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W M Herrmann

Publications and source records attributed to W M Herrmann.

At least 91 records · Page 5Linked to original sources
PubMed1981

[The use of electrophysiological techniques to project typical psychotropic drug effects: some examples (author's transl)].

A long existing hypothesis, i.e. that the EEG effects, in lead O2A2, of typical psychotropic drugs are substance class specific, when given as single oral dosages to healthy volunteers, is discussed. Using the technique of pharmacoelectroencephalograhpy, five typical representatives of neuroleptics, anxiolytics, antidepressives, psychostimulants (Fig. 2) as well as placebo were investigated in 75 volunteers, each receiving one representative of each substance class in a double blind 5-fach change over latin square design (Fig. 3). A five minute EEG record for lead O2A2 was obtained pre, 1 h and 3 hrs post drug intake unter RR (Relaxed Recording) conditions. Typical samples of th EEG records are shown in Figs. 4--7. Parametrisation was done using power spectrum analysis. Then 3 x 7 target variables were formed--six relative power values in predetermined frequency bands and the total power between 1.5 and 30.0 Hz for 3 occasions of measurement (Fig. 4--7). Using a (five-group) linear discriminant analysis the substance effects on the EEG were transformed into 5 probability measures for the five substance classes (Fig. 4--7). The present paper should provide a demonstration of some typical examples, using single subjects, of the projection of substance effects onto an electrophysiological level using a vector of 21 components (7 target variables for 3 occasions of measurement) as can be seen from Table 1. Furthermore, the transformation into probability measures of the five substance classes are shown in Table 2. Table 3 shows five examples of projections of substance effects, which do not fit into the classifications to which they belong. An attempt is made to explain, whether single target variables from the power spectrum can contribute differently to the discrimination between single substances of different substance classes. Within the accepted system of 4 psychotropic drug classes, the following variables seem to be of importance: a) The benzodiazepine anxiolytics show a marked increase in beta F1 (12.0--18.0 Hz) power and activity and, related to sedation, an increase in delta F-power and a decrease in alpha-power; b) The psychostimulants of the amphetamine type show an increase in total power and alpha-power, an increase in the power of the frequency ranges near to the alpha-band (slow beta, fast theta) and a decrease in delta F (1.5--5.5 Hz)-power, when delta F-power is high in the pre-values, indicating a stabilization in vigilance; c) The neuroleptics show a marked increase in theta F (5.5--8.5 Hz)-power, some increase in the delta F--and a decrease in the beta F1-and beta F3-power; d) Tricyclic antidepressants show an interaction between delta F-theta F-, alpha- and beta-power, in the sense of a dissociative shift in vigilance.

Adult↗
PubMed1981

Some examples for the possibilities and limitations of pharmacoelectroencephalography as a method in clinical pharmacology.

Pharmacoelectroencephalography is a new methodology using clinical pharmacological research designs and the method of electroencephalography, and its parametrisation by computer analysis. Pharmacoelectroencephalography is considered to be the most sensitive method for describing drug effects on the human CNS on a functional electrophysiological level. There is an unrevoked hypothesis that all drugs effecting the CNS do reflect those effects in well designed, well conducted and well analysed pharmacoelectroencephalographical studies. On the other hand, if a systematic pharmacoelectroencephalographical study does not verify an effect, then, according to this hypothesis, the drug does not have functional effects on the CNS. The EEG however, is not a direct indicator of toxic effects on the central nervous system. Therefore, from lack of pharmacoelectroencephalographical effects it cannot be concluded that a drug has no toxic effects on the CNS. Pharmacoelectroencephalography has been used to show the efficacy of drugs on a functional CNS level, to establish dose- and time relationships of CNS active drugs, and to suggest dosage levels for therapeutic use and time intervals for their application. Furthermore, with pharmacoelectroencephalography a drug's influence on vigilance and vigilance regulation can be described, and substances can - within certain limits - be screened for their eventual psychotropic properties. It will be demonstrated that pharmacoelectroencephalography provides a sensitive and very useful method for clinical pharmacology, without which the development of new drugs is nowadays almost impossible. However, there are strict limitations for the use of this method and the interpretation of its results: The EEG is not sufficiently validated externally. It is an experimental model based on the electrical activity of the awake brain. The meaning of the changes in this activity is almost completely unknown. Although it has been possible to classify a high number of psychotropic drugs into a predetermined five drug class system on the basic of their EEG effects (19) and although certain drugs have been found whose psychotropic properties were predicted from the EEG (26), it is not possible to describe a drug's psychotropic properties by means of the EEG. The EEG indicates CNS effects, but not necessarily psychotropic properties, even though useful information can be obtained at very early stages in a drug's development, about its influence on vigilance and the organization of the brain's electrical activity.

Adrenergic beta-Antagonists↗
PubMed1979

HZI systems for EEG parametrization and classification of psychotropic drugs.

The EEG effects of twenty, clinically most frequently used psychotropic drugs and five placebos were studied in 75 male volunteers in five simultaneously designed basic studies. In each of the five studies single oral dosages of five drugs (well known representatives of neuroleptics, antidepressants, anxiolytics and psychostimulants, as well as placebos) were investigated in 15 subjects in a double-blind latin-square research design using the methods of the Quantitative Pharmaco-EEG. The results demonstrated that the therapeutically equivalent effective compounds also have similar effects on human EEG. With a classification rule, based on discriminant function 20, and with a classification rule, based on correlation statistics 19 of 25 compounds could be reclassified into correct clinical-therapeutic psychotropic drug groups. It is suggested that CEEG is an important tool in predicting and describing psychotropic properties of compounds, and should routinely be used in psychotropic drug development.

Adult↗
PubMed1979

Development of a classification rule for four clinical therapeutic psychotropic drug classes with EEG power-spectrum variables of human volunteers.

An objective rule for the classification of psychotropic substances has been developed. Classification is based on data from five basic studies simultaneously designed and performed and involving 75 healthy volunteers who ingested 20 different psychotropic drugs and 5 placebos in single oral dosages. Each volunteer took one psychostimulant, one antidepressant, one neuroleptic, one minor tranquilizer and one placebo in a double-blind Latin square cross-over design. The variables were 6 frequency bands, based on power spectrum estimates and determined by factor analysis, plus total power in the 1.5-30.0 Hz range. An objective classification rule was established by multi-group (5 groups) linear discriminant analysis. Reclassification of the substances by the new rule yielded correct results for 17 out of 20 psychotropic drugs and 4 out of 5 placebos. Of placebos from various studies not used for the establishment of the classification rule, 7/9 were classified correctly. The validity of the rule for other classes of substances will have to be verified in independent studies.

Adult↗
PubMed1979

Reflections on the topics: EEG frequency bands and regulation of vigilance.

A critical analysis of quantitative pharmaco-electroencephalography begins with parametrization into variables. The determination of frequency bands according to clinical criteria should be reconsidered. Alternatives may be the determination of factor scores or the definition of frequency bands based on factor analysis. If the latter procedure is used, the clinical alpha-band is subdivided into a lower (alpha 1F = 8,5-10.5 HZ) and an upper (alpha 2F = 10.5-12.5 HZ) part. Furthermore parts of the clinical theta-band (and the delta-band are combined into the delta F-band (1.5-6.0 HZ), for awake healthy volunteers with an occipital alpha-rhythm. Existing concepts of vigilance for the awake stages are not contradictory to the following observations: the factor structure of EEG relative power spectrum variables shows a negative correlation of slow alpha-frequencies with those in the delta F- and beta 3F-band. There is also a negative correlation between slow and fast alpha-wave relative power values.

Arousal↗
PubMed1979

Effects of lithium on vigilance, psychomotoric performance and mood.

It can be expected that investigations on the effect of lithium on the "normal" human mind may elucidate the influence of lithium on experience and behaviour during the "free interval" of manic-depressive patients. In a placebo-controlled double-blind trial 24 normal healthy volunteers were given lithium sulphate (24--36 mval/die) or placebo over a period of two weeks. The subjects were tested after one and two weeks drug intake using the following tests: quantitative pharmaco-EEG, psychological performance, and mood scales. In comparison to placebo lithium shows decreased flicker fusion threshold, and mood change towards depression (Bf-S). In the resting EEG a decrease of relative slow alpha (7.5--9.0 cps)--and an increase of relative fast beta (20.0--30.0, and 30.0--48.0 cps)--power was observed. The results suggest that lithium leads to decreased vigilance and reduced spontaneous activity.

Adult↗
PubMed1978

The psychotropic properties of estrogens.

In this review article clinical literature and experimental work from biochemistry, electro-encephalography and experimental psychology will be reported. Like the androgens and progestogens reviewed earlier, estrogens have psychotropic properties comparable to those of well-known psychotropic compounds. These are: improvement of psychological test results and increase in extraversion and decrease in neuroticism according to the Eysenck Personality Model (1964). Such effects are usually associated with the psychostimulants. The immediate effect on EEG of 4 mg estradiol valerate (single oral dose, male subjects), is a standard EEG profile similar to that of the tricyclic antidepressants. High dosages of estrogens have antidepressant properties clinically. In terms of psycho-pharmacological profiles, the estrogens seem to be a new type of psychotropic compound.

Adult↗
PubMed1978

A multidimensional test approach for the description of the CNS activity of drugs in human pharmacology.

In a double-blind cross-over trial ten healthy male volunteers were administered placebo as well as one representative of each of the four hypothetical psychotropic drug classes, antipsychotics, antidepressants, anxiolytics, and psychostimulants. The drugs were: 75 mg of chlorpromazine, 75 mg of amitriptyline, 10 mg of diazepam and 18 mg of dextroamphetamine sulfate. The effects of the compounds were assessed by pharmaco EEG, an adjective checklist, and a battery of psychological performance tests. The results demonstrate that the test model differentiates well between sedative and stimulatory drug effects. In addition, this multidimensional test approach discriminates adequately the effects of the various sedative drugs. The advantages and limitations of multidimensional test approaches for the description of psychotropic drugs along with the importance of employing such an approach for the development of psychotropic drugs are discussed.

Adult↗
PubMed1978

Preventive treatment of migraine headache with a new isoergolenyl derivative.

In the present double-blind clinical trial an isoergolenyl derivative with periphal antiserotonin, central dopaminergic activity and alpha-increasing effect on the human EEG, lisuride hydrogen maleate, was tested against placebo in a six-month trial involving 240 patients. Lisuride in long-term administration significantly reduces the frequency of migraine attacks in comparison to placebo. Its advantages are good tolerance and minimal side-effects. It is therefore concluded that lisuride is a suitable and effective drug for the prevention of migraine.

Clinical Trials as Topic↗
PubMed1978

[The mathematical rationale for the clinical EEG-frequency-bands. 1. Factor analysis with EEG-power estimations for determining frequency bands].

In order to determine whether the clinically used frequency bands of the EEG can also be obtained by a mathematical system we did a factor analysis with 480 EEG recordings, 5 minutes each, in 60 healthy male volunteers. A power spectrum analysis was done and 57 frequency bands between 1.5 and 30.0 Hz in a half Hz steps were calculated. The factor structure obtained made the following frequency bands (Hz) reasonable: deltaF = 1.5 - 6.0, thetaF = 6.0 - 8.5, alpha1F = 8.5 - 10.5, alpha2F = 10.5 - 12.5, beta1F = 12.5 - 18.5, beta2F = 18.2 - 21.0, beta3F = 21.0 - 30.0. Except for alpha1F all other 6 frequency bands were represented by one general factor with the complexity 1. The variance of the alpha1F band is explained by several of the 6 factors. The clinically known and the by factor analysis obtained frequency bands in the beta-range are similar. The clinically alpha-band is subdivided into two frequency bands alpha1F and alpha2F by the factor analysis. The clinically known border line between delta- and theta-band of 3.5 Hz cannot be found by factor analysis.

Adult↗