Beyond Bell's: A Case Study of Bilateral Facial Paralysis From Lyme Neuroborreliosis.

Bilateral facial palsy is a rare neurological presentation that often reflects an underlying systemic disease that requires prompt and comprehensive diagnostic evaluation to guide appropriate management. A 50-year-old man presented with bilateral facial palsy without a recent history of vector exposure or characteristic rash. Extensive diagnostic studies included autoimmune panels, neurovascular and structural imaging, cerebrospinal fluid (CSF) analysis, infectious cultures, and various viral and bacterial serologies. The absence of a clear exposure history and variable latency period following initial exposure contributed to diagnostic uncertainty. Lyme meningitis was confirmed based on CSF findings and a markedly elevated Borrelia CSF to serum antibody index after other etiologies were excluded. The patient was treated with seven days of intravenous ceftriaxone and 14 days of oral doxycycline, achieving complete neurological recovery at three months. This case highlights the exhaustive workup required to identify the cause of bilateral facial palsy. Early specialty consultation is critical to expedite diagnostic workup. Clinicians should maintain a high index of clinical suspicion for Lyme disease despite an absent exposure history or rash. Prompt recognition of bilateral facial palsy and timely intervention are essential to ensure optimal neurological recovery.