Acamprosate reduces motor cortex excitability determined by transcranial magnetic stimulation

Acamprosate is effective in reducing alcohol intake in weaned alcoholics, W e were interested if acamprosate had an effect on the excitability of corti cal motoneurons determined by transcranial magnetic stimulation (TMS), We s tudied 12 male healthy volunteers (mean age 29.5 years, SD = 4.8) who were either treated with 6 tablets of acamprosate (each containing 333 mg verum) per day or placebo (randomized cross-over design) for 1 week. TMS was perf ormed after each treatment session including a paired stimulation paradigm. Motor evoked potentials (MEPs) of the placebo and verum group did not diff er with respect to paired stimulation, However, motor threshold increased i n the acamprosate group (verum: 61.5% (SD = 7.9) vs. placebo: 58.9% (SD = 8 .8), p = 0.036), We conclude that acamprosate leads to a hypoexcitability o f the motor cortex. This might be due to subcortical mechanisms, e.g. thala mocortical pathways since intracortical inhibition and facilitation was not affected. Copyright (C) 2000 S. Karger AG, Basel.