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Biomedical subjects

H Künkel

Publications and source records attributed to H Künkel.

15 recordsLinked to original sources
PubMed1992

[Automatic (computer-assisted) EEG analysis in comparison with visual EEG analysis in patients following minor cranio-cerebral trauma (a follow-up study)].

The study was designed to examine the clinical applicability and use of computer-assisted EEG-analysis in comparison to visual EEG-analysis in patients with minor head injuries. For this in 31 patients the following examinations were performed within the first 24 hours, one, three and eight weeks after traumatization: EEG, neurological examination and standardized evaluation of subjective complaints. The EEG was analysed visually as well as computer-assisted. The results were compared to the neurological findings and subjective complaints. Reversible posttraumatic EEG-changes were observed in 50% of all patients. The results of computer-analysis and visual analysis were equivalent in respect to baseline-activity (as one of the main characteristic EEG-features). Furthermore, based on computer-assisted analysis a discriminant function is provided, which is of diagnostic and prognostic value in the single patient. We conclude that the computer-assisted EEG-analysis can be a useful alternative in EEG-routine diagnosis after minor head injuries.

Adolescent↗
PubMed1990

Neurophysiological assessment of early hepatic encephalopathy.

The spontaneous EEG, pattern reversal VEPs, and the P300 wave were studied in patients with liver cirrhosis and early stages of hepatic encephalopathy (HE). The sensitivities of the different neurophysiological methods in the early stages of hepatic encephalopathy were compared with each other and with several neuropsychological tests. P300 latency was shown to be the most appropriate neurophysiological method for detection of early HE. The diagnostic sensitivity of the P300 latency resembled that of the number connection test (NCT). These results are discussed with regard to methodological considerations and the clinical use of both methods.

Adult↗
PubMed1990

Positron emission tomography in neuropsychiatric lupus erythematosus.

We performed positron emission tomography (PET) using 18F-labeled 2-F-2-deoxyglucose in 13 patients with systemic lupus erythematosus (SLE). Ten of them had clinical signs of central nervous system involvement (NP-SLE). All patients with neurologic symptoms showed pathologic changes on PET, always in accordance with the clinical state. Three patients without neuropsychiatric manifestations had normal PETs. Computed tomography of the brain and magnetic resonance imaging proved to be less sensitive to both presence and localization of CNS lesions. We conclude that the combination of PET and MRI constitutes the most useful diagnostic procedure for NP-SLE.

Adolescent↗
PubMed1990

[Event-related potentials in psychiatry--methodologic principles].

The methodological requirements for the use of event-related brain potentials (ERPs) in psychiatry are critically reviewed. In particular the development of psychophysiological models is considered as essential for a functional interpretation of ERP-experiments. In addition problems of signal-analysis and clinical diagnosis relevant to ERP-research in psychiatry are briefly discussed. The logic of ERP-research in psychiatry is illustrated by a series of dichotic listening experiments.

Arousal↗
PubMed1988

Effects of a cholinergic nootropic (WEB 1881 FU) on event-related potentials recorded in incidental and intentional memory tasks.

In a double-blind placebo-controlled randomized study the influence of a cholinergic nootropic (WEB 1881 FU) on event-related brain potentials (ERPs) related to memory performance was investigated. Two different encoding modes were imposed on the subjects, who had to memorize word lists. No significant drug effects were obtained on memory performance and the ERP-concomitant of encoding, the Dm, while ERP effects related to memory were clearly present. However, the two dosages of the drug significantly influenced the overall amplitude of the late cognitive ERP components, suggesting its effect on cognitive processes.

Adult↗
PubMed1979

The significance of personality traits in EEG evaluation of drug effects.

The relatively clear and compact picture of an electroencephalographic classification of psychotropic substances becomes extremely more complex if the influence of personality traits and topographic differentiations in the EEG are taken into account. Using the example of EEG alterations under diazepam, amitriptyline, pyritinol, EMD 21-657 and caffeine, the complex structure of substance effects, personality factors, topographical differentiations, placebo reactivity and spontaneous circadian variability of the EEG is demonstrated.

Amitriptyline↗
PubMed1978

[Annual rhythms in frequency of electroencephalographic patterns (author's transl)].

A series of electroencephalographic features were measured for about 11,500 patients from a clinical population, over a period of five years (1972 to 1976) and were documented using a standarized procedure. It could be shown that for males a definite yearly rhythm was present for the relative frequencies of alpha-type, partial beta-type, and low voltage EEGs, as well as for continuous and grouped dysrhythmias, the amplitudes of which were in the main 20--30% of the average. For females on the other hand, apart from grouped dysrhythmias, no such yearly rhythms could be proven, at the most such with a periodicity of between 14 and 16 months. The data often display trends that are more distinct than the rhythmicity and as such these should be taken into consideration when deciding upon the model used for statistical regression.

Alpha Rhythm↗
PubMed1976

[Multichannel EEG spectral analysis of the caffeine effect].

By means of multichannel Eeg spectral analysis the central effects of caffeine have been investigated during a controlled factorial study with 9 male volunteers. The effects of coffee and caffeine solution with equal concentration, decaffeinated coffee and hot water have been compared on the basis of analysis of variance. The factorial experimental design implemented a randomization concerning the sequence of substances as well as days of week. The principal findings are following: coffee and caffeine solution of equal concentration on the one hand cannot be readily distinguished concerning their Eeg effects, on the other hand the decaffeinated coffee and hot water exhibit very similar Eeg effects. Very marked differences, however, have been found between the two groups of substances. Coffee and caffeine solution both produce a remarkable, highly significant reduction of theta-amplitude, dominant theta-frequency and theta-frequency-variation. The alterations within the alpha range are mainly increase of dominant frequency and decrease of amplitude. These findings may be interpreted as signs of remarkable activation and elevation of vigilance. It should be pointed out that the Eeg effects of caffeine, as well as those of other compounds with central effects, are characterized by topographically different effects. These are not only quantitative, but partially qualitative differences.

Alpha Rhythm↗
PubMed1976

[EEG spectral analysis of caffeine effects].

Spectral EEG analysis is shown to quantify the centrally stimulating effects of caffeine. Comparing the effects of coffee, decaffeinated coffee, caffeine solution and placebo results in two groups of substances: coffee and caffeine solution on one side, decaffeinated coffee and placebo on the other. The within-group differences are negligible, whereas the between-group differences are highly significant. It may be concluded that caffeine is the effective factor. This study gives no valid evidence confirming possible effects of other coffee ingredients.

Adult↗