INTRATHECAL BACLOFEN THERAPY IN STIFF-MAN SYNDROME - A DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL

We performed a double-blind, placebo-controlled trial of intrathecal b aclofen (ITB) in stiff-man syndrome. Three patients, unresponsive to c urrent therapy, received 50 mu g of ITB or placebo on sequential days. Following ITB, all patients demonstrated improvement in reflex EMG ac tivity. The mean reduction in total EMG activity (from all muscles) fo llowing stimulation of the medial plantar nerve (cutaneous flexor refl ex) was 72% following 50 mu g of ITB compared with 18% following place bo (ANOVA: significance of F, p < 0.0001). The mean latency to onset o f the response was also significantly prolonged for all muscles follow ing ITB (ANOVA: significance of F,p < 0.05). Although reflex EMG activ ity was reduced in all patients, clinical improvement was evident in o nly one patient, who differed from the others studied by a longer dura tion of disease, greater severity of stiffness, less fear of falling, and greater electrophysiologic improvement.