Multidimensional outcome assessment in cerebral palsy: is it feasible and relevant?

Follow-up of walking quality after end of growth in 28 children with bilateral cerebral palsy

PURPOSE

Assessment of surgical treatments on gait in patients with bilateral cerebral palsy (CP) is often performed in short-term studies. The purpose of this study was to analyze the influence of single-event multilevel surgery (SEMLS) on long-term evolution of gait using gait deviation index (GDI) and walking speed.

METHODS

In all, 28 patients with bilateral CP (Gross Motor Function Classification System I to III) with two clinical gait analyses (CGA) were included (mean age: 9.0 years (sd 2.9) at the first CGA, 19.6 years (sd 4.1) at the last, all of them at skeletal maturity). GDI, walking speed and their changes were calculated. Statistical analysis was performed to observe differences between baseline and follow-up CGA. Pearson's correlations were conducted to evaluate the associations between GDI and walking speed changes with: GDI at baseline and walking speed at baseline. GDI and walking speed evolution have been analyzed for two groups of patients: with and without SEMLS.

RESULTS

Regardless of the treatment, GDI was significantly higher at follow-up CGA (baseline: 73.1 (sd 13.1) versus follow-up: 80.1 (sd 13.2); p = 0.014). Significant negative correlations were found between GDI change and GDI at baseline (r = -0.52; p = 0.004) and between walking speed change and walking speed at the baseline (r = -0.70; p < 0.001). Regarding the group of patients with or without SEMLS, only significant improvement of GDI was found for patients with SEMLS (at baseline: 69.0 (sd 12.1) versus follow-up: 77.8 (sd 11.2); p < 0.05).

CONCLUSION

Analysis at skeletal maturity showed a gait quality maintained for patients without SEMLS and an improvement for patients with SEMLS.

LEVEL OF EVIDENCE

Level III.

Variability explained by strength, body composition and gait impairment in activity and participation measures for children with cerebral palsy: a multicentre study

Objective:

To determine the amount of variability in scores on activity and participation measures used to assess ambulatory individuals with cerebral palsy explained by strength, body composition, gait impairment and participant characteristics.

Design:

Multicentre prospective cross-sectional study.

Setting:

Seven paediatric–orthopaedic specialty hospitals.

Participants:

Three hundred and seventy-seven ambulatory individuals (241 males, 136 females) with cerebral palsy, Gross Motor Function Classification System (GMFCS) levels I–III (I = 148, II = 153, III = 76), ages 8–18 years (mean 12 years 9 months, SD 2 years 8 months).

Methods:

Participants completed assessments of GMFCS level, patient history, lower extremity muscle strength, Gross Motor Function Measure (GMFM-66), Pediatric Outcomes Data Collection Instrument (PODCI), instrumented gait analysis, 1 minute walk test, Timed Up-and-Go and body composition. Multiple linear regression and bootstrap analyses were performed for each outcome measure, stratified by GMFCS level.

Results:

The amount of variability in outcome measures explained by participant characteristics, strength, and gait impairment ranged from 11% to 50%. Gait impairment was the most common predictor variable and frequently explained the greatest variance across all outcome measures and GMFCS levels. As gait impairment increased, scores on outcome measures decreased. Strength findings were inconsistent and not a primary factor. Body composition contributed minimally (<4%) in explaining variability. Participant characteristics (cerebral palsy type, gestational age and age at walking onset), were significant predictor variables in several models.

Conclusions:

Variability in outcome measure scores is multifaceted and only partially explained by strength and gait impairment illustrating the challenges of attempting to explain variation within this heterogeneous population. Clinicians treating individuals with cerebral palsy should consider this when developing treatment paradigms.

Repeatability and validation of gait deviation index in children: typically developing and cerebral palsy

The Gait Deviation Index (GDI) is a dimensionless parameter that evaluates the deviation of kinematic gait from a control database. The GDI can be used to stratify gait pathology in children with cerebral palsy (CP). In this paper the repeatability and uncertainty of the GDI were evaluated. The Correlation between the GDI and the Gross Motor Function Classification System (GMFCS) was studied for different groups of children with CP (hemiplegia, diplegia, triplegia and quadriplegia). Forty-nine, typically developing children (TD) formed our database. A retrospective study was conducted on our 3D gait data and clinical exams and 134 spastic children were included. Sixteen TD children completed the gait analysis twice to evaluate the repeatability of the GDI (test-retest evaluation). Monte Carlo simulations were applied for all groups (TD and children with CP) in order to evaluate the propagation of errors stemming from kinematics. The repeatability coefficient (2SD of test-retest differences), obtained on the GDI for the 16 TD children (32 lower limbs) was ± 10. Monte Carlo simulations showed an uncertainty ranging between 0.8 and 1.3 for TD children and all groups with CP. The Spearman Rank correlation showed a moderate correlation between the GDI and the GMFCS (r=-0.44, p<0.0001).

Management of children with ambulatory cerebral palsy: an evidence-based review. Commentary by Hugh Williamson Gait Laboratory staff

The evaluation of complex interventions, such as Single Event Multilevel Surgery (SEMLS) requires more than randomized controlled trials. Rehabilitation following SEMLS is prolonged and the outcomes of interest may not be apparent for 5 years or more after the surgery. We suggest long term, prospective cohort studies with objective outcome measures be recognized as of equal importance to randomized controlled trials. The evidence in support of instrumented gait analysis (IGA) is also reviewed. We suggest that clinical levels of evidence are not an appropriate method to evaluate a measurement tool. Specifically, IGA should be evaluated in terms of validity, reliability and cost effectiveness. We demonstrate that the use of IGA has improved medium and long term outcomes in ambulant children with cerebral palsy in a center where IGA has been used routinely both for planning SEMLS and for monitoring outcomes.

Comparison of the prevalence and impact of health problems of pre-school children with and without cerebral palsy

BACKGROUND

The range of health problems associated with children with cerebral palsy (CP) is well documented in the literature; however, the existing data are often either reported for samples of children with all types of CP, or stratified by typology of motor disorder, rather than using the Gross Motor Function Classification System (GMFCS), which has been shown to be the most reliable way of classifying children with CP. Furthermore, availability of research on pre-school-aged children (under 5 years) is sparse. The aim of this study is to compare the prevalence and impact of health problems in pre-school children with and without CP, stratified by the GMFCS.

METHODS

Parents of 430 pre-school-aged children with CP (243 boys, 187 girls; mean age = 3 years 2 months, SD = 11 months) and 107 typically developing (TD) children (56 boys, 51 girls; mean age = 3 years 4 months, SD = 11 months) participated. Using the consensus definition of CP and the World Health Organization's International Classification of Functioning, Disability and Health, a parent survey was developed to assess the prevalence and impact of 16 health problems. The measure demonstrates good test-retest reliability (ICC > 0.80) and discriminant validity across GMFCS levels (P < 0.001).

RESULTS

Both the prevalence and impact of health problems is greater in children with CP compared with TD children (P < 0.001). The number and impact of health problems increase with ascending GMFCS level (P ≤ 0.01), except for the impact of health problems between groups GMFCS I and GMFCS II/III (P= 0.19). Children with CP have an average of between 3.4 and 6.7 health problems, compared with fewer than one in TD children.

CONCLUSIONS

Service providers working with pre-school-aged children with CP need to consider health problems and their impact when planning care.