Neuritis Ossificans in the Facial Nerve: A Case Report.

Abstract

Objectives: Neuritis ossificans is a rare condition involving heterotopic ossification of nerves, usually affecting major peripheral nerves. Two cases involving cranial nerves are documented, with none affecting the facial nerve. The aim of this report is to present the first documented case of neuritis ossificans involving the facial nerve (CN VII), with a review of clinical, radiologic, and histologic findings.

Methods: An 88-year-old male with a history of radiation therapy for right ear basal cell carcinoma presented with 18 months of progressive right-sided facial weakness, resulting in complete flaccid paralysis. MRI revealed subtle enhancement of the right trigeminal nerve. He underwent facial nerve exploration. Intraoperatively, a large segment of the facial nerve appeared grossly abnormal, and biopsy revealed small rounded and linear mineral deposits with concentric internal structuring, lined focally by collections of histiocytes. This is a single case report with literature review.

Results: Histopathology confirmed the absence of malignancy and identified mineral deposits consistent with neuritis ossificans. Given the extensive nerve damage, nerve transfers were not feasible, leading to the decision to proceed with static suspension surgery.

Conclusion: This case is the first known instance of neuritis ossificans affecting the facial nerve, emphasizing the diagnostic challenge in this rare condition. Histopathological evaluation was critical for diagnosis, informing the decision for static suspension surgery due to irreversible paralysis.