Intrathecal Baclofen for Spastic Hypertonia from Stroke

Background And Purpose: We sought to determine whether continuous intrathecal delivery of baclofen can effectively decrease spastic hypertonia due to stroke.

Methods: Stroke patients with >6 months of intractable spasticity were screened via a randomized, double-blind, placebo-controlled crossover design of either intrathecal normal saline or 50 microgram baclofen. Those who dropped an average of 2 points in either their affected lower extremity side Ashworth or Penn spasm frequency scores were then offered computer-controlled pump implantation for continuous ITB and followed prospectively for up to 12 months.

Results: In 21 stroke patients 6 hours after the active drug bolus, the average (+/-SD) lower extremity Ashworth score on the affected extremities decreased from 3.3+/-1.2 to 1.4+/-0.7 (P<0.0001), spasm score from 1.2+/-1.2 to 0.1+/-0.3 (P=0.0224), and reflex score from 2.1+/-1.2 to 0.1+/-0.5 (P<0.0001). The average upper extremity Ashworth score on the affected extremities decreased from 2.8+/-1.1 to 1.8+/-0.8 (P<0.0001), spasm score from 0.7+/-1.0 to 0.2+/-0.4 (P=0.1544), and reflex score from 2.1+/-0.9 to 1.2+/-0.9 (P=0.0004). All active drug scores were statistically different from placebo scores at 6 hours (P<0.05). With up to 12 months of continuous infusion of ITB in 17 implanted patients, the average lower extremity Ashworth score on the affected extremities decreased from 3.7+/-1.0 to 1.8+/-1.1 (P<0.0001), the spasm score dropped from 1.2+/-1.3 to 0.6+/-1.0 (P=0.4282), and the reflex score decreased from 2.4+/-1.3 to 1.0+/-1.3 (P<0.0001). The average upper extremity Ashworth score in the affected extremities decreased from 3.2+/-1.1 to 1.8+/-0.9 (P<0.0001), the spasm score dropped from 0.7+/-1.0 to 0.3+/-0.8 (P=0.8685), and the reflex score decreased from 2.4+/-0.8 to 1.5+/-1.2 (P=0.3337). The average continuous ITB dose required to attain these effects was 268 microgram/d.

Conclusions: Intrathecal infusion of baclofen is capable of maintaining a reduction in the spastic hypertonia resulting from stroke.