Troubleshooting Complications of Intrathecal Baclofen Therapy

Special Article – Spasticity Management and Rehabilitation

Phys Med Rehabil Int. 2017; 4(4): 1126.

Troubleshooting Complications of Intrathecal Baclofen Therapy

Stevenson VL1,2*, Keenan E¹ and Jarrett L³

¹National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK

²University College London, Institute of Neurology, London, UK

³Royal Devon and Exeter NHS Foundation Trust, Exeter, UK

*Corresponding author: Valerie Stevenson, Box 113, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK

Received: September 25, 2017; Accepted: October 17, 2017; Published: October 24, 2017

Abstract

Intrathecal baclofen (ITB) is a well-recognised treatment for severe spasticity refractory to oral medications. However it is known to have a significant complication rate with serious potentially fatal consequences of baclofen overdose or withdrawal. It is therefore essential that patients receiving ITB therapy are managed by responsive, accessible multidisciplinary services with a systematic and timely approach to troubleshooting complications when they occur. A troubleshooting algorithm is presented here to facilitate prompt and effective investigations and treatment; this tool can be adapted by individual services to suit their own particular patient cohort and healthcare setting.

Keywords: Intrathecal baclofen; Troubleshooting; Algorithm; Complications; Spasticity

Introduction

Intrathecal baclofen (ITB) was first used in 1985 for spinal cord injury [1] and has since been shown to be an effective treatment in the management of severe spasticity of either cerebral or spinal origin [2-5] and in monophasic or progressive conditions [6,7].

In long-term follow-up studies, the benefit has proved to be sustainable over time [8-11], with many individuals demonstrating high levels of satisfaction and continuing to benefit following a pump replacement once the battery life of the original pump has been depleted.

Use of intrathecal baclofen requires a coordinated approach by an experienced multidisciplinary team including a neurologist or rehabilitation physician, neurosurgeon, physiotherapists, nurses, and occupational therapists. The process involves careful patient selection, detailed assessment including a trial of ITB, implantation and importantly both responsive and accessible follow up as ITB therapy is not without risk of complications. Whenever complications are suspected investigation and treatment should be instigated promptly and in a systematic way [1].

Complication rates of ITB therapy vary between published studies depending on their definition of adverse events, the population studied and the follow up period, rates are however not insignificant and range between 4 and 25%. Complications can be considered as mechanical (ie a hardware issue with the pump or catheter), infection related, drug or procedure related (for example baclofen overdose or deep vein thrombosis). Mechanical complications are the most frequently observed; these usually involve catheter malfunction (disconnection, kinks, breaks or displacement) [13-15]. Pump dysfunction is rare with the use of baclofen but corrosion of the internal tubing causing a motor stall can occur particularly if pumps are used off label with drug mixtures [16]. Data reported from Medtronic through their Implantable Systems Performance Registry on 7,459 patients with pumps (21.6% for intractable spasticity) revealed a total of 1,393 product performance events in 982 patients enrolled (13.17%), 75.7% of these were related to catheter malfunction [17].

Investigation of potential system malfunction

If there is any suspicion of ITB system dysfunction (symptoms of over or under dosage or failure to gain control of spasticity on escalating dosages) it is important to investigate promptly to avoid potentially fatal withdrawal syndromes. There is no agreed consensus on the process used for investigation; previously published algorithms have looked at different aspects including troubleshooting in the outpatient setting, managing ITB withdrawal and overdose as well as extensive investigations of the pump system [18-20].

We present our troubleshooting algorithm illustrated in Figure 1 which is based on the author’s own experience of ITB practice and takes a pragmatic approach ensuring investigation is sufficient to ensure confidence in the need for surgical intervention but also prevents delay in diagnosing mechanical complications. The National Hospital for Neurology and Neurosurgery, University College London Hospitals has been utilising ITB since 1994 (currently 155 patients under ITB pump follow up). The choice of particular investigations and the order they are used will of course be influenced by investigation availability and the particular nuances of the patient concerned. Other investigations not included in our algorithm, such as magnetic resonance imaging (MRI) or radio-isotope scintigraphy [21], are available however on a pragmatic note the demonstration of a non-functioning catheter requires surgical replacement and there is therefore often no need to proceed to extensive investigation and imaging.

Citation: Stevenson VL, Keenan E and Jarrett L. Troubleshooting Complications of Intrathecal Baclofen Therapy. Phys Med Rehabil Int. 2017; 4(4): 1126. ISSN:2471-0377