Histopatologic and functional effects of facial nerve following electrical stimulation

The aim of the study is to investigate the functional and histopathologic changes in facial nerve due to applying of various violence and number electrical stimulus to the facial nerve.The study was carried with wistar rats between 200-300 gr. The facial nerves of the subjects were found and stimulated with electrical stimulator. Then five groups were created which 18 subjects in each group. Group 1: 1 mA (miliamper) electrical stimulus applicated group. Group 2: 2 mA (miliamper) electrical stimulus applicated group. Group 3: 3 mA (miliamper) electrical stimulus applicated group. Group 4: 4 mA (miliamper) electrical stimulus applicated group. Group 5: 5 mA (miliamper) electrical stimulus applicated group. The all groups were divided into three subgroups consist of six subjects. The facial nerves of the subjects in first subgroup were stimulated 10 times, in second subgroup were stimulated 20 times and in third subgroup were stimulated 30 times. The functions of the facial nerves were evaluated on first day, first week and first month. The facial nerves with branches were dissected from the around tissues carefully. These specimens were investigated by light microscope about axonal degeneration, macrovacuolisation and vascular congestion.No loss in facial functions were observed in the subjects during follow process. There was no significant difference between groups about axonal degeneration, macrovacuolisation and vascular congestion (p>0.05). While the less axonal degeneration were observed in group which stimulated 10 times, the more axonal degeneration were observed in groups which stimulated 20 and 30 times (p<0.05). The axonal degeneration, macrovacuolisation and vascular congestion were more observed in one daily groups (p<0.05).Consequently, the less violence and the less number electrical stimulus application to the facial nerve is look like an important criterion for not damage of facial nerve in patients who used electrical stimulator.