A Rare Case of an Acoustic Tumor Diagnosed in an Elderly Patient with Atypical Nystagmus

Abstract

Journal of Case Reports in Medicine,2013,2,1,1-4.Published:April 2013Type:Case ReportAuthors:Hidetake Matsuyoshi, and Hidenori Goto Author(s) affiliations:Hidetake Matsuyoshi and Hidenori Goto Matsubase Otolaryngology and Internal Medicine Clinic, Kirara 2-2-15, Matsubase, Uki city, Kumamoto Prefecture 869-0503, JAPAN. Abstract:We describe a rare case of an acoustic tumor diagnosed in a 69-year-old female who presented with a history of persistent rotatory vertigo on shifting her head position since several weeks, which was accompanied by mixed upper eyelid-oriented counterclockwise rotation on standing. Pure-tone audiometry and auditory brainstem responses were symmetrical, and thermal stimulus test results were normal. These symptoms ruled out Meniere’s disease and acute vestibular neuronitis; therefore, benign paroxysmal positional vertigo (BPPV) of the right posterior canal was considered the most probable cause. However, no improvement was observed with the Epley maneuver. Furthermore, the eye-tracking test indicated ataxia, and optokinetic nystagmus was also abnormal, which warranted further examination using magnetic resonance imaging (MRI). T2-weighted images revealed a 5-mm tumor within the internal acoustic meatus. This case strongly suggests that MRI should be considered for all patients presenting with atypical nystagmus, even when BPPV is the most probable cause. Keywords:Acoustic tumor; Nystagmus; Benign paroxysmal positional vertigoView:PDF (1.34 MB) PDF Images Figure 1: Audiogram of pure-tone audiometry. A difference of > 10 dB between the right (◦) and left ear (×) was detected at an 8-kHz frequency at (a) the initial visit (March 26, 2009) (b) but not at a follow-up visit, when the acoustic tumor was no longer visible on MRI (May 12, 2012).