ITB Pump Utility in PLS — Clinical Short Communication 2021
This is one of the few published reports documenting intrathecal baclofen outcomes specifically in PLS patients. Published in the Journal of the Neurological Sciences in 2021, it reviewed five people with confirmed PLS who received ITB pump implantation for refractory spasticity. All five showed improvement in spasticity scores, with an average treatment duration of more than ten years. The study is small — five patients — but it matters because most ITB literature comes from spinal cord injury, multiple sclerosis, and cerebral palsy populations. This paper reports directly on PLS.
What they did
The authors retrospectively reviewed charts of PLS patients at their institution who had received intrathecal baclofen pump implantation for spasticity. Patients were included only if the diagnosis of PLS had been confirmed by a board-certified neuromuscular neurologist, with exclusion of any other cause of spasticity. PLS diagnosis required upper motor neuron dysfunction on examination combined with slow symptom progression over an extended period — consistent with established diagnostic criteria.
The chart review documented: age at pump insertion, time from diagnosis to implantation, length of treatment, pump model used, dose range achieved, clinical outcomes as measured by examination and Ashworth spasticity scores, and any complications. The outcome evaluation was based on clinical examinations conducted in the context of routine care, not on a standardized prospective protocol.
What they found
Five patients were identified who met the inclusion criteria. The average age at the time of pump insertion was 56.4 years. The average time from PLS diagnosis to pump implantation was 6.6 years — reflecting the typical clinical trajectory in which oral agents are tried first and the ITB pump is reserved for patients who have failed or cannot tolerate oral antispasticity medications.
The average length of ITB treatment was 10.4 years, with a range of 4 to 15 years. All five patients used the Medtronic SynchroMed II programmable baclofen pump. The dose range achieved was 35 mcg/day to 1,580 mcg/day, with a mean daily dose of 664.6 mcg/day and a median dose that reflected the substantial individual variation typical of ITB titration.
All five patients reported improvement in spasticity as measured by clinical examinations and Ashworth scores. One of the five had a complication involving catheter migration following a fall, requiring pump revision. No patients required permanent pump removal. Overall, the authors concluded that ITB was safe and effective for spasticity in PLS.
Why it matters
The rarity of PLS-specific data makes this small case series more important than its sample size might suggest. When a PLS patient and their neurologist are deciding whether to pursue an ITB pump implant, almost all of the available evidence comes from other populations. This report provides direct confirmation that the approach works in PLS and that patients tolerate it — and continue using it — for many years.
The ten-year average treatment duration is striking. It tells you that PLS patients who have their ITB pump implanted tend to stay on it. The pump becomes part of their long-term management. This is important for expectations: ITB is not a temporary intervention. It is a commitment to an ongoing device-based treatment that requires regular refills, periodic clinic visits, and access to a center that can manage hardware complications if they arise.
The dose range — 35 mcg to 1,580 mcg per day — is also notable. The wide range reflects the heterogeneity in PLS severity and the need for individualized titration. A starting dose that controls spasticity adequately for one patient may be far too low for another. This is consistent with the broader ITB literature and reinforces that dose titration in PLS should be gradual and guided by clinical response rather than a fixed protocol.
Limitations
Five patients is a very small sample, and retrospective chart review is subject to documentation variability. There is no control group, no standardized prospective assessment protocol, and no long-term quantitative functional data beyond Ashworth scores. The study cannot tell us what happened to PLS patients at this center who were considered for ITB but not implanted, or how the outcomes compare to continued oral therapy.
That said, the study does what it sets out to do: confirm feasibility and document real outcomes in a PLS population over a meaningful follow-up period. It is the kind of evidence that fills a gap in the absence of larger, more rigorous studies — and given how rarely PLS-specific procedural data are published, it occupies an important position in the evidence hierarchy for ITB decision-making in PLS.
How this connects
This study is the PLS-specific anchor in the ITB evidence chain. For the broader long-term data on what ITB looks like over four years in a mixed spasticity population, the Spinal Cord 2004 study provides that context. For understanding how cortical-origin spasticity (which PLS has) compares to spinal spasticity in ITB management, see the 2010 comparative analysis. The full spasticity evidence landscape is summarized on the Spasticity Research hub.
Citation
Zubair AS, Raymond M, Patwa HS. Clinical short communication: utility of intrathecal baclofen pump in primary lateral sclerosis. Journal of the Neurological Sciences. 2021;420:117227. doi:10.1016/j.jns.2020.117227.