To systematically review the effect of intrathecal baclofen pump insertion in children with cerebral palsy (CP) with respect to scoliosis.
A systematic literature search was conducted in PubMed, Embase, Cochrane Library, and Google Scholar databases up to June 2022. The inclusion criteria were as follows: (1) studies with a quantitative study design; (2) studies with a study group of children with CP; (3) studies comparing scoliosis in children with and without an intrathecal baclofen pump; and (4) studies with Cobb’s angle as a parameter.
Of the 183 studies found, four studies, all of which were retrospective comparative studies, met the aforementioned inclusion criteria. All studies were homogeneous (I2=0%, p=0.53) and intrathecal baclofen pump insertion accelerated the progression of scoliosis (standard mean difference=0.27; 95% confidence interval=0.07–0.48).
Intrathecal baclofen pumps have been used to alleviate spasticity in children with CP, thus aiding their daily activities and movements. However, their advantages and disadvantages should be reviewed after sufficient time considering the pumps’ negative effect on the course of scoliosis.
Cerebral palsy (CP) refers to a disorder of movement and posture with “non-progressive, but often changing motor impairment syndromes secondary to lesions or anomalies of the brain, arising in the early stages of its development [
Spastic CP is observed in 70%–80% of patients with CP [
The ITB pump was first devised in the 1980s [
There are no accurate statistical data with regard to the use of ITB in CP. In Vender et al. [
Although there are complications, such as infection, wound dehiscence, cerebrospinal fluid leakage, and overdose or withdrawal symptoms of baclofen, baclofen pump has been used so far to alleviate spasticity. Along with the pump’s effect on spasticity, ITB pump insertion has been shown to reduce the probability of additional orthopedic surgery [
Until now, the ITB-related meta-analysis in CP was limited to the comparison of the influence on spasticity and superiority with rhizotomy rather than on the risk of scoliosis progression [
Regarding the fact that the prevalence of scoliosis in CP patients reaches as high as 76% [
The Preferred Reporting Items for Systematic Review and Meta-Analyses checklist was used in this study (
In a systematic review of the literature, we selected studies that used ITB pumps and analyzed scoliosis in children with CP.
The search was performed using PubMed, Embase, Cochrane Library, and Google Scholar databases from inception to June 2022 using the following keywords: (cerebral palsy) AND (“intrathecal baclofen pump” or “intrathecal baclofen” or “continuous baclofen”) AND (“scoliosis” or “Cobb’s angle”). Abstracts were reviewed to select eligible studies.
The inclusion criteria were as follows:
1) Studies with a quantitative study design
2) Studies with study group of children with CP
3) Studies comparing scoliosis in children with and without ITB pumps
4) Studies with Cobb’s angle as a parameter
Studies comparing the effectiveness of ITB pumps with other procedures or studies comparing its effect on spasticity, not scoliosis, were excluded.
After the search, we documented the details of the selected studies, including patient group, study design, publication year, and results. Among them, four studies compared the extent of scoliosis in children with CP using Cobb’s angle as an objective tool between the two groups, one with an ITB pump and one without an ITB pump [
In case of Lins et al. [
All four studies calculated the annual change in Cobb’s angle to evaluate the speed of scoliosis progression. Both the mean±standard deviation (SD) values were presented in three studies [
The annual change in Cobb’s angle was statistically analyzed to examine the effect of ITB pumps on scoliosis. The heterogeneity of the study was calculated using the I2 test to observe variation across studies. The 95% confidence intervals (CIs) and two-tailed p-values were provided. R metapackage was used for statistical analysis and graphics (
Study selection was performed, as shown in
The total number of patients included in this metaanalysis was 387, which included 181 children with ITB pump insertion (experimental group) and 197 without (control group).
Lins et al. [
Three papers [
In the current meta-analysis of four papers, the mean±SD of annual Cobb’s angle change was used as a parameter for scoliosis progression. Pooled analysis revealed homogeneity (I2=0%, p=0.53) as shown in
A funnel plot analysis is shown in
The four studies [
Until now, the available systematic review of ITB pump in children with CP has focused mainly on whether there is an improvement in spasticity. In 2000, the American Academy for Cerebral Palsy and Developmental Medicine performed a systematic analysis of 17 studies after screening papers from 1956 to March 2000 [
There have been limited studies showing the relationship between spasticity and ITB pump in CP children, but studies on the factors that may affect scoliosis acceleration in CP children are abundant. In children with CP, Willoughby et al. [
Further, in another study by Gu et al. [
The association between ITB pump insertion and scoliosis has not yet been clearly elucidated. In addition, it is unclear how to distinguish between the natural course of scoliosis progression and the effect of the ITB pump. A possible mechanism is that hypotonia caused by baclofen increases instability and worsens scoliosis [
This study has some limitations. In this study, since Cobb’s angle was measured annually in patients with CP who were mainly about to undergo surgery, most of them progressed in the direction of aggravating scoliosis. Since the study was conducted on children with GMFCS levels of 4 or 5 and most of the patients who underwent baclofen pump insertion generally presented poor clinical manifestations, the annual scoliosis progression rate recorded by the Cobb’s angle might have been higher than that in the natural course of the disease. In addition, although a significantly larger number of procedures is currently performed than in the 1980s, the total number of patients who underwent pump procedures in this systematic review was limited to 181 due to the procedure’s invasiveness and the inclusion criteria. Despite these limitations, this systematic analysis is meaningful as it analyzed the effect of ITB pump insertion from a new perspective of scoliosis rather than spasticity, with Cobb’s angle as an objective indicator.
Our study supports the view that ITB pumps may accelerate the rate of scoliosis progression in children with CP. Managing scoliosis is clinically important because it affects the maintenance of a sitting or standing posture, the performance of activities of daily living, and the caregiver burden [
No potential conflict of interest relevant to this article was reported.
None.
Conceptualization: Koh SE. Methodology: Kwon HE. Formal analysis: Hyun C, Woo M. Project administration: Lee S, Koh SE. Visualization: KIM K. Writing - original draft: Lee S. Writing – review and editing: Lee S, KIM K, Koh SE. Approval of final manuscript: all authors.
Supplementary materials can be found via
Flowchart of study selection.
Forest plot of change in annual Cobb’s angle in the intrathecal baclofen pump insertion and control groups. SD, standard deviation; SMD, standardized mean difference; CI, confidence interval.
Funnel plot of estimate of fixed effects model. Diagonal lines refer to lines where 95% of points exist when publication bias is absent.
A summary of the effect of intrathecal baclofen pump insertion on Cobb’s angle
Study | Study design | Sampling | Gross motor function classification system | Group | Group characteristics and follow-up period | Cobb’s angle at presentation, final follow-up, mean annual Cobb’s angle progression | ||
---|---|---|---|---|---|---|---|---|
Lins et al. [ |
Single-center, retrospective review | Patient with cerebral palsy undergoing posterior spinal fusion | 4 and 5 | Pump (n=15) | Age at baseline, yr (p=0.4531) | Cobb’s angle at presentation (p=0.0384) | ||
Control (n=31) | Pump (n=15): 10.2±3.9 | Pump (n=15): 22.0±17.2 | ||||||
Control (n=31): 9.3±3.6 | Control (n=31): 35.1±20.7 | |||||||
Follow-up period, yr | Cobb’s angle at final follow-up (p=0.25) | |||||||
Pump (n=15): 3.1±1.6 | Pump (n=15): 60.0±20.3 | |||||||
Control (n=31): 2.6±1.4 | Control (n=31): 66.7±23.4 | |||||||
Mean annual Cobb’s angle progression (p=0.0346) | ||||||||
Pump (n=15): 14.8±9.1 | ||||||||
Control (n=31): 9.5±6.7 | ||||||||
Walker et al. [ |
Retrospective, case matched review | Cerebral palsy | Level 2 (n=2), level 3 (n=34), level 4 (n=46), level 5 (n=100) | Pump (n=91) | Age at baseline, yr (p<0.001) | Cobb’s angle at presentation (p=0.090) | ||
Control (n=91) | Pump (n=91): 8.75±3.10 | Pump (n=91): 21.4±12.9 | ||||||
Control (n=91): 6.42±2.80 | Control (n=91): 27.1±14.3 | |||||||
Follow-up period, yr (p<0.001) | Cobb’s angle at final follow-up (p=0.498) | |||||||
Pump (n=91): 5.5±2.1 | Pump (n=91): 48.6±24.3 | |||||||
Control (n=91): 7.5±3.2 | Control (n=91): 54.3±31.4 | |||||||
Mean annual Cobb’s angle progression (p=0.05) | ||||||||
Pump (n=91): 6.0±9.9 | ||||||||
Control (n=91): 3.8±4.5 | ||||||||
Rushton et al. [ |
Retrospectively matched cohort study | Quadriplegic spastic cerebral palsy | 5 | Pump (n=25) | Age at baseline, yr (p=0.16) | Cobb’s angle at presentation (p=0.06) | ||
Control (n=25) | Pump (n=25): 9.4±4.2 | Pump (n=25): 25.6±22.4 | ||||||
Control (n=25): 9.2±2.0 | Control (n=25): 29.7±21.9 | |||||||
Follow-up period, yr (p=0.16) | Cobb’s angle at final follow-up (p=0.39) | |||||||
Pump (n=25): 4.3 (1.0–7.8) | Pump (n=25): 76.1±29.8 | |||||||
Control (n=25): 3.5 (1.0–7.5) | Control (n=25): 69.1±29.2 | |||||||
Mean annual Cobb’s angle progression (p=0.72) | ||||||||
Pump (n=25): 13.6±9.1 | ||||||||
Control (n=25): 12.6±7.6 | ||||||||
Shilt et al. [ |
Controlled clinical trial | Cerebral palsy | 4 and 5 | Pump (n=50) | Age at baseline, yr (p=0.15) | Cobb’s angle at presentation (p=0.06) | ||
Control (n=50) | Pump (n=50): 9.8±3.7 | Pump (n=50): 15±13 | ||||||
Control (n=50): 9.7±3.9 | Control (n=50): 13±13 | |||||||
Follow-up period, yr (p=0.56) | Cobb’s angle at final follow-up (p=0.38) | |||||||
Pump (n=50): 2.7±1.4 | Pump (n=50): 28±20 | |||||||
Control (n=50): 3.0±1.6 | Control (n=50): 27±21 | |||||||
Mean annual Cobb’s angle progression (p=0.39) | ||||||||
Pump (n=50): 6.6±11.3 | ||||||||
Control (n=50): 5.0±6.1 |
Values are presented as mean±standard deviation or mean (range).