Effect of Intrathecal Baclofen on Pain and Quality of Life in Poststroke Spasticity

Abstract

Background and Purpose- Intrathecal baclofen (ITB) is an effective treatment for managing patients with severe poststroke spasticity, who can experience continued pain and decline in their quality of life (QoL). SISTERS (Spasticity In Stroke-Randomized Study) was a randomized, controlled, open-label, multicenter, phase 4 study to evaluate ITB therapy versus conventional medical management (CMM) with oral antispastic medications for treatment of poststroke spasticity. Methods- Poststroke patients with spasticity in ≥2 extremities and an Ashworth Scale score of ≥3 in ≥2 affected lower extremity muscle groups were randomized (1:1) to ITB (N=31) or CMM (N=29). Both treatment arms received physiotherapy throughout. The primary outcome was the change in average Ashworth Scale score in the lower extremities of the affected side from baseline to month 6. Here, we report results for secondary outcomes: pain via the Numeric Pain Rating Scale, health-related QoL by the EuroQol-5 dimensional 3 level utility score and health status visual analog scale score, stroke-specific QoL, and patient satisfaction. Analyses were performed on an intention-to-treat basis. Results- We observed significant treatment effects in favor of ITB over CMM for changes from baseline to month 6 in Numeric Pain Rating Scale scores for actual pain (ITB versus CMM: mean, -1.17 [SD, 3.17] versus 0.00 [3.29]; median, -1.00 versus 0.00; P=0.0380) and least pain (mean, -1.61 [2.29] versus 0.24 [3.07]; median, -1.00 versus 0.00; P=0.0136), and EuroQol-5 dimensional 3 level utility scores (mean, +0.09 [0.26] versus +0.01 [0.16]; median, +0.07 versus 0.00; P=0.0197). Between-group differences were not statistically significant for EuroQol-5 dimensional 3 level visual analog scale, stroke-specific QoL summary, or Numeric Pain Rating Scale worst pain scores, although ITB patients showed greater numeric improvements from baseline during follow-up. More ITB patients than CMM patients (73% versus 48%) were satisfied with the spasticity reduction at month 6. Conclusions- These data support that ITB therapy is associated with improvements in pain and QoL in poststroke patients. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01032239.

Keywords: baclofen; muscle spasticity; pain; quality of life; stroke.

Figure 1.

Patient flow diagram. CMM indicates conventional medical management; ITB, intrathecal baclofen; and ITT, intent-to-treat. Reproduced from Creamer et al with permission. Copyright ©2018, BMJ Publishing Group Ltd.

Figure 2.

Mean (SEM) changes from baseline (BL) in Numeric Pain Rating Scale (NPRS) pain scores by visit for (A) actual pain, (B) least pain, and (C) worst pain related to spasticity or spasm. Last observation carried forward (LOCF) imputation was performed for the month 6 assessment using month 3 data. CMM indicates conventional medical management; and ITB, intrathecal baclofen.

Figure 3.

Mean (SEM) changes from baseline (BL) by visit for (A) EuroQol–5 dimensional 3 level (EQ-5D-3L) utility index, (B) EQ-5D-3L visual analog scale (VAS), and (C) stroke-specific quality of life (SS-QOL) summary scores. Last observation carried forward (LOCF) imputation was performed for the month 6 assessment using month 3 data. CMM indicates conventional medical management; and ITB, intrathecal baclofen.

Figure 4.

Distribution of EuroQol–5 dimensional 3 level (EQ-5D-3L) responses (percent of patients on each level of problem) for individual dimensions by visit. Only patients with data for baseline, month 3, and month 6 visits were included (N=23 for both treatment arms). CMM indicates conventional medical management; and ITB, intrathecal baclofen.

Figure 5.

Patient satisfaction with the reduction of spasticity provided by the therapy (A) and patient recommendation of the therapy (B) at month 6. Number of patients analyzed is 22 for intrathecal baclofen (ITB) arm and 23 for conventional medical management (CMM) arm.