Effect of Minocycline on Traumatic Facial Nerve Injury: An Experimental Study

This study aimed to investigate the efficacy of minocycline (M) and methylprednisolone (MP) in the treatment of trauma to the facial nerve (FN).

The study was conducted on 35 male Wistar albino rats. The subjects were randomly divided into 5 groups. Buccal branches were traumatized except those in the sham group. Group 2 received 3 mg/day saline intramuscularly, the third group (M group) 90 mg/day M intraperitoneally, the fourth group (MP group) 1 mg/kg/day MP intramuscularly, the fifth group (M + MP group) 90 mg/day M intraperitoneally and 1 mg/kg/day MP treatment for 14 days. Electrophysiological tests were performed before and after the trauma, and the results were recorded. Then, the relevant nerve parts in the buccal branches of the subjects were removed and sent for histopathological examination.

The best results were observed in Group 1 and Group 5, while Group 2 had the worst results in terms of axonal diameter measurement, myelin sheath degeneration, and mast cell count parameters measured in histopathological examinations. In the electrophysiological analyses, the differences between the third week (posttreatment) and the first measured (pre-traumatic) NET (nerve excitability test) and MST (maximum stimulation test)values were observed to be significantly lower in Groups 1, 4, and 5 compared to Group 2. This was statistically significant.

Positive effects on nerve fibers were observed when M was used alone and together with MP. It is suggested that M, whose effectiveness in traumatic FN injury has not been previously investigated in the literature, be used as a treatment in humans for this purpose, and that more diverse and advanced comparative studies be conducted.