Objective: In the management of spasticity, intramuscular neurolysis with small amount of dilute aqueous phenol has proved to be a useful measure. But, considerable problem has taken place in utilization of phenol. This study was attempted to compare the effect of phenol and alcohol for the peripheral nerve blocking in the management of spasticity.

Method: Intraneural injection of 5% phenol, 50% alcohol and 90% alcohol solution carried out in each group of 10 rats. A total of 30 rat were injected and examined electrophysiologically before and after blocking the nerve (24 hour, 1 weeks, 2 weeks, 4 weeks, 8 weeks). The randomized one rat of each group was sacrificed for the histological examination of the sciatic nerve at every examined day.

Results: There was no difference of the distal latencies and amplitudes of compound muscle action potentials among the groups before injection. The latencies were prolonged at 24 hours post-injection and shortened at 1 week post-injection in all the groups. The amplitudes were markedly decreased at 24 hours post-injection and increased at 1 week post- injection and reached the pre-injection value at 8 week post-injection in all the groups. Histologic studies showed necrosis at 1 week post-injection and regeneration at 2 week post- injection in 50% and 90% ethanol groups. Phenol injection group showed necrosis at 4 week post-injection and regeneration after 8 weeks.

Conclusion: Our preliminary experience with alcohol for peripheral nerve blocking with encouraging result has been described.

Keywords :Phenol, Ethanol, Nerve block, Rat, Sciatic