A New Animal Model of Facial Nerve Palsy Using a Freezing Method
The etiology of Bell’s palsy is still unknown. It is generally accepted that the edema and the ischemia in the fallopian canal are the major pathogenic factors of Bell’s palsy. From this standpoint, few animal models have been established. A new animal model of facial nerve palsy caused by freezing is reported. Mongoian gerbils were used. The middle ear space was frozen microscopically with dimethylether liquid propane gas, after myringotomy. The onset of palsy was confirmed by the loss of both blink and movement of the whiskers. Facial movement was evaluated, and the evoked EMG was recorded 1, 3, and 5 weeks later after the onset of facial palsy. Temporal bones were sectioned and subjected to histopathological study.