Correlating the cochleovestibular deficits with tumor size of acoustic neuroma

Abstract

There is a trend of correlation between tumor size and audiographic configuration, with small-sized tumor in normal and rising types, medium-sized tumor in mid- and high-frequency hearing loss, and large-sized tumor in flat and deafness types. Five patients with bilateral gaze nystagmus had significantly larger tumor size than those without nystagmus. When 1 and 0 are used to represent abnormal and normal responses, respectively, the relationship between tumor size and vestibular function can be expressed as: tumor size (cm)=1.43 (caloric response)+1.35 (VEMP response), indicating that the estimated tumor size for those with abnormal caloric or VEMP responses increased by 1.43 or 1.35 cm, respectively.