Hyperbaric oxygen versus steroid in facial nerve injury: an experimental animal study.

Abstract

OBJECTIVE: The aim of this experimental study was to evaluate the effects of hyperbaric oxygen, methylprednisolone and combined hyperbaric oxygen-methylprednisolone treatments on traumatic facial nerve regeneration in rats. SUBJECTS AND METHODS: After exposure to facial nerve injury, four groups of rats were created with five subjects in each group: Group 1 (hyperbaric oxygen), group 2 (control), group 3 (combined hyperbaric oxygen-methylprednisolone), group 4 (methylprednisolone). Facial nerve specimens from sacrificed animals were examined for axonal degeneration, vascular congestion, macro vacuolization, axon diameter and thickness of myelin sheath. RESULTS: There were significant differences with regard to axonal degeneration, vascular congestion and axon diameter between group 3 and the control group. In addition to lower axonal degeneration and vascular congestion, a larger diameter of axons was observed in group 3. There were significant differences with regard to vascular congestion and axon diameter between group 4 and the control group. We observed thicker myelin and lower axonal degeneration in group 3 compared with group 4. CONCLUSION: The combination therapy with hyperbaric oxygen and methylprednisolone had an additive beneficial effect on regeneration of the facial nerve and may provide better treatment outcomes than methylprednisolone or hyperbaric oxygen therapy alone.