A study on preoperative electronystagmography in chronic otitis media

Abstract

Preoperative electronystagmography (ENG) recordings were done in 100 patients with chronic otitis media to detect vestibulocular disturbance associated with this condition.ENG recordings were performed under five conditions : gazing, eyes closed, eyes covered and performance of mental calculation with eyes closed and eyes covered. The optokinetic pattern test (OKP) and eye tracking test (ETT) were also done.The rate of appearance of spontaneous nystagmus in these 100 patients was compared with the rate of appearance of the 100 normal individuals in the report of Kaga et al. Both slow phase velocity (degree/second) and frequency (number/second) were measured on ENG recordings and also compared with the normal results. The relation between the rate of appearance of the spontaneous nystagmus with the following clinical signs and symptoms were investigated : 1) vertigo, 2) otorrhea, 3) unilateral, or bilateral chronic otitis media, 4) history of operation, 5) cholesteatoma and 6) bone conduction abnormalities. Spontaneous nystagmus was found in 67% of the patients with chronic otitis media. Both slow phase velocity and frequency of spontaneous nystagmus of the patients were remarkably larger than that of the normal individuals in each of the above conditions. Significant difference was seen with respect to the following : vertigo, bone conduction abnormalities and unilateral cholesteatoma. The direction of the spontaneous nystagmus in patients with unilateral chronic otitis media with otorrhea was contralateral to the lesion rather than ipsilateral. Six patients showed abnormal optokinetic patterns and they also had abnormal results on the eye tracking test.