Vagus nerve stimulation (VNS) is a therapeutic option in drug-resistant epilepsy. VNS leads to ≥ 50% seizure reduction in 50 to 60% of patients, termed "responders". The remaining 40 to 50% of patients, "non-responders", exhibit seizure reduction < 50%. Our work aims to differentiate between these two patient groups in preimplantation EEG analysis by employing several Entropy methods. We identified 59 drug-resistant epilepsy patients treated with VNS. We established their response to VNS in terms of responders and non-responders. A preimplantation EEG with eyes open/closed, photic stimulation, and hyperventilation was found for each patient. The EEG was segmented into eight time intervals within four standard frequency bands. In all, 32 EEG segments were obtained. Seven Entropy methods were calculated for all segments. Subsequently, VNS responders and non-responders were compared using individual Entropy methods. VNS responders and non-responders differed significantly in all Entropy methods except Approximate Entropy. Spectral Entropy revealed the highest number of EEG segments differentiating between responders and non-responders. The most useful frequency band distinguishing responders and non-responders was the alpha frequency, and the most helpful time interval was hyperventilation and rest 4 (the end of EEG recording).
The objective is to study the involvement of the posterior medial cortex (PMC) in encoding and retrieval by visual and auditory memory processing. Intracerebral recordings were studied in two epilepsy-surgery candidates with depth electrodes implanted in the retrosplenial cingulate, precuneus, cuneus, lingual gyrus and hippocampus. We recorded the event-related potentials (ERP) evoked by visual and auditory memory encoding-retrieval tasks. In the hippocampus, ERP were elicited in the encoding and retrieval phases in the two modalities. In the PMC, ERP were recorded in both the encoding and the retrieval visual tasks; in the auditory modality, they were recorded in the retrieval task, but not in the encoding task. In conclusion, the PMC is modality dependent in memory processing. ERP is elicited by memory retrieval, but it is not elicited by auditory encoding memory processing in the PMC. The PMC appears to be involved not only in higher-order top-down cognitive activities but also in more basic, rather than bottom-up activities.
- MeSH
- akustická stimulace MeSH
- dospělí MeSH
- elektroencefalografie metody MeSH
- epilepsie patofyziologie MeSH
- implantované elektrody MeSH
- lidé MeSH
- mozek fyziologie MeSH
- paměť fyziologie MeSH
- počítačové zpracování signálu MeSH
- sluchové evokované potenciály fyziologie MeSH
- světelná stimulace MeSH
- zrakové evokované potenciály fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVE: The aim of this work was to study the oscillatory changes during target and distractor stimuli processing. We focused mainly on responses after distractor stimuli in the prefrontal cortex and their possible relation to our previous results from the basal ganglia. METHODS: Five epilepsy surgery candidates with implanted depth electrodes performed a three-stimulus paradigm. The frequent stimulus (70%; without required response) was a small blue circle, the target stimulus (15%; with motor response) was a larger blue circle, and the distractor stimulus (15%; without required response) was a checkerboard. The SEEG signals from 404 electrode contacts were analysed using event-related de/synchronization (ERD/S) methodology. RESULTS: The main response to the target stimuli was ERD in the alpha and low beta bands, predominantly in the motor control areas, parietal cortex and hippocampus. The distractor stimuli were generally accompanied by an early theta frequency band power increase most markedly in the prefrontal cortex. CONCLUSIONS: Different ERD/S patterns underline attentional shifting to rare target ("go") and distractor ("no-go") stimuli. SIGNIFICANCE: As an increase in lower frequency band power is considered to be a correlate of active inhibition, the prefrontal structures seem to be essential for inhibition of non-required movements.
- MeSH
- alfa rytmus EEG fyziologie MeSH
- beta rytmus EEG fyziologie MeSH
- biologické hodiny fyziologie MeSH
- dospělí MeSH
- elektroencefalografie * MeSH
- epilepsie patofyziologie MeSH
- evokované potenciály fyziologie MeSH
- kognice fyziologie MeSH
- korová synchronizace fyziologie MeSH
- lidé MeSH
- mladiství MeSH
- modely neurologické * MeSH
- prefrontální mozková kůra fyziologie MeSH
- psychomotorický výkon fyziologie MeSH
- světelná stimulace metody MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
BACKGROUND: Low-dose oral methotrexate (MTX) is an effective immunosuppressive therapy for chronic plaque psoriasis. However, its use is hampered by the risk of liver fibrosis. AIM: To compare the results of serial measurements of serum fibrosis markers during the remission-induction phase of treatment with MTX to those of patients on biological therapy and long-term MTX therapy (>2 years). SUBJECTS AND METHODS: Serum concentrations of hyaluronic acid, N-terminal propeptide of collagen type III (PIIINP) and the results of two multi-test algorithms Fibrotest and Hepascore were evaluated in patients with chronic plaque psoriasis (N = 24, age: 28-79 years, baseline Psoriasis Area Severity Index PASI 13.5, range 2.2-33) at baseline and weeks 16 and 26 after the start of pharmacokinetically guided therapy with MTX (Group A). Patients on established therapy with biologics (N = 15, Group B) and long-term MTX users (N = 10, Group C) with the mean baseline PASI scores of 0.9 and 1.2 were studied in parallel cohorts. RESULTS: At baseline, HA, Hepascore and PIIINP were correlated with PASI of Group A patients. At weeks 16 and 26, HA decreased by 48% and 40% (P < 0.001) and Hepascore by 31 (P < 0.01) and 20% (P < 0.05) respectively. PASI75 (≥ 75% improvement from baseline PASI) was observed in 76% of Group A patients by week 26 and the absolute decreases in PASI and both fibrosis markers were correlated (HA: r = 0.49, P = 0.018, Hepascore: r = 0.47, P = 0.022). In contrast, no significant within-group differences were found in HA and Hepascore results of patients in the groups B and C. PIIINP and Fibrotest were stable in all groups. CONCLUSION: The fibrosis markers hyaluronic acid and Hepascore (the multiple test algorithm which includes hyaluronic acid) are less liver specific and more prone to reflect psoriasis activity than PIIINP and Fibrotest.
- MeSH
- biologické markery krev MeSH
- dospělí MeSH
- fibróza krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- methotrexát terapeutické užití toxicita MeSH
- prospektivní studie MeSH
- psoriáza farmakoterapie patologie MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
