Transient profound hearing loss and severe facial nerve palsy in schwannomas within the internal acoustic canal: A case report

Vestibular schwannoma is the most common intracranial schwannoma and constitutes similar to 8% of all intracranial tumors in adults with an estimated incidence rate of similar to 1.3/100.000. Facial nerve schwannomas and cochlear nerve schwannomas are rare, and information regarding incidence rates of these is still missing in the literature. All three variants of nerve origin present most frequently with unilateral hearing loss, unilateral tinnitus and disequilibrium. Facial nerve palsy is a common finding in facial nerve schwannomas but a rare finding with vestibular schwannomas. The symptoms are normally persistent and often progress over time, leading to therapeutic interventions that predispose to quality of life-reducing morbidities, e.g., deafness and/or imbalance. The case report describes a 17-year-old male who, during a 1-month period, presented with profound unilateral hearing loss and severe facial nerve palsy followed by complete remission. An MRI scan showed a 5x8-mm schwannoma within the internal acoustic canal. Profound hearing loss together with concomitant severe peripheral facial nerve palsy in small schwannomas within the internal acoustic canal may show spontaneous and total remission within weeks of symptom debut. This knowledge, as well as possible remission of objective findings, should be considered before interventions with potential severe morbidity are suggested.