Biomedical subjects

B Saletu

Publications and source records attributed to B Saletu.

At least 19 recordsLinked to original sources

PubMed1995

Nicergoline in senile dementia of Alzheimer type and multi-infarct dementia: a double-blind, placebo-controlled, clinical and EEG/ERP mapping study.

In a double-blind, placebo-controlled study on the therapeutic efficacy and central effects of nicergoline, an ergot alkaloid with metabolic, antithrombotic and vasoactive action, 112 patients with mild to moderate dementia, diagnosed according to DSM III-R criteria (MMS 13-25), living in pensioners' homes, were included. Fifty-six were subdiagnosed as senile dementia of the Alzheimer type (SDAT), 56 as multiinfarct dementia (MID), based on computed tomography and Hachinski scores (< or = 49 SDAT, > or = 7 MID). They received, after 2 weeks' run-in period (placebo), randomized for 8 weeks either 2 x 30 mg nicergoline (NIC) or 2 x 1 placebo (PLAC) orally. The four subgroups (SDAT/NIC. SDAT/PLAC, MID/NIC, MID/PLAC; 4 x 28 patients) were comparable in regard to age and sex. Only four, four, four and two patients of the respective groups did not finish the study for minor reasons. Confirmatory statistical analysis demonstrated in the target variable-the Clinical Global Impression (CGI)-a significant superiority of Global Impression (CGI)-a significant superiority of NIC over PLAC in both the SDAT and MID groups. Global improvement (CGI item 2) was seen in both nicergoline subgroups (3 and 3), while no changes occurred under placebo (4 and 4, respectively). The responder versus non-responder ratio was in the SDAT/NIC group 16/8, versus 8/16 in the SDAT/PLAC group (chi 2 = 4.1, P = 0.04); in the MID/NIC group 17/7, versus 7/19 in the MID/PLAC group (chi 2 = 7.96, P < 0.005). Furthermore, there was a significant improvement of the Mini-Mental State and the SCAG score in both the MID and SDAT group after 8 weeks of nicergoline, which was significantly superior to the minimal improvement or no change in placebo-treated SDAT and MID patients. EEG mapping demonstrated in NIC-treated SDAT and MID patients a significant decrease in delta and theta, increase in alpha 2 and beta activity and an acceleration of the centroid of the total power spectrum as compared with pretreatment, while opposite changes occurred in PLAC-treated SDAT and MID patients. The differences between PLAC and NIC reached the level of statistical significance. Event-related potential (ERP) recordings demonstrated a significantly shortened P300 latency under NIC treatment in both SDAT and MID patients, while there was a trend towards lengthening under PLAC. Thus, nicergoline improved vigilance and information processing at the neurophysiological level, which leads at the behavioural level to clinical improvement both in degenerative and vascular dementia.

Alzheimer Disease↗

PubMed1995

Cognitive psychophysiology in nootropic drug research: effects of Ginkgo biloba on event-related potentials (P300) in age-associated memory impairment.

Extracts from the leaves of Ginkgo biloba have been suggested to be useful in the treatment of various symptoms of impaired brain functions in advanced age. To elucidate specific mechanisms of the possible clinical benefit, the effects of Ginkgo biloba extract Ginkobene on cognitive information-processing were investigated by means of long-latency auditory event-related potentials. In a double-blind placebo-controlled study, 48 patients (29 women and 19 men) aged between 51 and 79 years with the diagnosis of age-associated memory impairment had 57 days' treatment with a daily dosage of 3 x 40 mg Ginkobene or placebo. To evaluate acute, chronic, and superimposed drug effects, psychophysiological investigations were carried out on day 1 and day 57 before and 3 hours after drug administration. ERP investigations were carried out by means of a two-tone auditory oddball paradigm. In addition to 17 EEG leads, vertical and horizontal EOGs were recorded. After minimizing ocular artifacts and visual artifact rejection, latencies and topographic distributions of N1 and P2 components (non-targets) and N2 and P300 components (targets) were calculated by an automatic procedure. When compared to the placebo group, in the Ginkobene group no consistent and unequivocal changes on N1, P2, N2, and P300 amplitudes or on N1, P2, and N2 latencies were observed. P300 latency was shortened by 31 ms, 38 ms, and 32 ms in the Ginkgo biloba group after acute, chronic, and superimposed drug administration. It may therefore be hypothesized that the decrease of P300 latency in the Ginkgo biloba group may reflect shorter stimulus-evaluation time.(ABSTRACT TRUNCATED AT 250 WORDS)

Affect↗

PubMed1995

Isoflurane narcotherapy in depressive patients refractory to conventional antidepressant drug treatment. A double-blind comparison with electroconvulsive treatment.

This is the first report on a controlled study comparing the therapeutic and non-therapeutic (side) effects of electroconvulsive treatment (ECT) and isoflurane narcotherapy (ISONAR; deep anesthesias with the inhalation of anesthetic isoflurane) in drug-refractory, severely depressed women, who had been randomly allocated either to ECT (n = 10) or ISONAR (n = 10). Patients from each group were subjected to a total of six treatment sessions (two sessions per week) and maintained on a fixed antidepressant drug dose. The antidepressant efficacy of either treatment was evaluated for each treatment session (in search of a 'rapid antidepressant effect') and at weekly intervals. Cognitive functions or signs of an organic brain syndrome were evaluated by means of psychological tests and extensive EEG analyses. Rapid antidepressant effects of the first treatment session were only significant in patients on ISONAR; in the subsequent treatment sessions, ECT also induced rapid antidepressant effects. Antidepressant effects during the treatment period were comparable, and patients on ISONAR improved further during follow-up, whereas patients on ECT tended to relapse. ISONAR-treated patients improved in most psychometric variables, whereas patients on ECT deteriorated. Finally, the EEG patterns of the ISONAR-treated patients remained normal or augmented (dominant alpha power), whereas patients on ECT developed an increase in abnormalities in EEG patterns and theta/delta power. This indicates an organic brain syndrome in patients on ECT.

Adult↗

PubMed1995

Double-blind, placebo-controlled, pharmacokinetic and -dynamic studies with 2 new formulations of piracetam (infusion and sirup) under hypoxia in man.

In a double-blind, placebo-controlled study, pharmacokinetics and pharmacodynamics of 12 g piracetam in 2 different formulations were investigated utilizing blood gas analysis, EEG mapping and psychometry under a transient, reversible, hypoxic hypoxidosis. The latter was induced by a fixed gas combination of 9.8% oxygen (O2) and 90.2% nitrogen (N2, found in 6,000 m altitude), which was inhaled for 23 minutes under normobraic conditions by 18 healthy volunteers. They received after an adaptation session randomized at weekly intervals 12 g piracetam i.v. (250 ml infusion over 30 minutes), 12 g piracetam p.o. (60 ml sirup) and placebo. Blood levels were determined by means of an HPLC at the hours 0, 1, 2, 4, 6, 8 and 24. The 2 formulations showed a very similar time-course, with slightly higher blood levels in the 1st hour after the intravenous than oral administration, and vice versa thereafter. The elimination half-life was 4.3 hours for both formulations, the area under the curve and the clearance value were also almost identical. Evaluation of blood gases, EEG mapping and psychometry were carried out at 0, 2, 4, 6 and 8 hours post-drug. Blood gas analysis demonstrated a drop in SaO2 from 99 to 73 and 70%, in PO2 from 100 to 35 and 33 mmHg, in PCO2 from 36 to 31 and 31 mmHg in the 14th and 23rd minute of inhalation, respectively. pH increased from 7.43 to 7.48 in the respective minutes, while base excess and standard bicarbonate remained stable. EEG mapping exhibited under hypoxia a marked increase of total power, mostly due to an augmentation of delta/theta, and a decrease of alpha activity, which reflects deterioration of vigilance. Both piracetam preparations significantly attenuated this vigilance decrement, with 12 g piracetam i.v. showing its encephalotropic peak effects in the earlier hours, 12 g piracetam sirup in the later hours. At the behavioral level, hypoxic hypoxidosis induced a deterioration of the noo- and thymopsyche, which was mitigated by both piracetam preparations, mostly in the 6th hour. Both formulations were well tolerated.

Administration, Oral↗

PubMed1995

Acute central effects of the calcium channel blocker and antiglutamatergic drug caroverine. Double-blind, placebo-controlled, EEG mapping and psychometric studies after intravenous and oral administration.

In a double-blind, placebo-controlled study, the effects of caroverine (CAS 23465-76-1, Spasmium)--a quinoxaline derived from isoquinoline, the basic structure of papaverine, originally developed as a spasmolytic drug which may, however, exert central effects due to an unspecific calcium channel blocking action and glutamate antagonism--were investigated utilizing EEG-mapping, psychometric and psychophysiological measures. Fifteen healthy volunteers (8 males and 7 females), aged 20-35 years, received randomized and at weekly intervals 40 and 80 mg caroverine intravenously, 40 and 80 mg caroverine orally, as well as placebo. EEG recordings, psychometric and psychophysiological tests, as well as evaluation of pulse, blood pressure and side-effects were carried out at 0, 1, 2, 4, 6 and 8 h. Multivariate analysis of EEG mapping data demonstrated that caroverine exerted a significant action on human brain function, as compared with placebo, at all given dosages, as early as in the 1st and as late as in the 8th hour after both intravenous and oral administration during resting (R-EEG) and vigilance-controlled recording (V-EEG). Subsequent univariate analyses revealed, however, differential effects of caroverine--dependent on recording conditions and doses. In the resting condition, an increase of absolute and relative delta and theta power, a decrease of alpha and beta power and a slowing of the centroid of the delta and theta activity occurred, reflecting sedative action. The latter was slightly time- and dose-dependent (more sedation in earlier hours after higher doses). However, in the vigilance-controlled EEG, a dose-dependent decrease of delta and theta power, an increase of alpha power and an acceleration of the centroid of the delta and theta suggested vigilance-promoting effects, which were more pronounced in the later than earlier hours. Psychometric investigations confirmed these differential central effects. In regard to the noopsyche, an improvement was noted 6 h after the lowest oral dose. In the thymopsyche, a deterioration occurred after all doses except the highest oral dose, suggesting sedation. The latter was also seen after all active compounds as a trend in psychophysiological variables. The drug was well tolerated.

Administration, Oral↗

PubMed1995

Technetium-99m-HMPAO SPECT imaging of cerebral blood flow during REM sleep in narcoleptics.

UNLABELLED: This study was performed to demonstrate global and regional cerebral blood flow (rCBF) changes during rapid eye movement (REM) sleep in six patients with narcolepsy using SPECT and 99mTc-HMPAO. METHODS: Global and hemispheric HMPAO uptake as well as regional (RI) and asymmetry indices were estimated and compared between polysomnographically verified sleep onset (SO)REM and wakefulness. RESULTS: The estimated global HMPAO uptake did not differ between the two conditions indicating a similar overall cortical activity. During (SO)REM sleep, hemispheric HMPAO uptake as well as calculated RI, especially in the supratemporal plane, were significantly higher on the right side than contralateral. This indicates an initially right-sided cerebral activation and a special involvement of the right, nondominant hemisphere during dreaming which is responsible for visual-spatial perceptions. Furthermore, increased RI in superior parietal regions during sleep were evident and were explained by an activation of associative areas. In thalamic regions, decreased RI were found during sleep, which may reflect thalamic dysfunction. CONCLUSION: A definite assignment of these CBF alterations to (SO)REM sleep might be problematic because of unstable boundaries between sleep stages in narcolepsy. On the other hand, specificity of such CBF changes for narcolepsy requires further study.

Adolescent↗

PubMed1994

Discrimination between demented patients and normals based on topographic EEG slow wave activity: comparison between z statistics, discriminant analysis and artificial neural network classifiers.

The topographic distributions of absolute delta and theta powers were used to classify demented patients and normals by means of z statistics, discriminant analysis and artificial neural networks (NN). The data were taken from two psychopharmacological studies in mildly to moderately demented patients (111 and 96 patients for studies I and II, respectively) and from 56 normal healthy controls. All patients were diagnosed according to DSM-III criteria and were free of medication for at least 2 weeks. The NN used was a strictly layered feed-forward network with complete connections. The z-transformed absolute power values in the combined delta and theta frequency range at 17 electrodes, recorded in a 3 min vigilance-controlled EEG with eyes closed, were used as input. After having trained the NN successfully by backpropagating of errors, the generalization test with independent data results in a classification performance of 90% determined by "relative operating characteristic" analysis. The NN out-performed z statistics and discriminant analysis. This high percentage of correct classifications may justify the development of further application of NNs based on topographic EEG data.

Aged↗

PubMed1994

Placebo-controlled trial of the xanthine derivative propentofylline in dementia.

Treatment of dementing illnesses is still unsatisfactory and agents that might have potential for improving cognitive functions are therefore under extensive investigation. Over a 3-month period a multicenter, double-blind, placebo-controlled, parallel-group study was conducted in 190 patients with dementia to examine whether administration of the xanthine derivative propentofylline at 0.9 g/d might either improve cognition or slow the progression of the disease. Improvement in performance on the Gottfries-Brane-Steen scale (GBS) and in at least two of eight psychometric assessments were defined a priori as the primary efficacy measures. The total scores on the GBS decreased in both the propentofylline and the placebo groups, with improvement however being significantly (p < 0.0001) higher in the propentofylline group. The mean scores in the Mini-Mental State Examination increased significantly (p < 0.05) in both groups, but the increase was significantly (p < 0.02) higher in the propentofylline-treated group. In contrast, psychometric assessments and the cognitive difficulties scale failed to demonstrate a therapeutic benefit of propentofylline after three months. Performance in these categories showed a significant (p < 0.05) improvement for the propentofylline-treated patients and for the placebo-treated patients, but was comparable for both groups. Thus, in spite of the positive results in GBS, the efficacy of propentofylline could not be established according to the definition of the primary efficacy measures. The clinical parameters, however, can be positively influenced by propentofylline. In addition, the results indicate that patient performance can already be enhanced if subjects are required to engage in cognitive tasks.

Aged↗

PubMed1994

BMS-181168 for protection of the human brain against hypoxia: double-blind, placebo-controlled EEG mapping studies.

In a double-blind, placebo-controlled, cross-over trial, the antihypoxidotic properties of BMS-181168 (previously BMY 21502)--a 1-[[1-[2-(trifluoromethyl)-4-pyrimidinyl]-4-piperidinyl]methyl]-2- pyrrolidinone alleviating impairment of learning and memory in the animal--were studied utilizing EEG mapping under an experimental hypoxic hypoxidosis. The latter was induced by a fixed gas combination of 9.8% oxygen (O2) and 90.2% nitrogen (N2) (found at 6000 m altitude), which was inhaled for 23 minutes under normobaric conditions by 16 healthy male volunteers (aged 23-35 years, mean 27.2 years). After an adaptation session, they received in randomized order at weekly intervals oral single doses of placebo, or of 100 mg, 200 mg, and 400 mg BMS-181168. Evaluation of blood gases (PO2, PCO2, SO2), adverse events, and EEG mapping was carried out prior to drug administration and 2, 4, 6 and 8 hours post-drug, on each occasion under normoxic and transient hypoxic conditions. Hypoxemia was controlled by drawing arterialized capillary blood samples from the earlobes after hyperemization of the latter (after 0, 14, and 23 minutes of hypoxic gas inhalation) and by oximetry. After 23 minutes of inhalation, analysis showed a drop in PO2 from 98 to 48 mm Hg, in PCO2 from 41 to 31 mm Hg, and in SO2 from 97 to 80%. Descriptive statistical analyses of EEG mapping data demonstrated under hypoxia/placebo conditions an increase in delta/theta activity and a decrease in alpha activity as well as a slowing of the delta/theta centroid and an increase in the alpha and beta centroid, which suggests a marked deterioration in physiological vigilance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Pharmacokinetic and -dynamic studies with a new anxiolytic, suriclone, utilizing EEG mapping and psychometry.

1. In a double-blind, placebo-controlled, cross-over study, acute pharmacokinetic, neurophysiological and psychotropic effects of suriclone, a new cyclopyrrolone derivative, were investigated and compared with alprazolam. 2. Fifteen normal young volunteers received randomized oral single doses of placebo, 0.1, 0.2 and 0.4 mg suriclone as well as 1 mg alprazolam as reference compound. Investigations were carried out before and 1, 2, 4, 6 and 8 h after drug administration. 3. Pharmacokinetic investigations by radioimmunoassay showed a dose-dependent fast rise of plasma concentrations with a peak at 1 h and a rapid decline thereafter. Both the Cmax and the AUC values exhibited a linear relationship to dose. 4. EEG brain mapping demonstrated significant CNS effects of both compounds, characteristic for tranquillizers (increase of beta, decrease of alpha and increase of delta activity; attenuation of total power and acceleration of the centroid, i.e. centre of gravity frequency). When compared with alprazolam, suriclone exerted less sedative effects. 5. Time-efficacy calculations showed the pharmacodynamic peak effect of suriclone from the 2nd to the 4th hour, and of alprazolam in the 1st hour. Dose-efficacy calculations showed that the most pronounced CNS changes occurred after 1 mg alprazolam, followed by 0.4, 0.2 and 0.1 mg suriclone. 6. Psychometric investigations demonstrated no significant effects after the two lower doses of suriclone, while 0.4 mg and 1 mg alprazolam induced a decrement both in noopsychic and thymopsychic variables seen after higher doses of anxiolytic sedatives. Psychophysiology (critical flicker fusion, pupillometry, and skin conductance measures) pulse rate, systolic and diastolic blood pressure remained unchanged. 7. Psychophysiology (critical flicker fusion, pupillometry and skin conductance measures) showed differential dose-dependent effects. Pulse rate, systolic and diastolic blood pressure remained unchanged. Anxiolytic-characteristic side-effects (tiredness, drowsiness, etc.) occurred predominantly after the highest doses 0.4 mg suriclone and 1 mg alprazolam.

Administration, Oral↗

PubMed1994

Insomnia in generalized anxiety disorder: polysomnographic, psychometric and clinical investigations before, during and after therapy with a long- versus a short-half-life benzodiazepine (quazepam versus triazolam).

Within a double-blind, comparative study on the effects of the long-half-life benzodiazepine (BDZ), quazepam, and the short-half-life BDZ, triazolam, on clinical symptomatology, sleep and anxiety of 45 patients with insomnia based on a mild to moderate generalized anxiety disorder (GAD) (ICD-9 code: 307.42-1, 300,0; ASDC-APSS-Code: A.2.a), we compared, in a first step at baseline, drug-free polysomnographic and psychometric data of 22 patients recorded in the laboratory (L-group) and 21 patients recorded by the Oxford Medilog 9000 system at home (H-group) with those of normal controls. Sleep efficiency, total sleep time, wake within total sleep period (middle insomnia) and wake before buzzer (late insomnia) were significantly deteriorated in both patient groups as compared with controls, while sleep induction time only differed significantly in home recordings. Regarding sleep architecture, stage (S)2 was reduced, S3 and S4 increased in the H-group only, while no intergroup differences were seen in S1, SREM and REM latency. Subjective sleep quality was reduced in both patient groups, but not awakening quality. Psychometric tests in the morning demonstrated for the noopsyche, only a significantly deteriorated psychomotor activity in both patient groups. In the thymopsyche, evening well-being and mood in the morning were reduced in both the L- and H-group, affectivity and morning well-being only in the H-group. The psychopharmacological part of the study was completed by 40 patients (there were 4 drop-outs in the triazolam, 1 in the quazepam group). They were treated after 1 week placebo with either 15-30 mg (median 15 mg) quazepam or 0.25-0.5 mg (median 0.25 mg) triazolam for 4 weeks, and thereafter for 2 weeks with placebo. Anxiety (rated by HAMA and SAS) improved significantly with both drugs and remained improved throughout 2 weeks post-drug placebo, with quazepam being slightly superior to triazolam. Polysomnography demonstrated a shortened sleep onset only after quazepam. Sleep efficiency improved after acute administration of both drugs, but the improvement was maintained by quazepam only (tolerance development with triazolam). Rebound insomnia was observed only in the 1st post-triazolam placebo night (significant intergroup difference based on confirmatory testing). S2 increased, S3 + S4 decreased under and after quazepam, which represents a normalization in home-recorded GAD patients. S1 decreased with both drugs, SREM only under quazepam. Subjective sleep quality behaved very similarly to objective sleep efficiency. Awakening quality improved after acute therapy with both drugs, somatic complaints only with quazepam.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1994

Clinical, EEG mapping and psychometric studies in negative schizophrenia: comparative trials with amisulpride and fluphenazine.

Based on recent quantitative EEG findings of increased slow activity in negative schizophrenia indicating organicity, it was hypothesized that neuroleptics decreasing delta/theta activity should be beneficial for schizophrenics with predominantly negative symptoms. Thus, a double-blind, clinical, psychometric and neurophysiological study was carried out in 40 hospitalized patients with unproductive schizophrenia (mean age: 31 years; ICD diagnoses: 295.0, 295.1 and 295.6) who were treated randomly either with the benzamide amisulpride (AMI; n = 19) or low doses of fluphenazine (FLU; n = 21). In the first 2 weeks the daily doses were 50 mg AMI or 2 mg FLU, respectively, from the third week on up to the sixth week 100 mg AMI and 4 mg FLU. Clinical evaluations, psychometry and EEG mapping were performed on day 1 (hours 0 and 4--acute effect), on day 14 (hour 0--subacute effect) and on day 42 (hours 0 and 4--chronic and superimposed effects). Three AMI patients discontinued therapy prematurely because of productive symptoms (days 14, 28 and 35), while in the FLU group 2 patients dropped out due to depressive symptoms (days 21, 28), 1 due to productive symptoms (day 35), 1 due to ineffectiveness (day 28), and 1 because of an akinetic crisis (day 6). Statistical evaluation demonstrated a significant improvement in the AMDP apathy and Andreasen SANS score in both groups with the patients remaining severely ill as rated by the CGI. FLU-treated patients needed significantly more anticholinergic medication than the AMI-treated group. Psychometric evaluation showed in regard to the noopsyche significant improvement after subacute, chronic and superimposed AMI, while FLU-treated patients showed significant improvement only after subacute treatment. AMI was significantly superior to FLU at the hours 0 and 4 of day 42. The thymopsyche improved after subacute, chronic and superimposed administration of both compounds with a significant superiority of AMI on days 14 and 42 (4 h postdrug). EEG mapping showed a decrease of delta/theta and increase of beta activity as well as an acceleration of the centroid after acute and superimposed AMI on day 42 as compared with baseline; FLU patients exhibited a decrease of delta/theta activity and an acceleration of the total centroid too, while alpha activity was augmented and beta activity tended to be reduced. Our study demonstrated that, in addition to the new benzamide AMI, FLU in low doses may also be regarded as a neuroleptic with activating properties and may be utilized in the treatment of schizophrenics with predominantly negative symptoms.

Adult↗

PubMed1994

Automatic sleep-spindle detection procedure: aspects of reliability and validity.

The paper describes a reliable and valid method for the automatic detection of sleep spindles in whole night polygraphy. The recording of a multi-channel EEG during sleep polysomnography was performed in 10 healthy volunteers aged 20-35 years. This objective method should improve the time-consuming and subjective visual evaluation by increasing the accuracy and allowing the calculation of quantitative variables (i.e., frequency and amplitude), thereby facilitating scientific work with quantitative data. An important part of the method is the treatment of artifacts (i.e., muscle and spindle-like alpha activity). Compared to hardware solutions, our software method has the advantage of higher flexibility in regard to artifact identification and usual spindle definitions.

Adult↗

PubMed1994

[Epidemiology of sleep disorders in Austria].

UNLABELLED: Epidemiologic data on sleep disturbances in Austria were collected for the first time in March/April 1993 in a representative inquiry ( SAMPLE: n = 1000, 471 males, 529 females). 26% of the subjects reported sleep disturbances which were mostly chronic (21% had suffered from sleep disturbance for more than one year). The incidence of sleep disturbances increased with age, namely 13% in 14-30 year-old subjects, 22% in 31-50 year-old ones and 41% in subjects over 50. 7% suffered from disturbances in sleep initiation, i.e., they had a sleep latency of over 30 minutes. 19% of them had difficulties in getting to sleep at least once a week. Disturbances in maintaining sleep were reported by 28% of subjects, 56% of them needing longer than one hour to get back to sleep. 30% suffered from daytime sleepiness, 43% of the subjects were impaired by their sleep disturbances in some way, but only 34% had consulted their doctor.

Adolescent↗

PubMed1994

[A new method for measuring central activation: fourier analysis of pupillary oscillations in depressed patients].

While the changes in pupillary size during wakefulness and drowsiness are easy to understand, the origin of pupillary oscillations is quite mysterious. Waves of spontaneous pupillary constriction and dilation accompany periods of increasing sleepiness and spontaneous arousal. Lowenstein et al. (1963) demonstrated that in the dark, the pupils of young normal alert subjects show waves of dilatation and contraction lasting from about 4 to 40 s and measuring up to 0.5 mm. Furthermore, superimposed fast and very extensive oscillations were observed. The first described oscillations seemed to reflect central nervous activation. Therefore we analysed pupillary oscillations during the recording period of static pupillometry (described by the authors in 1992) which lasted for 25.6 s. Before calculating the Fourier analysis, blinks have to be identified and eliminated by means of a new technique which is called "smoothing". Using the Fourier analysis, the spectrum was divided into 5 frequency bands (0.0-0.2; 0.21-0.4; 0.41-0.60; 0.61-0.8; 0.81-1 Hz). We were also interested in the total spectrum. In order to demonstrate utilisation of the new technique, 146 male and female depressed patients (ICD-Diagnosis 296.1, 296.3, 296.1, 296.3 + 300, respectively, 300.4, 301.1, 296.1, 296.3 + 290, respectively), aged between 18 and 45 years, were investigated by means of pupillometry, followed by analysis of pupillary oscillations. The whole group of depressive patients who received antidepressive medication was compared with 64 healthy subjects of similar age to demonstrate differences in the frequency bands.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Topographic mapping of EEG during sleep.

Topographic aspects of all night sleep EEG were investigated in 10 healthy volunteers (age 20-35 years). EEG brain maps showed an increase of delta power from stage 1 to 4, a decrease of alpha power most pronounced parieto-occipitally and a slowing of the dominant alpha frequency. Differences of EEG power in different sleep stages (as compared to wakefulness) are displayed topographically. Analysis of the course of stage 2 showed an increase of delta power and a decrease of theta power in the first sections of the night, and an increase of beta power later in the night.

Adult↗

PubMed1993

Influence of partial sleep deprivation on the secretion of thyrotropin, thyroid hormones, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone, and estradiol in healthy young women.

The influence of partial sleep deprivation during the second half of the night on the secretion of thyroid stimulating hormone (TSH), thyroxin (T4), free T4 (fT4), triiodothyronine (T3), prolactin (PRL), growth hormone (GH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol (E2) was investigated in 10 healthy young women. Blood samples were drawn at hourly intervals over a 64-hour period (i.e., 3 consecutive days and nights). During night 2, all subjects were awakened at 1:30 a.m. During partial sleep deprivation, TSH concentrations increased significantly and remained elevated throughout the following day. Levels of T4, fT4, and T3 were enhanced during the partial sleep deprivation hours only, and changes in these hormones seemed to be independent of TSH. PRL levels decreased, LH and E2 concentrations increased, and GH and FSH secretion remained unchanged during partial sleep deprivation. This pattern of change of different endocrine axes during partial sleep deprivation resembles those seen after total sleep deprivation, suggesting that similar neurochemical changes are induced by both forms of antidepressant therapy. The late evening GH peak occurred almost exclusively before the onset of sleep. Partial sleep deprivation did not influence the chronobiological profiles of any of the hormones investigated. The chemical changes underlying these alterations are speculated to involve enhancement of central norepinephrine and dopamine activity with a concomitant increase in the activity of the sympathetic nervous system.

Adult↗

PubMed1993

The effect of biologically-active light on the noo- and thymopsyche and on psychophysiological variables in healthy volunteers.

The study was carried out to show how bright light affects intellectual mnestic performance alertness, mood and psychophysiological variables in order to understand the mechanism of bright light which is still unclear. 15 healthy normal volunteers (8 males, 7 females) aged 22-34 years (mean 27) participated in the study. Exposure to bright light (2500 lux) or dim light (500 lux) was intermittent for 4 h between 9 a.m. and 5 p.m. Psychometric investigations for assessment of noopsychic variables, such as attention and concentration on the one hand, and thymopsychic variables, such as drive, on the other hand, as well as flexibility and psychophysiological measurements were carried out before, as well as 1, 2, 4, 6 and 8 h after baseline. As compared to the dim-light condition, subjects who were exposed to biologically-active light showed an improvement of noopsyche in the 6th and 8th hour. Also, the subjective thymopsyche revealed an improvement lasting for the whole investigation period. Psychophysiological measurements reflected an improvement of central and autonomous activation, which was parallel to the improvement of cognition and of well-being. However, biologically-active light did not affect flexibility.

Adult↗