Tick-Borne Encephalitis Presenting as Brachial Plexus Injury: A Case Report.

Tick-borne encephalitis (TBE) is a viral infection with variable clinical presentations, including neurological complications. We report a case of TBE in a 34-year-old farmer from an endemic region in Poland. The patient initially presented with paresis of the right brachial plexus. The diagnosis was challenging due to the absence of previous flu-like symptoms, often related to TBE infection. Neurological evaluations revealed paresis and muscle atrophy in the right upper limb, and serological tests confirmed TBE infection. Despite treatment efforts, neurological deficits persisted. This case highlights the need to consider TBE in the differential diagnosis of sudden-onset neurological disorders, especially in TBE-endemic regions, to ensure prompt intervention and prevent long-term complications.