Gross motor function measure (GMFM‐66) trajectories in children recovering after severe acquired brain injury

Rehabilitation is a complex process requiring a dynamic and, if necessary, constantly adjusting process of support. As Kelly et al. point out, the requirement for rehabilitation following acquired brain injury (ABI) is increasing within populations and remains a significant cause of childhood disability. Measuring outcomes of rehabilitation has always been problematic. Randomized controlled trials are not ethically possible. Individual children will have innate abilities to recover from injury, dependent upon as yet mostly undiscovered genetic potentials, which theoretically can enhance or be detrimental to plasticity as the injured brain attempts to restore its functionality. There is agreement within the literature that rehabilitation contributes to recovery. This is best summarized by Overman et al. who concluded that ‘for moderate and severe brain injury there was strong evidence of benefit from formal intervention’. They also noted: ‘for patients with moderate to severe acquired brain injury. already in rehabilitation, there was “strong” evidence that more intensive programmes are associated with earlier functional gains, and “moderate” evidence that continued outpatient therapy could help to sustain gains made in early postacute rehabilitation’. From their own work studying plasticity in the recovering brain they concluded: ‘Activity-, experience-, and injury-dependent plasticity alter neuronal network function and behavioral output, and in the case of brain injury, may produce neurological recovery’. In children, age is also an important factor. Kelly et al. note that: ‘younger age at injury was associated with slower recovery’. The follow-up of the study is short as is appropriate for the goals the paper had set. Other literature looks at longer time periods particularly with a view to adult employment. The goal of all rehabilitation is to restore the maximum functional potential in all aspects of brain functioning and, as far as is possible, put the child’s developmental trajectory as close to its original course as is possible. Adult employment is, therefore, a logical proxy for the success or not of this endeavour. In a paper by Asikainen et al. the main outcome measures were functional outcome, measured by the Glasgow Outcome Scale (GOS), the educational level reached, and postinjury occupation, as well as the incapacity for work at the end of follow-up. In the severe category of brain injuries, children aged 7 years or younger at the time of injury suffered severe disability as measured by the GOS scores more often than did the older age groups (p=0.010, v). They were less often capable of independent employment (p=0.011, v) than the children injured at the age of 8 to 16 years. In another study by Koskiniemi et al. of 39 children who experienced a brain injury during the pre-school years, nine were capable of full-time employment as adults. It seems to make sense, therefore, to strive to engage all children in rehabilitation following ABI. The loss of significant numbers of children with brain injury to the employable adult population not only removes their ability to contribute to the economy but also creates care costs that the state, at present, is accepting responsibility for. These costs are significant. Turner-Stokes et al. comment that ‘the balance between intensity and cost-effectiveness has yet to be determined’. This comment is echoed by the Royal College of Physicians and the British Society of Rehabilitation Medicine joint report who state that ‘more work is required, in particular with respect to demonstrating cost effectiveness and identifying those patients most likely to benefit’. There is still very little literature to help with this calculation in either adult or paediatric populations. In the United States the acute care and rehabilitation median costs were $5233 per child, $11 478 for hospitalized children, and $230 for those only seen in the emergency department. Expanded to the entire population of the United States, the estimates for the average lifetime costs of care for a person with severe traumatic brain injury in all ages range from $600 000 to $1 875 000. The paper by Kelly et al., therefore, contributes to this overall picture by showing how we can use an established tool (the GMFM-66) combined with a statistical model to show change over time with remarkable accuracy. Their comment that ‘the shape of recovery trajectories may give insights into the biology of recovery’ is, to my mind, exciting. If this methodology is shown to be repeatable in other studies of ABI it gives us a tool where a validated activitylevel outcome measure can be used to evaluate and compare rehabilitation interventions aiming to restore function. Randomized controlled trials of rehabilitation in its totality are not possible, but this methodology potentially creates a way of introducing targeted interventions without proven value in a randomized way and measuring their efficacy in terms of changes in recovery trajectories, both for populations and individuals. Finally it is important, in my opinion, to remember that rehabilitation and the recovery process from ABI is a complex process with a large number of variables coming