Psychometric evaluation of memory function in epilepsy patients

The purpose of the present study was the psychometric evaluation of memory function in epilepsy patients, the study of the effect that temporal and generalized epilepsy have on declarative memory and finally, the exploration of the way the brain systems that constitute declarative memory are organized. Ninety one epilepsy patients participated voluntarily in our study, fifty six patients with temporal epilepsy (29 patients with right temporal lobe epilepsy and 23 patients with left temporal lobe epilepsy) and twenty seven with generalized epilepsy (18 patients with idiopathic generalized epilepsy and 9 patients with juvenile myoclonic epilepsy). Twenty four age- and education- matched healthy subjects were chosen to serve as control group. All participants were administered neuropsychological tasks assessing aspects of episodic, semantic and autobiographical memory. Regarding the construct validity of the neuropsychological tasks, it was found that in comparison with the control group, patients with generalized epilepsy performed poorly in semantic and autobiographical episodic tasks while their performance in autobiographical semantic memory was almost similar to that of control group. Patients with right temporal lobe epilepsy showed deficits mostly in episodic and autobiographical tasks, while those with left temporal lobe epilepsy performed poorly in episodic, semantic and autobiographical memory tasks. In addition, patients with right temporal lobe epilepsy performed better in semantic memory tasks compared to left temporal lobe patients and all temporal lobe patients performed better in semantic memory task compared to generalized epilepsy patients. All of epilepsy patients performed better in autobiographical semantic memory than in autobiographical episodic memory. The duration of the disease, the amount of antiepileptic drugs and the seizure frequency were the factors that predict patient’s performance in episodic, semantic and autobiographical semantic memory tasks. Moreover, the reliability of the memory tasks was evaluated by applying a number of appropriate methods and in the majority of tasks a high degree of reliability for the different groups of epilepsy patients was found. In conclusion, epilepsy patients show deficits in autobiographical and declarative memory. Specifically, generalized epilepsy patients performed poorly mostly in autobiographical episodic and semantic memory tests. Temporal lobe epilepsy, on the other hand, seems to function selectively, while our results indicate that the right temporal lobe is mostly responsible for episodic memories and the left temporal lobe is mostly responsible for semantic memories. Finally, this study seems to confirm Multiple Trace Theory (Nadel & Moscovitch, 1997), based on the fact that epilepsy patients showed deficits in both recent and remote autobiographical memory and also, autobiographical semantic memory was better than autobiographical episodic memory.Ο σκοπός της παρούσας διατριβής είναι η ψυχομετρική εκτίμηση μνημονικών λειτουργιών σε ασθενείς με επιληψία μέσω εφαρμογής αξιόπιστων κι έγκυρων μεθόδων και δοκιμασιών, η διερεύνηση της επίδρασης που ασκούν η κροταφική και η γενικευμένη επιληψία στη λειτουργία της δηλωτικής μνήμης και η διερεύνηση του τρόπου οργάνωσης και λειτουργίας των εγκεφαλικών συστημάτων που υποστηρίζουν τη δηλωτική μνήμη. Στην έρευνα έλαβαν μέρος 91 ασθενείς με διαγνωσμένη επιληψία, οι οποίοι κατηγοριοποιήθηκαν σε ομάδες, ανάλογα με τον εντοπισμό των επιληπτικών κρίσεων και 24 υγιή άτομα, χωρίς ιστορικό νευρολογικής ή ψυχιατρικής διαταραχής ή χρήσης ουσιών. Οι νευροψυχολογικές δοκιμασίες που εφαρμόστηκαν για την αξιολόγηση της μνήμης επεισοδίων και της σημασιολογικής μνήμης, επιλέχθηκαν με βάση την εφαρμογή τους σε προηγούμενες έρευνες, που εξέταζαν τη δηλωτική μνήμη σε ασθενείς με επιληψίες. Η στατιστική επεξεργασία των εμπειρικών δεδομένων της έρευνας αφορούσε στον έλεγχο των ψυχομετρικών χαρακτηριστικών των μνημονικών δοκιμασιών και συγκεκριμένα της εννοιολογικής εγκυρότητας και της αξιοπιστίας των μετρήσεων τους. Στο πλαίσιο της εννοιολογικής εγκυρότητας, τα αποτελέσματα έδειξαν ότι η ομάδα ελέγχου υπερείχε στα περισσότερα μνημονικά έργα έναντι των υπολοίπων ομάδων των ασθενών με επιληψία. Οι ασθενείς με κροταφική επιληψία και ιπποκάμπεια σκλήρυνση ήταν η ομάδα με τις περισσότερες μνημονικές μειονεξίες, σε σύγκριση πάντα με τους υγιείς, ενώ οι ασθενείς με γενικευμένη επιληψία παρουσίασαν κυρίως διαταραχές σημασιολογικής μνήμης και αυτοβιογραφικής μνήμης επεισοδίων. Επιπρόσθετα, η έρευνα ανέδειξε ότι οι ασθενείς με δεξιά κροταφική επιληψία έχουν σημαντικά καλύτερες επιδόσεις σε δοκιμασίες σημασιολογικής μνήμης συγκριτικά με τους ασθενείς με αριστερή κροταφική επιληψία, ενώ οι ασθενείς με κροταφική επιληψία υπερείχαν σε έργο σημασιολογικής μνήμης έναντι των ατόμων με γενικευμένη επιληψία. Βρέθηκε ακόμα ότι η αυτοβιογραφική σημασιολογική μνήμη υπερείχε σε σημαντικό βαθμό της αυτοβιογραφικής μνήμης επεισοδίων. Τέλος, σύμφωνα με τα αποτελέσματα, η διάρκεια της νόσου και της φαρμακευτικής αγωγής, η φαρμακευτική αγωγή σε αριθμό σκευασμάτων και η συχνότητα των επιληπτικών κρίσεων ήταν οι παράγοντες εκείνοι που προβλέπουν σε μεγαλύτερο βαθμό τις επιδόσεις των ασθενών με επιληψία, ανεξαρτήτως αιτιολογίας, σε δοκιμασίες μνήμης επεισοδίων, σημασιολογικής και αυτοβιογραφικής σημασιολογικής μνήμης. Όσον αφορά στην αξιοπιστία των δοκιμασιών, αυτή ελέγχθηκε μέσω ενός συνόλου κατάλληλων μεθόδων και στην πλειονότητα των δοκιμασιών βρέθηκε υψηλός βαθμός αξιοπιστίας για τις διάφορες κατηγορίες των ασθενών με επιληψία. Συμπερασματικά, η παρούσα διατριβή έδειξε ότι οι ασθενείς με επιληψία παρουσιάζουν διαταραχές στην αυτοβιογραφική και στη δηλωτική τους μνήμη. Ειδικότερα, οι ασθενείς με γενικευμένη επιληψία παρουσιάζουν διαταραχές κυρίως στην αυτοβιογραφική μνήμη επεισοδίων καθώς και στη σημασιολογική τους μνήμη, ενώ από τις αναλύσεις των αποτελεσμάτων των ασθενών με κροταφική επιληψία φαίνεται ότι υπάρχει λειτουργική και νευροανατομική διάκριση μεταξύ μνήμης επεισοδίων και σημασιολογικής μνήμης. Τέλος, τα αποτελέσματα της παρούσα έρευνας επιβεβαιώνουν κυρίως τη Θεωρία Πολλαπλών Μνημονικών Ιχνών

Increased circulating endothelial progenitor cells (EPCs) in prepubertal children born prematurely: a possible link between prematurity and cardiovascular risk

BackgroundEndothelial progenitor cells (EPCs) ensure vascular integrity and neovascularization. No studies have investigated EPCs in preterm-born children beyond infancy.MethodsOne hundred and thirty-six prepubertal children were enrolled: 63 preterm and 73 born at term (controls). Circulating CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs were measured in preterm-born children compared to controls. Body mass index (BMI), waist-to-hip ratio (WHR), neck circumference, systolic and diastolic blood pressure (SBP and DBP, respectively), fasting glucose, insulin, lipid profile, common carotid and abdominal aortic intima-media thickness (cIMT and aIMT, respectively), endothelium-dependent brachial artery flow-mediated dilation (FMD), and echocardiographic parameters were also assessed.ResultsCirculating CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs were significantly higher in preterm-born children compared to controls (p<0.001 and p<0.001, respectively). In total study population and in the preterm-born group, EPCs were significantly lower in children born to mothers with gestational diabetes compared to non-diabetic mothers. Prematurity was associated with higher WHR, neck circumference, SBP, DBP, cIMT, aIMT, mean pressure, and velocity of pulmonary artery; the peak velocity of the brachial artery was significantly lower in children born prematurely. In multiple regression analysis, preterm birth and maternal gestational diabetes were recognized as independent predictors of EPCs.ConclusionsCirculating EPCs were increased in prepubertal preterm-born children in comparison with peers born full-term. Maternal gestational diabetes was associated with a decrease in EPCs.ImpactMounting evidence supports the adverse effect of prematurity on cardiovascular health. However, the underlying mechanisms that could lead to endothelial dysfunction in preterm-born individuals are not fully understood.Endothelial progenitor cells (EPCs) ensure vascular integrity, normal endothelial function and neovascularization.No studies have investigated the EPCs counts in peripheral blood beyond infancy in children born prematurely.Circulating EPCs were significantly higher in preterm-born prepubertal children compared to controls, thus indicating that prematurity is possibly associated with endothelial damage.In total study population and in the preterm-born group, maternal gestational diabetes was associated with decreased EPCs concentrations

Elevated circulating endothelial microparticles (EMPs) in prepubertal children born preterm

Background Endothelial microparticles (EMPs) act as early biomarkers of endothelial activation and damage. No studies have investigated EMPs in preterm-born individuals. Methods Sixty-three preterm-born children and 52 children born full-term (controls) were studied. Circulating CD62E(+), CD144(+), and CD31(+)/CD42b(-) EMPs were measured in preterm-born children compared to controls; possible associations with cardiovascular risk factors and endothelial function parameters were also assessed. Results Circulating CD62E(+), CD144(+), and CD31(+)/CD42b(-) EMPs were significantly higher in preterm-born children compared to controls (p = 0.003, p < 0.001, and p < 0.001, respectively). Preterm birth was recognized as an independent predictor of each EMP subpopulation studied; moreover, the mean pressure and velocity of pulmonary artery were independently correlated with CD62E(+) (beta = 0.20, p = 0.04) and CD144(+) EMPs (beta = 0.22, p = 0.02), respectively, whereas age (beta = 0.21, p = 0.03) and being born SGA (beta = 0.26, p = 0.01) correlated independently with CD31(+)/CD42b(-) EMPs in the study population. Furthermore, diastolic blood pressure (beta = 0.24, p = 0.04), being born SGA (beta = 0.24, p = 0.04) and the hyperemic peak velocity of the brachial artery (beta = -0.65, p = 0.02) were independently associated with CD31(+)/CD42b(-) EMPs in the preterm-born group. Conclusion Circulating EMPs were higher in preterm-born children compared to children born full-term. Whether EMPs could act, in clinical practice, as a complementary tool for non-invasive evaluation of endothelium in preterm-born children, remains under investigation. Impact Circulating endothelial microparticles (EMPs) are small membrane vesicles released from endothelial cells and they act as novel biomarkers of endothelial activation and damage. No studies have investigated circulating EMPs in preterm-born individuals. Circulating EMPs were significantly higher in prepubertal preterm-born children compared to children born at term. In the preterm-born group, the hyperemic peak velocity of the brachial artery was independently associated with CD31(+)/CD42b(-) EMPs. Whether assessment of circulating EMPs could act, in clinical practice, as a complementary tool for non-invasive evaluation of endothelium in preterm-born children, remains to be defined in future investigations

Haemostatic profile of riboflavin-treated apheresis platelet concentrates.

BACKGROUND: The haemostatic activity of platelet concentrates (PCs) treated with pathogen reduction technology (PRT) remains a subject of debate. Our aim was to investigate the effect of Mirasol PRT on the haemostatic properties of PCs stored in plasma. MATERIAL AND METHODS: Untreated and Mirasol-treated platelets stored in plasma and derived from ten split double-dose apheresis PCs were evaluated in vitro on days 1, 3 and 5 post collection for functionality, microparticle procoagulation activity (MPA), endogenous thrombin potential (ETP), and haemostatic profile using rotational thromboelastometry (ROTEM). RESULTS: P-selectin expression was significantly higher in Mirasol-treated platelets compared with untreated counterparts on days 3 and 5 (p=0.003 and p=0.002, respectively). Clot strength, as shown by EXTEM maximum clot firmness (MCF), was significantly lower in the Mirasol-treated platelets at all time points (days 1, 3, 5) than in untreated platelets (p=0.009, p<0.001, p<0.001, respectively). There was a considerable increase in MPA over time (p<0.001) and this was significantly higher in the Mirasol-treated platelets on day 5 (p=0.015). A notable acceleration of decrease in ETP values was observed for Mirasol-treated PCs over time (p<0.001), with significant differences between PRT-treated and untreated PCs on days 3 and 5 (p=0.038 and p=0.019, respectively). Clot strength attenuation was significantly associated with pH reduction (p<0.001, Spearman’s rho: 0.84), increased microparticle procoagulant activity (p<0.001, Spearman’s rho: -0.75), and with decreased ETP (p<0.032, Spearman’s rho: 0.41). DISCUSSION: Increased platelet activation induced by PRT treatment leads to a decrease in in vitro haemostatic capacity as seen by reduced clot strength and thrombin generation capacity over time. The clinical relevance of this needs to be investigated