Search results for "STAGE"
showing 10 items of 1393 documents
Limbic activity in slow wave sleep in a healthy subject with alpha–delta sleep
2001
All-night electroencephalographic (EEG) activity was recorded in a healthy subject with known alpha-delta sleep. Recordings were made from all 19 of the 10/20 system electrode sites, and low resolution electromagnetic tomography (LORETA) was used to estimate intracerebral current densities. Sleep stages were compared within classical frequency bands by statistical parametric mapping (SPM). With the onset of sleep, occipital alpha abated. With increasing depth of sleep, alpha power increased in a region comprising the left frontal lobe, the anterior and parietal cingulum, and the anterior and medial right front lobe. In slow wave sleep (SWS), frontal alpha power was much greater than in wake…
Sleep investigations in erectile dysfunction
2003
Abstract Regarding the aetiology of erectile dysfunction, beside numerous organic causes in many cases psychological factors play an important role. The pathophysiological mechanisms underlying the so-called psychogenic erectile dysfunction are not yet understood. Based on a neurobiological approach to psychogenic erectile dysfunction, polysomnographic investigations were carried out with the aim of identifying possible alterations of the sleep EEG. 24 male patients with psychogenic erectile dysfunction without detectable organic factors or other mental disorders were studied in the sleep laboratory, as well as an age-matched control group without sexual dysfunctions. Beside a reduction of …
A longitudinal study of sleep disorders in early-stage chronic kidney disease
2010
Few studies have addressed the problem of sleep disturbances in patients with early-stage chronic kidney disease (CKD). A total of 220 patients newly diagnosed with CKD and 220 patients newly diagnosed with chronic hepatitis C were studied within 1 month from the diagnosis. They were evaluated by using the Charlson Comorbidity Index, the Pittsburgh Sleep Quality Index, and the Beck Depression Inventory. Patients with CKD were followed up for 4 years. Sleep disturbances affected 59.5% of patients with chronic hepatitis C and 84.6% of patients with CKD. Sleeping disorders that were severe and peculiar in early CKD improved significantly over time. Beck Depression Inventory disclosed significa…
Macrostructural EEG characterization based on nonparametric change point segmentation: application to sleep analysis
2001
In the present investigation a new methodology for macrostructural EEG characterization based on automatic segmentation has been applied to sleep analysis. A nonparametric statistical approach for EEG segmentation was chosen, because it minimizes the need for a priori information about a signal. The method provides the detection of change-points i.e. boundaries between quasi-stationary EEG segments based on the EEG characteristics within four fundamental frequency bands (delta, theta, alpha and beta). Polysomnographic data of 18 healthy subjects were analyzed. Our findings show that nonparametric change-point segmentation in combination with cluster analysis enables us to obtain a clear pic…
Digital image analysis of liver collagen predicts clinical outcome of recurrent hepatitis C virus 1 year after liver transplantation.
2011
Clinical outcomes of recurrent hepatitis C virus after liver transplantation are difficult to predict. We evaluated collagen proportionate area (CPA), a quantitative histological index, at 1 year with respect to the first episode of clinical decompensation. Patients with biopsies at 1 year after liver transplantation were evaluated by Ishak stage/grade, and biopsy samples stained with Sirius red for digital image analysis were evaluated for CPA. Cox regression was used to evaluate variables associated with first appearance of clinical decompensation. Receiver operating characteristic (ROC) curves were also used. A total of 135 patients with median follow-up of 76 months were evaluated. At 1…
Online detection of rem sleep based on the comprehensive evaluation of short adjacent eeg segments by artificial neural networks
1997
Abstract 1. 1. For scientific and clinical requirements the present objective is a robust automatic online algorithm to detect rapid eye movement (REM) steep from single channel sleep EEG data without using EMG or EOG information. 2. 2. For data preprocessing 20 seconds time periods of the continuous EEG activity are digitally filtered in 7 frequency bands. Then the RMS values of these filtered signals are calculated along segments of 2.5 seconds. The resulting matrix of RMS values is representing information on the power of the signal localized in time and frequency and serves as input to an artificial neural network. A pooled set of EEG data together with the corresponding manual evaluati…
Dynamical properties of the sleep EEG in different frequency bands.
1993
The information concerning the dynamic behavior of the sleep process gained by the usual evaluation of sleep EEGs according to the criteria of Rechtschaffen and Kales is limited. Therefore a new methodical approach is presented, which is a special case of spectral analyzed data processing. After digital band-pass filtering of the sleep EEG the root-mean-square (RMS) value of successive 20 s EEG epochs is calculated in defined frequency ranges. This procedure ensures to take into account the influence of the phase relation between different frequency components. The temporal course of these RMS values during the night reveals smooth curves with continuous transitions between different sleep …
Conventional and spectral power analysis of all-night sleep EEG after subchronic treatment with paroxetine in healthy male volunteers.
1998
Paroxetine is a selective and potent serotonin reuptake inhibitor with reported antidepressant properties. Since changes in the regular sleeping pattern were described as side effects under treatment with paroxetine, the impact of the drug on the sleep architecture is of major interest. The present study addressed the question of subchronic effects of paroxetine medication (30 mg/day) in eight healthy male volunteers in a double blind, placebo-controlled crossover-design. Conventional sleep EEG parameters and additionally computed spectral power analysis based on FFT of 20-s time epochs in the delta, theta, alpha, beta and gamma frequency range for different sleep stages after 4 weeks of tr…
Urological dysfunctions in patients with Parkinson’s disease: clues from clinical and non-invasive urological assessment
2018
Abstract Background Autonomic nervous system dysfunction, common in patients with Parkinson’s disease (PD), causes significant morbidity and it is correlated with poor quality of life. To assess frequency of urinary symptoms in patients with PD, without conditions known to interfere with urinary function. Methods Non-demented PD patients were consecutively enrolled from the outpatients clinic of our department. Scales investigating motor and non-motor symptoms were carried out. Evaluation of urinary dysfunctions was carried out using the AUTonomic Scale for Outcomes in Parkinson’s disease (SCOPA-AUT) questionnaire. Patients underwent noninvasive urological studies (nUS), including uroflowme…
Intracytoplasmic sperm injection with cryopreserved testicular spermatozoa
2001
To assess if testicular sperm cryopreservation is a valid alternative to repetition of testicular sperm retrieval techniques, results of a cryopreservation technique in pills have been retrospectively analyzed. Enough motile spermatozoa for ICSI were obtained in 172 from 190 (90.5%) frozen-thawed testicular sperm samples. Overall, 249 couples underwent 390 ICSI cycles, 156 using fresh and 234 using cryopreserved testicular sperm. Mean two-pronuclear fertilization rates per cycle were not significantly different after ICSI with fresh (62.0%) or with cryopreserved (63.2%) spermatozoa. Mean embryo cleavage rate per cycle was higher in the fresh (90.6%) than in the cryopreserved (84.6%) group (…