http://mscare.com/a0112/page_02.htm
December 2001
International Journal of MS Care
page 2, Volume 3, Issue 4
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
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 cerebral1,2 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:
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.
| Goals identified | No. |
| Improve transfers | 9 |
| Relieve pain | 8 |
| Improve sitting | 6 |
| Use standing equipment | 4 |
| Improve perineal access | 3 |
| Improve sleep | 2 |
| Reduce systemic toxicity | 1 |
| Improve scoliosis | 1 |
| Total | 34 |
Table 1. Type and Number of Goals Relating to Spasticity
Management.
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.
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.
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.
| Postoperative complications | No. |
| Transient fever | 11 |
| Excessive weakness | 5 |
| Headache | 4 |
| Drowsiness | 3 |
| Respiratory depression | 3 |
| Lumbar wound complications | 2 |
| Abdominal wound complications | 2 |
| Neck stiffness and pain | 2 |
| Other | 8 |
| Total | 34 |
Table 2. Type and Number of Postoperative Complications
and Medical Side Effects.
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).
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Table 3. Algorithm for using ITB in the management
of severe spasticity.
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 documented5, 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.
References