Structural Mimics of Recurrent Bell's Palsy: A Case Report Highlighting Diagnostic Red Flags in Facial Nerve Schwannoma and Metastasis.

Background and Clinical Significance: Recurrent peripheral facial palsy is most often attributed to idiopathic Bell's palsy (BP), yet a minority of patients harbor underlying structural lesions. Early recognition of such lesions is essential for timely and appropriate management. Case Presentation: We retrospectively reviewed recurrent unilateral facial palsy at a single tertiary center and selected two illustrative patients in whom serial clinical, electrodiagnostic, and magnetic resonance imaging (MRI) findings ultimately indicated structural pathology. The first patient experienced three strictly right-sided episodes over 3.5 years, with worsening House-Brackmann grades (II → III → V) and progressive axonal loss on serial facial nerve conduction studies, culminating in a mass-like enhancing lesion at the geniculate ganglion consistent with schwannoma. The second patient had two left-sided recurrences within seven months. MRI evolved from a subtle intrameatal nodular suspicion without enhancement to a clearly enhancing intrameatal nodule with dural thickening. Additional intracranial nodular enhancements were discovered later and the patient was diagnosed with leptomeningeal metastasis.

Conclusions

These cases illustrate that strictly ipsilateral recurrences, progressive electrophysiologic deterioration, and atypical or evolving MRI enhancement patterns should prompt thorough re-evaluation for structural causes rather than repeated labeling as idiopathic BP.