Infection-associated Opsoclonus: A Systematic Review.

Opsoclonus is a chaotic, multidirectional eye movement characterized by rapid saccades. We aimed to systematically review infection-associated opsoclonus to define its pathogen spectrum, clinical features, treatments, and outcomes. PRISMA 2020 compliant review, PROSPERO registered (CRD420251161567). PubMed, Embase, Scopus and Google Scholar were searched. All search results were imported into EndNote 21 for deduplication. Two reviewers independently conducted screening and data extraction. Quality was assessed by Murad et al. and Newcastle–Ottawa Scales. In this analysis of 210 published cases of opsoclonus, the mean age was 35 years, with Asia contributing 43% of reports and India being the most frequent reporting country. Most patients were immunocompetent or presumed immunocompetent (78%). Viral infections predominated (63%), led by Severe Acute Respiratory Syndrome Coronavirus 2 (30%), followed by scrub typhus, Human Immunodeficiency Virus, West Nile virus, Borrelia, Epstein–Barr virus, Mycoplasma pneumoniae, and dengue virus. Latency was short, with 62% presenting within two weeks, supporting a para-infectious immune mechanism. Cerebrospinal fluid was normal in 43% and magnetic resonance imaging in 67%, indicating that normal investigations should not delay treatment. Management was mainly immunotherapy-based, with corticosteroids alone (40%) or combined with intravenous immunoglobulin (24%). Outcomes were favourable, with 43% recovering within one week and 41% within eight weeks. Immune mediation was inferred in 78%, a pattern consistently reproduced across sixteen cohort studies. Infection-associated opsoclonus is a treatable neurological syndrome arising from a broad infectious spectrum, predominantly viral. Early diagnosis and prompt immunotherapy are associated with rapid clinical improvement.