Does intracochlear brain-derived nerve growth factor improve auditory brainstem click thresholds in sensorineural hearing loss?

OBJECTIVE To determine whether intracochlear administration of brain-derived nerve growth factor (BDNF) is associated with lower auditory brainstem response (ABR) click thresholds after cisplatin-induced sensorineural hearing loss. STUDY DESIGN Animal research study. METHODS Fifteen normal hearing guinea pigs were studied. In 11 animals, hearing loss was created using cisplatin. One month later, bilateral cochleostomies were then performed. In one ear, BDNF was injected, and in the other, an equivalent volume of saline was injected prior to plugging with fat. In four animals, no cisplatin or BDNF was given, but the cochleostomies were performed bilaterally as surgical controls. ABR testing was then carried out for two subsequent months using clicks to determine thresholds. RESULTS There were no statistically significant changes in ABR click thresholds between BDNF-treated versus BDNF-untreated ears. The thresholds for the control group that underwent cochleostomy only were actually worse than those for either of the groups that received cisplatin, and the ears that received BDNF had better hearing than either saline or surgical controls, but the results were not statistically significant. CONCLUSION Our data do not support the use of intracochlear BDNF for severe hearing loss correction in guinea pigs as used in this protocol.