Percutaneous chemical nerve block with ultrasound-guided intraneural injection.

Ultrasound-guided, intraneural chemical nerve block was performed to control intractable limb spasticity and its feasibility was evaluated. Twenty-nine patients showing spastic limb were controlled by 53 intraneural injections of chemical agents, either lidocaine or phenol. The main targets were the sciatic, tibial and musculocutaneous nerves. After identification of the spastic muscle and target nerve, an ultrasound-guided, intraneural injection was administered through a 25-G needle. The average effective duration was 9.1+/-19.6 days in the lidocaine injection group and was 164.5+/-169.4 days in the permanent blocking group with phenol injection. The ultrasound-guided intraneural injection technique was convincing. Intraneural injection of phenol achieved long-lasting improvement of spasticity.