CONCLUSIONS: Riluzole promoted increase and/or preservation of axon density in the animals treated with this drug as compared to the control group; it did not increase the mean diameter of facial nerve fibres as compared to the non-treated group; and it did not provide a better functional motor recovery than in the control group. OBJECTIVE: Traumatic peripheral facial paralysis is a frequent affection. In incomplete nerve injuries, systemic drugs acting on regeneration may decrease the patient's period of morbidity. This study aimed to determine the effect of the drug riluzole on regeneration of the facial nerve of rabbits submitted to post-traumatic facial paralysis. MATERIALS AND METHODS: Eighteen rabbits were submitted to compression of the facial nerve and divided into control (A) and treated (B) groups. The animals were sacrificed 4 weeks after the injury and their nerves were studied regarding density of myelinated axons and measure of external axon diameters. RESULTS: Partial functional recovery was observed within 2 weeks and complete recovery 5 weeks after injury. Mean neural density was 12,679.7 axons/mm2 (SD+/-237.5) in group A, and 19,073.8 axons/mm2 (SD+/-3549.9) in group B. Group A presented less than two-thirds the density of group B. There was no statistical difference in axon diameters between the studied groups.
CONCLUSIONS:Riluzole promoted increase and/or preservation of axon density in the animals treated with this drug as compared to the control group; it did not increase the mean diameter of facial nerve fibres as compared to the non-treated group; and it did not provide a better functional motor recovery than in the control group. OBJECTIVE:Traumatic peripheral facial paralysis is a frequent affection. In incomplete nerve injuries, systemic drugs acting on regeneration may decrease the patient's period of morbidity. This study aimed to determine the effect of the drug riluzole on regeneration of the facial nerve of rabbits submitted to post-traumatic facial paralysis. MATERIALS AND METHODS: Eighteen rabbits were submitted to compression of the facial nerve and divided into control (A) and treated (B) groups. The animals were sacrificed 4 weeks after the injury and their nerves were studied regarding density of myelinated axons and measure of external axon diameters. RESULTS: Partial functional recovery was observed within 2 weeks and complete recovery 5 weeks after injury. Mean neural density was 12,679.7 axons/mm2 (SD+/-237.5) in group A, and 19,073.8 axons/mm2 (SD+/-3549.9) in group B. Group A presented less than two-thirds the density of group B. There was no statistical difference in axon diameters between the studied groups.