Trigeminal Schwannoma Presenting with Masticatory Muscle Atrophy: A Rare Case Report

Trigeminal schwannoma (TS) presenting with masticatory muscle atrophy is very rare. Here, we report the case of an 80 year-old male patient with TS presenting with masticatory muscle atrophy in October 2014. The patient had been diagnosed with hypertrophic pachymeningitis and right intracranial TS in 2013 by his neurologist, for which he was treated with steroids. However, his symptoms in the trigeminal innervation region persisted. He visited our department due to difficulty in opening his mouth as well as eating. Surgery was not performed owing to his advanced age and general condition. His trismus was improved by mouth opening training via manual manipulation for three years. We suggest that TS should be considered in the differential diagnosis of patients with masticatory muscle atrophy. Consultation with a neurologist is also essential. Manual manipulation may be an effective non-surgical treatment option for patients with difficulty in mouth opening owing to TS.