0000000000076513
AUTHOR
Michael Grözinger
Recognition of rapid-eye-movement sleep from single-channel EEG data by artificial neural networks: a study in depressive patients with and without amitriptyline treatment.
An automatic procedure for the online recognition of REM sleep appears to be a necessary tool for selective REM sleep deprivation in depressive patients. To develop such a procedure we applied an artificial neural network to preprocessed single-channel EEG activity. EOG and EMG information was purposely not provided as input to the network. A generalized back-propagation algorithm was used for computer simulation. The sleep profile scored manually according to Rechtschaffen and Kales served as the desired output during the training period and as standard for the judgement of the network output during working mode. Polysomnographic recordings from 5 healthy subjects were pooled to train the …
Melperone is an Inhibitor of the CYP2D6 Catalyzed O-demethylation of Venlafaxine
INTRODUCTION Melperone, a butyrophenone neuroleptic, is frequently used for its sleep-inducing properties. Despite its common use for more than 30 years, it is not yet characterized regarding its effects on cytochrome P450 s (CYPs). In an open pilot study, effects of melperone on the steady-state blood levels of venlafaxine, a recently introduced serotonin- and noradrenaline reuptake inhibiting antidepressant, were assessed. METHODS The dose-corrected serum concentrations of venlafaxine and O-desmethylvenlafaxine were analyzed retrospectively in a therapeutic drug-monitoring (TDM) database comprising 94 patients. In addition, three patients received venlafaxine and melperone concomitantly a…
Alterations of Continuous MEG Measures during Mental Activities
In a pilot study, we investigated the topography of 11 continuous MEG measures for the eyes-opened and eyes-closed condition together with three simple mental tasks (mental arithmetic, visual imagery, word generation). One-minute recordings for each condition from 16 right-handed subjects were analyzed. The electrophysiological measures consisted of 6 spectral band measures together with spectral edge frequency and spectral entropy, plus the time-domain-based entropy of amplitudes (ENA) and the nonlinear measures correlation dimension D2 and Lyapunov exponent L1. In summary, our results indicate a pronounced task-dependent difference between the anterior and the posterior region, but no lat…
Online detection of rem sleep based on the comprehensive evaluation of short adjacent eeg segments by artificial neural networks
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…
Automatic recognition of rapid eye movement (REM) sleep by artificial neural networks.
Artificial neural networks are well known for their good performance in pattern recognition. Their suitability for detecting REM sleep periods on the basis of preprocessed EEG data in humans under clinical conditions was tested and their performance compared with the manual evaluation. A single channel of the EEG signal was analysed in time periods of 20 s and preprocessed into a vector of six real numbers, which served as input to the network. EOG and EMG information was ignored. Backpropagation was used as a learning rule for the network, which consisted of 12 neurons and 39 synapses. Training datasets were put together from the input vectors and the corresponding sleep stages were scored…
An approach to single trial analysis of event-related potentials based on signal detection theory.
Abstract The aim of the present paper was to introduce a single trial analysis to event-related potential measurement in order to illuminate the mechanisms behind an impaired P300 amplitude occurring under certain experimental conditions. For this purpose we applied tools from linear system theory and signal detection theory to single trials in an oddball paradigm in order to estimate the amplitude of the positive deflection around the P300 latency following target and nontarget stimuli. According to the density functions of these amplitude distributions we operationally defined ‘P300 absent in target’ (P300 amplitude smaller than an individual threshold under target conditions) as well as …
The benefit from whole body acupuncture in major depression.
Background: In a single-blind placebo-controlled study design we investigated the efficacy of acupuncture additionally applied to drug treatment in major depression. Methods: We randomly included 70 inpatients with a major depressive episode in three different treatment groups: verum acupuncture, placebo acupuncture and a control group. All three groups were pharmacologically treated with the antidepressant mianserin. The verum group received acupuncture at specific points considered effective in the treatment of depression. The placebo group was treated with acupuncture at non-specific locations and the control group received pharmacological treatment plus clinical management. Acupuncture …
The Influence of All-Night Exposure to Pulsed Radiofrequency Electromagnetic Fields on Human Sleep. Der Einfluss kontinuierlicher nachtlicher Exposition mit gepulsten hochfrequenten elektromagnetischen Feldern auf den Schlaf beim Menschen
Question of the study The widespread use of mobile telephones has led to public discussion about the putative health hazards as well as scientific interest in the interactions of pulsed, high-frequency electromagnetic fields with physiological systems. This article presents a survey of three consecutive studies carried out by a research group at the University of Mainz.
Electrophysiological evidence for an inverse benzodiazepine receptor agonist in panic disorder.
Abstract Inverse agonists of the GABA A receptor clearly decrease the amplitudes of the spontaneous EEG in the P-frequency range. Therefore, we tested the hypothesis that panic patients exhibit a reduction of the EEGs spectral power in the P-frequency band. Ten unmedicated patients with panic disorder and agoraphobia according to DSM-III-R criteria and 10 matched controls were investigated under baseline conditions, after hyperventilation and 30 min after hyperventilation. EEG recordings from the position P z and C z were performed under eyes closed conditions. At baseline conditions the patients suffering from panic disorder depicted a reduced P-power reaching statistically significance fo…
A replication study on P300 single trial analysis in schizophrenia: confirmation of a reduced number of 'true positive' P300 waves.
A single trial analysis of event-related potentials (auditory odd-ball paradigm) of 20 schizophrenics was performed in comparison to matched healthy controls. The purpose of the study was to test the hypothesis that in schizophrenia the well-known P300 amplitude reduction of averaged event-related potentials is due to fewer elicited single trial P300 waves. The results of the present study support this finding of our previous exploratory investigation and point to the view that schizophrenics reveal basal disturbances in information processing due to inadequately elicited electrophysiological responses to target stimuli.
Effects of REM sleep awakenings and related wakening paradigms on the ultradian sleep cycle and the symptoms in depression.
In 1975 Vogel and coworkers published their classical study where they compared selective rapid eye movement (REM) sleep deprivation by brief awakenings to a control intervention paradigm in depressed patients. The superior antidepressive impact of the first procedure was attributed to the REM pressure accumulating during the treatment period. The laborious procedure and the considerable effort necessary to evaluate the sleep profiles in real time have prevented similar experiments so far. Based on artificial neural networks we developed a software for the real time detection of REM sleep. In combination with an alarm system the algorithm allowed us to wake up subjects automatically and to …
Human Sleep EEG under the Influence of Pulsed Radio Frequency Electromagnetic Fields
Former exploratory investigations of sleep alterations due to global system for mobile communications (GSM) signals have shown a hypnotic and REM-suppressive effect under field exposure. This effect was observed in a first study using a power flux density of 0.5 W/m<sup>2</sup>, and the same trend occurred in a second study with a power flux density of 0.2 W/m<sup>2</sup>. For the present study, we applied a submaximal power flux density of 50 W/m<sup>2</sup>. To investigate putative effects of radio frequency electromagnetic fields (EMFs) of cellular GSM phones on human sleep EEG pattern, all-night polysomnographies of 20 healthy male subjects both with …
Neural net classification of REM sleep based on spectral measures as compared to nonlinear measures
In various studies the implementation of nonlinear and nonconventional measures has significantly improved EEG (electroencephalogram) analyses as compared to using conventional parameters alone. A neural network algorithm well approved in our laboratory for the automatic recognition of rapid eye movement (REM) sleep was investigated in this regard. Originally based on a broad range of spectral power inputs, we additionally supplied the nonlinear measures of the largest Lyapunov exponent and correlation dimension as well as the nonconventional stochastic measures of spectral entropy and entropy of amplitudes. No improvement in the detection of REM sleep could be achieved by the inclusion of …
Effects of Lorazepam on the automatic online evaluation of sleep EEG data in healthy volunteers.
In earlier publications we described an automatic algorithm to detect rapid eye movement (REM) sleep from a single-channel EEG recording without using EMG or EOG information. This system consisted of an artificial neural network operating on the basis of preprocessed EEG data and was composed to provide a maximum of robustness for online applications. In the present study the influence of acute administration of lorazepam on the performance of the REM detection procedure was evaluated. Following an adaptation to laboratory conditions, sleep EEG data were obtained from healthy subjects in three nights each. On the evening of the second night the volunteers received a single dosage of 2.5 mg …
Is the nonREM–REM sleep cycle reset by forced awakenings from REM sleep?
In selective REM sleep deprivation (SRSD), the occurrence of stage REM is repeatedly interrupted by short awakenings. Typically, the interventions aggregate in clusters resembling the REM episodes in undisturbed sleep. This salient phenomenon can easily be explained if the nonREM–REM sleep process is continued during the periods of forced wakefulness. However, earlier studies have alternatively suggested that awakenings from sleep might rather discontinue and reset the ultradian process. Theoretically, the two explanations predict a different distribution of REM episode duration. We evaluated 117 SRSD treatment nights recorded from 14 depressive inpatients receiving low dosages of Trimipram…
Increased bioavailability of oral melatonin after fluvoxamine coadministration*1
Background Fluvoxamine, a selective serotonin reuptake inhibitor, is known to elevate melatonin serum concentrations. It has not been clear whether these effects might be attributed to an increased melatonin production or to an decreased elimination of melatonin. The latter hypothesis was tested by this study. Methods Five healthy male volunteers (one CYP2D6 poor metabolizer) received 5 mg melatonin either with or without coadministration of 50 mg fluvoxamine. Serum concentrations of melatonin and fluvoxamine were assessed from 0 to 28 hours after melatonin intake. Results Coadministration of fluvoxamine, on average, led to an 17-fold higher (P <.05) area under concentration–time curve (AUC…