Purpose Peripheral nerve injury (PNI) is common disorder that represents more than 3 % of all traumatic injury cases. One type of PNI, sciatic nerve injury, leads to considerable motoneuron dysfunction. Because Riluzole is clinically approved for the treatment of motoneuron disease, we evaluated whether Riluzole treatment could enhance the nerve regeneration process and improve functional outcome after sciatic nerve crush in rats. Methods In acute treatment groups, a single dose of Riluzole (6 and 8 mg/kg) was administered intra- eritoneally 15 min after the crush nerve injury. In the chronic treatment groups, animals were treated with Riluzole (4 and 6 mg/kg/d) for 8 days. Sciatic functional index (SFI) was evaluated for 9 weeks after injury. Furthermore, electrophysiological and morphometric evaluations were performed at the 9th week following injury. Results Acute and chronic administrations of Riluzole immediately after sciatic nerve crush result in significantly delayed regeneration and reduced motor function outcome. Conclusions These findings suggest that early administration of even a single dose of Riluzole after sciatic nerve crush injury can delay motor function recovery. This effect may not depend on its anti-nociceptive activity.

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