Search PubMed⌕ Search

Biomedical subjects

G Dumermuth

Publications and source records attributed to G Dumermuth.

At least 37 records · Page 2Linked to original sources
PubMed1981

Joubert syndrome: clinical and polygraphic observations in a further case.

To our knowledge, only 10 cases of Joubert syndrome have been published so far. In this paper, we describe the clinical, radiological (computerized tomography) and polygraphic findings in an additional patient. The female presented here is the product of consanguineous parents and a sibling of a previously reported infant. In addition to the well-known episodic tachypnea in an awake state, representing the clinical hallmark of this syndrome, this child also had bouts of tachypnea while asleep. Interestingly enough, these were confined only to non-REM sleep.

Cerebellar Ataxia↗
PubMed1981

EEG power and coherence during non-REM and REM phases in humans in all-night sleep analyses.

All-night spectral power and coherence analysis of six channels of EEG data from 6 healthy volunteers was performed. Integrated power and integrated coherence for the frequency bands of 0.1-7 and 7-12 Hz in 20 s epochs was plotted over the entire nights. Power and coherence increased with deepening slow wave sleep. With the onset of REM periods, power expectedly decreased, whereas coherence showed a further increase or maintained levels. With post-REM phase awakenings, power showed further reductions, and coherence decreased. The REM coherence results were most pronounced in interhemispheric right to left parietal comparisons (recorded vs. a Cz reference) in the 0.1-7 Hz band. It is hypothesized that the high interhemispheric coherence facilitates or reflects right-left transfer of information.

Electroencephalography↗
PubMed1979

EEG data acquisition and preprocessing by microcomputer satellite system.

Recent development in computer technology allows already medium scale EEG data processing to be performed within the clinical neurophysiology department, if a fast minicomputer with adequate mass storage and graphical output facilities is used. Data acquisition, however, should be delegated to a microcomputer which also should take over as much preprocessing as possible. A system is presented, where one or several microcomputer-based satellite units perform analog-digital conversion, Fourier transformation (FFT), calculation of power spectra and crossproducts, as well as event related averaging or other preprocessing procedures. The units are connected to a fast central minicomputer, where a supervisor program loads the microprocessors with their programs, supervises their activity, receives preprocessed data and activates appropriate postprocessing programs to produce the final results.

Analog-Digital Conversion↗
PubMed1978

The computation of EEG bispectra.

This paper presents a FORTRAN program for computation of bispectra of multichannel EEG on a PDP-11/55 computer. Input data are already digitized and file-structured. Output of power spectra, bicoherence and biphases is produced in synoptic form on a line printer.

Computers↗
PubMed1978

Nonketotic hyperglycinemia treated with strychnine, a glycine receptor antagonist.

A 6 1/2-month-old boy suffering from nonketotic hyperglycinemia has been treated for at least 12 months with oral strychnine. The drug caused improvement of muscle tone, motoricity, vigilance and social behavior. Glycine is one of the putative neurotransmitters of postsynaptic inhibition, particularly at the spinal and reticular levels, strychnine its antagonist at the postsynaptic membrane. Strychnine improved the patient's motoricity presumably by blocking the excessive glycine-mediated inhibition of motoneurons. The beneficial effect of strychnine on vigilance and social behavior is more difficult to explain but may have been related to its antagonism of glycine inhibition of brainstem reticular neurons.

Amino Acid Metabolism, Inborn Errors↗
PubMed1977

Studies on EEG activities in the beta band.

A report on first findings of quantitative investigations of beta activity in the frequency domain is presented. Spectral analysis techniques were applied in three parallel still ongoing clinical studies, i.e. (1) an exploration of beta activities in a broad clinical material, (2) a study of the possible use of quantitative beta assessment in antiepileptic drug therapy, and (3) an investigation of special patterns with harmonic components in the beta band. Several clearly distinguishable types of spectral shapes, different coherence characteristics, significant alterations by changes of drug composition and a rich variation of harmonic patterns indicate a large and fascinating new field for clinical EEG research.

Adolescent↗
PubMed1974

[Quantification and analysis of the EEG].

Quantification and analysis are of major interest in modern electroencephalography. During recent years developments in mathematical-statistical analysis of time series and in electronics and computer technology have brought significant advances. A common feature of almost all procedures proposed so far is that they treat the EEG as a random variable. Various statistical descriptors are estimated either in the time or in the frequency domain, for one or several simultaneous EEG channels. This paper reviews the various methods available today to quantize and analyze the main categories of EEG activities, i.e. (1) spontaneous non-paroxysmal activities, (2) spontaneous paroxysmal activities and (3) activities evoked by external sensory stimulation. Due to personal preferences of the author, emphasis is put on analysis methods in the frequency domain. The main problem today lies much less in the technical installation of the one or the other analytical method than in the treatment of artifacts and in postprocessing the large amount of analyzer output. Therefore, applications must be restricted to carefully selected special questions. Clinical electroencephalography is still far from automatization.

Cerebral Cortex↗