Hyperbaric Oxygen Treatments Attenuate the Neutrophil-to-Lymphocyte Ratio in Patients with Idiopathic Sudden Sensorineural Hearing Loss

AbstractObjective. Hyperbaric oxygen therapy (HBOT) is a promising treatment in the management of idiopathic sudden sensori neural hearing loss (ISSNHL), but the specific mechanisms of HBOT in ISSNHL are still unclear. The curative effects ofHBOT in many diseases are related to the attenuation of inflammatory response. The neutrophil-to-lymphocyte ratio (NLR) is a new inflammatory marker that can be assessedquickly. We investigated the relationship between HBOT and the inflammatory response in ISSNHL using the NLR.Study Design. Case series with chart review Setting. Tertiary teaching and research hospitalSubjects and Methods. Between December 2007 and December 2013, 41 ISSNHL patients who underwent HBOT, 45 ISSNHL patients who did not undergo HBOT, and 14 healthycontrol subjects who underwent HBOT were included in the study. NLRs were assessed at 2 time points: at baseline (pretreat ment) and on day 1 after 10 sessions of HBOT (posttreatment).Audiometric testing was performed at the above 2 time points. Results. The mean post-HBOT NLRs, neutrophil, and white blood cell count values of the ISSNHL patients were significantly lower than their pretreatment values (P .001). Comparedwith the ISSNHL patients who did not undergo HBOT, the posttreatment NLR levels of the ISSNHL patients who under went HBOT were much lower (P = .036). Higher relative hear ing gains were significantly associated with a greater reduction inthe NLR after HBOT (r = –0.885, P = .001).Conclusions. The beneficial effect of HBOT on ISSNHL may be mediated at least in part by a decrease of inflammation.