Biomedical subjects

Gerda M Saletu-Zyhlarz

Publications and source records attributed to Gerda M Saletu-Zyhlarz.

7 recordsLinked to original sources

PubMed2006

EEG topography and tomography (LORETA) in the classification and evaluation of the pharmacodynamics of psychotropic drugs.

By multi-lead computer-assisted quantitative analyses of human scalp-recorded electroencephalogram (QEEG) in combination with certain statistical procedures (quantitative pharmaco-EEG) and mapping techniques (pharmaco-EEG mapping or topography), it is possible to classify psychotropic substances and objectively evaluate their bioavailability at the target organ, the human brain. Specifically, one may determine at an early stage of drug development whether a drug is effective on the central nervous system (CNS) compared with placebo, what its clinical efficacy will be like, at which dosage it acts, when it acts and the equipotent dosages of different galenic formulations. Pharmaco-EEG maps of neuroleptics, antidepressants, tranquilizers, hypnotics, psychostimulants and nootropics/cognition-enhancing drugs will be described. Methodological problems, as well as the relationships between acute and chronic drug effects, alterations in normal subjects and patients, CNS effects and therapeutic efficacy will be discussed. Imaging of drug effects on the regional brain electrical activity of healthy subjects by means of EEG tomography such as low-resolution electromagnetic tomography (LORETA) has been used for identifying brain areas predominantly involved in psychopharmacological action. This will be shown for the representative drugs of the four main psychopharmacological classes, such as 3 mg haloperidol for neuroleptics, 20 mg citalopram for antidepressants, 2 mg lorazepam for tranquilizers and 20 mg methylphenidate for psychostimulants. LORETA demonstrates that these psychopharmacological classes affect brain structures differently. By considering these differences between psychotropic drugs and placebo in normal subjects, as well as between mental disorder patients and normal controls, it may be possible to choose the optimum drug for a specific patient according to a key-lock principle, since the drug should normalize the deviant brain function. Thus, pharmaco-EEG topography and tomography are valuable methods in human neuropsychopharmacology, clinical psychiatry and neurology.

Brain↗

PubMed2005

EEG mapping and low-resolution brain electromagnetic tomography (LORETA) in diagnosis and therapy of psychiatric disorders: evidence for a key-lock principle.

Different psychiatric disorders, such as schizophrenia with predominantly positive and negative symptomatology, major depression, generalized anxiety disorder, agoraphobia, obsessive-compulsive disorder, multi-infarct dementia, senile dementia of the Alzheimer type and alcohol dependence, show EEG maps that differ statistically both from each other and from normal controls. Representative drugs of the main psychopharmacological classes, such as sedative and non-sedative neuroleptics and antidepressants, tranquilizers, hypnotics, psychostimulants and cognition-enhancing drugs, induce significant and typical changes to normal human brain function, which in many variables are opposite to the above-mentioned differences between psychiatric patients and normal controls. Thus, by considering these differences between psychotropic drugs and placebo in normal subjects, as well as between mental disorder patients and normal controls, it may be possible to choose the optimum drug for a specific patient according to a key-lock principle, since the drug should normalize the deviant brain function. This is supported by 3-dimensional low-resolution brain electromagnetic tomography (LORETA), which identifies regions within the brain that are affected by psychiatric disorders and psychopharmacological substances.

Brain↗

PubMed2004

EEG-mapping differences between narcolepsy patients and controls and subsequent double-blind, placebo-controlled studies with modafinil.

The aim of the present study was to investigate the role of EEG mapping as an objective and quantitative measure of vigilance in untreated and modafinil-treated narcoleptics, and compare it with the conventional neurophysiological method of the Multiple Sleep Latency Test (MSLT) and the subjective Epworth Sleepiness Scale (ESS). In 16 drug-free narcoleptics and 16 normal controls a baseline 3-min vigilance-controlled EEG (V-EEG) and a 4-min resting EEG (R-EEG) were recorded during midmorning hours. Thereafter, in a double-blind, placebo-controlled crossover design, patients were treated with a 3-week fixed titration of modafinil (200, 300, 400 mg) and placebo. EEG-mapping, MSLT and ESS measures were obtained before and at the end of the third week of therapy. Statistical overall analysis by means of the omnibus significance test demonstrated significant EEG differences between untreated patients and controls in the resting condition only (R-EEG). Subsequent univariate analysis revealed an increase in absolute and relative theta power, a decrease in alpha-2 and beta power as well as a slowing of the dominant frequency and the centroids of the alpha, beta and total power spectrum and thus objectified a vigilance decrement in narcolepsy. Modafinil 400 mg/d significantly improved vigilance as compared with placebo (p < or = 0.01), inducing changes opposite to the aforementioned baseline differences (key-lock principle). The MSLT and the ESS also improved under modafinil as compared with placebo, but changes were less consistent. Spearman rank correlations revealed the highest correlations between EEG mapping and the ESS, followed by those between EEG mapping and the MSLT, while the lowest correlation was found between the MSLT and the ESS. In conclusion, EEG mapping is a valuable instrument for measuring vigilance decrements in narcolepsy and their improvement under psychostimulant treatment.

Adult↗

PubMed2002

Hormone replacement therapy and vigilance: double-blind, placebo-controlled EEG-mapping studies with an estrogen-progestogen combination (Climodien, Lafamme) versus estrogen alone in menopausal syndrome patients.

UNLABELLED: The aim of the double-blind, placebo-controlled study was to investigate the effects of a continuous combined estrogen-progestogen treatment (Climodien, Lafamme) as compared with estrogen alone on vigilance in insomniac postmenopausal syndrome patients, objectified by EEG mapping. METHODS: In a 3-arm, 2-month parallel group design phase, patients received a combination of estradiol valerate 2 mg and the novel progestogen dienogest 3 mg (Climodien 2/3) or estradiol valerate 2 mg alone or placebo. In a subsequent open-label phase, all patients received estradiol valerate 2 mg+dienogest 2 mg (Climodien 2/2). EEG mapping was carried out before and after the 2-month double-blind phase as well as after the 2-month open-label treatment. RESULTS: As compared with placebo, Climodien 2/3 induced a marked and highly significant increase in absolute power in all frequency bands, specifically in alpha-2 activity. Moreover, a significant increase in relative alpha-2 power, a decrease in relative delta and beta power as well as an acceleration of the dominant frequency and of the delta and alpha centroids suggested a marked improvement in vigilance. In contrast, under estradiol valerate 2 mg alone, only a slight augmentation of alpha and attenuation of relative delta and beta power occurred, suggesting only a slight vigilance improvement as compared with placebo. Thus, dienogest 2 mg increased the estrogen effect, which was also confirmed by a statistical evaluation of the differences between Climodien 2/3 and estradiol valerate alone (augmentation of alpha-2, attenuation of relative beta, acceleration of the dominant frequency). Moreover, Climodien 2/2 also markedly increased alpha-2 power, decreased relative beta-2 power and accelerated the alpha centroid. Finally, comparing Climodien 2/3 with Climodien 2/2, there was even a dose-efficacy relation. CONCLUSIONS: Estradiol valerate 2 mg improves vigilance slightly, thereby confirming previous findings. The additional administration of dienogest does not minimize the effect of estrogen, but on the contrary increases it, which makes the combination superior to both placebo and estradiol valerate alone. Vigilance improvement may be of great therapeutic benefit to menopausal syndrome patients at a time when increased adaptability is needed to adjust to increasing sexual, marital, occupational and social difficulties known to occur specifically in this period of life.

Aged↗

PubMed2002

Visualizing central effects of S-adenosyl-L-methionine (SAMe), a natural molecule with antidepressant properties, by pharmaco-EEG mapping.

In a double-blind, placebo-controlled, cross-over study, the central effects of the natural molecule S-adenosyl-L-methionine (SAMe), or ademetionine (ADE), used in low doses as a nutraceutical and in higher doses as a pharmaceutical, were investigated by means of EEG mapping and psychometry. Ten young, normal healthy volunteers of both sexes, with a mean age of 25.2+3.9 yr received, in random order, infusions of 800 mg ADE in 250 ml of isotonic solution, and placebo consisting of 250 ml of isotonic solution administered over 30 min for 7 d, with a wash-out period of 3 wk in between. EEG recordings and psychometric tests were carried out 0, 1, 3 and 6 h after drug administration on days 1 and 7. While there were no significant changes in psychometric findings, multivariate analyses of the EEG results based on MANOVA/Hotelling T 2 tests demonstrated significant encephalotropic effects of ADE compared to placebo. ADE-induced changes were characterized by a decrease in total power, an increase in absolute delta power and a decrease in absolute alpha and beta power, further by an increase in relative delta and beta power and a decrease in relative alpha power, a slowing of the delta/theta centroid, an acceleration of the alpha centroid as well as a slowing of the centroid of the total power spectrum. These changes are typical of classical antidepressants of the thymoleptic type such as imipramine and amitriptyline. Time-efficacy calculations demonstrated a significant central effect of ADE in the first hour after the first infusion, declining slowly until the third hour and thereafter steeply until the sixth hour; a further significant effect was after 1 wk of daily infusions and in the third hour after one superimposed infusion on day 7 of subacute treatment. Our pharmaco-EEG findings suggest both inhibitory and excitatory drug effects at the neurophysiological level, underlying the antidepressant properties well-documented in clinical trials.

Adult↗

PubMed2000

Nonorganic insomnia in panic Disorder: comparative sleep laboratory studies with normal controls and placebo-controlled trials with alprazolam.

Objective and subjective sleep and awakening quality was investigated in 11 drug-free patients (4 females, 7 males) aged 30-55 (mean: 44+/-9) years with nonorganic insomnia (F 51.0) related to panic disorder (F 41.0) as compared with 11 age- and sex-matched normal controls aged 30-58 (mean: 44+/-9) years, utilising polysomnography (PSG) and psychometry. PSG demonstrated decreased sleep efficiency (primary target variable), total sleep time (TST) and S2 as well as increased middle and late insomnia, S1, S3+S4, snoring and PLM in patients. There were no intergroup differences in REM variables. Subjective sleep quality deteriorated, as did drive and fine motor activity in the morning, while concentration increased. Blood pressure in the evening and morning and pulse rate in the evening were elevated. These differences as compared with normals were distinct from those observed in other sleep disorders. In a subsequent acute, placebo-controlled cross-over design study, patients received alprazolam 0.5 mg (Xanor((R));) and placebo. As compared with placebo, alprazolam induced an increase in sleep efficiency (primary target variable), TST and S2, a decrease in wakefulness during the total sleep period, S3+S4 and the oxygen desaturation and PLM indices, and improved subjective sleep quality, somatic complaints, drive, affectivity and drowsiness in the morning. There were no changes in REM variables. Thus, alprazolam induced changes that were opposite to the differences observed between patients and controls before treatment, thereby normalizing sleep and awakening quality. As observed in insomnia related to GAD and subsequent benzodiazepine therapy, the present study also points to a key-lock principle in the treatment of insomnia caused by anxiety disorders and neurophysiologically visualizes processes at the receptor level (e.g. benzodiazepine agonists versus inverse agonists). Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗

PubMedDate not supplied

Differences in brain function between relapsing and abstaining alcohol-dependent patients, evaluated by EEG mapping.

AIMS: Early clinical electroencephalographers reported that low-voltage fast desynchronized patterns were frequently seen in chronic alcoholism, suggesting hyperarousal of the central nervous system (CNS). The aim of the present study was to investigate the brain function of drug-free, detoxified alcoholics, and compare this with that of normal controls, utilizing computerized quantitative EEG analysis and subsequent EEG mapping. Moreover, differences between patients relapsing or abstaining during 6 months of relapse prevention therapy, pharmacologically supported by either flupentixol decanoate 10 mg or placebo i.m. every 2 weeks, were determined. METHODS: 22 drug-free, detoxified patients (15 men, seven women) aged between 27 and 58 (mean 41.5 +/- 8.1) years, diagnosed as alcohol-dependent (ICD-10: F10.23) were included in the study. They were subdivided into abstainers (n = 11) and relapsers (n = 11), and matched with normal healthy controls according to age (mean 41.5 +/- 8.4 years) and sex. A 3-min vigilance-controlled EEG (V-EEG) was obtained and analysed off-line by multi-lead EEG power spectral analysis and subsequent mapping methods. RESULTS: The drug-free, detoxified, alcohol-dependent patients showed, as compared with controls, aberrant brain function characterized by a decrease in delta and slow alpha and an increase in beta activity as well as an acceleration of the total centroid. These findings were more pronounced in relapsing than in abstaining patients. After 6 months of treatment, abstaining patients showed an increase in slow activity, a decrease in fast alpha, an acceleration of the delta/theta centroid and a deceleration of the alpha centroid, reflecting a normalization of brain function. CONCLUSION: EEG maps of alcohol-dependent patients differ significantly from those of normal controls and patients suffering from other mental disorders and thus EEG mapping may be used for diagnostic purposes. Moreover, the quantitative EEG may also be of prognostic value as relapsing patients differ from abstaining ones, since they show a significantly more pronounced hyperarousal of the CNS.

Adult↗