ENG profile in auditory neuropathy

ABSTRACT

Twelve patients with auditory neuropathy aged 11 - 34 years were subjected to ENG test battery including gaze, random saccades, pursuit, optokinetic, positional and bithermal water caloric tests. Twenty age and gender matched normal subjects were included as a control group. None of the 12 patients had history of vertigo or unsteadiness. Neither gaze evoked nor positional nystagmus was recorded in any patient. 7 patients out of 12 had abnormal gain of pursuit tracking and optokinetic nystagmus [< 0.7] and 2 out of the 7 had abnormal fixation index [> 50%]. Moreover, the average slow phase velocity of the total caloric response in auditory neuropathy patients showed statistically significant reduced values as compared to those obtained from the control group, however none of the 12 patients had total caloric response < 22 degrees/second. These results are suggestive of a potential peripheral vestibular dysfunction in addition to central vestibular dysfunction mainly at the level of brainstem