Objective
To know the effect of intrathecal baclofen on increased muscle tone, spasm and ambulation.

Methods
Six patients with a severe chronic spasticity were evaluated with 10∼75 ㄍg of intrathecal baclofen infusion. Two patient were infused more than two times (25 ㄍg, 50 ㄍg, 75 ㄍg). After each bolus infusion, an assesment was done for the patient's Ashworth score, spasm score, reflex score, peak eccentric torque by Cybex 6000 system^Ⱂ, H/M ratio, subjective feeling of walking and the gait analysis.

Results
Spasticity decreased from the mean prebolus Ashworth score of 3.4 to mean postbolus Ashworth score of 1.4 and the pre- and postbolus mean reflex score were 3.9 and 1.6 respectively for a minimum of 4 hours. All patients showed that spasms disappeared, and the peak eccentric torque and H/M ratios also decreased. For the bipedal locomotion, all patients improved in their gait speed, step length, and maximal knee flexion angle, but only two patients improved in their subjective ambulatory functions. These two patients could control the spastic limbs voluntarily and walk independently at the prebolus stage. Four patients had more difficulty in gait because of the subjective weakness of extensor muscles of the lower extremities.

Conclusion
Intrathecal baclofen decreased the spasticity, and spasm effectively in patients who had failed the conservative treatment with medication and physical therapy.