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.

Lower frequency of antibodies to MOG in Brazilian patients with demyelinating diseases: An ethnicity influence?

OBJECTIVE: Antibodies against Myelin Oligodendrocyte glycoprotein (MOG-Ab) have been investigated as potential biological marker for neuromyelitis optica (NMO) and high-risk syndromes (HR) negative for AQP4-Ab in populations with different ethnic background. We tested AQP4 and MOG antibodies in a Brazilian population with high African ethnic background. METHOD: The study population was composed of adult patients from Rio de Janeiro with inflammatory demyelinating diseases (new and old cases). Blood samples were sent blindly to test the AQP4 and MOG antibodies by CBA. The frequency of positive MOG-Ab was estimated in the NMOHR and the NMO spectrum disorders (NMOSD). A systematic review with meta-analysis assessed the frequency of MOG-Ab in Caucasians and non-Caucasians. RESULTS: 200 adult patients (52% Afro-Brazilian) 115 of them with NMOHR were tested. MOG antibodies were found in 5/68 negative cases of AQP4-Ab negative (7%). The criteria for NMOSD were fulfilled by 70 patients with NMOHR and none of them was positive for MOG-Ab. A low prevalence of MOG antibodies and a predominant phenotype of bilateral Optic Neuritis were found in most non-Caucasian patients. CONCLUSION: The low frequency of MOG Ab in patients from Rio de Janeiro and in other non-Caucasian populations suggests a racial/ancestral influence.