THE SUPRASPINAL ANXIOLYTIC EFFECT OF BACLOFEN FOR SPASTICITY REDUCTION

Recent studies in the psychiatric literature indicate that baclofen has an anxiolytic action in certain psychopathologic conditions. Clinical observation has shown that manifestations of spasticity are increased in anxious individuals, implicating a supraspinal site of mediation for these responses. The purposes of this study were to determine if baclofen reduced anxiety in individuals with traumatic spinal cord lesions and whether that reduction was correlated with decreased spasticity from the baclofen. Five adult males with traumatic spinal cord injury were randomly assigned to the study protocol. A double-blind, repeated measures, multiple base-line, single-case research design was employed. The independent variable was dose of medication with the three levels being placebo, 40 mg/day of baclofen and 80 mg/day of baclofen, in four evenly divided doses. The dependent variable was the score obtained on the Beck Inventory-A anxiety scale (BIA). The subjects were administered to BIA twice per week for a nine-week period of time, during which they received the doses of medication as described. Quantitative measurements of spasticity were also taken at each session. Visual inspection analysis of the data showed that two subjects had no measurable anxiety on the BIA throughout the study. Three subjects had measurable anxiety on the BIA during the base-line/placebo phase. They showed a decreased level of their BIA scores with 40 mg/day of baclofen, and a further level reduction with 80 mg/day of baclofen. The reduction in BIA scores was statistically significant using the standard deviation band test in one of these subjects. These data indicate that BIA probably has an anxiolytic effect for individuals status post-traumatic spinal cord injury. None of the five subjects had a reduction in quantitative measurements of spasticity in response to baclofen administration as compared to placebo. Correlation of spasticity reduction to anxiety reduction could consequently not be performed. The results of this and other recent studies indicate that baclofen has similar anxiolytic effects to diazepam, indicating that further evaluation of this effect for reduction of spasticity should be pursued.