology from that of MIS-C is important in formulating an individualized treatment plan.

A study of referral bias in NMOSD and MOGAD cohorts.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are rare disorders often seen in highly specialized services or tertiary centres. We aimed to assess if cohort characteristics depend on the origin of the referral catchment areas serviced by our centre (i.e. local, regional or national). METHODS: Retrospective cohort study using a national referral service database including local (Oxfordshire), regional (Oxfordshire and neighbouring counties), and national patients. We included patients with the diagnosis of NMOSD, seronegative NMOSD or MOGAD, followed at the Oxford Neuromyelitis Optica Service. RESULTS: We included 720 patients (331 with MOGAD, 333 with aquaporin-4 antibody (AQP4)-NMOSD, and 56 with seronegative NMOSD. The distribution of diagnoses was similar across referral cohorts. There were no significant differences in the proportion of pediatric onset patients, sex, or onset phenotype; more White AQP4-NMOSD patients were present in the local than in the national cohort (81 % vs 52 %). Despite no differences in follow-up time, more relapsing MOGAD disease was present in the national than in the local cohort (42.9 % vs. 24 %, p = 0.029). CONCLUSION: This is the first study assessing the impact of potential referral bias in cohorts of NMOSD or MOGAD. The racial difference in the AQP4-NMOSD cohorts likely reflects the variation in the population demographics rather than a referral bias. The over representation of relapsing MOGAD patients in the national cohort probably is a true referral bias and highlights the need to analyze incident cohorts when describing disease course and prognosis. It seems reasonable therefore to compare MOGAD and NMOSD patients seen withing specialised centres to general neurology services, provided both use similar antibody assays.

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.

Validation of the 2023 International Diagnostic Criteria for MOGAD in a Selected Cohort of Adults and Children.

BACKGROUND AND OBJECTIVES: To test the performance of the 2023 myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) criteria in adults and children with inflammatory demyelinating conditions who were tested for MOG antibodies (Abs). METHODS: This was a retrospective study of patients tested for MOG-Abs from 2018 to 2022 in 2 specialist hospitals. The inclusion criteria comprised ≥1 attendance in an adult or pediatric demyelinating disease clinic and complete clinical and MRI records. The final clinical diagnosis of MOGAD, made by the treating neurologist, was taken as the benchmark against which the new criteria were tested. The international MOGAD diagnostic criteria were applied retrospectively; they stipulate at least 1 clinical or MRI supporting feature for MOGAD diagnosis in positive fixed MOG cell-based assay without a titer. The performance MOG-Ab testing alone for MOGAD diagnosis was also assessed and compared with that of MOGAD criteria using the McNemar test. RESULTS: Of the 1,879 patients tested for MOG-Abs, 539 (135 pediatric and 404 adults) met the inclusion criteria. A clinical diagnosis of MOGAD was made in 86/539 (16%) patients (37 adults, 49 children), with a median follow-up of 3.6 years. The MOGAD diagnostic criteria had sensitivity of 96.5% (adults 91.9%, children 100%), specificity of 98.9% (adults 98.8%, children 98.9%), positive predictive value of 94.3% (adults 89.4%, children 98%), negative predictive value of 99.3% (adults 99.2%, children 100%), and accuracy of 98.5% (adults 98.3%, children 99.2%). When compared with MOG-Ab testing alone, a difference was seen only in adults: a significantly higher specificity (98.9% vs 95.6%, p = 0.0005) and nonstatistically significant lower sensitivity (91.9% vs 100%, p = 0.08). DISCUSSION: The international MOGAD diagnostic criteria exhibit high performance in selected patients with inflammatory demyelinating diseases (who had a high pretest probability of having MOGAD) compared with best clinical judgment; their performance was better in children than in adults. In adults, the MOGAD criteria led to an improvement in specificity and positive predictive value when compared with MOG-Ab testing alone, suggesting that the requirement of at least 1 clinical or MRI supporting feature is important. Future work should address the generalizability of the diagnostic criteria to cohorts of greater clinical diversity seen within neurologic settings.

Long term outcome in non-multiple sclerosis paediatric acquired demyelinating syndromes.

OBJECTIVES: We aimed to study the risks of relapse and long term disability in children with non-MS acquired demyelinating syndromes (ADS). METHODS: In this prospective, multi-centre study, from the 14 UK pediatric neurology centres, children (<16 years) experiencing a first episode of ADS were recruited from 2010 to 2014. Case report forms were collected prospectively. RESULTS: A total of 269 children were recruited and followed up for a median of 7.2 years. Median age at onset was 9y (IQR 9.5-14.5, 126 females). At last follow-up, 46 (18 %) had MS, 4 AQP4-Ab NMOSD and 206 (80 %) had other ADS, of which 27 (13 %) relapsed. Relapsing MOGAD was the diagnosis in 12/27, 6 were seronegative and 9 did not have antibodies tested. Frequency of relapse differed according to first presentation in non-MS ADS, being least likely in transverse myelitis (p = 0.025). In the non-MS group, MOG-Ab was predictive of relapse (HR = 8.42; p < 0.001) occurring 8 times as often decreasing over time. Long-term difficulties did not differ between children with monophasic vs relapsing diseases. CONCLUSION: The risk of relapse in non-MS ADS depends on initial diagnosis, and MOG-Ab positivity. Long-term difficulties are observed regardless of relapses and are determined by presenting phenotype.