Systematic review of 55 cases and cohort data describing a spectrum of movement disorders (most commonly opsoclonus-myoclonus and cerebellar syndromes, with parkinsonism in ~12.7% of cases) associated with scrub typhus that are typically reversible with generally good outcomes.

Low direct value for Parkinson's therapeutic discovery, but it underscores infection-triggered, often inflammatory and reversible parkinsonism phenomena that are relevant for differential diagnosis and may marginally inform hypotheses about infection/inflammation contributing to movement-disorder…

BACKGROUND: Scrub typhus is a major rickettsial infection in Asia, occasionally presenting with movement disorders due to central nervous system involvement. This systematic review aimed to summarize their frequency, spectrum, diagnostic profile, treatment, and outcomes. METHODS: A comprehensive search of PubMed, Embase, Scopus, and Google Scholar was conducted up to August 2025. All case reports, case series, and cohort studies reporting movement disorders associated with scrub typhus were included. Data were extracted and analyzed descriptively. The protocol was prospectively registered with PROSPERO under the identifier PROSPERO 2025 CRD420251156525. RESULTS: Across 55 published cases, scrub typhus-associated movement disorders occurred predominantly in young adults (median age 28 years), with a male predominance (61.8%). Opsoclonus and related ocular motor disorders were the most frequent manifestations (41.8%), followed by cerebellar syndromes (34.5%), parkinsonism (12.7%), myoclonus (7.3%), and rare presentations such as ballismus, dystonia, opisthotonus, and akinetic mutism (7.3%). Associated neurological signs included cerebellar involvement (32.7%), altered sensorium (25.5%), extrapyramidal features (21.8%), and seizures (10.9%). In cohort studies including 2437 patients, 63 (2.6%) developed movement disorders, with opsoclonus-myoclonus seen in 22 (34.9%), ataxia in 17, myoclonus in 11 (17.4%), and extrapyramidal features in 25 (39.6%). Rare hyperkinetic manifestations such as hemiballismus and choreoathetoid movements were occasionally reported. Most patients had favorable outcomes, with complete recovery in 38 (69.1%), near-complete recovery in 6 (10.9%), partial recovery in 5 (9.1%), and death in 1 (1.8%). CONCLUSIONS: Movement disorders in scrub typhus, though uncommon, display a wide clinical spectrum and are often reversible.