Working memory and processing speed abilities are related to habituation and change detection in school-aged children: An ERP study

High cognitive performance is related to efficient brain processing while accomplishing complex cognitive tasks. This efficiency is observed through a rapid engagement of the brain regions and the cognitive processes required for task accomplishment. However, it is unclear if this efficiency is also present in basic sensory processes such as habituation and change detection. We recorded EEG with 85 healthy children (51 males) aged between 4 and 13 years old, while they listened to an auditory oddball paradigm. Cognitive functioning was evaluated using the Weschler Intelligence Scales for Children Fifth Edition and the Weschler Preschool & Primary School for Intelligence Fourth Edition. Auditory evoked potentials (AEPs) analyses and repeated measure analysis of covariance as well as regression models were performed. The analysis revealed that P1 and N1 repetition effects were observed across levels of cognitive functioning. Further, working memory abilities were related to repetition suppression on the auditory P2 component amplitude, while faster processing speed was related to repetition enhancement on the N2 component amplitude. Also, Late Discriminative Negativity (LDN) amplitude, a neural correlate of change detection, increased with working memory abilities. Our results confirm that efficient repetition suppression (i.e. greater reduction in amplitudes with greater levels of cognitive functioning) and more sensitive change detection (greater amplitude changes of the LDN) are related to the level of cognitive functioning in healthy children. More specifically, working memory and processing speed abilities are the cognitive domains related to efficient sensory habituation and change detection.

How to interpret high levels of distress when using the Distress Thermometer in the long-term follow-up clinic? A study with Acute Lymphoblastic Leukemia survivors

OBJECTIVES

Recent guidelines recommend to assess emotional distress in pediatric oncology during treatment and in after care. One tool used to do this is the distress thermometer (DT), a simple tool which has almost exclusively been studied in its screening abilities. Given its increased used as a measure of distress per se, it is necessary to document its concurrent validity. The goal of this study was to identify clinical domains (eg, depression, anxiety) and individual symptoms associated with pediatric cancer survivors' rating on the DT.

PARTICIPANTS

To do so we used data collected from 84 young (≤18 years old), and 120 older (>18 years old) survivors who were treated for pediatric leukemia.

METHODS

Participants responded to self-report questionnaires as part of a research visit.

RESULTS

Results from stepwise regressions show that in the younger group, high scores on the thermometer were associated with higher negative affectivity only. In adults, high scores were associated with higher anxiety, higher negative affectivity, and lower positive affectivity. When exploring associations with individual items, we found that the main emotional tone reflected by the thermometer score was anxiety.

CONCLUSIONS

Interpreting ratings on the thermometer should probably focus on anxiety in childhood cancer survivors. This widely used tool also does not measure the same domains in young versus older survivors, so that age groups should be considered separately in future work.

Adverse neuropsychological effects associated with cumulative doses of corticosteroids to treat childhood acute lymphoblastic leukemia: A literature review

Corticosteroids (CS) are an essential component of childhood acute lymphoblastic leukemia treatments (cALL). Although there is evidence that daily doses of CS can have neuropsychological effects, few studies have investigated the role of cumulative doses of CS in short- and long-term neuropsychological effects in cALL. The aims of this review were to identify the measures used for documenting adverse neuropsychological effects (ANEs) of CS treatment and to study the association between cumulative doses of CS and the presence of ANEs. Twenty-two articles met the inclusion criteria. A variety of measures were used to evaluate outcomes in the domains of emotion, behaviour, neurocognition, and fatigue/sleep. The results suggest that we cannot conclude in favour of an association between the cumulative dosage of CS and ANEs. Yet, several factors including the heterogeneity of measures used to evaluate outcomes and reporting biases may limit the scope of the results. We offer several recommendations that could help improve the future published evidence on ANEs in relation to CS treatment in cALL.

Children with a history of atypical febrile seizures show abnormal steady state visual evoked potential brain responses

Atypical febrile seizures (FSs) are considered a risk factor for the onset of epilepsy in later life as well as for potential cognitive impairment. However, distinctive characteristics defining the group of children at risk for negative outcomes are not well established. In the following study, children from 6 to 59 months with a history of atypical FSs were investigated using steady state visual evoked potentials (ssVEP), a brain response known to increase with age. Abnormally, low theta and alpha ssVEP brain responses were found in children with a history of atypical FSs.

Electrophysiological Markers of Visuocortical Development

The development of noninvasive techniques for the assessment of functional brain maturation is critical. The present study analyzed 63 babies' and children's (27 days to 5.5 years) cerebral responses to a pattern-reversal visual stimulation using high-density (128 electrodes) electrophysiological recordings. Developmental data were further compared with those of young adults (n = 16). Tremendous changes in pattern visual evoked potentials (pVEPs) morphology were observed between 7 and 24 months characterized by the emergence of negative components labeled "N70" and "N145" and the reduction of the P100 amplitude. The adult pattern of response appears from 24 months onward. Spectral density values show an increase of higher frequencies with age. Coherence values show a reduction between 3 and 23 months of age as well as a further increase toward adulthood between areas implicated in visual processing. These results are discussed in light of developmental features such as synaptogenesis, myelination, and neuronal networks refinement.

[Neuropsychological profile of intractable partial epilepsies]

The neuropsychological assessment is an essential part of the clinical work-up of patients suffering from pharmaco-resistant epilepsy. The aim of the present article is to give an overview of the assessment with regard to the functions tested, the techniques employed and the factors influencing the interpretation of the results. In the first part of the article, the role of the neuropsychological evaluation is discussed in relation to other methods of clinical investigation, such as EEG, brain imaging techniques and sodium amytal exploration, all of which intend to identify the localization (region and laterality) of the epileptogenic focus. This is particularly important for patients slated for epilepsy surgery. In addition, the neuropsychological exam aims to determine the extent of the deficits in various cognitive and sensori-motor domains by taking into account the structural and/or functional reorganization that may have taken place and the compensatory mechanisms that are available to the patient. In this context, the effect of various factors influencing the mental and emotional functioning of the patient, such as the age at onset and duration of the epilepsy, the presence of a structural lesion, the type and number of anticonvulsant drugs, the personality and the adaptability of the patient must be considered. In children, the effect of recurrent seizures may be more devastating since these risk to interfere with normal brain development. On the other hand, the greater plasticity of the immature brain provides a larger window in which compensation can take place. Evidence suggests that attentional processes are affected in all types of epilepsy. Furthermore, the antiepileptic medication may have a deleterious effect on the cognitive and emotional status of the patient, particularly in patients with pharmaco-resistant epilepsy who are usually taking a combination of anticonvulsant drugs. The second part of the article presents localization-specific neuropsychological impairments and the tests most suited to reveal these deficits. Thus, in temporal lobe epilepsy, memory functions are more affected than in other types of partial epilepsy, whereas intellectual functions are usually preserved. However, recent studies cast some doubt on the prevailing view that left-hemisphere foci are associated with verbal memory deficits only and that right-hemisphere foci solely affect visuo-spatial memory. The dichotomy appears to be more subtle, especially in patients with a long-standing seizure history. Frontal foci produce deficits in motor coordination, attention, working memory and executive functions. These deficits appear to be more pronounced in children than in adults. Few studies have explored the neuropsychological consequences of parieto-occipital foci given that this type of epilepsy is relatively rare. The neuropsychological profile of the patient should guide healthcare providers to implement the necessary remedial measures to facilitate the patient's social integration and to improve his quality of life.