Abnormal visual habituation in pediatric photosensitive epilepsy

Objective - To investigate visual habituation – a measure of visual cortical excitability – in photosensitive patients in pediatric age and compare the findings with a matched sample with idiopathic generalized epilepsies without photosensitivity and with normally developing children. Methods - We presented a full-field black-and-white checkerboard pattern, at 3 reversal/s with 100% contrast binocularly for 600 consecutive trials and measured the N75–P100 and P100–N145 pattern-reversal visual evoked potential inter-peak amplitudes and N75, P100, N145 latencies for the six blocks of 100 responses. As a measure of habituation we used the slope of the linear regression line of the N75–P100 and P100–N145 peak-to-peak amplitudes. The slope of the linear regression line of the N75–P100 and P100–N145 latencies was also analyzed. Results - Statistical analysis revealed significant differences between the three groups in the slope index of N75–P100 PR-VEP amplitude, with increased or constant amplitude in the PS group compare to the IGE and ND across the six blocks. Conclusions - Our results support the notion that photosensitivity is associated with altered control of excitatory and inhibitory cortical processes. The causal relationship between habituation deficit and photo-paroxysmal response needs to be further investigated with longitudinal studies. Significance This study supports the hypothesis that suppression of PR-VEP is a sensitive intermediate phenotype, which discriminates patients with photosensitivity from those with generalized epilepsies in pediatric age.

Technological challenges of pediatric MEG and potential solutions:the Aston experience

Magnetoencephalography (MEG) offers significant opportunities for the localization and characterization of focal and generalized epilepsies, but its potential has so far not been fully exploited, as the evidence for its effectiveness is still anecdotal. This is particularly true for pediatric epilepsy. MEG recordings on school-age children typically rely on the use of MEG systems that were designed for adults and children's smaller head-size and stature can cause significant problems. Reduced signal-to-noise ratio when recording from smaller heads, increased movement, reduced sensor coverage of anterior temporal regions and incomplete insertion into the MEG helmet can all reduce the quality of data collected from children. We summarize these challenges and suggest some practical solutions.

Clinical significance of medication reconciliation in children admitted to a UK pediatric hospital:observational study of neurosurgical patients

Background: In December 2007, the National Institute for Health and Clinical Excellence and the National Patient Safety Agency in the UK (NICE-NPSA) published guidance that recommends all adults admitted to hospital receive medication reconciliation, usually by pharmacy staff. A costing and report tool was provided indicating a resource requirement of d12.9 million for England per year. Pediatric patients are excluded from this guidance. Objective: To determine the clinical significance of medication reconciliation in children on admission to hospital. Methods: A prospective observational study included pediatric patients admitted to a neurosurgical ward at Birmingham Childrens Hospital, Birmingham, England, between September 2006 and March 2007. Medication reconciliation was conducted by a pharmacist after the admission of each of 100 consecutive eligible patients aged 4 months to 16 years. The clinical significance of prescribing disparities between pre-admission medications and initial admission medication orders was determined by an expert multidisciplinary panel and quantified using an analog scale. The main outcome measure was the clinical signficance of unintentional variations between hospital admission medication orders and physician-prescribed pre-admission medication for repeat (continuing) medications. Results: Initial admission medication orders for children differed from prescribed pre-admission medication in 39%of cases. Half of all resulting prescribing variations in this setting had the potential to cause moderate or severe discomfort or clinical deterioration. These results mirror findings for adults. Conclusions: The introduction of medication reconciliation in children on admission to hospital has the potential to reduce discomfort or clinical deterioration by reducing unintentional changes to repeat prescribed medication. Consequently, there is no justification for the omission of children from the NICENPSA guidance concerning medication reconciliation in hospitals, and costing tools should include pediatric patients. © 2010 Adis Data Information BV. All rights reserved.

Pediatric CNS pathophysiology

Research in pediatric central nervous system pathophysiology is focused around three primary goals: identification of neurodevelopmental disorders, understanding the differences in brain development which underlie these disorders, and improving treatment for these young children. Autism spectrum disorders (ASDs) are a complex set of disorders which are characterized by difficulties in language and social interactions. These behavioral measures are highly variable and a number of underlying causes can generate similar behavioral effects. Therefore, it is important to identify neurophysiological markers to better identify and characterize these disorders. Recent ASD findings using MEG show atypical latency and amplitude responses and poor cortical connectivity in children with ASDs across the cognitive spectrum from basic auditory processing, multisensory integration, to face and semantic processing. These results further support the view that ASDs are a complex neurologically-based disorder. On the other hand, the cause of Down syndrome is well understood as originating from a partial or full replication of chromosome 21. However, the cognitive and neurological consequences of this chromosomal abnormality are not yet well understood. Using a simple observation and motor execution task, poor functional connectivity in sensory-motor areas, particularly in the gamma band range, has been identified in children with Down syndrome and is consistent with behavioral deficits in the sensory-motor realm. Additional studies are needed to better understand whether targeted identification of these abnormalities can facilitate treatment in this disorder. Finally, while epilepsy can be reliably diagnosed, seizure control is still limited in many cases where the seizure onset zone is not readily apparent. Advances in pre-surgical evaluation and intra-operative co-registration will be described. These studies describing pediatric CNS pathophysiology will be discussed. © Springer-Verlag 2010.