Despite similar clinical presentation, children with ABI and CP likely have different developmental trajectories, and no study to date has examined the suitability of utilising GMFCS to classify children with ABI as a classification and communication tool. The primary aim of this study was to evaluate the feasibility of GMFCS-ER to classify gross motor function of children with ABI measured by the Gross Motor Function Measure-66 (GMFM-66), the shorter version of GMFM-88. The secondary aim was to identify factors that may influence gross motor recovery from ABI over time.
This was a retrospective study utilising Gross Motor Function Measure-88 (GMFM-88) and GMFCS-ER data routinely collected for all children with ABI aged 5 months to 16 years during first assessement, admitted to an inpatient residential rehabilitation centre in United Kingdom. Only data from children with at least three GMFM-88 assessments and GMFCS-E&R levels were utilised.
Individual item scores from GMFM-88 were converted into GMFM-66 interval scores using the Gross Motor Ability Estimator version II. McNemar’s Chi-square test was applied to evaluate the likelihood of GMFCS-ER reclassification during inpatient residential rehabilitation. Linear correlation between GMFM-66 and GMFCS-ER scores and their changes were compared with Spearman’s rank correlation coefficient. Mean or median GMFM-66 scores were also computed for each GMFCS-ER level to examine if there were distinct GMFM-66 stratifications. Generalised Linear Mixed effects Modelling (GLMM) was undertaken to evaluate factors that may influence gross motor recovery.
The GMFCS-ER levels of 95 children with ABI (age-at-injury range: 0.6-15.7 years) with combined 386 GMFM-88 assessments were utilised and converted to GMFM-66. The GMFCS-ER levels and GMFM-66 scores demonstrated very strong inverse correlation (ρ=-0.90, p0.001), and the change in GMFCS-ER levels were moderately correlated to change in GMFM-66 scores (ρ =-0.66, p0.001). Change in GMFCS-ER levels was demonstrated in 53.7% of children with ABI with very high specific improvement in GMFCS-ER levels towards level I (p0.001). GLMM revealed that aetiology, baseline GMFCS-ER levels, days from ABI event, and if participants were enrolled in inpatient rehabilitation within a year of injury significantly affected overall GMFM-66 scores.
The GMFCS-ER demonstrates potential as a gross motor functional classification tool for children with ABI but unlike for children with CP, should not be used for prognostication due to lack of stability due to prolonged recovery time. Further research is required to tailor and validate both tools for children with ABI before firm clinical recommendations can be made.
This study suggests that GMFCS-ER should only be used as a classification communication tool within that specific time window for children with ABI, and any communication regarding mobility recovery should be interpreted prudently or in conjunction with GMFM-66 scores.
Paediatrics
Acquired Brain Injury
