Original Research

Long-term Intrathecal Baclofen: Outcomes AfterMore than 10 Years of TreatmentSunjay N. Mathur, MD, Samuel K. Chu, MD, Zack McCormick, MD,George C. Chang Chien, DO, Christina M. Marciniak, MD

S.N.M. Department of Physical Medicine andRehabilitation, Rehabilitation Institute of Chi-cago, McGaw Medical Center, NorthwesternUniversity Feinberg School of Medicine, Chi-cago, ILDisclosures not related to this publication:board membership, travel /accommodation formeetings, American Academy of PhysicalMedicine and Rehabilitation Resident Physi-cian Council and Board of Governors (nomonetary compensation); travel/accommoda-tions/meeting expenses, Rehabilitation Instituteof Chicago (employer) to present at PhysicalMedicine and Rehabilitation conferences;other, American Pain Society - supported byeducational grant from Endo Pharmaceuticals(no monetary compensation), travel to attendan educational course. Endo was not involvedin the manufacture of baclofen or the devicepumps as it relates to this publication

S.K.C. Department of Physical Medicine andRehabilitation, Rehabilitation Institute of Chi-cago, McGaw Medical Center, NorthwesternUniversity Feinberg School of Medicine, Chi-cago, ILDisclosure: nothing to disclose

Z.M. Department of Physical Medicine andRehabilitation, Rehabilitation Institute of Chi-cago, 345 East Superior Street, Room 1610,Chicago, IL. Address correspondence to: Z.M.;e-mail: zmccormick@ric.orgDisclosure: nothing to disclose

G.C.C.C. Department of Physical Medicine

Objective: No study has reported outcomes of intrathecal baclofen (ITB) therapy forspasticity in a cohort of patients who had received this treatment for at least 10 years. Thisstudy explored long-term outcomes of ITB for spasticity management.Design: A cross-sectional survey and retrospective chart review.Setting: An academic rehabilitation outpatient clinic.Participants: Adult patients with spasticity treated with ITB for at least 10 years.Main Outcome Measurements: Surveys included the Brief Pain Inventory, PennSpasm Frequency Scale, Epworth Sleepiness Scale, Fatigue Severity Scale, Diener Satis-faction with Life, Life Satisfaction Questionnaire, and Intrathecal Baclofen Survey.Results: Twenty-four subjects completed the surveys. The subjects had been treated withITB from 10.0-28.4 years, with a mean (standard deviation) of 14.7 � 4.2 years. The mean(standard deviation) dose of ITB was 627.9 � 306.7 mg/d, with only 6 subjects averagingdaily dose changes of more than 10% compared with 3 years earlier. The mean (standarddeviation) scores on outcomes surveys were the following: 2.6 � 2.3 for pain severityon the Brief Pain Inventory, 1.4 � 0.7 for spasm severity on the Penn Spasm FrequencyScale, 7.9 � 5.4 on the Epworth Sleepiness Scale, 4.1 � 1.6 on the Fatigue Severity Scale,19.4 � 8.1 on the Diener Satisfaction with Life, 3.9 � 0.9 on the Life Satisfaction Ques-tionnaire, and 8.8 � 1.9 for overall satisfaction with ITB on the Intrathecal Baclofen Survey.On the Brief Pain Inventory, the mean scores for pain severity and interference of pain withlife showed moderate inverse correlations with ITB dose (r ¼ �0.386, P ¼ .115; andr ¼ �0.447, P ¼ .062, respectively). On the Life Satisfaction Questionnaire, the meanscores for life satisfaction showed statistically significant positive correlation with ITB dose(r ¼ 0.549, P ¼ .021).Conclusions: The subjects reported low levels of pain, moderate levels of life satisfaction,normal levels of sleepiness, low-to-moderate levels of fatigue, infrequent spasms at mild-to-moderate severity, and high levels of satisfaction. The efficacy and favorable adverse effectprofile of ITB therapy was sustained in this cohort of subjects with more than a decade oftreatment.

PM R 2014;-:1-9

and Rehabilitation, Rehabilitation Institute ofChicago; McGaw Medical Center, North- western University Feinberg School of Medi-cine, Chicago, ILDisclosure: nothing to disclose

C.M.M. Department of Physical Medicine andRehabilitation, Rehabilitation Institute of Chi-cago; McGaw Medical Center, NorthwesternUniversity Feinberg School of Medicine, Chi-cago, ILDisclosures not related to this publication:grants/grants pending, Allergan, Ipsen, Merz(money to institution)

The findings of this study were presentedduring the poster session at the AmericanAcademy of Physical Medicine and Rehabili-tation Annual Assembly on November 16,2012 in Atlanta, GA.

Submitted for publication July 19, 2013;accepted December 7, 2013.

INTRODUCTION

Since introduced by Penn and Kroin in 1984 [1], intrathecal baclofen (ITB) has become animportant treatment option for individuals with severe spasticity. When oral antispasticityagents do not adequately achieve control of symptoms without excessive adverse effects,ITB may provide a solution. ITB stimulates g-aminobutyric acidb receptors in the centralnervous system more directly than oral baclofen, which allows the use of smaller drugdoses with predictable infusions rates [2]. Baclofen dosages used with ITB are frequently100-fold less than the equivalent oral dose, and systemic absorption of baclofen from thesubarachnoid space is minimal [3]. Spasticity, as measured by the Ashworth Scale, as wellas spasm frequency and severity scores, consistently improves after intervention with ITB[2]. ITB has been shown to reduce secondary effects of spasticity, such as pain, contracture,impairments in mobility and activities of daily living [4-6].

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2 Mathur et al LONG-TERM INTRATHECAL BACLOFEN

ITB is delivered through a catheter that is surgicallyimplanted and fluoroscopically guided into the intrathecalspace, typically to the level of the thoracic spine. Thiscatheter is connected to a pump that controls ITB releasefrom a reservoir. ITB pumps are most frequently implantedsubcutaneously into the abdomen and must be easilyaccessible for periodic reservoir refills. Patients must visittheir care providers to periodically refill their pump reservoirand, at some point, replace their ITB pump due to normalbattery depletion.

Most case series that document ITB efficacy andcomplication rates have been limited to patients who havereceived ITB therapy for as little as 1 year and up toapproximately 10 years, with few subjects reported withmore than 10 years of follow-up [7-9]. Campbell et al [10]published a complication rate of 0.48 incidents per recip-ient-year of follow-up. Given patients’ required commitmentand consistency of punctual pump refills and repeated sur-geries for pump placement, it is important to investigate thelong-term durability and safety of ITB therapy because pa-tients are living longer with severe disability [11,12]. To ourknowledge, no study has evaluated such long-term patientsatisfaction, efficacy, and safety of ITB treatment.

In this study, we describe characteristics of ITB therapyin patients who have received this treatment for at least10 years, including dose amounts, dose stability, catheterand pump life, rates of adverse pharmacologic events, theneed for ITB discontinuation, and hardware complications aswell as patient perceptions through measures of spasticity,pain, fatigue, sleepiness, and quality of life.

METHODS

Design

This was a cross-sectional survey study as well as a retro-spective medical record review of patients who received ITBtherapy for 10 or more years. Surveys were prospectivelyadministered by telephone or at the time of subjects’ ITBrefill clinic appointments. This study was approved by aninstitutional review board, and all subjects, or their legalauthorized representative, gave informed consent.

Participants

Patients 18 years of age or older were recruited from a single-site outpatient academic spasticity clinic in a free-standingrehabilitation hospital. Patients were approached duringtheir routine ITB refill clinic visits about their length of ITBtherapy and willingness to participate, regardless of theirdiagnosis and spasticity etiology. Electronic medical recordsalso were queried for diagnostic and billing codes for ITBprogramming and refills to identify patients who met criteriafor inclusion. Clinicians at the study site were surveyed toidentify all patients who had received long-term ITB therapy,

including those patients who had discontinued ITB afterlong-term use. Chart review of patient records identifiedthose who had received ITB pump therapy for a total of10 years or more and who were currently being followed-upat the institution from April 2011 to March 2013. Medicalrecords from subjects’ baclofen pump refill visits and thoseof the device manufacturer were reviewed to verify thelength of ITB therapy; the date(s) of pump and catheterplacements and revisions; current ITB dose; and dose 1, 2,and 3 years before the date of survey.

Patients consented and completed surveys by telephoneor during their routine ITB pump refill clinic appointments.Respective legally authorized representatives gave consent ifthe subjects were unable to provide consent due to cognitiveimpairment. Subjects who were not able to understand theconsent process due to their cognitive impairment and didnot have an authorized representative available for consentwere excluded.

Outcome Measures

The subjects were surveyed regarding their experience withITB by using various standardized questionnaires chosen toassess the effectiveness of the treatment, through pain andspasticity ratings, and potential adverse drug effects bymeasures of sleep, fatigue, and satisfaction with life. A surveywas developed to specifically assess subjects’ perceptionsregarding the long-term use of this treatment.

The following standardized surveys were used in thisstudy:

1. Brief Pain Inventory (BPI). This questionnaire measuresintensity of pain and pain interference, with responsesgraded on a scale from 0-10 [13].

2. Penn Spasm Frequency and Severity Scale (PSFS). Thismeasure combines both a spasm frequency scale (ratedfrom 0-4, with 0 representing no spasms and 4 repre-senting spasms that occurred more than 10 times perhour) and a spasm severity scale, (rated as mild [1],moderate [2], and severe [3]) [2,14].

3. Epworth Sleepiness Scale (ESS). ESS indicates the level ofdaytime sleepiness or sleep propensity in adults. Thequestionnaire solicits the chance that subjects might dozein 8 specific situations on a scale of 0-3, and scores canrange from 0-24 [15,16].

4. Fatigue Severity Scale (FSS). FSS uses a 7-point Likertscale to rate the level of agreement or disagreement for9 statements, and scores are averaged [17].

5. Satisfaction with Life (SWLS). SWLS measures overall lifesatisfaction by using 5 statements rated on a 7-point scale,for a total of 35 points [18,19].

6. Life Satisfaction Questionnaire (LSQ). LSQ measuresglobal life satisfaction as well as satisfaction in specificdomains (leisure, occupation, etc) on a 6-point Likertscale [20].

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In addition, the Intrathecal Baclofen Survey (IBS) wasdeveloped by the authors of this study to help assess im-provements in pain and spasticity, pump and cathetercomplications, and overall satisfaction. “Yes” and “no” re-sponses were requested for questions regarding deviceadjustment, device care, device complications, device use,recommendation to others, and willingness to undergorepeated placement of an ITB pump. Free responses werepermitted and recorded separately. Reduction in pain,reduction in spasticity, and overall satisfaction were recordedon an 11-point numeric scale (Appendix 1). Participantswho were currently receiving ITB therapy and who werecognitively intact completed all surveys. Authorized repre-sentatives for the subjects with cognitive impairment wereasked to respond to the ESS, PSFS, and IBS.

Statistical Analysis

Means and standard deviations (SD) were calculated for thedemographic and questionnaire data given normallydistributed data. The total number of years of ITB therapywas calculated by subtracting the implantation date from thedate that the subjects were surveyed. Patient-years of treat-ment were calculated by summing all years of ITB therapyfor all of the subjects in the study. Pump and catheter lifewere calculated by determining the time between implan-tations. The long-term stability of the ITB daily dose wasevaluated by chart review and by calculating the change indose between the time of the survey and 1, 2, and 3 yearsearlier. We compared BPI, LSQ, SWLS, and PSFS scores forsubjects with spasticity due to spinal versus cortical causes.Individuals with multiple sclerosis, neuromyelitis optica,hereditary spastic paraplegia, or spinal cord injury weregrouped as “spinal.” Those with cerebral palsy, stroke, ortraumatic brain injury were grouped as “cortical,” as previ-ously defined by Saval and Chiodo. [21] A 2-sample t-testwas used to compare the survey results of the spinal andcortical groups. The dose of total daily ITB was correlatedwith BPI, LSQ, SWLS, ESS, FSS, PSFS, and IBS scores byusing Pearson correlation coefficients. Statistical significancewas defined as a P value of less than .05.

Table 1. Patient characteristics and length of treatment

Age, mean (SD) (range), y 44.3 � 12.4 (19.2-75.1)Length of treatment,mean (SD) (range), y

14.7 � 4.2 (10.0-28.4)

No. men 11No. women 13Primary diagnosis, no.Spinal cord injury 9Cerebral palsy 7Traumatic brain injury 3Hereditary spastic paraplegia 1Hypoxic ischemic encephalopathy 1Multiple sclerosis 1Neuromyelitis optica 1Stroke 1

SD ¼ standard deviation.

RESULTS

Records of 191 subjects with ITB were screened for eligi-bility. Thirty-seven subjects on initial review were noted tohave had ITB treatment for 10 or more years. Three subjectswere cognitively impaired, and their authorized representa-tives were unable to be reached to participate in the study.Another 3 subjects were not interested in participating in thestudy. Thirty-one subjects consented. Two subjects wereexcluded because ITB therapy did not reach 10 years uponverification with pump manufacturer data. Five subjectsdid not complete the surveys despite multiple attempts atcontact during scheduled clinic visits and by telephone. No

subjects requested to be withdrawn from the study. All thesubjects had a Medtronic SynchroMed II Pump (MedtronicInc, Minneapolis, MN). Complete records from the devicemanufacturer were obtained for 24 subjects.

Surveys were completed by 24 subjects. Six of thesesubjects were cognitively impaired, and, thus, their respec-tive caregivers completed portions of the questionnaire asdescribed previously. Thirteen of these subjects werewomen, and 11 were men (Table 1). The average age was44.3 years with a range from 19.2-75.1 years. Spinal cordinjury (n ¼ 9) and cerebral palsy (n ¼ 7) were the mostcommon diagnoses. The mean (SD) ITB dose at the time ofthe survey was 627.9 � 306.7 mg/d. Current and previousITB dosing over the prior 3 years to survey are presentedin Table 2. Twenty-four subjects had complete ITB doseinformation for 3 years preceding the date of their survey.Comparing ITB doses from the time of survey to 3 yearsprior, 6 subjects had ITB average daily dose changes of morethan 10%. Of these 6 subjects, 4 had increases in dose and2 had decreases in doses. Of the remaining 18 subjects witha less than 10% change in average daily dose, 15 had lessthan 3% change in dose over the 3-year period (Figure 1).

ITB treatment had been used by the subjects from10.0-28.4 years, with a mean (SD) of 14.7 � 4.2 years. In353.7 patient-years of ITB use, there were a total of 77 pumpplacements, including 53 pump changes, with 24 thatoccurred within 5 years of prior pump implantation(45.2%). The average pump life expectancy was 5.1 years.There were a total of 34 catheter placements, including10 catheter changes, with 3 changes that occurred within5 years of prior catheter implantation (30%), and 1 patientrequired 2 catheter changes. Pumps and catheters wereimplanted by 15 different neurosurgeons.

Survey responses are reported in detail in Table 3. Someoutcome measures did not include data for all participantsdue to incomplete questionnaires. The number of responsesfor each outcome measure is listed in Table 3. On the BPI,typical daily pain was reported by 18 of the 24 subjects, witha “low” mean (SD) score of 3.2 � 2.5. The mean (SD)

Table 2. Baclofen pump information

Total no. ITB pump changes 53No. ITB pump changes within 5 yof previous placement

24 (45.3%)

Average life expectancy of ITB pump, y 5.1Total no. ITB catheter changes 10No. ITB catheter changesper patient-year

0.03

Mean (SD) dose of ITB, mg/dAt date of survey 627.9 � 306.71 y before survey 636.5 � 348.22 y before survey 642.7 � 336.53 y before survey 639.3 � 334.2

ITB ¼ intrathecal baclofen; SD ¼ standard deviation.

4 Mathur et al LONG-TERM INTRATHECAL BACLOFEN

current pain at the time of the survey was 2.6 � 2.6, andpain interference scores, on average, also were low. Painscore quartiles are presented in Figure 2.

Mean (SD) spasm frequency on the PSFS reported was1.1 � 0.9, an average representative of “mild spasmsinduced by stimulation.” The mean (SD) spasm severitywas 1.4 � 0.7, an average representative of “mild intensity.”The subjects reported that ITB resulted in a “large” (mean[SD], 9.4 � 0.9) reduction in the number of spasmsand a “moderate-to-large” reduction in pain (mean [SD],8.0 � 2.4). The mean (SD) sleepiness score on ESS was 7.9� 5.4, an average that indicates a “slight chance of dozing”during various activities. The mean (SD) score on the FSSwas 4.1 � 1.6, an average that indicates a neutral score(neither agreement or disagreement with a range of

Figure 1. Stability of average daily intrathecal baclofen dose.

questions about fatigue that affects various aspects of dailyfunctioning). Mean (SD) satisfaction with life as measured byLSQ was 3.9 � 0.9, in which 4 represents “rather satisfying.”Domain-specific satisfaction scores are shown in Figure 3.SWLS was consistent with LSQ with a mean (SD) score of19.4 � 8.1.

The subjects responded to the IBS that ITB maintenancewas on average (SD) a 0.8 � 1.9 on a scale of 0 (very easy) to10 (very difficult). Twenty-five percent of subjects reporteddifficulty with refilling the pump, 17.4% reported difficultywith making pump adjustments, 30.4% reported becomingphysically comfortable with ITB, 27.3% found mentallyadjusting to ITB challenging, 10.0% had reported problemswith infections of the device hardware, and 40.0% reportedmalfunction or early replacement of the ITB pump or cath-eter. Ninety-six percent of the subjects reported that theywould undergo ITB placement again and would recommendITB therapy to others with similar medical problems. Mean(SD) satisfaction with ITB was “high,” at 8.8 � 1.9, with0 representing very unsatisfied and 10 representing verysatisfied.

Dose correlations with survey responses are shown inTable 4. On the BPI, the mean scores for pain severity andinterference of pain with life showed moderate inverse cor-relations with dose (severity: r ¼ �0.386, P ¼ .115; inter-ference: r ¼ �0.447, P ¼ .062). Mean satisfaction on theLSQ showed a statistically significant positive correlationwith the ITB dose (r ¼ 0.549, P ¼ .021). Mean satisfactionon the SWLS also showed moderate positive correlation withITB dose but did not reach statistical significance (r ¼ 0.454,P ¼ .058). Fatigue on the FSS demonstrated a moderateinverse correlation with dose (r ¼ �0.308, P ¼ .234).

When comparing spinal level versus cortical level pa-thology as a cause of spasticity, there were 12 subjects ineach group. There were 6 subjects in the cortical group whowere cognitively impaired and did not complete the BPI,LSQ, and SWLS. The subjects with a cortical etiology hadsignificantly less pain according to results of the BPIcompared with the subjects with spinal cord injury (a scoreof 1.17 compared with 4.17; P ¼ .0104). No significantdifferences in life satisfaction (LSQ and SWLS) or spasmfrequency or severity (PFPS) were found.

Two subjects were identified who had their ITB pumpsremoved after 16 and 25 years of use due to complications.One subject had déjà vu episodes that persisted despitean extensive neurologic evaluation, including magneticresonance imaging, electroencephalogram, and cerebrospinalfluid testing. The episodes only subsided after ITB dose wasdecreased to a level that was not helpful for spasticitymanagement. The subject subsequently elected to undergopump removal, and the episodes have not recurred in 1 yearof follow-up at the time of this writing. The second subjectunderwent baclofen withdrawal after an infection thatnecessitated ITB pump removal and elected not to have thepump replaced for fear of a repeated occurrence of this

Table 3. Long-term ITB pump survey results

Scale Mean (SD) Yes, no. (%) No, no. (%)

Brief Pain InventoryAverage pain (n ¼ 18) 0-10 3.2 � 2.5Pain at its worst in past 24 h (n ¼ 18) 0-10 3.3 � 3.2Pain at its least in past 24 h (n ¼ 18) 0-10 1.3 � 1.6Pain right now (n ¼ 18) 0-10 2.6 � 2.6Pain severity score* (n ¼ 18) 0-10 2.6 ± 2.3

Last 24 h pain interfered with:General activity (n ¼ 18) 0-10 3.4 � 3.4Mood (n ¼ 18) 0-10 3.3 � 3.3Relations with other people (n ¼ 18) 0-10 2.6 � 2.9Sleep (n ¼ 17) 0-10 3.9 � 3.9Enjoyment of life (n ¼ 18) 0-10 3.7 � 3.6

Pain Interference Scorey (n ¼ 18) 0-10 3.3 ± 3.2Penn Spasm Frequency ScaleSpasm frequency (n ¼ 22) 0-4 1.1 � 0.9Spasm Severity Score (n ¼ 22) 1-3 1.4 � 0.7

Epworth Sleepiness Scale: total score (n ¼ 23) 0-24 7.9 � 5.4Fatigue Severity Scale: average score (n ¼ 17) 1-7 4.1 � 1.6Diener Satisfaction with Life Scale: total score (n ¼ 18) 7-35 19.4 � 8.1Life Satisfaction Questionnaire: average score (n ¼ 17) 1-6 3.9 � 0.9Intrathecal Baclofen SurveyDifficulty keeping ITB pump in goodworking condition (n ¼ 24)

0-10 0.8 � 1.9

Difficulty with:Refilling ITB pump (n ¼ 24) 6 (25.0) 18 (75.0)Making adjustments to ITB pump (n ¼ 23) 4 (17.4) 19 (82.6)Becoming physically comfortably with ITB pump (n ¼ 23) 7 (30.4) 16 (69.6)Mentally adjusting to idea of having a ITB pump (n ¼ 22) 6 (27.3) 16 (72.7)Infection of ITB pump or catheter (n ¼ 10) 1 (10.0) 9 (90.0)Malfunction and/or early replacement of ITBpump and/or catheter (n ¼ 10)

4 (40.0) 6 (60.0)

Extent ITB reduced no. spasms (n ¼ 24) 0-10 9.4 � 0.9Extent ITB reduced level of pain (n ¼ 22) 0-10 8.0 � 2.4Would undergo ITB pump placement again (n ¼ 23) 22 (95.7) 1 (4.3)Would recommend ITB pump to others with spasticityand/or pain (n ¼ 24)

23 (95.8) 1 (4.2)

Overall level of satisfaction with ITB pump (n ¼ 24) 8.8 � 1.9

ITB ¼ intrathecal baclofen.*The pain severity score is calculated by summing best, worst, and average numeric pain score with and current numeric pain score and then dividing this numberby 4.yThe Pain Interference Score is a rating on a scale from 1 to 10 of how much an individual feels that his or her pain interferes with daily functioning.

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problem. The subject tolerated ITB pump removal well,and the subject’s spasticity has been well managed withoral baclofen at the time of this writing.

DISCUSSION

To our knowledge, this is the first study to describe thecharacteristics of subjects who have been treated with ITBfor at least 10 years. In our literature review, we found only 6subjects in other studies who had received ITB for morethan 10 years, with the longest being 13 years [7,8,22].Furthermore, few studies bring attention to patient experi-ences with ITB on activities of daily living [23]. Analysisof our data suggests that long-term ITB therapy continues tobe effective for reducing self-reported spasticity frequency,severity, and associated pain during long-term treatment.Although PSFS scores in our cohort had a mean spasm

frequency score of 1.1, higher than a previously reportedmean (SD) of 0.3 � 0.6 at follow-up of 10-33 months [2],this score indicates “infrequent” spasm frequency and “mild”spasm severity. The subjects reported a large reduction inthe number of spasms and a moderate-to-large reductionin pain associated with each spasm on the IBS. We did notfollow-up physician-recorded Modified Ashworth Scalescores in relation to the ITB dose because the ModifiedAshworth Scale correlates poorly with patient self-report[24,25].

Analysis of the BPI data suggests that long-term ITBtreatment is associated with low levels of current, average,least, and worst daily pain levels. Analysis of our datademonstrated lower pain interference throughout all areastested compared with those previously reported in thesubjects with spinal cord injury [26] and consistent with thecerebral palsy literature, which has found pain to not

Figure 2. Distribution of average pain scores on the Brief PainInventory.

Table 4. ITB dose correlation

Outcome Measure r P Value

BPI (n ¼ 18)Average pain �0.423 .081Pain severity �0.386 .115Pain interference �0.447 .062

LSQ average score (n ¼ 17) 0.549* .021SWLS total score (n ¼ 18) 0.454 .058ESS total score (n ¼ 23) 0.047 .834FSS average score (n ¼ 17) �0.308 .234PSFSSpasm frequency average (n ¼ 22) 0.081 .725Spasms severity average (n ¼ 22) 0.108 .636

Satisfaction with ITB therapy (n ¼ 23) 0.167 .446

ITB ¼ intrathecal baclofen; BPI ¼ Brief Pain Inventory; LSQ ¼ Life SatisfactionQuestionnaire; SWLS¼Diener Satisfaction with Life; ESS¼ Epworth SleepinessScale; FSS ¼ Fatigue Severity Scale; PSFS ¼ Penn Spasm Frequency Scale.*Statistically significant, P < .05.

6 Mathur et al LONG-TERM INTRATHECAL BACLOFEN

significantly interfere with life, as defined by a pain inter-ference rating of less than 5 [27].

Subjective well-being scores on the SWLS showed slightdissatisfaction, with a mean of 17.6, in which a score of20 represents neither satisfied nor dissatisfied [19]. Thisis consistent with prior findings in subjects with a chronicdisease, for example, traumatic brain injury [28]. Life satis-faction scores on the LSQ reflected an overall slight dissat-isfaction, with a mean of 3.7, although subjects’ globalsatisfaction with “life as-a-whole” was “rather satisfying,” witha mean of 4.3. This discrepancy appears to be accountedfor by domain-specific “dissatisfaction,” particularly withoccupation, economy, and sexual life.

The subjects reported a slight increase in sleepiness on theESS, similar to patients with traumatic brain injury [29]. Thegeneral population reports a mean score of 5.9. Individualswith obstructive sleep apnea had an average (SD) score of

Figure 3. Satisfaction with life overall on the Life SatisfactionQuestionnaire.

11.7 � 4.6 [15]. The subjects showed elevated fatigue on theFSS at 4.1 compared with healthy adults, who scored 2.3, butless fatigue compared with subjects with rheumatoid arthritisand multiple sclerosis, who scored a mean of 4.2 and 5.7,respectively [17,30]. Patient satisfaction with long-term ITBtherapy was high. In our cohort, 95.7% of patients stated thatthey would undergo ITB placement again, consistent withother studies [7,23]. Similarly, 95.8% of subjects wouldrecommend ITB therapy to others with spasticity.

There is concern about the development of tolerance withlong-term ITB therapy. Patients who undergo initial ITBplacement require increasing doses over the first 18 monthsof therapy to achieve spasticity control, followed by a periodof dose stabilization [2,9]. Analysis of our data indicatesthat, after subjects had received treatment for a minimum of7 years, ITB dose remained stable and did not consistentlyincrease. A minority of subjects had dose increases by asmuch as 500 mg/d as well as decreases by as much as470 mg/d, with no trend. The majority of patient dosesremained stable.

Pearson correlation analysis demonstrated that higherdoses of ITB were moderately correlated with lower painseverity and interference of pain with life scores on the BPI,higher life satisfaction on the LSQ and SWLS, and less fa-tigue on the FSS. However, ITB dose did not correlate withsleepiness on the ESS. The contradiction between fatigueand sleepiness correlation with dose suggests that furtherstudy is warranted. ITB dose did not correlate or did weaklycorrelate with spasm frequency and severity on the PFPS andsatisfaction with treatment on the IBS. Analysis of these datasuggests that once a given patient is titrated to an optimaldose, he or she should have an equivalent chance of con-trolling spasm frequency and severity as well as finding arelative level of satisfaction with treatment compared withother patients on ITB, regardless of the dose.

Comparison of spinal versus cortical pathology as a causeof spasticity showed that subjects with a cortical etiology had

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significantly lower average pain scores according to resultsof the BPI compared with subjects with a spinal etiology.Discrepant pain scores could be related to differing baselinepain scores between primary conditions (ie, spinal cordinjury versus cerebral palsy), unrelated to ITB therapy. Inaddition, only half of the cortical group completed the BPIdue to cognitive impairment, which may have impacted thecomparison of pain scores between the groups. No signifi-cant differences in life satisfaction on the LSQ and the SWLS,or in spasm frequency or severity on the PFPS were foundwhen comparing these groups.

There were a total of 10 catheter changes in our cohort,equivalent to 0.03 catheter changes per patient-year. Ourfindings contrast with several studies that consistentlydescribe a greater incidence of catheter-related complicationsand changes [7,9,22,23,31]. These prior studies reportedrates of 0.06-0.33 catheter complications per patient-year.Further research is warranted to confirm our finding oflower catheter changes and complications over a long-termtime frame.

With regard to ITB pump life, normal operation of ITBtherapy would presume more pump changes than catheterchanges because the pumps require regular replacementwhen their battery is completely discharged. However,analysis of our data suggests that pump changes are morefrequent than would be expected with battery-life estimates,a possible indicator that pump failure is more common thanpreviously thought. Although this study is limited withoutthe surgical indication for pump removal, it may be useful toinform patients that the need for pump revisions may bemore frequent than simply for routine battery depletion.

ITB requires that patients continue to elect to have thistherapy and undergo repeated surgeries for pump replace-ment to continue therapy. It has been presumed that, ifpatients are willing to undergo repeated operations for atherapy, they are likely to believe that the benefits outweighthe drawbacks. When asked if they would undergo ITBplacement again, most subjects responded in the affirmative,a finding that is consistent with other studies [7,23]. Thissatisfaction rate is particularly notable given the large num-ber of repeated surgeries that were required in our cohort.

This study was limited by a potential selection bias. Giventhat we only included subjects who had received ITB therapyfor a minimum of 10 years, it was expected that this cohortwould likely demonstrate relatively successful outcomescompared with those who chose or were forced to discon-tinue ITB therapy before 10 years. To minimize the chanceof selection bias, we attempted to identify all patients whohad discontinued use after 10 years. We found 2 subjectswho had discontinued use despite long-term treatment andattempted to identify such subjects in several ways. It ispossible that other such subjects may have been lost tofollow-up. However, the fact that abrupt discontinuation ofITB may cause potentially life-threatening complicationsfrom baclofen withdrawal within a few months if patients do

not re-establish medical care somewhere does reduce thepossibility of this particular selection bias. Given the lowlikelihood of loss to follow-up and our experience thatdiscontinuation of ITB usually occurs within a few yearsof initiating treatment, a cohort that chooses to discontinueITB treatment after 10 years of treatment may have valuableinsights about the feasibility of chronic ITB care. In theliterature, it is suggested that complications, physical di-mensions, unmet goals, and the burden of baclofen refills aresome reasons that patients decide that ITB therapy is notsuited to their needs [7,32,33].

CONCLUSIONS

In our cohort of patients who received treatment with ITBfor more than 10 years, low levels of pain and sleepinessas well as high levels of satisfaction with treatment werereported. A relatively stable long-term ITB dose and a lowtotal number of early pump and catheter replacements wereevident. Analysis of these data suggests efficacy and afavorable safety profile for long-term ITB use.

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APPENDIX 1INTRATHECAL BACLOFEN SURVEY

Date of visit: ____/____/______ Subject number: _________mm dd yyyy

Thank you for completing this survey. Your responses will help us understand your satisfaction with intrathecal baclofenover the years. Please answer the questions as best as you can; there are no right or wrong answers. All information will be keptconfidential.Thank you.

1. On average, how much assistance do you currently need to dress your lower body?

0 1 2 3 4 5 6 7Dependent Minimum assistance Completely independent(I need someone to do it all for me.) (I can do it all myself.)

2. On average, how much assistance do you currently need to get in and out of bed?

0 1 2 3 4 5 6 7Dependent Minimum Assistance Completely independent(I need someone to do it all for me.) (I can do it all myself.)

3. Currently, how often would you say your spasms interfere with your leisure or community activities?

0 1 2 3 4 5 6 7 8 9 10Never or rarely Sometimes Always

4. Currently, how often would you say you feel too tired to participate in leisure or community activities?

0 1 2 3 4 5 6 7 8 9 10Never or rarely Sometimes Always

5. Overall, how hard is it for you to keep your intrathecal baclofen pump in good working condition?

0 1 2 3 4 5 6 7 8 9 10Very easy Somewhat easy Very difficult

6. Have you had any of the following difficulties with your intrathecal baclofen pump?a. Refilling the pump Yes Nob. Making adjustments to the pump Yes Noc. Becoming physically comfortable with the pump Yes Nod. Mentally adjusting to the idea of an implanted pump Yes Noe. Infection of pump or catheter Yes Nof. Malfunction or early replacement of pump or catheter Yes Nog. Other difficulties? ___________________________________________

7. Overall, to what extent has the intrathecal baclofen reduced the number of spasms that you have?

0 1 2 3 4 5 6 7 8 9 10No or mild reduction Moderate reduction Large reduction

8. Overall, to what extent has the intrathecal baclofen reduced your level of pain during each spasm?

0 1 2 3 4 5 6 7 8 9 10No or mild reduction Moderate reduction Large reduction

9. Besides any reduction in spasticity and/or pain, please describe other ways that you feel the pump hashelped you? ___________________________________________

10. With your current knowledge and experience with the intrathecal baclofen pump, would you undergo intrathecalbaclofen placement again? Yes No

11. Would you recommend to others with spasticity and/or pain to get an intrathecal baclofen pump? Yes No12. What is your overall level of satisfaction with the intrathecal baclofen pump?

0 1 2 3 4 5 6 7 8 9 10Very unsatisfied Somewhat satisfied Very satisfied

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