Editorial

This issue begins an occasional series of republishing papers of particular interest to paediatric rehabilitation, selected from contemporary or historical sources. The aim is to draw attention to papers of importance and interest that would bene®t a wider audience. We would be pleased to hear from readers with their suggestions. The selected review of the frontal lobes and executive function by Vicky Anderson [1] covers one of the most important areas of development and rehabilitation. The fundamental role of the pre-frontal cortex and related sub-cortical structures to learning and behaviour has been widely reported [2±5]. The integration of frontal lobe functions is essential for goaldirected activity in learning generally and, in particular, in attention [6] and memory [7], self-regulation and inhibitory control, awareness of self and others [8], moral and social reasoning [9], emotional and social behaviour and adjustment [10]. De®cits in frontal lobe functioning are ubiquitous after brain injury in adults and children [11] and may arise directly from insult or indirectly from distant sites or aberrant development. Secondary degeneration and abnormal development of the brain are common late effects in the immature organism [12] and may have direct and indirect effects upon the cognitive and behavioural functions of the brain, but especially the highlevel functions of the frontal lobes. Ciesielski et al. [13] recently reported morphological changes in the mammillary bodies, caudate nuclei and pre-frontal cortices after chemotherapy for childhood leukaemia. Cognitive and behaviour dif®culties are found in children with widely different conditionsÐpre-natal alcohol exposure [14], environmental toxicity [15], non-traumatic coma [16], prematurity [17] and cancer [18, 19]. With increasing survival, more children suffer abnormal neurological development, with progressive impairments, disability and handicap that extend beyond academic learning to include social and emotional development into adulthood. As Eiser [19] notes, there are clear age effects in all such populations, with the poorest outcome for children under 3-years old at the time of insult. This is consistent with the experimental evidence on age and vulnerability and the risk of chronic disability arising from post-insult development [20]. Brain damage primarily affects the ability to learn new information [21], with consequent failure to acquire skills at an age-appropriate rate. Further, age at injury and time since injury interact with the severity of insults so that even mild impairment in learning during infancy and pre-school years may have wide-ranging and long-term implications for the child’s educational performance and progress, and their potential for employment and independent living. Impaired or inef®cient learning results in unstable foundations of development, poor academic progress and achievement, and impaired psychosocial adjustment. Behaviour dif®culties often re ̄ect, at least in part, the child’s inability to understand or cope with underlying cognitive impairments. However, those children with non-verbal learning dif®culties may be at much greater risk of behavioural disturbance and poor psychosocial adjustment [22]. The unique vulnerability of emerging and developing functions does not allow one to assume the future absence of impairment and disability. A clear example of this can be seen in pre-schoolers or the young child’s return to school. Impaired executive function creates a need for an external structure to guide organizing, planning and reasoning. However, the high degree of environmental structure and support in early childhood and school allow children with prefrontal dysfunction to navigate rather well through pre-school and primary school years [23]. As academic and social demands increase in adolescence and early adulthood, so their social and emotional skills, self regulation, reasoning and decision making become paramount Similarly one cannot rely upon a child’s self-awareness of impairment and disability. Awareness will be primarily a function of the age of the child at the time of insult and the subsequent development of pre-frontal functioning. Studies of children with cancer have generally reported normal outcomes for a child’s psychosocial status [24]. However, some problems have been identi®ed and the notion of `normalcy’ does not ®t easily with the clinical consequences of early brain injury. Apajasalo et al. [25] speculated that the perceived high quality of life of long-term survivors of childhood malignancies was at least in part a consequence of denial mechanisms which compensate or even over-compensate for the objectively measurable late effects of child brain injury. Whilst self-concept and self-esteem in survivors of childhood cancer have been widely reported, the parallel concepts of awareness and denial have not been investigated [26]. Further, the child’s cognitive ability to make realistic judgements and the neurological substrates of awareness have not been determined. Thus, it is not known whether the absence of psychiatric disorder, or the normalcy of psychosocial functioning, re ̄ects awareness, lack of insight or pathological denial. The child’s capacity to deal with chronic illness and disability will be reviewed in a forthcoming issue of Pediatric Rehabilitation. For the child who suffers neonatal insult and/or speci®c physical impairment, there are likely to be secondary but very signi®cant compromises in learning, personality development and adaptive responses. Impaired mobility places further restrictions upon action and interaction. For example, exploratory behaviour is an ordered, sequential part of cognitive development that allows the child to gather information about objects and the immediate environment. The child learns to use or apply that information to new situations that he encounters. Absent or limited exploratory activity during early years of development may result in a wide-range of impairments and disabilities, including sensorimotor function, problem-solving and personality. There is increasing recognition of the need to improve outcome and achieve a better quality of life for childhood survivors of illness or injury, but are there likely to be suf®cient resources to meet this range of needs? Early rehabilitation in