Effect of intrathecal baclofen (ITB) therapy in ambulatory patients with generalized spasticity

Background: The effect of interthecal baclofen (ITB) therapy on spasticity in central neurological disease (MS, CP, SCI, stroke) has been proven. However, literature on the effect on walking performance is scarce although there are indications that ITB therapy has a positive effect on patients’ walking performance when spasticity in the legs is problematic. In clinical practice, clinicians are often reluctant to expose patients with walking function to ITB therapy because of the risk of losing walking function due to spasm reduction. So far, objective evaluation of the effect of ITB therapy on walking performance is insufficiently investigated. Therefore, we would like to investigate the effect of ITB therapy on walking performance in patients with central neurological diseases.
Objective: The aim of this study is to investigate effectiveness of ITB therapy on walking performance in patients with central neurological diseases and impaired walking due to spasticity. A secondary explorative aim is investigating the dose-response relationship between the baclofen dose and daily walking activity.
Study design: Prospective observational cohort study (No controls).
Study population: 12-15 patients with central neurological suffering (e.g. MS, CP, SCI, stroke); in chronic phase (>6 months) and generalized spasticity during walking; indication for ITB therapy with planned admittance to SMK; ≥16 years.Intervention: To objectively explore the effect of the ITB therapy patients will be asked to wear IMUs on both ankles during daytime of their inpatient admissions of the ITB trial pump (ITBext admission) and, if placed, the permanent ITB pump (ITBint admission). And during two physical therapy sessions; at baseline (preITB) and at twelve months follow-up (ITBfollow-up).
Main study parameters/endpoints: Primary outcome is the covered distance (meters) during the 2 minute walking test (2MWT). Secondary outcomes are spatiotemporal gait parameters, 10mWT, TUG, MAS, GAS, and BRPE & VAS scores regarding pain sensation, ease of walking and the hindrance from spasm during the 2MWT. Primary outcome for the dose-response relationship is the 10mWT score. Secondary outcomes are the MAS, gait parameters and VAS score regarding ease of walking during the 10mWT.

It is hypothesized that patients will improve their gait performance overtime and an exponential curve is expected between baclofen dose and daily walking activity.

This observational cohort study has four timepoints. preITB: The baseline measurement will take place one week before the ITB trial, during physical therapy. ITBext: the ITB trial measurement will take place around the 4th day after placement of the ITB trial pump, during physical therapy. ITBint: the ITB measurement (if permanent ITB pump is placed) will take place around the 4th day after placement of the permanent ITB pump, during physical therapy. ITBfollow-up: The follow-up measurement (if permanent ITB pump is placed) will take place approximately 12 months after placement of the permanent ITB pump. During inpatient rehabilitation the participant will be monitored (ITBext admission and ITBint admission). All timepoints are part of usual care.

To objectively explore the effect of the ITB therapy patients will be asked to wear IMUs on both ankles during daytime of their inpatient admissions of the ITB trial pump (ITBext admission) and, if placed, the permanent ITB pump (ITBint admission). And during two physical therapy sessions; at baseline (preITB) and at twelve months follow-up (ITBfollow-up).