Cranial Nerve Metastasis Mimicking Bell's Palsy: A Case Report

Cranial nerve metastasis is a common complication of head and neck malignancies which can present with a variety of neurological deficits. Clinical presentation varies based on which nerves are affected and can provide diagnostic challenges to the clinician and radiologist alike by mimicking nerve palsy or acute stroke. Facial nerve involvement is a common manifestation, often mimicking Bell's palsy, the most frequent cause of facial weakness. This case report presents a 79-year-old male with a history of squamous cell carcinoma (SCC) of the lip status post resection and chemoradiation therapy who developed new-onset facial droop, paresthesia, and taste disturbance three years after remission. Initial imaging with contrast-enhanced MRI of the brain was equivocal for Bell's palsy versus facial nerve metastasis. This case highlights the challenges in differentiating cranial nerve metastasis from other etiologies of facial nerve palsy and emphasizes the importance of maintaining a high index of suspicion in patients with a history of malignancy presenting with new-onset neurological symptoms.