Tissue Hypoxia and Associated Innate Immune Factors in Experimental Autoimmune Optic Neuritis.

Visual loss in acute optic neuritis is typically attributed to axonal conduction block due to inflammatory demyelination, but the mechanisms remain unclear. Recent research has highlighted tissue hypoxia as an important cause of neurological deficits and tissue damage in both multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) and, here, we examine whether the optic nerves are hypoxic in experimental optic neuritis induced in Dark Agouti rats. At both the first and second peaks of disease expression, inflamed optic nerves labelled significantly for tissue hypoxia (namely, positive for hypoxia inducible factor-1α (HIF1α) and intravenously administered pimonidazole). Acutely inflamed nerves were also labelled significantly for innate markers of oxidative and nitrative stress and damage, including superoxide, nitric oxide and 3-nitrotyrosine. The density and diameter of capillaries were also increased. We conclude that in acute optic neuritis, the optic nerves are hypoxic and come under oxidative and nitrative stress and damage. Tissue hypoxia can cause mitochondrial failure and thus explains visual loss due to axonal conduction block. Tissue hypoxia can also induce a damaging oxidative and nitrative environment. The findings indicate that treatment to prevent tissue hypoxia in acute optic neuritis may help to restore vision and protect from damaging reactive oxygen and nitrogen species.

The Queen Square Encephalitis Multidisciplinary Team Meeting - experience over three years, pre and post the COVID-19 pandemic.

BACKGROUND: Patients with suspected encephalitis continue to represent a diagnostic and therapeutic challenge, even in highly resourced centres. In February 2018, we set up a monthly in-person multidisciplinary team meeting (MDT). We describe the experience and outcomes of the MDT over three years. METHODS: A retrospective analysis was performed to summarise patient demographics, MDT outcomes and final diagnoses. RESULTS: Over the three-year period, 324 discussions of 238 patients took place. Cases were diverse; approximately 40% related to COVID-19 or brain infection, 40% autoimmune or other inflammatory disorders and 20% encephalitis mimics or uncertain aetiologies. Feedback from an online survey sent to referring teams and attendees highlighted the value of the MDT; 94% reported the discussion was useful and 69% reported resulting change in patient management. CONCLUSIONS: Multidisciplinary input is crucial in this challenging area, ensuring that all diagnostic avenues are explored and opening doors to novel diagnostics and therapeutics. It also supports clinicians dealing with unwell patients, including in centres where less specialist input is available, and when decisions have to be made where there is little or no evidence base.

Prevalence of Multiple Sclerosis in the Republic of Moldova.

BACKGROUND: The occurrence of multiple sclerosis (MS) increases in populations featuring both high and low disease burden, and variations across regions at the same latitude are reported. MS epidemiological data in Eastern Europe are scarce and out of date. We report on sex- and age-specific prevalence of MS in the Republic of Moldova. METHODS: Benefitting from a nationwide survey aimed to quantify the MS burden in Moldovans (3,559,541 population in 2012), multiple epidemiological sources were scrutinized. RESULTS: On prevalence day, December 31, 2012, 747 MS patients (McDonald criteria) resided in the study area, yielding a crude prevalence of 20.9 per 100,000 (95% CI 14.7-27.1), 25.7 (95% CI 20.5-30.5) in women and 15.8 (95% CI 12.2-19.3) in men (F:M ratio of 1.63), and standardized estimates of 20.2, 24.3 and 15.5 per 100,000, respectively. Prevalence was highest in the age group 40-49 years (43.9 per 100,000) and higher in rural (72.6%) than in urban (27.4%) areas. CONCLUSIONS: This is the first report on sex- and age-specific prevalence of MS in the Republic of Moldova, which was lower than in Europe on average, but consistent with that of neighboring countries, Romania and Ukraine. Moldovans represent a population wherein MS natural history is not yet influenced by use of disease-modifying drugs.