Optic neuritis in Asian type opticospinal multiple sclerosis (OSMS-ON) in a non-Asian population: A functional-structural paradox.

BACKGROUND: Biomarkers have improved the classification of autoimmune inflammatory disorders, including optic neuritis (ON) as a frequent presentation of multiple sclerosis, neuromyelitis spectrum disorders, MOG antibody-related disease (MOGAD), and opticospinal multiple sclerosis (OSMS). The phenotype of OSMS in non-Asian populations is less well known. OBJECTIVE: We investigated the clinical features and prognosis of OSMS-ON in a Brazilian cohort. METHODS: This was a single-center cohort study of patients from Rio de Janeiro (Brazil) with OSMS. All individuals were MOG- and AQP4-seronegative, clinically diagnosed with ON, and had magnetic resonance imaging-confirmed transverse myelitis (TM). Subjects and healthy controls (HCs) were assessed for visual acuity (logMAR VA), automated perimetry mean deviation (MD), intraocular pressure, and spectral-domain optical coherence tomography (OCT), followed by automated retinal layer segmentation of the peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell and inner plexiform layer (mGCIPL). Receiver operator characteristic curves were plotted and the area under the curve (AUC) was calculated for group comparisons of retinal asymmetry of the pRNFL and mGCIPL. RESULTS: The 30 patients with OSMS were predominantly female and white. The mean age was 48 years (range 20-70 years). Unilateral ON was the index event in 83.3% of patients. Over the average 18-year follow-up period, there were 89 relapses of ON. In individuals with OSMS, the average VA was 0.07±0.14 in the right eye (RE) and 0.13±0.30 in the left eye (LE). The MD was -5.37±5.88 dB and -5.23±3.34 dB for the RE and LE, respectively. There was a significant cumulative loss of VA (p = 0.0003) and MD (p = 0.0001) with a higher number of recurrent episodes. Atrophy of the pRNFL thickness was significant in OSMS (RE, 78.62 ± 16.01 µm; LE, 79.86 ± 13.79 µm) relative to the HC group (RE, 98.87 ± 10.68 µm; LE, 97.87 ± 10.85 µm, p = 0.0001). Likewise, there was significant mGCIPL atrophy in patients with OSMS (RE, 74.96 ± 14.46 µm; LE, 73.88 ± 13.79 µm) relative to the HC group (RE, 90.50 ± 6.74 µm; LE, 90.41± 6.89 µm; p = 0.0001). Retinal asymmetry, inter-eye percentage, and absolute differences accurately separated patients with unilateral ON from HCs (AUC=0.89 and AUC=0.85, respectively). CONCLUSION: A structural-functional paradox was found in OSMS with a high diagnostic value for a novel metric based on retinal asymmetry. The functional visual outcome are excellent despite significant structural damage to the inner retinal layers in patients with a high ON relapse rate and long-term bilateral sequential involvement.

CLINICAL course of acute disseminated encephalomyelitis in adults from Rio de Janeiro: Retrospective study of 23 cases and literature review.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is a rare inflammatory demyelinating disorder. Most studies involve white children in developed countries in the northern hemisphere. The authors aimed to describe the clinical course and prognostic of a cohort of adult patients with ADEM from Rio de Janeiro city, where most of the population is Afro-descendant. METHODS: We performed a longitudinal study with retrospective data collection of patients with ADEM seen from 1999 to 2016 at a reference center for demyelinating diseases, identifying demographic, clinical, and laboratory data. Then we compared our findings with data from an extensive review of previously published reports. The literature review was carried out using Google Scholar, PubMed, and the reference lists of included studies. Searches were limited to English language original manuscripts published between 2000 and 2019. RESULTS: Among 1396 registers, we identified 23 cases of ADEM, mostly women (78.3%), Afro-descendant (52.4%) with a mean age of 30.8 ± 11.9 years at onset. One quarter had a previous viral infection and, 4.3% vaccination. The presentation was polyfocal, characterized by the association of pyramidal 82.6%, brainstem 69.6%, mental 65.2%, cerebellar 39.1%, sensory 39.1%, sphincter 43.5%, and visual 34.8% syndromes with severe disability in 86.6%. The breakdown of the blood-brain barrier occurred at 60%. MRI was suggestive of ADEM in 87%, with good radiological evolution. A majority had a significant recovery after treatment. CONCLUSIONS: ADEM in adults is a rare, severe, polyfocal disease with a favorable prognosis. The absence of encephalopathy does not exclude the diagnosis.

Is Asian type MS an MS phenotype, an NMO spectrum disorder, or a MOG-IgG related disease?

BACKGROUND: A specific particularity of neurological diseases in Asia is the relative commonality of neuromyelitis optica (NMO) and Asian type MS (OSMS). Both conditions also occur in South American patients. The Brazilian population differs from the European and the Asian populations due to the mixture of ancestralities between European colonizers and African slaves. To better know the clinical characteristics of Brazilian patients with Asian type MS this study aimed to analyze the clinical, radiological and serological data that would help to distinguish between OSMS and NMO and clarify, in a Non-Asian population, if OSMS is an MS phenotype, an NMO spectrum disorder by 2015 classification, or a complement activating antibody to myelin oligodendrocyte glycoprotein (MOG-IgG) antibody-related disease. METHODS: We selected cases retrospectively with NMO and OSMS in the medical registry of patients with idiopathic inflammatory demyelinating diseases under follow-up since 1997 in Federal Hospital da Lagoa, the principal reference center for MS treatment in Rio de Janeiro, Brazil. OSMS has selective involvement of the optic nerve and spinal cord with no cerebral or cerebellar symptoms associated with small spinal cord lesions and negativity for the aquaporin-4 antibody (AQP4-IgG). NMO full-filled the revised criteria (2006) associated with longitudinally extensive transverse myelitis (LETM). We recorded the following data: ethnicity/skin color, neurologic impairment "at nadir" and "at recovery" of the index events (optic neuritis and transverse myelitis), long term disability, mortality, health quality of life scores by the SF-36 questionnaire, CSF IgG oligoclonal bands and serological AQP4-IgG and MOG-IgG antibodies tested by Cell-based assay. The last brain MRIs were classified as either satisfying or not satisfying MAGNIMS radiologic criteria for MS or typical or not typical for NMOSD. The new classification of NMO spectrum disorders (2015) was applied. RESULTS: Forty-one OSMS and 122 NMO cases were analyzed. OSMS affected mainly young white women, causing unilateral optic neuritis and partial myelitis with excellent recovery. After a mean disease duration of 20 years, 90% of the patients had free ambulation, and 70% had a mild disability or no disability. Only 7.2% presented a secondary progressive course, and no deaths occurred. All cases had negativity to AQP4-IgG and MOG-IgG biomarkers. 95% had resonance criteria for MS. OSMS differed from NMO by ethnicity, morbidity, and mortality: most were African descendants, with severe motor and visual dysfunction, and one third died. Only NMO cases full-filled the new NMOSD classification (52 AQP4-IgG positive, 29 AQP4-IgG negative, and 41 AQP4-IgG unknown). CONCLUSION: In Brazilian patients, OSMS and NMO are different immune-mediated diseases. OSMS is a milder MS phenotype.