Intrathecal baclofen for multiple sclerosis related spasticity: A twenty year experience.

OBJECTIVE: Evaluate long-term efficacy and safety of ITB in treating MS-related spasticity over ∼ 20 years of service provision in a single centre. METHODS: A single centre prospective observational cohort study was performed. Eligible subjects underwent ITB trial by bolus dose via lumbar puncture and responders proceeded to pump implantation. Demographics, spasticity scores (Ashworth), spasm score (Penn), stiffness, pain and discomfort (Visual Analogue Scale), mobility (10 M walk), spasticity treatment, and ITB doses were analysed longitudinally. RESULTS: 106 people were included with 568 patient years of data. Ashworth, Penn and VAS/NRS mean scores improved post-trial compared with baseline (p < 0.001). Sustained efficacy was reported on Ashworth, Penn and VAS scores over time. After 1 year, 73 (69%) discontinued all oral antispasticity medications. Complication rates were low at 0.05 complications per pump year and mostly mechanical (usually catheter) related. In 8 ambulatory subjects, 7 (87%) continued to walk one year after pump insertion, 5 (62%) were still walking at time of analysis (mean follow up 3.4 years). CONCLUSIONS: ITB is an effective and safe long term treatment for refractory MS related spasticity. Efficacy was sustained over time and the majority of subjects subsequently discontinued systemic medications. In a small cohort, ability to walk was preserved, indicating ITB should be considered earlier in this cohort.

A novel cause of intrathecal baclofen overdosage: lessons to be learnt.

CASE PRESENTATION: A serious intrathecal baclofen overdose occurred in a 45-year-old woman with primary progressive multiple sclerosis following a catheter dye study with concomitant change in baclofen concentration. The pump and catheter were emptied of baclofen 2000 microg/mL, refilled and primed with baclofen 1000 microg/mL. No correction was made for the ;dead space' between the reservoir and catheter access port, which contained baclofen 2000 microg/mL. Failure of the priming bolus to account for the residual baclofen concentration within the dead space resulted in a serious overdose.Action: Amendments are being made to both our local and the Medtronic protocols. CONCLUSION: We hope that by reporting this incident the risk of this potentially fatal error re-occurring is minimized.