Louise Jarrett, RGN, BA; Siobhan M. Leary, MRCP; Bernadette Porter, RGN; Davina Richardson, BSc, MSc, CSP; Tiziana Rosso, MD; Michael Powell, FRCS; and Alan J. Thompson, MD, FRCP

Louise Jarrett is a Spasticity Management Clinical Nurse Specialist, National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London, United Kingdom. Siobhan M. Leary is a Research Fellow, Institute of Neurology, Queen Square, London, United Kingdom. Bernadette Porter is a Multiple Sclerosis Clinical Nurse Specialist, National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London, United Kingdom. Davina Richardson is a Clinical Physiotherapy Specialist, National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London, United Kingdom. Tiziana Rosso was a Visiting Research Fellow, Institute of Neurology, Queen Square, London, United Kingdom, at the time this paper was prepared. Dr. Rosso is now at Servizio di Neurologia ad indirizzo Riabilitativo, Dipartimento di Scienze Neurologiche e della Visione, Universita’ degli Studi di Verona, Italy. Michael Powell is a Consultant Neurosurgeon, National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London, United Kingdom. Alan J. Thompson is a Professor of Clinical Neurology and Neurorehabilitation, Institute of Neurology, Queen Square, London, United Kingdom.

Abstract

The effectiveness of intrathecal baclofen therapy (ITB) in the management of severe spasticity in people with multiple sclerosis (MS) was reviewed retrospectively. The multidisciplinary team reviewed the medical, therapy, and nursing notes of 19 people with MS who were treated with ITB. The audited information included surgical procedures, postoperative complications, medical side effects, dose requirements, and multidisciplinary input.

Seventeen people were included in the audit. A total of 23 problems and 34 functional goals as objects for ITB treatment were recorded. Eighty-seven percent of the patients had sustained improvement in at least one problem, and 79% in at least one goal. Only two patients had no sustained improvement in any problem or goal. These results suggest that ITB can be an effective intervention in people with severe spasticity in MS. However, this approach requires careful patient selection, a dynamic goal-oriented approach, expert implantation, and ongoing evaluation of individual responses to treatment over time.

Suggested citation: Managing Spasticity in People With Multiple Sclerosis: A Goal-Oriented Approach to Intrathecal Baclofen Therapy. Jarrett, L et al. Int J MS Care [Serial on-line]. December 2001;3(4).

Intrathecal baclofen (ITB) is an effective treatment option in the management of severe spasticity of either cerebral^1,2 or spinal origin,^3,4 and benefit is sustained over a period of time.^5,6 The use of ITB, however, is not without risk. To assure that complications are minimized while therapeutic benefit is maximized, a coordinated approach by an experienced team including a neurologist, a neurosurgeon, physiotherapists, nurses, and occupational therapists is advisable.^7,8

Baclofen (Lioresal^®) acts by binding to gamma-aminobutyric acid (GABA) receptors. It has a presynaptic inhibitory effect on the release of excitatory neurotransmitters.⁹ Postsynaptically it decreases the firing of motor neurons.¹⁰ This results in inhibition of monosynaptic and polysynaptic spinal reflexes,¹¹ with associated reductions in spasm, clonus, and pain. Delivering baclofen intrathecally accentuates its antispasticity effect while minimizing the troublesome systemic side effects associated with oral intake.

Baclofen can be administered intrathecally via a subcutaneously implanted electronic pump with a reservoir and a catheter (SynchroMed Infusion System, Medtronic Ltd.) with the tip placed at L2/L3 or higher. This system is externally programmed using a computer and telemetry, allowing different dose regimes to be delivered. A 24-hour dose can have up to 10 steps, each prescribing the dose, rate, and duration, allowing the delivery of complex regimes. The two pumps currently available are of identical diameter (70.4 mm) and battery life (five to seven years) but differ in reservoir size (10 mL and 18 mL). It should be noted, however, that our recommendations are based on our experience with previous models, which had a battery life of three to five years.

This paper is a retrospective audit of one unit’s experience of using ITB during a five-year period. It provides evidence of efficacy as recorded in clinical practice, demonstrating the need for a comprehensive, multidisciplinary management strategy, incorporating clearly defined goals and responsive to changing clinical needs.

Methods

The medical, therapy, and nursing notes were retrospectively reviewed for 19 people with MS who had ITB pumps implanted for management of severe spasticity. The review panel consisted of two neurologists, two nurse specialists, and one physiotherapist involved in the subjects’ care. The problems and goals agreed upon before treatment were identified from the notes for each individual. Problems related to impairment or symptoms, such as spasms. Goals—which had been set from the patient perspective and had to be realistic and potentially achievable—concerned improvement of function or comfort, such as improved sitting posture. To evaluate treatment outcome, the sustained improvement in the problems and the level of achievement of the goals over time were identified and graded by the multidisciplinary team. Achievement had to last for at least three months. The following grading system was used: nil (not improved or achieved), mild, moderate, or marked improvement or achievement. Transient response was also recorded.

Surgical procedures, postoperative complications, medical side effects, dose requirements, and multidisciplinary involvement were noted. Outcome measures used to assess spasticity were documented, but these varied during the five years, making comparison difficult. Therefore, they were not included in the data.

Surgical Technique

Certain aspects of the surgical technique were modified to make the procedure more effective. These include where the Touhy needle is inserted and the position of both the lumbar and abdominal incisions. Current practice is summarized as follows:

• The body of the patient is flexed and placed in the lateral position with the upper arm elevated on an arm support, thus exposing the abdomen for the pump placement, but also ensuring the true upright position. This eases the insertion of the lumbar catheter.
• A 4- to 5-cm horizontal incision over the area of lumbar vertebrae 3 and 4 has proved sufficient. Therefore, a longitudinal incision has been abandoned, because it makes it more difficult to secure the catheter.
• The Touhy needle (SIMS Portex Ltd, Kent, UK) is inserted off the midline to pass through the muscle of erector spinae rather than through the interspinous ligament. This reduces cerebrospinal fluid (CSF) from flowing back, perhaps because the muscle makes a more permanent seal.
• The needle is passed directly through to the CSF rather than using the standard air injection method. Once the dura is penetrated and clear CSF flow is demonstrated, the stylet of the needle is replaced to minimize leakage.
• The catheter is inserted with the guidewire cephalad to about 10 cm or between the third and fourth marks. If it will not pass initially, the needle is withdrawn a few millimeters, which usually unblocks the tip opening, although CSF flow must be reconfirmed. First the needle, then the guidewire, are removed, the latter by holding the catheter at the entry point to the spine and pulling the guidewire at the loose end. A curved channel is the best way to anchor the catheter as this takes strain off the entry point and directs the catheter toward the pump.
• The abdominal pocket is fashioned at the same time by a second surgeon, either in the left or right abdominal quadrant. An oblique 10- to 12-cm incision is sufficient. This prevents producing a relatively avascular flap and avoids an incision line that lies over the pump itself. Both of these modifications can aid in reducing infection. The pocket is then fashioned medial to this incision. A dummy pump is useful for determining the correct size.
• While the first surgeon is still at work creating the anchorage for the catheter, the pocket can be packed with a povidone-iodine–soaked swab both to minimize oozing and reduce infection.
• Any tunneling device can be used to connect the two incisions. Once the pump is prepared, it can be connected to the suitably shortened catheter, leaving enough slack to allow some movement from subsequent spasms. The pump is inserted with the catheter lying behind it, and the incisions are closed.

Results

Nineteen sets of notes were reviewed: 17 were included in the audit, one patient’s care had been transferred locally, and one patient had died (unrelated to ITB therapy). The review group consisted of six men and 11 women with a mean age of 49 years (range, 38 to 67 years). The mean duration of therapy was 43 months (range, four to 79 months). Twenty-seven pumps (25 electronic, two manual) were implanted; eight were replacements—four due to expiration of batteries and three were due to malfunction (one electronic and two manual). One pump was replaced and relocated onto the other side of the abdomen because of an infection at the pump site. Five catheters were replaced, and one catheter was resutured.

Problems and Goals

Twenty-three problems were identified—10 related to painful spasms, eight to non-painful spasms, four to spasticity, and one to pain not associated with spasticity. Thirty-four treatment goals relating to spasticity management were set (Table 1). The most common goals were improvement of transfers and pain relief.

Sustained improvement to varying degrees was seen in 87% of the problems, with the largest number of patients showing moderate improvement (44%, n = 10) (Figure 1). Although three patients showed no sustained improvement, all three problems demonstrated a transient improvement: moderate in two patients, and marked improvement in the third patient.

Figure 1: Percentage of problems with sustained improvement following ITB therapy.

The patients attained sustained goal achievement in 79% of the goals they had set (Figure 2). Of the 21% of goals for which achievement was not sustained, 15% (n = 5) showed transient achievement: mild, 6% (n = 2); moderate, 3% (n = 1); and marked, 6% (n = 2).

Fifteen patients (88%) had sustained improvement in at least one problem and one goal. Only two patients (12%) had no sustained benefit for any problem or goal.

Figure 2: Percentage of goal achievement following ITB therapy.

Postoperative and Follow-up Complications

Table 2 summarizes the postoperative complications and medical side effects experienced by this group. Transient, low-grade fever was the most common postoperative complication; it tended to resolve in 24 to 48 hours. The main medical side effect is excessive weakness, predominantly truncal. This required frequent dose titration, balancing reduction in tone against exposing underlying weakness to avoid worsening upper body function and wheelchair posture.

Five patients reported weight gain following use of ITB. This has the potential of causing difficulties refilling the reservoir, even when using a template, and on one occasion an x-ray was required to facilitate refilling.

Four radiopaque studies have been carried out to assess the patency of systems demonstrating suboptimal performance. One study was complicated by a baclofen overdose. The person was ventilated overnight until the effects of the baclofen had worn off and subsequently made a complete recovery.

Dose Adjustments

In response to clinical need, from 0 to 10 dose adjustments were required per patient per year. Currently, 12 people are being administered a continuous infusion of a specific dose throughout 24 hours. Five people have a repetitive sequence of between two and four steps. The dose during 24 hours ranges from 3 µg to 625 µg, with a mean of 283.2 µg. The length of time needed to reach an optimal therapeutic dose is extremely variable and is an ongoing process based on the clinical status of the person. Follow-up of individual patients ranged from one to six months, which was dependent upon how well the spasticity/pain was being controlled and the dose and concentration of drug used. In addition, one patient experienced temperature-related changes in tone: during the hot summer months less baclofen was required for spasm control without weakness. This variation is now managed by twice-yearly dose adjustments. Four patients described a "wearing off effect" within one month before requiring a pump refill, which resolved 24 hours after having their pump refilled.

Multidisciplinary Input

Following implantation, 12 patients had their wheelchair posture and seating reassessed and revised. The adjustments improved posture and comfort when sitting. Twelve patients made gains with targeted therapy input as an outpatient, and seven benefited from a focused inpatient rehabilitation admission. Following neurophysiotherapy, four patients used standing equipment who previously had been unable to use it.

Discussion

Intrathecal baclofen is not without complications, but in carefully selected patients it can be an effective treatment for spasticity in MS. To maximize efficacy, it should be only one part of a comprehensive multidisciplinary management strategy that incorporates clearly defined goals that are responsive to changing needs. The key points to consider when using ITB include providing an infrastructure to ensure a coordinated multidisciplinary service, identifying problems and goals to guide patient management, and being alert to any practical difficulties possibly unique to this treatment. The audit demonstrated that a successful ITB service requires collaboration between the patient and a number of health care professionals, including neurologists, neurosurgeons, therapists, and nurses at all four stages of the treatment process: assessment, trial, implant, and ongoing follow-up (Table 3).

Table 3. Algorithm for using ITB in the management of severe spasticity.
STAGE ONE: MULTIDISCIPLINARY ASSESSMENT IN SPASTICITY CLINIC Trial of intrathecal baclofen chosen as treatment option Verbal and written information given to patient by team and ongoing education by Clinical Nurse Specialist-Spasticity Management (CNS-SM) Treatment goals agreed between team members, patient, and if appropriate, caregivers Post clinic CNS-SM telephones patient to answer any further questions, to clarify goals, and to confirm patient’s decision re treatment
YES CNS-SM arranges admission date for trial		NO CNS-SM discusses with consultant and patient
STAGE TWO: TRIAL OF INTRATHECAL BACLOFEN. Day One Admit to designated ward Medical assessment CNS-SM clarifies trial procedure with patient CNS-SM and physiotherapist review spasticity clinic documentation and complete measurement scores
Day Two Review by neurology consultant before proceeding to trial; a positive response needs to be demonstrated on two trial doses To facilitate measurement of response at peak dose (approx. 4 hours) 25 µg of baclofen is administered via lumbar puncture (LP) by the doctor before 1200 Patient remains on bed rest, nurses record regular vital observations and monitor for signs of overdose: drowsiness, weakness in limbs, dizziness/light-headedness, diplopia, nausea/vomiting and depressed respirations CNS-SM and physiotherapist complete measurement scores 4 hours after LP
		If 25 µg causes side effects, discuss future plans/treatment strategies with neurology consultant and patient
		If no adverse effect		Repeat LP with 50 µg Repeat assessment
				No response
RESPONSIVE TO TWO TRIAL DOSES CNS-SM gives further information on implant procedure, clarifies goals of treatment, suggests potential sites for pump, and confirms whether or not patient wants to proceed				Day Four Repeat LP with 75/100 µg Repeat assessment
STAGE THREE: IMPLANTATION OF PUMP Pump implanted under general anesthetic Pump primed and continuous dose commenced Nursing staff observe for signs of overdose as above Medical staff, CNS-SM, physiotherapist, and patient assess response and titrate dose accordingly CNS-SM and physiotherapist repeat outcome measures				NO RESPONSE ITB not suitable. CNS-SM and medical team discuss options with patient
DISCHARGE CNS-SM continues education and ensures patient is aware of contact procedures, the signs of overdose, and underdose CNS-SM organizes refill clinic appointments
STAGE FOUR: ONGOING FOLLOW-UP Regular and ongoing follow-up with neurologist and CNS-SM for spasticity review, dose titration, and reservoir refill Liaison with community therapists or members of primary health care team as appropriate Regular team meetings with the consultant to review long-term management plan

Assessment

Skilled multidisciplinary assessment allows accurate selection of individuals who may benefit from ITB therapy and the identification of achievable goals. Education of patients at each stage is key to informing them about the process and, most important, being clear about what ITB can and cannot achieve. The results show that identifying problems and goals amenable to treatment provides a useful focus for the patient and the multidisciplinary team to assess effectiveness.

Trial

The trial stage is important, as it allows the patient to experience the effect of ITB, and it indicates whether a person will respond to the therapy. However, it does not provide an indication of the appropriate therapeutic dose. This is best achieved by multidisciplinary assessment of response and careful post-implant dose titration.

Implant

A consultant neurosurgeon implanted all the pumps; this led over time to the modification of the surgical technique to optimize the functioning of the implanted system. Although it is usually a straightforward neurosurgical procedure, pump implantation is intricate. Patients with spasticity can be thin and often have unusual fixed deformities, which can lead to neurosurgical complications. These include leaking back of cerebrospinal fluid around the catheter track, damage to or dislodging of the catheter, and infection and breakdown of the abdominal wound. For these reasons, it is suggested that the procedure be carried out by an experienced surgeon. This differs from other common neurosurgical procedures, such as the implantation of lumboperitoneal shunts, for which senior trainees have the lowest complication rate.¹²

Postsurgical complications and catheter problems have been previously documented^{5, 13-16} and were evident in this review. A one-piece new catheter design (rather than a two-piece design) has recently been introduced to try to minimize catheter revisions. It is easier to implant and reduces the need for dye studies to check the patency of systems. Such studies require the pump to be stopped, emptied, and filled with sterile saline. Because such a procedure carries the risk of drug overdose, an inpatient admission is required, adding to the cost of running the service.

Careful consideration needs to be given regarding the size of pump to be implanted. A smaller pump may be preferred in a patient with a low body weight or little muscle bulk, but the relatively small advantages in the dimensions of the pump need to be outweighed against losing 8 mL of reservoir volume, which can mean frequent refilling of the pump. One patient in our review with a 10-mL reservoir required refilling on a monthly cycle. This cannot be counteracted by using a higher concentration of baclofen, as it is not currently available in a stable form above 3,000 µg/mL.

Ongoing Management

Skilled assessment and treatment by a neurophysiotherapist and occupational therapist is pivotal to spasticity management and continues to be so when using ITB. Postural tone and spasticity can be affected by an individual’s position in lying, standing, and sitting. Selecting appropriate physical treatment strategies will help to manage tone and to minimize secondary soft tissue changes. Standing (with or without supportive devices) with good limb and body alignment can help to improve tone.¹⁷ Symmetrical posture and alignment in a wheelchair prevents joints and muscles from becoming fixed in abnormal and often painful positions and can promote functional use of the upper limbs.

Adequate time and personnel to carry out safe, effective follow-up need to be incorporated into delivering an ITB service, without which the benefits of ITB may not be realized. In this audit, monthly refill clinics were run by a neurologist and a nurse practitioner, during which a spasticity management review was completed, the pump refilled, dose adjustments made, and any further education with regard to tone management was discussed. If required, liaison with members of their primary health care team or outpatient therapists helped to maximize an individual’s spasticity management.

Patients who experienced a "wearing off effect" may be sensitive to changes in the stability of baclofen. To prevent this in practice, the pumps of these patients are refilled earlier than indicated by their low reservoir alarm date.

A backup system to respond to emergencies out of hours also needs to be established. One method is to designate a ward where the nursing staff are trained in certain aspects of ITB and have access to detailed protocols. In the event of a complication out of hours they can offer support or put the patient or any member of their primary health care team in contact with a neurologist. A further advantage of this system is that the nurse practitioner (under the supervision of a neurologist) is able to forewarn the ward nurses and doctors of specific patients who are experiencing problems and may require advice or admission outside of normal office hours. This has facilitated smoother admissions into the hospital.

Conclusion

This review of data on 17 patients with MS who use ITB demonstrates that it can be an effective treatment for improving problems relating to spasticity and for achieving specific treatment goals. The service requires a multidisciplinary, coordinated approach during the assessment, selection, implantation phase, and long-term follow-up. A further study to examine the cost implications of this treatment would be timely.

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