Case Report of Acoustic Neurinoma Presenting Sudden Profound Sensorineural Hearing Loss with Vertigo

There have been many reports of patients with Acoustic Neurinoma (AN) with an atypical course and clinically we have also encountered many cases of AN with sudden onset of sensorineural hearing loss (SNHL). However, cases of AN with sudden profound SNHL are very rare. In this report, we describe 3 cases of AN with sudden onset of profound SNHL and rotary vertigo. In all 3 cases the AN were small. One patient recovered nearly all of his normal hearing ability. Even with the use of magnetic resonance imaging (MRI), two cases could not be diagnosed the first time, and one of these two cases was diagnosed with permanent hearing loss at a previous hospital. In this patient radiological findings at 6 months from onset showed the existence of AN. The other case has been followed at our hospital and a diagnoses of AN was made 2 years and 5 months after onset. None of the three cases showed any characteristic findings of idiopathic sudden SNHL, which made diagnosis difficult, particularly since radiological examinations such as MRI suggested normal findings. In patients with SNHL, careful long-term follow we should be performed.