Circulating microRNAs as potential biomarkers for genetic generalized epilepsies: a three microRNA panel.

BACKGROUND AND PURPOSE: Genetic generalized epilepsies (GGEs) encompass a group of syndromes of mainly genetic causes, characterized by the involvement of both hemispheres. MicroRNAs (miRNAs) are small non-coding RNAs with a critical role in the regulation of neuronal biological processes through gene expression modulation. Dysregulated miRNA expression has been shown in epilepsy. Due to their stability in biological fluids like serum, miRNAs have assumed a prominent role in biomarker research. Our aim was to evaluate circulating levels of three miRNAs in GGE patients and assess their putative diagnostic value. METHODS: MiR-146a, miR-155 and miR-132 were quantified by real-time polymerase chain reaction in the serum of 79 GGE patients (47 women, 32 men, 35.1 ± 12.4 years) and 67 healthy individuals (41 women, 26 men, 42.4 ± 10.1 years). Relative expression values were calculated using the 2-ΔΔCt method. Receiver operating characteristic curve analysis was performed to assess diagnostic value. MiRNA expression was correlated with clinicopathological features. RESULTS: Serum levels of miR-146a and miR-155 were significantly upregulated in GGE patients relative to controls (3.13 and 6.05, respectively). Combined miR-146a, miR-155 and miR-132 serum levels performed well as a diagnostic biomarker, discriminating GGE patients from controls with an area under the curve of 0.85, 80% specificity and 73% sensitivity. CONCLUSIONS: Our results indicate that miR-146a, miR-155 and miR-132 may partake in GGE epileptogenesis. A panel of three circulating miRNAs with potential value as a GGE biomarker is reported for the first time. Novel biomarkers may help to identify new treatment targets and contribute to improved patients' quality of life through earlier diagnosis and a more precise prognosis.

Photosensitivity and epilepsy: Current concepts and perspectives-A narrative review.

The authors review the influence of photic stimuli on the generation of epileptic seizures, addressing the first descriptions of the phenomenon and its subsequent exploration. Initially defined in the 1950's, links between intermittent photic stimulation (IPS) and seizures were well understood by the 1970. Since then the increasing exposure to photic stimuli associated with modern life (for instance through TVs, patterns, computer games and electronic instruments with flickering displays) has led to an increased interest in this issue. Diverse stimulation procedures have been described and difference in the effects of stimulation frequencies and types, colour and lighting have been recognised. Approximately 5% of patients with epilepsy have photosensitive epilepsy (PSE). PSE is commoner in younger individuals, more frequent in women, often time-limited, generally easy to treat and closely related to generalised epilepsies, especially Juvenile Myoclonic Epilepsy (JME). Structural and functional studies of PSE indicate abnormalities beyond the frontal lobes and evidence for the role of the visual cortex in human PSE. A reduction in connectivity between prefrontal and frontopolar regions and increased connectivity between occipital cortex and the supplementary motor area may be the basis for triggering motor seizures in JME. Due to the changes observed in such areas, it is hypothesised that photoparoxysmal responses (PPR) could be a final expression of pathogenic phenomena in the striato-thalamocortical system, and possibly a core feature of JME as system epilepsy. The familial transmission of epileptiform responses to IPS is well-recognised, but no clear relation between PSE and specific genes has emerged. Although the influence of ethnic factors on PSE has been widely studied, clear conclusions are still lacking. Pharmacological therapeutic approaches are beyond the scope of this review although preventive measures allowing patients to avoid PS seizure initiation and/or generalisation are discussed. Given the gender/age group most commonly affected by PSE, the risks and benefits of drug treatment need to be carefully weighed up.

Co-morbidities and sleep apnoea severity. A study in a cohort of Portuguese patients. / Comorbilidades y gravedad de la apnea del sueño. Estudio en una cohorte de pacientes portugueses.

INTRODUCTION: Obstructive sleep apnoea syndrome (OSAS) is frequently associated to other morbid conditions that act as risk factors influencing OSAS morbidity and mortality. AIM: To analyse the presence of co-morbidities in OSAS patients, recruited from a sleep outpatient clinic in Northern Portugal, stratified as a function of OSAS severity. PATIENTS AND METHODS: A cohort of 319 sleep-disordered patients was assessed by clinical and sleep video-polygraphic recording. Patients (n = 209) with sleep respiratory distress had OSAS (n = 145) and severity defined according to Apnoea/Hypopnea Index (AHI); 64 had primary snoring or respiratory distress with AHI < 5; and 110 had other sleep disorders. A full individual background study was possible in 128 OSAS patients. The association to unique or multiple co-morbidities was assessed by clinical and analytical studies in general group or as a function of OSAS severity. RESULTS: The presence of co-morbidities was of 75% in all OSAS patients and of 79.5% in the severe group of OSAS. Forty seven of patients had only one co-morbidity. The most common was obesity (56.3%) followed by high blood pressure, diabetes and other cardiovascular disorders. Obesity was present in 84% among the most severe OSAS cases and always present in those with multiple co-morbidities. When compared with the group of patients without sleep respiratory distress the co-morbidity condition was more frequently related to OSAS (p = 0.0196). CONCLUSION: Comorbidities are commonly associated to OSAS independently of disease severity. Among the comorbidities present obesity was the most common in the most severe OSAS cases.

TITLE: Comorbilidades y gravedad de la apnea del sueño. Estudio en una cohorte de pacientes portugueses.Introduccion. El sindrome de apnea obstructiva del sueño (SAOS) se asocia frecuentemente a otras enfermedades que actuan como factores de riesgo que influyen en la morbilidad y mortalidad del SAOS. Objetivos. Analizar la presencia de comorbilidades en pacientes con SAOS, seleccionados en una clinica del sueño ambulatoria en el norte de Portugal y clasificados atendiendo a la gravedad del SAOS. Pacientes y metodos. Una cohorte de 319 pacientes con trastornos del sueño fueron evaluados mediante estudios clinicos y registro videopoligrafico durante el sueño. Del total de pacientes (n = 209) con distres respiratorio durante el sueño, 145 tenian SAOS con gravedad definida segun el indice de apnea/hipopnea (IAH); 64 presentaban ronquidos primarios o distres respiratorio con IAH < 5; y 110 tenian otros trastornos del sueño. Resultados. La presencia de comorbilidades fue del 75% en todos los pacientes con SAOS y del 79,5% en el grupo de pacientes con SAOS grave; 47 pacientes presentaban una unica comorbilidad, la mas comun de las cuales fue la obesidad (56,3%), seguida de hipertension, diabetes y otros trastornos cardiovasculares. La obesidad estuvo presente en el 84% de los casos mas graves de SAOS y en el 100% de casos con multiples comorbilidades. En comparacion con el grupo de pacientes con distres respiratorio durante el sueño, la comorbilidad aparece normalmente relacionada con el SAOS (p = 0,0196). Conclusion. Las comorbilidades se asocian con frecuencia al SAOS, independientemente de la gravedad de la enfermedad. Entre las comorbilidades presentes, la obesidad resulto ser la mas comun en los casos mas graves de SAOS.

Association between IGF2 and CYP21 gene polymorphisms and characteristics of economic interest in Nellore cattle.

We analyzed two single nucleotide polymorphisms (SNPs) of the IGF2 and CYP21 genes in Nellore cattle participating in the Brazilian Animal Breeding Program. The SNPs were found in exon 6 of the IGF2 (insulin-like growth factor 2) gene (RFLP/MboII) as well as in the promoter region of the CYP21 (steroid 21-hydroxylase) gene (RFLP/HpaII) of these animals. The TC heterozygotes were significantly more frequent than CC and TT homozygotes in the RFLP/MboII polymorphism. The T allele was significantly more frequent than the C allele in RFLP/HpaII polymorphism. This population was found to be in Hardy-Weinberg equilibrium for these SNPs. Association of these polymorphisms with expected progeny differences of reproductive and productive traits was investigated, but proved to be significant only for DP550 (expected progeny differenced for weight at 365 days - IGF2 - RFLP/MboII) and DP450 (expected progeny differenced for weight at 450 days - CYP21 - RFLP/HpaII). This is the first study on the occurrence of these two polymorphisms in this Zebu breed of cattle. A total of 147 Nellore animals participating in the Breeding Program of the Nellore Breed (PMGRN) under the management of the National Association of Breeders and Researchers (ANCP) in the city of Ribeirão Preto were analyzed.

IGF2/Mboll polymorphism in Gir and Nelore cattle.

The imprinted gene insulin-like growth factor 2 (IGF2) carries out important functions in the development of placental mammals, during the embryonic and fetal stages and is located on bovine chromosome 29. The main aim of this study was to verify the occurrence of a polymorphism (C/T transversion) in exon 6 of the IGF2 gene in Gir and Nelore cattle, Zebu breeds of great economic importance in Brazil for dairy and beef production, respectively. A 193 bp fragment of bovine IGF2 exon 6 was amplified by PCR with specific primers for this region and digested with Mboll enzyme to analyze the polymorphic segment. In a total of 39 Gir animals (29 females and 10 males), the estimated frequencies of the C and T alleles were 0.42 and 0.58, respectively. The genotypic frequencies were 0.10 for CC, 0.26 for TT and 0.64 for CT. For 28 Nelore animals (17 females and 11 males), the estimated frequencies of the C and T alleles were 0.43 and 0.57, respectively. The genotypic frequencies were 0.18 for CC, 0.32 for TT, and 0.50 for CT. This is the first report of the occurrence of this polymorphism in these breeds. The polymorphic site can be a regulatory motif with functional significance to gene regulation of the IGF2 gene. This polymorphism could be used to investigate the allele-specific expression of the IGF2 gene, its epigenetic status, and its role in developmental, growth and reproductive traits.

Subspace techniques to remove artifacts from EEG: a quantitative analysis.

In this work we discuss and apply projective subspace techniques to both multichannel as well as single channel recordings. The single-channel approach is based on singular spectrum analysis(SSA) and the multichannel approach uses the extended infomax algorithm which is implemented in the opensource toolbox EEGLAB. Both approaches will be evaluated using artificial mixtures of a set of selected EEG signals. The latter were selected visually to contain as the dominant activity one of the characteristic bands of an electroencephalogram (EEG). The evaluation is performed both in the time and frequency domain by using correlation coefficients and coherence function, respectively.

Greedy kernel PCA applied to single-channel EEG recordings.

In this work, we propose the correction of univariate single channel EEGs using a kernel technique. The EEG signal is embedded in its time-delayed coordinates obtaining a multivariate signal. A kernel subspace technique is used for denoising and artefact extraction. The proposed kernel method follows a greedy approach to use a reduced data set to compute a new basis onto which to project the mapped data in feature space. The pre-image of the reconstructed multivariate signal is computed and the embedding is reverted. The resultant signal is the high amplitude artifact which must be subtracted from the original signal to obtain a corrected version of the underlying signal.

A novel dry active electrode for EEG recording.

The design and testing of a "dry" active electrode for electroencephalographic recording is described. A comparative study between the EEG signals recorded in human volunteers simultaneously with the classical Ag-AgCl and "dry" active electrodes was carried out and the reported preliminary results are consistent with a better performance of these devices over the conventional Ag-AgCl electrodes.

Automatic removal of high-amplitude artefacts from single-channel electroencephalograms.

In this work, we present a method to extract high-amplitude artefacts from single channel electroencephalogram (EEG) signals. The method is called local singular spectrum analysis (local SSA). It is based on a principal component analysis (PCA) applied to clusters of the multidimensional signals obtained after embedding the signals in their time-delayed coordinates. The decomposition of the multidimensional signals in each cluster is achieved by relating the largest eigenvalues with the large amplitude artefact component of the embedded signal. Then by reverting the clustering and embedding processes, the high-amplitude artefact can be extracted. Subtracting it from the original signal a corrected EEG signal results. The algorithm is applied to segments of real EEG recordings containing paroxysmal epileptiform activity contaminated by large EOG artefacts. We will show that the method can be applied also in parallel to correct all channels that present high-amplitude artefacts like ocular movement interferences or high-amplitude low frequency baseline drifts. The extracted artefacts as well as the corrected EEG will be presented.

Video games are exciting: a European study of video game-induced seizures and epilepsy.

BACKGROUND: Video game seizures have been reported in photosensitive and non-photosensitive patients with epilepsy. The game Super Mario World, has led to many cases of first seizures. We examined whether this game was indeed more provocative than other programs and whether playing the game added to this effect. METHODS: We prospectively investigated 352 patients in four European cities, using a standard protocol including testing of a variety of visual stimuli. We correlated historical data on provocative factors in daily life with electroencephalographic laboratory findings. RESULTS: The video game, Super Mario World proved more epileptogenic than standard TV programs and as provocative as programs with flashing lights and patterns. Most striking was the fact that video game-viewing and-playing on the 50 and 100 Hz TV was significantly more provocative than viewing the standard program (P < 0.001, P < 0.05 respectively). Playing the video game Mario World on a 50 Hz TV, appeared to be significantly more provocative than playing this game on the 100 Hz TV (P < 0.001). Of 163 patients with a history of TV-, VG- or CG-seizures, 85% of them showed epileptiform discharges in response to photic stimulation, 44% to patterns, 59% to 50 Hz TV and 29% to 100 Hz TV. CONCLUSIONS: Children and adolescents with a history of video game seizures are, in the vast majority, photosensitive and should be investigated with standardised photic stimulation. Games and programs with bright background or flashing images are specifically provocative. Playing a video game on a 100 Hz TV is less provocative [published with videosequences].

Impact of epilepsy on QOL in a Portuguese population: exploratory study.

OBJECTIVES: To develop an outcome measure of QOL (quality of life) for the Portuguese population; describe QOL in epileptics; analyse how QOL is affected by epilepsy and analyse how QOL is affected by patients' characteristics. PATIENTS AND METHODS: Study of a consecutive sample of 92 epileptics from an outpatient clinic, men and women, aged 15-65, having the basic education level. Firm diagnosis of epilepsy (with or without seizures) without other illness. A questionnaire based on ESI-55 and Health Insurance Experiment Short-Forms was used. Principal component analysis (orthogonal varimax) showed a solution explaining 55.6 of total variance. After the inspection, the 33 items were grouped into 5 sub-scales (dimensions). RESULTS: Results showed that QOL was poor for people with partial seizures. The best scores were found on patients now free from seizures. CONCLUSION: The QOL measure is sensitive to cultural differences, demographic and disease variables which could explain the results found.

Glycogen content and phosphorylase activities in deciduous dental pulp. Study on porcine teeth during root formation, fully formed root and root resorption phases.

Glycogen content and glycogen phosphorylases (a and total) were measured in dental pulps from pigs sacrificed at 20, 40, 50, 70, 90, 120, 180, 270 and 300 days of age. The following conclusions were drawn: (a) pulp glycogen content was higher during root formation than during root resorption; (b) the phosphorylase activities (a and total), were higher during root resorption than in the other phases; (c) pulps from different teeth, when in the same developmental stage, possessed a similar glycogen metabolism, as revealed by glycogen content and enzyme activity determinations.

Temporal characteristics of seizures and epileptiform discharges.

The time relations of epileptic events have been studied in 3 sets of data: (I) counts of individual epileptiform discharges in twelve 48 h EEG recordings, (IIa) seizure calendars of 30 therapy-resistant outpatients participating in a drug trial, (IIb) seizure calendars of 10 mentally subnormal epileptic patients resident in a long-stay unit. The EEG data I were characterized most often by a Poisson distribution of intervals between discharges and the occurrence of marked periodicities, particularly at night. The periods of rhythmic nocturnal events ranged from 13 to 142 min and did not appear to correspond to the REM/non-REM cycle. In the seizure data IIa and b a Poisson distribution of intervals between events was found in half the patients. Periodicities occurred only in group IIa and did not correspond to weekly or monthly cycles. A stochastic process is considered to be the model which best fits these data.

The circadian distribution of interictal epileptiform EEG activity.

Eighteen continuous 48 h monitoring studies are reported from 17 patients with epilepsy. The numbers of epileptiform discharges over corresponding epochs of the 2 days were significantly positively correlated in 16 studies. However, this was explicable by masking due to the sleep/wake cycle and when waking and sleep were considered separately a minority of studies showed significant correlations. The difference in total 24 h production of discharges between the 2 days ranged from 1.3 to 30.3%, mean 15.1%. The maximum discharge rate in 75% of the studies occurred during sleep; during waking the distribution of discharges was random. Even in the waking state the 0.5 h discharge rate was extremely variable and in few patients could a single 30 min epoch be regarded as a reliable sample of the mean rate over the waking day. The intervals between events showed a Poisson distribution during 9 days and 5 nights, but there was no within-patient consistency between the first and second 24 h period. The occurrence of discharges was periodic significantly more often at night than during the day, but the periodicities did not clearly correspond to the REM cycle. Discharges increased overall during sleep in 14 studies, were unchanged in 2 and decreased in 4. The time of occurrence of maximal discharge rate during sleep was consistent from night I to night II only in patients exhibiting generalized regular spike-wave activity but random in the others. A negative correlation between antiepileptic drug levels and discharge rate was rarely observed.

Bromocriptine combined with levodopa in Parkinson's disease.

Bromocriptine (Parlodel) was given for 2 years to 17 parkinsonian patients showing inadequate response to treatment over a mean of 7 years with levodopa combined with a decarboxylase inhibitor. 11 of the patients had developed dyskinesia and 13 the on-off phenomenon during levodopa therapy. When the dose of bromocriptine reached 30 mg daily, after 4 weeks' treatment, a highly significant improvement (p less than 0.001) was observed in the following six variables: bradykinesia, rigidity, tremor, feeding, dressing and speech. These improvements have now been maintained for 2 years. The on-off phenomenon disappeared in 9 out of 13 patients. Side effects were mild and transient. Involuntary movements existing prior to bromocriptine administration were improved by reducing the dose of levodopa. The mean daily dose--after progressive and individual adjustment--was 46 mg bromocriptine combined with 435 mg levodopa plus decarboxylase inhibitor.