1311 - Let it Flow: Troubleshooting Intrathecal Baclofen Pump Catheter Issues with Pump Setting and Concentration Adjustments

Case Diagnosis: loss of efficacy for ITB therapy

Case Description: Three patients with previously well controlled spasticity on intrathecal baclofen (ITB) presented with loss of efficacy for ITB therapy with constant or intermittent spasticity exacerbation and histories concerning for partial or intermittent flow disruption. One had significant spasms without other withrdawal symptoms, another had intermittent withdrawal progressing to moderate constant withdrawal symptoms, and a third had severe spasms but did not exhibit withdrawal until later in the course. Catheter access port (CAP) aspiration with fluid analysis, CT imaging, and in one case CT myelogram, were performed and unrevealing. In all cases, baclofen concentration was decreased and flex dosing initiated in efforts to improve flow. At least mild temporary improvement in symptoms resulted and in 2 cases helped abate withdrawal symptoms while weaning in anticipation of pump/catheter replacements.

Discussions: Mild to moderate withdrawal symptoms in a patient previously well managed on ITB therapy raises concern for partial disruption of flow, which may occur by catheter/connector leak, microfracture, granuloma, catheter migration or kinking. While published best practices guide the work up for moderate to severe withdrawal, adjustments to pump settings and concentration change can provide temporary relief and inform further decisions. The algorithm for troubleshooting intrathecal catheter issues includes CAP aspiration to confirm beta-2 transferrin positivity. A CT myelogram can further evaluate catheter integrity. It may take days to result fluid for beta-2 transferrin and additional time to coordinate CT myelogram on a non-emergent basis. Pump setting and concentration adjustments can yield diagnostic clues and provide immediate therapeutic benefit for mild to moderate withdrawal symptoms.

Conclusions: Loss of efficacy of ITB therapy is challenging for patients and clinicians. Best practices guide the diagnostic work up. Changes to concentration and pump settings can provide temporary relief and may further support suspicion for partial flow disruption.