RT Journal Article SR Electronic T1 Effect of intrathecal baclofen on the monosynaptic reflex in humans: evidence for a postsynaptic action. JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 515 OP 519 DO 10.1136/jnnp.56.5.515 VO 56 IS 5 A1 P Azouvi A1 A Roby-Brami A1 A Biraben A1 J B Thiebaut A1 C Thurel A1 B Bussel YR 1993 UL http://jnnp.bmj.com/content/56/5/515.abstract AB Intrathecal baclofen is a very powerful antispastic agent. Its mechanism of action on the monosynaptic H-reflex in spinal patients was investigated. It could inhibit rapidly and profoundly monosynaptic reflexes in lower limbs, but did not modify Ia vibratory inhibition of the soleus H-reflex. To assess more precisely its effect on Ia afferents, an experimental paradigm using Ia heteronymous facilitation of the soleus H-reflex was used. Intrathecal baclofen did not modify the amount of monosynaptic facilitation of the soleus H-reflex brought about by stimulation of the femoral nerve. This demonstrates that the main part of the inhibitory effect of baclofen on the H-reflex in spinal patients is not due to a presynaptic effect, suggesting a postsynaptic site of action.