Bilateral Facial Nerve Schwannoma: A Case Report and Review of the Literature

Abstract

Aim and objective: To show a case with bilateral hemifacial spasm and bilateral facial nerve schwannoma (FNS) and explain few differential diagnoses for the facial nerve schwannomas, clinical presentation, genetic association, and their CT and MRI characteristics. Background: Hemifacial spasm (HFS) is a hyperactive cranial neuropathy that causes paroxysmal facial muscle contraction. Bilateral hemifacial spasm (BHFS) is a very rare neurological syndrome whose diagnosis depends on excluding other facial dyskinesias. Facial nerve schwannoma (FNS) potentially affects any segment of the facial nerve (FN). Bilateral hemifacial spasm caused by bilateral FNS is a rare presentation also. Case description: The patient was a 39-year-old female with bilateral HFS and bilateral FNS. Grade II House-Brackmann Facial Nerve Grading System was observed on the right side of her face. Continuous facial tics were occurring during the examination on both sides of her face, particularly around the left eye. The patient was received bilateral injections of botulinum toxin A. The patient underwent a scheduled close follow-up regarding hearing, facial nerve function, signs, and symptoms. In 1-month, 3-month, 6-month, and a year follow-ups, her symptoms were improved. We performed another MRI following a year, and the sizes of the lesions were equal as the first MRI. The patient was received bilateral injections of botulinum toxin A every 6 months. We decided to follow her up every 6 months for injection and every year by imaging. Conclusion: Surgery is a good option to remove the FNS, but close follow-up and symptomatic treatment, sometimes, are the best approaches when there are no significant facial nerve palsy and hearing loss.