Recurrent nonconvulsive status epilepticus in a patient with progressive left hemispheric leukoencephalopathy after a remote viral meningoencephalitis.

Nonconvulsive status epilepticus (NCSE), defined as changes in behavior and/or mental processes from baseline with continuous epileptiform discharges, remains a diagnostic and treatment challenge. Here, we present a 68-year-old female who developed 3 episodes of NCSE 10 years after a viral meningoencephalitis which gradually progressed to left hemispheric leukoencephalopathy. In this case, we hypothesize that immune-mediated mechanisms and perhaps genetic predisposition played a role in epileptogenesis, and these will be discussed. This article is part of a Special Issue entitled "Status Epilepticus".

Genetic linkage analysis of a large family with photoparoxysmal response.

In this study, we report the results of a genetic linkage analysis of a large family with photoparoxysmal response, defined by the presence of a photoparoxysmal response (PPR) on EEG. The participants were genotyped using an 8 cM whole genome wide scan, and both parametric and non-parametric linkage analysis were carried out. The parametric analysis by MLINK did not identify any definite conclusion but a region of interest on chromosome 1 near marker D1S2865; and non-parametric linkage analysis found a locus of interest on chromosome 16, near marker D16S2621. The possible confounding factors for, and pathogenic implication of, and the results are discussed.

Adaptive selection of an incretin gene in Eurasian populations.

Diversities in human physiology have been partially shaped by adaptation to natural environments and changing cultures. Recent genomic analyses have revealed single nucleotide polymorphisms (SNPs) that are associated with adaptations in immune responses, obvious changes in human body forms, or adaptations to extreme climates in select human populations. Here, we report that the human GIP locus was differentially selected among human populations based on the analysis of a nonsynonymous SNP (rs2291725). Comparative and functional analyses showed that the human GIP gene encodes a cryptic glucose-dependent insulinotropic polypeptide (GIP) isoform (GIP55S or GIP55G) that encompasses the SNP and is resistant to serum degradation relative to the known mature GIP peptide. Importantly, we found that GIP55G, which is encoded by the derived allele, exhibits a higher bioactivity compared with GIP55S, which is derived from the ancestral allele. Haplotype structure analysis suggests that the derived allele at rs2291725 arose to dominance in East Asians ∼8100 yr ago due to positive selection. The combined results suggested that rs2291725 represents a functional mutation and may contribute to the population genetics observation. Given that GIP signaling plays a critical role in homeostasis regulation at both the enteroinsular and enteroadipocyte axes, our study highlights the importance of understanding adaptations in energy-balance regulation in the face of the emerging diabetes and obesity epidemics.

Saccadic eye movements and anti-epileptic drugs.

Saccadic eye movements can be used to evaluate different aspects of brain function, and in this article we are concerned with possible applications in relation to anti-epileptic drug treatment. Recent improvements in the technology of measurement have improved the sensitivity and objectivity of the measures. Here we review the neurophysiology of saccades, their classification, their anatomical basis and cortical control, and then published research articles concerned with the influence of anti-epileptic drugs on saccades and their parameters. It seems likely that certain anti-epileptic drugs (especially those acting on ion channels) exert their effect on saccades through ion channels, and this may have relevance to clinical and pharmacogenetic studies.