Tick-Borne Infection as a Precipitant of Guillain-Barré Syndrome: A Case of Lyme Neuroborreliosis.

Overlapping clinical features between Lyme disease and Guillain-Barré Syndrome (GBS) can complicate diagnosis, and a definitive causal relationship has not been established. A 58-year-old woman experiencing unsheltered homelessness was referred to the emergency department by her street medicine physician with progressive symmetric weakness, unilateral facial nerve palsy, dysphagia, and dyspnea following tick bites obtained at her encampment in the woods. Workup showed elevated cerebrospinal fluid (CSF) protein with lymphocytic pleocytosis and positive serum Lyme serology tests, consistent with acute infection with Borrelia burgdorferi. Electromyography (EMG) demonstrated proximal demyelination, raising concern for concurrent GBS. She was treated with intravenous ceftriaxone and intravenous immunoglobulin (IVIG), resulting in gradual neurological improvement. This case underscores that Lyme neuroborreliosis can mimic or precipitate GBS-like neuropathy, and when overlap cannot be excluded, combined antibiotic and immunotherapy may be necessary. Early recognition is crucial to prevent respiratory or cardiac complications from overlapping Lyme and GBS pathology. This case underscores the importance of diagnosing and distinguishing GBS from Lyme neuroborreliosis when features overlap. Recognition of atypical findings, particularly inflammatory cerebrospinal fluid profiles, is essential to guide appropriate combined therapy and optimize neurological outcomes.