Typical Absence Research Articles

F135. Ictal connectivity in childhood absence epilepsy: Associations with outcome

Introduction The understanding of Childhood Absence Epilepsy (CAE) has been revolutionized over the past decade but the biological mechanisms responsible for variable treatment outcomes are unknown. Our purpose was to determine how pre-treatment ictal network pathways, defined using a combined EEG-functional magnetic resonance imaging (EEG-fMRI) and magnetoencephalography (MEG) effective connectivity analysis, were related to treatment response. Methods Sixteen children with newly diagnosed and drug naive CAE had 31 typical absence seizures during EEG-fMRI and 74 during MEG. The spatial extent of the pre-treatment ictal network was defined using fMRI hemodynamic response with an event related independent component analysis (eICA). This spatially defined pre-treatment ictal network supplied prior information for MEG effective connectivity analysis calculated using phase slope index (PSI). Treatment outcome was assessed 2 years following diagnosis and dichotomized to ethosuximide (ETX) treatment responders (N = 11) or non-responders (N = 5). Effective connectivity of the pre-treatment ictal network was compared to the treatment response. Results Patterns of pre-treatment connectivity demonstrated strongest connections in the thalamus and posterior brain regions (parietal, posterior cingulate, angular gyrus, precuneus, and occipital) at delta frequencies and the frontal cortices at gamma frequencies (p Conclusion Pre-treatment ictal connectivity differences in children with CAE were associated with response to anti-epileptic treatment. This is a possible mechanism for the variable treatment response seen in patients sharing the same epilepsy syndrome.

Ictal connectivity in childhood absence epilepsy: Associations with outcome.

The understanding of childhood absence epilepsy (CAE) has been revolutionized over the past decade, but the biological mechanisms responsible for variable treatment outcomes are unknown. Our purpose in this prospective observational study was to determine how pretreatment ictal network pathways, defined using a combined electroencephalography (EEG)-functional magnetic resonance imaging (EEG-fMRI) and magnetoencephalography (MEG) effective connectivity analysis, were related to treatment response. Sixteen children with newly diagnosed and drug-naive CAE had 31 typical absence seizures during EEG-fMRI and 74 during MEG. The spatial extent of the pretreatment ictal network was defined using fMRI hemodynamic response with an event-related independent component analysis (eICA). This spatially defined pretreatment ictal network supplied prior information for MEG-effective connectivity analysis calculated using phase slope index (PSI). Treatment outcome was assessed 2years following diagnosis and dichotomized to ethosuximide (ETX)-treatment responders (N=11) or nonresponders (N=5). Effective connectivity of the pretreatment ictal network was compared to the treatment response. Patterns of pretreatment connectivity demonstrated strongest connections in the thalamus and posterior brain regions (parietal, posterior cingulate, angular gyrus, precuneus, and occipital) at delta frequencies and the frontal cortices at gamma frequencies (P<.05). ETX treatment nonresponders had pretreatment connectivity, which was decreased in the precuneus region and increased in the frontal cortex compared to ETX responders (P<.05). Pretreatment ictal connectivity differences in children with CAE were associated with response to antiepileptic treatment. This is a possible mechanism for the variable treatment response seen in patients sharing the same epilepsy syndrome.

Italian Wikipedia and epilepsy: An infodemiological study of online information-seeking behavior

Wikipedia is the most commonly accessed source of health information by both healthcare professionals and the lay public worldwide. We aimed to evaluate information-seeking behavior of Internet users searching the Italian Wikipedia for articles related to epilepsy and its treatment.Using Pageviews Analysis, we assessed the total and mean monthly views of articles from the Italian Wikipedia devoted to epilepsy, epileptic syndromes, seizure type, and antiepileptic drugs (AEDs) from January 1, 2015 to October 31, 2017. We compared the views of the article on epilepsy with those of articles focusing on Alzheimer's disease, migraine, multiple sclerosis, syncope, and stroke and adjusted all results for crude disease prevalence.With the only exception of the article on multiple sclerosis, the adjusted views for the Italian Wikipedia article on epilepsy were higher than those for the other neurological disorders. The most viewed articles on seizure type were devoted to tonic–clonic seizure, typical absence seizure, tonic convulsive seizures, and clonic convulsive seizures. The most frequently accessed articles on epilepsy syndromes were about temporal lobe epilepsy and Lennox–Gastaut syndrome. The most frequently viewed articles on AEDs were devoted to valproic acid, carbamazepine, and levetiracetam.Wikipedia searches seem to mirror patients' fears and worries about epilepsy more than its actual epidemiology. The ultimate reasons for searching online remain unknown. Epileptologists and epilepsy scientific societies should make greater efforts to work jointly with Wikipedia to convey more accurate and up-to-date information about epilepsy.

Resolving the host galaxy of a distant blazar with LBT/LUCI 1 + ARGOS

BL Lac objects emitting in the Very High Energy (VHE) regime are unique tools to peer into the properties of the Extragalactic Background Light (EBL). However, due to the typical absence of features in their spectra, the determination of their redshifts has proven challenging. In this work we exploit the superb spatial resolution delivered by the new Advanced Rayleigh guided Ground layer adaptive Optics System (ARGOS) at the Large Binocular Telescope to detect the host galaxy of HESS J1943+213, a VHE emitting BL Lac shining through the Galaxy. Deep H-band imaging collected during the ARGOS commissioning allowed us to separate the contribution of the nuclear emission and to unveil the properties of the host galaxy with unprecedented detail. The host galaxy is well fitted by a S\'ersic profile with index of n~2 and total magnitude of H~16.15 mag. Under the assumption that BL Lac host galaxies are standard candles, we infer a redshift of z~0.21. In the framework of the current model for the EBL, this value is in agreement with the observed dimming of the VHE spectrum due to the scatter of energetic photons on the EBL.

Typical absence seizures and related epilepsy sendromes

Typical absence seizures and related epilepsy sendromes

Amantadine for the Treatment of Refractory Absence Seizures in Children.

Introduction:Childhood epilepsy is a generalized epilepsy syndrome with a favorable response to antiepileptic drugs; however, a small percentage of typical absence seizures remain refractory to drugs. We studied the safety and efficacy of amantadine in children with refractory absence seizures.Materials and Methods:Of 48 children with typical absence seizures attending the outpatient department of a tertiary care neurological center over a period of 3 years from July 2013 to June 2016, 4 children who were refractory to standard treatment for at least 1 year were selected and were started on amantadine 4–6 mg/kg/day, after obtaining informed consent.Observations:The children, aged between 7 and 14 years, had more than 10 episodes of seizures per day in spite of polytherapy with valproate, lamotrigine, clonazepam, levetiracetam, and topiramate in various combinations. Electrographically, all showed the typical generalized 3 Hz spike wave discharges activated by hyperventilation. All the children became seizure free within 1 week after starting amantadine, and there was improvement in their school performance. The children continue to remain seizure free for 6–30 months now. No significant adverse effects were observed on addition of amantadine.Discussion:Amantadine can be tried as a safe add-on drug for children with absence epilepsy refractory to multiple drugs. Further multicenter trials may be needed to prove its effectiveness, as the numbers are small.

Expression of Elafin in Dermatitis Herpetiformis.

Elafin is a serine protease inhibitor that has various epithelial cell regulatory and immunomodulatory effects including inactivation of neutrophil elastases. This later role originated the interest of elafin in certain neutrophil-rich dermatoses. Interestingly, it has been speculated that elafin has a protective role by slowing the deamidation process of gliadin in celiac disease (CD), despite the typical absence of neutrophils in intestinal histologic samplings. Dermatitis herpetiformis (DH) is a chronic recurrent vesicular dermatitis associated with gluten hypersensitivity and also characterized by a neutrophilic infiltrate and granular immunoglobulin A deposits in papillary dermis. We selected 31 formalin-fixed paraffin-embedded skin specimens of DH that demonstrated typical immunopathologic findings and probed them with rabbit polyclonal immunoglobulinG antielafin antibodies through standard immunohistochemistry analysis. Negative controls consisted of normal skin from elbow and knee surgical re-excisions specimen lacking residual tumor. Positive controls included skin biopsies of active plaque psoriasis, Sweet syndrome, and pyoderma gangrenosum. Similar to what has been previously reported in intestinal sampling of patients with active CD, abnormal expression of elafin was noted in virtually all probed skin biopsies of DH patients with active cutaneous disease. Under normal circumstances, keratinocytes overexpress elafin to downregulate a neutrophil mediated inflammatory response. The deficient expression of elafin in the aforementioned probed DH specimens correlates with previous similar elafin underexpression in intestinal samples of active CD. These histological findings suggest that these 2 gluten mediated disorders carry an abnormal elafin underexpression during disease activity.

Prevalence of idiopathic epilepsy among school children in Gharbia Governorate, Egypt

BackgroundEpilepsy is one of the most common neurological disorders among children. Data about its prevalence in Egypt is limited. Our aim was to study the prevalence of idiopathic epilepsy among school children in Gharbia governorate, Egypt. Subjects and MethodsA Cross-sectional school-based survey study was conducted; a validated screening questionnaire was distributed among urban and rural primary and preparatory school children. Students with suspected epilepsy were subjected to clinical evaluation, Electroencephalogram (EEG), and neuroimaging. Results9545 students completed the questionnaire, of whom 69 children proved to have idiopathic epilepsy. The lifetime prevalence of idiopathic epilepsy among school students aged 6–14 years was 7.2/1000. Higher prevalence was reported in males (7.7/1000) and in children from urban areas (8.25/1000). Generalized seizures were observed in 56.5% of the children with epilepsy, whereas focal seizures were present in 43.5%. Thirty-four (49.27%) children were diagnosed with specific childhood epileptic syndrome: 25 children had benign childhood epilepsy with centrotemporal spikes and nine children had typical childhood absence epilepsy. Treatment gap is around 12.5% in the studied children. Family history of epilepsy and parental consanguinity were evident in 73.9% and 21.7% of the epileptic children, respectively. The odds ratio for idiopathic epilepsy in children with family history of epilepsy was 23.9. ConclusionThe prevalence of idiopathic epilepsy among school students aged 6–14 years in Gharbia Governorate was 7.2/1000. The reported prevalence is similar to the prevalence of epilepsy in other Arab countries, but lower than the prevalence in Upper Egypt and in most developing countries.

Bacterial PhyA protein-tyrosine phosphatase-like myo-inositol phosphatases in complex with the Ins(1,3,4,5)P4 and Ins(1,4,5)P3 second messengers

myo-Inositol phosphates (IPs) are important bioactive molecules that have multiple activities within eukaryotic cells, including well-known roles as second messengers and cofactors that help regulate diverse biochemical processes such as transcription and hormone receptor activity. Despite the typical absence of IPs in prokaryotes, many of these organisms express IPases (or phytases) that dephosphorylate IPs. Functionally, these enzymes participate in phosphate-scavenging pathways and in plant pathogenesis. Here, we determined the X-ray crystallographic structures of two catalytically inactive mutants of protein-tyrosine phosphatase-like myo-inositol phosphatases (PTPLPs) from the non-pathogenic bacteria Selenomonas ruminantium (PhyAsr) and Mitsuokella multacida (PhyAmm) in complex with the known eukaryotic second messengers Ins(1,3,4,5)P4 and Ins(1,4,5)P3 Both enzymes bound these less-phosphorylated IPs in a catalytically competent manner, suggesting that IP hydrolysis has a role in plant pathogenesis. The less-phosphorylated IP binding differed in both the myo-inositol ring position and orientation when compared with a previously determined complex structure in the presence of myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6 or phytate). Further, we have demonstrated that PhyAsr and PhyAmm have different specificities for Ins(1,2,4,5,6)P5, have identified structural features that account for this difference, and have shown that the absence of these features results in a broad specificity toward Ins(1,2,4,5,6)P5 These features are main-chain conformational differences in loops adjacent to the active site that include the extended loop prior to the penultimate helix, the extended Ω-loop, and a β-hairpin turn of the Phy-specific domain.

Effect of the coordinated reset stimulations on controlling absence seizure

Based on a macroscopic mean-field model associating with the thalamus and cerebral cortex, we investigate how the newly proposed coordinated reset stimulation (CRS) strategy controls the absence seizures as some key parameters are changed. Different from the previous stimulation processes, CRS represents the intermittent pulse current administered to different structures including cortex, specific relay nuclei (SRN) and thalamus reticular nucleus (TRN) at different time by using three different micro-electrodes. In particular, we first simulate a typical absence epilepsy activity under the combined effect of the coupling strength between inhibitory interneurons (IIN)-excitatory pyramidal neurons (EPN) and EPN-TRN pathway. And then we explore the control mechanism of different parameters of 3:2 ON-OFF CRS on spike and slow-wave discharges (SWDs) region. Through analyzing the corresponding two-dimensional bifurcation diagrams, we find CRS is effective on controlling absence seizures in proper ranges of stimulation parameters. Especially, the combination of frequency and positive input duration can inhibit the pathological area more effectively. The obtained results might be helpful to study the pathophysiology mechanism of epilepsy, although the CRS’s feasibility still needs further exploration in clinical experiments.

Spatiotemporal propagation patterns of generalized ictal spikes in childhood absence epilepsy.

This work investigates the spatial distribution in time of generalized ictal spikes in the typical absences of childhood absence epilepsy (CAE). We studied twelve children with CAE, who had more than two typical absences during their routine video-EEG. Seizures were identified, and ictal spikes were marked over the maximum electronegative peak, clustered, waveform-averaged and spatiotemporaly analyzed in 2D electrode space. Consistency of spatiotemporal patterns of ictal spikes was high between the absences of the same child, but low between children. Three main discharge patterns were identified: of anterio-posterior propagation, of posterio-anterior propagation and confined to the frontal/prefrontal regions. In 4 patients, the propagation patterns transformed during the seizure into either a lateralized diminished or a non-lateralized reverse direction form. Most spikes originated fronto-temporaly, all maximized over the frontal/prefrontal electrodes and mostly decayed prefrontaly. In 4 patients, lateralized propagation patterns were identified. Ictal spike propagation patterns suggest that epileptogenic CAE networks are personalized, interconnect distal areas in the brain - not the entire cortex - with a tendency to generate bilateral symmetrical discharges, sometimes unsuccessfully. The transformation of propagation patterns during the seizure indicates the existence of dynamic interplay within epileptogenic networks. Our results support the revised concept of ictogenesis of ILAE definition in genetic (also known as idiopathic) generalized epilepsies. Understanding the focal features in CAE avoids misdiagnosis as focal epilepsy and inappropriate treatment.

The signifficance of focal EEG abnormalities in typical absence seizures – Long term observations

Objective: In last years it becomes more and more evident that focal EEG changes can be detected in patients with idiopathic generalized epilepsies. In order to estimate the frequency of this changes and their possible prognostic value present study was undertaken. Methods: Patients with typical absence seizures who were hospitalized or consulted at Dept. of Developmental Neurology between 2000–2015 were included in the study and followed prospectively. All patients underwent video-EEG monitoring at regular intervals. 189 patients who fulfilled criteria for typical absence seizures were included in the study. In 17% of them we found interictal epileptiform discharges, and in 37% intermittent temporal slow waves. Results: We found significant correlation between presence of interictal focal epileptiform discharges and long term prognosis, but did not find the correlation between worse prognosis and presence of temporal interictal slow wave activity. Interestingly, we did not found correlation between presence of focal abnormalities and worse performance in cognitive tests. Conclusion: The value of focal interictal EEG abnormalities should not be overestimated according to prognosis and cognitive performance in children with CAE.

Myoclonic jerks are commonly associated with absence seizures in early-onset absence epilepsy.

Typical absence seizures are observed in various epilepsy syndromes, however, few series have focused on early-onset absence epilepsy (EOAE). We aimed to evaluate the occurrence of this seizure type in children under 4 years of age in order to evaluate their electroclinical characteristics and outcome. We retrospectively studied (2006-2014) the electroclinical features of children with normal development and typical absence seizures starting before the age of 4 (with available pre-treatment video-EEG). Nine patients were included. Among them, eight patients had rhythmic myoclonic jerks involving the muscles of the upper face (eyebrows and eyelids) or neck, present from the onset to the end of the typical absence discharge. The myoclonia were synchronous with spike-wave complexes. One patient with GLUT-1 deficiency was refractory to antiepileptic polytherapy. The other eight became seizure-free; five with one antiepileptic drug and three with a combination of two drugs. The treatment was successfully withdrawn in five of the six patients who achieved two years of seizure freedom. None of them exhibited any other seizure type. Four of the eight patients with normal schooling required some support. We observed a positive correlation between the duration of absence seizure and the age of the patient at examination. Most of the patients under four years with only typical absence seizures had EOAE, and the motor symptoms may represent a distinctive age-related feature of EOAE. Further investigations are required to better correlate the role of brain maturation with the duration of the absence. [Published with video sequence on www.epilepticdisorders.com].

Metabolic Profile of Synthetic Cannabinoids 5F-PB-22, PB-22, XLR-11 and UR-144 by Cunninghamella elegans.

The knowledge of metabolic profile of synthetic cannabinoids is important for the detection of drugs in urinalysis due to the typical absence or low abundance of parent cannabinoids in human urine. The fungus Cunninghamella elegans has been reported to be a useful tool for metabolism study and thus applicability to synthetic cannabinoid metabolism was examined. In this study, 8-quinolinyl 1-(5-fluoropentyl)-1H-indole-3-carboxylate (5F-PB-22), 8-quinolinyl 1-pentyl-1H-indole-3-carboxylate (PB-22), [1-(5-fluoropentyl)-1H-indol-3-yl](2,2,3,3-tetramethylcyclopropyl)methanone (XLR-11) and (1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone (UR-144) were incubated with C. elegans and the metabolites were identified using liquid chromatography-quadrupole time-of-flight mass spectrometry. The obtained metabolites were compared with reported human metabolites to assess the suitability of the fungus to extrapolate human metabolism. 5F-PB-22 underwent dihydroxylation, dihydrodiol formation, oxidative defluorination, oxidative defluorination to carboxylic acid, ester hydrolysis and glucosidation, alone and/or in combination. The metabolites of PB-22 were generated by hydroxylation, dihydroxylation, trihydroxylation, dihydrodiol formation, ketone formation, carboxylation, ester hydrolysis and glucosidation, alone and/or in combination. XLR-11 was transformed through hydroxylation, dihydroxylation, aldehyde formation, carboxylation, oxidative defluorination, oxidative defluorination to carboxylic acid and glucosidation, alone and/or in combination. UR-144 was metabolised by hydroxylation, dihydroxylation, trihydroxylation, aldehyde formation, ketone formation, carboxylation, N-dealkylation and combinations. These findings were consistent with previously reported human metabolism except for the small extent of ester hydrolysis observed and the absence of glucuronidation. Despite the limitations, C. elegans demonstrated the capacity to produce a wide variety of metabolites including some major human metabolites of XLR-11 and UR-144 at high abundance, showing the potential for metabolism of newly emerging synthetic cannabinoids.

Eliminating Absence Seizures through the Deep Brain Stimulation to Thalamus Reticular Nucleus.

Deep brain stimulation (DBS) can play a crucial role in the modulation of absence seizures, yet relevant biophysical mechanisms are not completely established. In this paper, on the basis of a biophysical mean-field model, we investigate a typical absence epilepsy activity by introducing slow kinetics of GABAB receptors on thalamus reticular nucleus (TRN). We find that the region of spike and slow-wave discharges (SWDs) can be reduced greatly when we add the DBS to TRN. Furthermore, we systematically explore how the corresponding stimulation parameters including frequency, amplitude and positive input duration suppress the SWDs under certain conditions. It is shown that the SWDs can be controlled as key stimulation parameters are suitably chosen. The results in this paper can be helpful for researchers to understand the thalamus stimulation in treating epilepsy patients, and provide theoretical basis for future experimental and clinical studies.

Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents.

This is an updated version of the original Cochrane review originally published in 2003, Issue 3, and updated in 2005, Issue 4.Absence seizures are brief epileptic seizures which present in childhood and adolescence. Depending on clinical features and electroencephalogram (EEG) findings they are divided into typical, atypical absences, and absences with special features. Typical absences are characterised by sudden loss of awareness and an EEG typically shows generalised spike wave discharges at three cycles per second. Ethosuximide, valproate and lamotrigine are currently used to treat absence seizures. This review aims to determine the best choice of antiepileptic drug for children and adolescents with typical absence seizures. To review the evidence for the effects of ethosuximide, valproate and lamotrigine as treatments for children and adolescents with absence seizures, when compared with placebo or each other. We searched the Cochrane Epilepsy Group's Specialized Register (1 September 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO, 1 September 2016), MEDLINE (Ovid, 1946 to 1 September 2016), ClinicalTrials.gov (1 September 2016) and the WHO International Clinical Trials Registry Platform ICTRP (1 September 2016). Previously we searched Embase (1988 to March 2005) and SCOPUS (1823 to 31 March 2014). No language restrictions were imposed. In addition, we contacted Sanofi Winthrop, Glaxo Wellcome (now GlaxoSmithKline) and Parke Davis (now Pfizer), manufacturers of sodium valproate, lamotrigine and ethosuximide respectively. Randomised parallel group monotherapy or add-on trials which include a comparison of any of the following in children or adolescents with absence seizures: ethosuximide; sodium valproate; lamotrigine; or placebo. Outcome measures were: (1) proportion of individuals seizure free at one, three, six, 12 and 18 months post randomisation; (2) people with a 50% or greater reduction in seizure frequency; (3) normalisation of EEG and/or negative hyperventilation test; and (4) adverse effects. Data were independently extracted by two review authors. Results are presented as risk ratios (RR) with 95% confidence intervals (95% CIs). Eight small trials were found (three of them not included in the previous version of the review). Six of them were of poor methodological quality and seven recruited less than 50 participants. There are no placebo-controlled trials for ethosuximide or valproate, and hence, no evidence from randomised controlled trials to support a specific effect on absence seizures for either of these two drugs. Due to the differing methodologies used in the trials comparing ethosuximide, lamotrigine and valproate, we thought it inappropriate to undertake a meta-analysis. One large randomised, parallel double-blind controlled trial comparing ethosuximide, lamotrigine and sodium valproate in children with newly diagnosed childhood absence epilepsy found that at 12 months, the freedom-from-failure rates for ethosuximide and valproic acid (VPA) were similar and were higher than the rate for lamotrigine. The frequency of treatment failures due to lack of seizure control (P < 0.001) and intolerable adverse events (P < 0.037) was significantly different among the treatment groups, with the largest proportion of lack of seizure control in the lamotrigine cohort, and the largest proportion of adverse events in the VPA group. Overall, this large study demonstrates the superior effectiveness of ethosuximide and VPA compared to lamotrigine as initial monotherapy aimed to control seizures without intolerable adverse effects in children with childhood absence epilepsy. With regards to both efficacy and tolerability, ethosuximide represents the optimal initial empirical monotherapy for children and adolescents with absence seizures. However, if absence and generalised tonic-clonic seizures coexist, valproate should be preferred, as ethosuximide is probably inefficacious on tonic-clonic seizures.

Sedimentary macrofossil records reveal ecological change in English lakes: implications for conservation

Aquatic macrophytes play a key role in providing habitat, refuge and food for a range of biota in shallow lakes. However, many shallow lakes have experienced declines in macrophyte vegetation in recent decades, principally due to eutrophication. As changes in macrophyte composition and abundance can affect overall ecological structure and function of a lake, an assessment of the timing and nature of such changes is crucial to our understanding of the wider lake ecosystem. In the typical absence of historical plant records, the macro-remains of macrophytes preserved in lake sediments can be used to assess long-term changes in aquatic vegetation. We generated recent (150–200 years) plant macrofossil records for six English lakes subject to conservation protection to define past macrophyte communities, assess trajectories of ecological change and consider the implications of our findings for conservation targets and strategies. The data for all six lakes reveal a diverse submerged macrophyte community, with charophytes as a key component, in the early part of the sedimentary records. The stratigraphies indicate considerable change to the aquatic vegetation over the last two centuries with a general shift towards species more typically associated with eutrophic conditions. A common feature is the decline in abundance of low-growing charophytes and an increase in tall canopy-forming angiosperms such as fine-leaved Potamogeton species, Zannichellia palustris and Callitriche species. We hypothesise, based on findings from long-term datasets and palaeoecological records from enriched shallow lakes where plants are now absent, that the observed shifts provide a warning to managers that the lakes are on a pathway to complete macrophyte loss such that nutrient load reduction is urgently needed. It is the sound understanding of present-day plant ecology that affords such reliable interpretation of the fossil data which, in turn, provide valuable context for current conservation decisions.

Rapid and Specific Detection of the Escherichia coli Sequence Type 648 Complex within Phylogroup F.

The Escherichia coli sequence type 648 complex (STc648) is an emerging lineage within phylogroup F-formerly included within phylogroup D-that is associated with multidrug resistance. Here, we designed and validated a novel multiplex PCR-based assay for STc648 that took advantage of (i) four distinctive single-nucleotide polymorphisms in icd allele 96 and gyrB allele 87, two of the multilocus sequence typing alleles that define ST648; and (ii) the typical absence within STc648 of uidA, an E. coli-specific gene encoding β-glucuronidase. Within a diverse 212-strain validation set that included 109 STs other than STc648, from phylogroups A, B1, B2, C, D, E, and F, the assay exhibited 100% sensitivity (95% confidence interval [CI], 82% to 100%) and specificity (95% CI, 98% to 100%). It functioned similarly well in two distant laboratories that used boiled lysates or DNAzol-purified DNA as the template DNA. Thus, this novel multiplex PCR-based assay should enable any laboratory equipped for diagnostic PCR to rapidly, accurately, and economically screen E. coli isolates for membership in STc648.

Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques.

The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). Patients (n=19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n=19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p<0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies.

Detection of Paroxysms in Long-Term, Single-Channel EEG-Monitoring of Patients with Typical Absence Seizures.

Absence seizures are associated with generalized 2.5–5 Hz spike-wave discharges in the electroencephalogram (EEG). Rarely are patients, parents, or physicians aware of the duration or incidence of seizures. Six patients were monitored with a portable EEG-device over four times 24 h to evaluate how easily outpatients are monitored and how well an automatic seizure detection algorithm can identify the absences. Based on patient-specific modeling, we achieved a sensitivity of 98.4% with only 0.23 false detections per hour. This yields a clinically satisfying performance with a positive predictive value of 87.1%. Portable EEG-recorders identifying paroxystic events in epilepsy outpatients are a promising tool for patients and physicians dealing with absence epilepsy. Albeit the small size of the EEG-device, some children still complained about the obtrusive nature of the device. We aim at developing less obtrusive though still very efficient devices, e.g., hidden in the ear canal or below the skin.