Assessment of thermal treatment via irrigation of external ear to reduce cisplatin-induced hearing loss

Systemic and local changes in body temperature can have a profound effect on traumatic injuries including those to the inner ear. Therefore, we investigated the effects of acutely increasing or decreasing the temperature of the external ear canal on cisplatin-induced hearing loss. The external auditory canals of male guinea pigs were acutely irrigated with warm (44 degrees C), euthermic (37 degrees C), or cool (30 degrees C) water and subsequently injected with cisplatin (12 mg/kg, i.p.). Hearing was assessed by the auditory brainstem response and cochleograms were prepared to determine loss of hair cells. Ear canal irrigation with warm water potentiated cisplatin-induced hearing loss and outer hair cell loss whereas cool ear canal irrigation showed significant protection from cisplatin-induced hearing loss and outer hair cell loss. These results suggest that non-invasive cool water ear canal irrigation may be highly effective clinical procedure for protecting against cisplatin-induced hearing loss. (C) 2015 Elsevier B.V. All rights reserved.