BOTULINUM TOXIN IN UPPER-LIMB SPASTICITY - STUDY OF RECIPROCAL INHIBITION BETWEEN FOREARM MUSCLES

To establish whether botulinum A toxin (BTX-A) acts on modifying recip rocal inhibition between forearm muscles in spasticity, 20 patients wi th post-stroke upper limb spasticity lasting for more than 1 year were studied. Clinical examination, physiotherapeutic evaluation, standard ized video-tape assessment and electrophysiological testing (flexor ca rpi radialis muscle M and H responses with study of reciprocal inhibit ion) were performed at baseline and 2 weeks, 1, 2, 3, 4 months after B TX-A treatment. BTX-A induced a significant decrease of tone and an im provement of motility and functional status, with a significant decrea se of the M wave and the H reflex. The reduction in both inhibitory ph ases of reciprocal inhibition did not change after BTX-A treatment dif ferently from that reported in upper limb dystonia. These findings ind icate that the efficacy of BTX-A in upper limb spasticity is mainly du e to peripheral effects.