Neuromyelitis Optica Spectrum Disorder in Latin America: State-of-the-Art and Current Challenges.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system characterized by severe attacks of optic neuritis, myelitis, and/or area postrema. Advances in understanding the pathophysiology of NMOSD have led to improved diagnostic and therapeutic approaches. There has been a notable increase in research efforts worldwide, including in Latin America (LATAM). In recent years, LATAM has witnessed a surge in research on NMOSD, resulting in a growing body of evidence on various aspects such as epidemiology, clinical manifestations, paraclinical features (including AQP4-IgG [Aquaporin-4-immunoglobulin G] and imaging), acute and long-term treatment strategies, as well as accessibility to diagnostic tests. This narrative review aims to present the most relevant findings from different NMOSD cohorts in LATAM, providing a comprehensive overview of the current understanding of the disease in the region, while considering its unique characteristics and challenges. LATAM-focused evidence is crucial for adding valuable information to the international dataset and is therefore summarized in this review.

COVID-19 in multiple sclerosis and neuromyelitis optica spectrum disorder patients in Latin America: COVID-19 in MS and NMOSD patients in LATAM.

BACKGROUND: There is no data regarding COVID-19 in Multiple Sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients in Latin America. OBJECTIVE: The objective of this study was to describe the clinical characteristics and outcomes of patients included in RELACOEM, a LATAM registry of MS and NMOSD patients infected with COVID-19. METHODS: RELACOEM is a longitudinal, strictly observational registry of MS and NMOSD patients who suffer COVID-19 and Dengue in LATAM. Inclusion criteria to the registry were either: (1) a biologically confirmed COVID-19 diagnosis based on a positive result of a COVID-19 polymerase chain reaction (PCR) test on a nasopharyngeal swab; or (2) COVID-19-typical symptoms (triad of cough, fever, and asthenia) in an epidemic zone of COVID-19. Descriptive statistics were performed on demographic and clinical variables. The cohort was later stratified for MS and NMOSD and univariate and multivariate logistic regression analysis was performed to identify variables associated with hospitalizations/intensive critical units (ICU) admission. RESULTS: 145 patients were included in the registry from 15 countries and 51 treating physicians. A total of 129 (89%) were MS patients and 16 (11%) NMOSD. 81.4% patients had confirmed COVID-19 and 18.6% were suspected cases. 23 (15.8%) patients were hospitalized, 9 (6.2%) required ICU and 5 (3.4 %) died due to COVID-19. In MS patients, greater age (OR 1.17, 95% CI 1.05 - 1.25) and disease duration (OR 1.39, 95%CI 1.14-1.69) were associated with hospitalization/ICU. In NMOSD patients, a greater age (54.3 vs. 36 years, p=<0.001), increased EDSS (5.5 vs 2.9, p=0.0012) and disease duration (18.5 vs. 10.3 years, p=0.001) were significantly associated with hospitalization/ICU. CONCLUSION: we found that in MS patients, age and disease duration was associated with hospitalization and ICU admission requirement, while age, disease duration and EDSS was associated in NMOSD.

Holmes tremor: Clinical description, lesion localization, and treatment in a series of 29 cases.

OBJECTIVE: To describe the clinical features, etiology, findings from neuroimaging, and treatment results in a series of 29 patients with Holmes tremor (HT). METHODS: A retrospective study was performed based on review of medical records and videos of patients with HT diagnosis. RESULTS: A total of 16 women and 13 men were included. The mean age at the moment of CNS insult was 33.9 ± 20.1 years (range 8-76 years). The most common causes were vascular (48.3%), ischemic, or hemorrhagic. Traumatic brain injury only represented 17.24%; other causes represented 34.5%. The median latency from lesion to tremor onset was 2 months (range 7 days-228 months). The most common symptoms/signs associated with HT were hemiparesis (62%), ataxia (51.7%), hypoesthesia (27.58%), dystonia (24.1%), cranial nerve involvement (24.1%), and dysarthria (24.1%). Other symptoms/signs were vertical gaze disorders (6.8%), bradykinesia/rigidity (6.8%), myoclonus (3.4%), and seizures (3.4%). Most of the patients had lesions involving more than one area. MRI showed lesions in thalamus or midbrain or cerebellum in 82.7% of the patients. Levodopa treatment was effective in 13 out of 24 treated patients (54.16%) and in 3 patients unilateral thalamotomy provided excellent results. CONCLUSIONS: The most common causes of HT in our series were vascular lesions. The most common lesion topography was mesencephalic, thalamic, or both. Treatment with levodopa and thalamic stereotactic lesional surgery seems to be effective.