Differences in efficacy, safety and procedure during a continuous intrathecal baclofen trial to treat severe...

Spasticity is a common issue following from various conditions and affects daily functioning and quality of life. Intrathecal baclofen (ITB) therapy is offered to patients unresponsive to conventional treatments. Before a permanent ITB-pump is installed, a trial treatment is administered. In our daily practice, we observed that patients with Multiple Sclerosis (MS) experience continuous trials differently compared to patients with other aetiologies. Thus, we aim to compare efficacy, safety, and procedure of continuous ITB-trials between patients with MS and those with other underlying causes of spasticity.

Adult and ambulatory patients with disabling spasticity, who underwent continuous ITB-trials between January 2014 and January 2022 were included. Data from their medical records were analyzed retrospectively. The study population's characteristics, procedure details, spasticity, (Serious) Adverse Events ((S)AE), patient goals and satisfaction were abstracted and compared between an MS- and a comparator-group.

Records of 54 patients were included; one third had MS. Spasticity improved significantly after the ITB-trial in both groups. Overall, 67% of patients had one or more adverse events. The most common AE was postdural puncture headache (PDPH), which occurred significantly more often in patients with MS than in the comparison group (67%vs. 33%). Severe PDPH was reported in 44% of MS patients compared to 13.9% in the other group. Despite this, MS patients reported greater satisfaction with trial outcomes and were more often seen as suitable for permanent pump implantation.

Continuous ITB-trials effectively reduce spasticity but adverse events, especially (severe) PDPH, were common and particularly impacted patients with MS. These results raise doubts about whether continuous ITB-trials should be the first choice for ambulatory MS patients.