The dosage and administration of long-term intrathecal baclofen therapy for severe spasticity of spinal origin.

STUDY

DESIGN

Retrospective chart audit.

OBJECTIVE

To indicate the appropriate baclofen dosage to control severe spasticity of spinal origin and to develop the optimal administration protocol for long-term intrathecal baclofen (ITB) therapy.

SETTING

Department of Orthopaedic Surgery, Spinal Injuries Center, Japan.

METHODS

Thirty-four people with spasticity of various spinal origins who were consistently treated at our hospital were included. The median follow-up period was 6 years and 11 months. Measures of Ashworth score were taken before and after surgical implant of baclofen pump. We decided not to increase the baclofen dosage after the Ashworth score reached 1. We recorded the control of spasticity, changes in the baclofen dose, and the incidence of complications.

RESULTS

The average Ashworth score was 3.31 (1.75-4.0) before implant surgery, 1.38 (1.0-2.25) after implant surgery, and 1.39 (1.0-2.25) at the final follow-up, while the average baclofen dose (therapeutic/optimal dose) was 230.6 μg/day (50-450). The incidence of each complication was as follows: 8.8% (n = 3) catheter-related, 2.9% (n = 1) pump-related and 5.9% (n = 2) drug tolerance. No patients experienced withdrawal syndrome. Dose fluctuation with changes in the pathology of the original disease was observed in three cases.

CONCLUSIONS

The usage of the Ashworth score as a guide for dose adjustment was found to be a good objective indicator for ITB therapy. The administration based on this objective indicator made it possible to effectively manage patients with a relatively low dose of baclofen and a low rate of drug-related complications.