The aim of this study was to evaluate the effects of intrathecal bacolfen (ITB) on patients with severe generalized dystonia. Eighty-six participants ranging in age from 3 to 42 years (median age 13 years) with generalized dystonia refractory to oral medications were offered treatment with ITB. Dystonia was associated with cerebral palsy in 71% of participants. Response to ITB was tested by continuous infusions in 72%, and by bolus injections in 17% of participants who had both dystonia and spasticity. Ninety-one percent of participants responded to the screening infusion and 93% to the bolus injections. Pumps were implanted in 77 participants. Dystonia scores at 3, 6, 12, and 24 months were significantly decreased (p<0.005) compared with baseline scores. Dystonia scores were significantly lower in those with intrathecal catheters positioned at T4, or higher than in those with catheters at T6 or lower (p=0.005). Ninety-two percent of participants implanted with a pump retained their responses to ITB during a median follow-up of 29 months. Patient questionnaires indicated that quality of life and ease of care improved in 86% and speech improved in 33%. Side effects of ITB occurred in 26% of participants. Surgical complications occurred in 38% and included CSF leaks, infections, and catheter problems. ITB is probably the treatment of choice for generalized dystonia if oral medications are ineffective.

The reliability and responsiveness of the Barry-Albright Dystonia (BAD) Scale, a 5-point ordinal severity scale for secondary dystonia, was assessed. For interrater reliability, 13 raters scored 10 videotaped patients; for intrarater reliability, two raters rated the videotape again. For test-retest reliability, patients were rated on two occasions. Four inexperienced raters scored patients, received training, then scored additional patients. To assess responsiveness, we compared patient and physician global ratings of change (better, same, and worse) with BAD Scale score changes for 18 patients on intrathecal baclofen (ITB) trials. We assessed reliability with the intraclass correlation coefficient (ICC). The mean ICC for total BAD Scale scores were as follows: interrater reliability 0.866, intrarater reliability 0.967 and 0.978, test-retest reliability 0.978 (before training) and 0.967 (after training). We found the BAD Scale responsive to change, with most improved scores in patients rated by the patient, family, and neurosurgeon as 'better'. The total scores were reliable for experienced raters. We recommend training for clinicians interested in using the scale.

The reliability and responsiveness of the Barry–Albright Dystonia (BAD) Scale, a 5‐point ordinal severity scale for secondary dystonia, was assessed. For interrater reliability, 13 raters scored 10 videotaped patients; for intrarater reliability, two raters rated the videotape again. For test–retest reliability, patients were rated on two occasions. Four inexperienced raters scored patients, received training, then scored additional patients. To assess responsiveness, we compared patient and physician global ratings of change (better, same, and worse) with BAD Scale score changes for 18 patients on intrathecal baclofen (ITB) trials. We assessed reliability with the intraclass correlation coefficient (ICC). The mean ICC for total BAD Scale scores were as follows: interrater reliability 0.866, intrarater reliability 0.967 and 0.978, test–retest reliability 0.978 (before training) and 0.967 (after training). We found the BAD Scale responsive to change, with most improved scores in patients rated by the patient, family, and neurosurgeon as‘better'. The total scores were reliable for experienced raters. We recommend training for clinicians interested in using the scale.

Baclofen is a GABA B receptor agonist commonly used to relief spasticity related to motor disorders. The effects of baclofen on voluntary motor output are limited and not yet understood. Using noninvasive transcranial magnetic and electrical stimulation techniques, we examined electrophysiological measures probably involving GABA B (long-interval intracortical inhibition and the cortical silent period) and GABA A (short-interval intracortical inhibition) receptors, which are inhibitory effects mediated by subcortical and cortical mechanisms. We demonstrate increased active long-interval intracortical inhibition and prolonged cortical silent period during voluntary activity of an intrinsic finger muscle in humans with chronic incomplete cervical spinal cord injury (SCI) compared with age-matched controls, whereas resting long-interval intracortical inhibition was unchanged. However, long-term (ϳ6 years) use of baclofen decreased active long-interval intracortical inhibition to similar levels as controls but did not affect the duration of the cortical silent period. We found a correlation between signs of spasticity and long-interval intracortical inhibition in patients with SCI. Short-interval intracortical inhibition was decreased during voluntary contraction compared with rest but there was no effect of SCI or baclofen use. Together, these results demonstrate that baclofen selectively maintains use-dependent modulation of largely subcortical but not cortical GABA B neuronal pathways after human SCI. Thus, cortical GABA B circuits may be less sensitive to baclofen than spinal GABA B circuits. This may contribute to the limited effects of baclofen on voluntary motor output in subjects with motor disorders affected by spasticity.