The study carried out by Bodimeade et al. is of great scientific interest since it highlights executive dysfunction as a central focus of neuropsychological disorders in children with cerebral palsy (CP). The results are also important in that they are based on a more comprehensive cognitive assessment of executive function than proposed in previous studies. In addition, data are derived from an accurate psychological reference framework of executive function adapted to the paediatric population, which provides a consistent approach to the understanding of the disease.
Within the context of this study, executive function disorders in children with CP appear particularly marked and diffuse, since all investigated executive function is disrupted. Besides providing precious clinical information that may help anticipate executive function impairment, the results indicate that the risk of executive dysfunction in children with CP is probably high and potentially frequent, if not symptomatic. Despite this, the data do not prejudge the inter-individual variability of patients' profiles and one has to be careful not to overgeneralize group effects to all individual cases.
This notwithstanding, the clinical implications of this study are decisive, both in terms of identification and recognition of neuropsychological complications following early CP, as well as their potential impact on learning abilities. These issues are critical for patients and their families, but also for teachers and caregivers who support them day-to-day. Clinical challenges also include the patients' professional future and their social integration, as executive function is a key factor for success in these areas. It follows from the above-mentioned considerations that a systematic neuropsychological examination has to be proposed for children with CP, paying particular attention to executive function.
From a theoretical perspective, the current study reinforces the early brain vulnerability hypothesis, which might be particularly pronounced for executive function as evidenced by a recent study from a sample of 164 children who sustained early brain injury. Impairment across all aspects of executive function was found in these children (i.e. attentional control, cognitive flexibility/working memory, goal setting, and processing speed) and can be compared with the severity and extent of executive disorders observed in children with CP from Bodimeade et al.'s research. Taken together, those results further support the hypothesis that the specific protracted development of executive function from infancy to late adolescence represents a significant risk factor for disruption after brain injury, as those brain skills are emerging or partially developed.
Essential work remains to be done in order to refine the dysexecutive symptomatology within the broader neuropsychological phenotype linked to CP in children. Several issues and perspectives are worth mentioning, in addition to replication of the results with a larger clinical sample using such an exhaustive assessment. For instance, the relationship between executive function and intelligence in children with CP needs to be examined more accurately, with the correlation found in Bodimeade et al.'s study supporting the idea that they are highly interrelated. However, only an abbreviated assessment of IQ was proposed in this study; in addition, the correlation reflects a concomitant impairment more than a specific relationship. Patients demonstrated a strong decline in IQ compared with control children, which could also be partially linked to the ‘basic skills’ deficits (e.g. verbal and visuospatial abilities) potentially responsible for the weakening of executive tasks. Insofar as basic skills were not thoroughly controlled for, the specificity of executive dysfunction has yet to be discovered, as well as its links with several aspects of IQ in this clinical population.
Another focus of investigation relates to the cerebral origin of executive function impairment in children with CP. Executive function profile could be influenced by different kinds of brain abnormalities, such as parieto-occipital periventricular haemorrhagic infarction or white matter reduction. In addition, some results showed that bilateral lesions compared with unilateral lesions, or right unilateral sided lesions compared with left ones, were associated with poorer executive function performance, which was not found in Bodimeade et al.'s study. Though the prevalent hypothesis is that executive function impairment is independent of lesion location in the context of early brain lesions, this issue is still to be examined in CP. According to other researchers, differential dysexecutive symptoms could depend on specific prefrontal area lesions.
Moreover, it remains essential to better understand the impact of executive function impairment on the daily life of children with CP and their families, as data are still too limited (a single study used a questionnaire focused on teachers' points of view). Similarly, Bodimeade et al.'s examination of executive dysfunction exclusively concerns the cognitive dimension, leaving unanswered the question of whether ‘hot’ aspects of executive function are impaired. Taking into account the social adjustment problems in children with CP and social behavior disorders after early brain lesions,[7, 10] further investigation of these aspects as well as their relationships with the so-called ‘cool’ executive function is to be encouraged. In order to understand the long-term effect of executive function impairment and its potential progressive greater impact on daily life (as a consequence of higher environmental and societal requirements), longitudinal follow-up will be a key issue.