Outcome of Intrathecal Baclofen Test Injection in Patients with Multiple Sclerosis and Severe Spasticity Based on Ambulation Status

Background: Spasticity is a common symptom of multiple sclerosis (MS), which can significantly interfere with the performance of activities of daily living and quality of life. Intrathecal baclofen therapy (ITBT) has been shown to provide relief of severe spasticity in MS patients. Performing an ITB test injection assists providers in further identifying which patients could benefit from a pump, and allows patients to experience the effects of ITB prior to having the pump surgically implanted.  

Objectives: To characterize a cohort of MS patients with severe spasticity who underwent an ITB test injection, and compare the clinicians’ evaluation with the patients’ final decision.

Methods: Patients were identified through an IRB-approved clinical registry. Data from clinical encounters were extracted from both the electronic medical record and the registry. MS patients who underwent an ITB test injection between November 2000 and November 2017 were included. Demographics, MS disease characteristics, and ambulation status were collected. Test injection outcomes included clinician determination (successful, equivocal, or unsuccessful) and patient decision (pursue or decline ITBT, and reason for declining).

Results: The cohort consisted of 179 patients (age 49.3 +/- 9.2 years, 62% women, duration of MS symptoms 16.5 +/- 9.0 years). Ninety four (52.5%) were ambulatory. Among 154 (86.1%) who were considered by the provider to have successful test injections, 95 (62%) underwent surgery (24 (32%) ambulatory patients and 35 (44%) non-ambulatory patients declined ITB therapy). More ambulatory patients noted worsening active function as a reason for declining the therapy. Medical complications as a reason to forego ITB implant surgery was more common in non-ambulatory patients.

Conclusions: We found that only 62% of MS patients who were considered appropriate candidates for ITB therapy actually moved forward with the treatment. Loss of function was the most common concern in the ambulatory group, while ‘personal choice’ was most commonly noted by non-ambulatory patients, likely reflecting the fact that the results of the test did not meet their expectations. Our results support the importance of the ITB test injection in the patient decision process. Retrospectively analyzing why patients declined ITB therapy despite the provider’s recommendation for the treatment, can be useful to an MS clinical practice in terms of patient selection, patient education, appropriate goal-setting, and long term success with the therapy.