Pharmacological interventions for spasticity following spinal cord injury

Spasticity is a major health problem for patients with a spinal cord injury (SCI) that limits patients' mobility and affects independence in activities of daily living and work. Spasticity may also cause pain, loss of range of motion, contractures, sleep disorders and impair ambulation in patients with an incomplete lesion. The effectiveness of available drugs is still uncertain and they may cause adverse effects. Assessing what works in this area is complicated by the lack of valid and reliable measurement tools. The aim of this systematic review is to critically appraise and summarise existing information of the effectiveness of available treatments and to identify areas where further research is needed.

To assess the effectiveness and safety of Baclofen, Dantrolene, Tizanidine and any other drugs for the treatment of long term spasticity in SCI patients as well as the effectiveness and safety of different routes of administration of Baclofen.

We searched the Injuries Group specialised register, the Cochrane Controlled Trials Register, MEDLINE, EMBASE and CINHALH up to 1998. Drug companies and experts active in the area were also contacted.

All parallel and crossover RCTs including spinal cord injury patients complaining of "severe spasticity". Studies where less than 50% of patients had a spinal cord injury were excluded.

Methodological quality of studies (allocation concealment, blinding, patients characteristics, inclusion and exclusion criteria; interventions; outcomes; lost to follow up) was independently assessed by two investigators. The heterogeneity among studies did not allow quantitative combination of results.

Nine out of 53 studies met the inclusion criteria. Study design was: 8 cross over, 1 parallel-group trial. Two studies (14 SCI patients), showed a significant effect of intrathecal baclofen in reducing spasticity (Ashworth Score and ADL performances), compared to placebo, without any side effect. The study comparing tizanidine to placebo (118 SCI patients) showed a significant effect of tizanidine in improving Ashworth Score but not in ADL performances. Tizanidine group reported significant rates of adverse effects (drowsiness, xerostomia). For the other drugs (Gabapentine, Clonidine, Diazepam, Amytal and oral Baclofen ) the results do not provide evidence for a clinical significant effectiveness.

There is insufficient evidence to assist clinicians in a rational approach to antispastic treatment for SCI. Further research is urgently needed to improve the scientific basis of patient care.