[Analyse of the site of lesion in auditory neuropathy].

OBJECTIVE

To analyze the clinic signs, the site of lesion and terminology of a kind of hearing loss which is characterized by speech hearing loss.

METHOD

The data of 11 patients were collected and analyzed including the clinic symptoms, pure tone audiometry, acoustic impedance audiometry, auditory brainstem response (ABR), electrocochleogram(ECochG), distortion product otoacoustic emission (DPOAE), CT/MRI.

RESULT

All these cases had following contradictory phenomena: Pure tone audiograms were low-frequency hearing loss; ABRs were absent or seriously abnormal, and ABR response threshold was worse than pure tone threshold and click subjective threshold; ECochG could be recorded in some patients; The stapes muscle reflex was absent; DPOAEs were normal or near normal, the average amplitude of low-frequency was higher than normal hearing group, but the average amplitude of high frequency was lower than normal hearing group; The imaging examination did not show any abnormality.

CONCLUSION

All data of this group show that the sites of lesion in most patients may be in lower brainstem, but the sites of lesion in some patients may be in the spiral ganglion of cochlea. The research of this disease should be continued.