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Biomedical subjects

M Matousek

Publications and source records attributed to M Matousek.

9 recordsLinked to original sources

Optoelectronic movement analysis in Parkinson's disease: effect of selegiline on the disability in de novo parkinsonian patients--a pilot study.

New opto-electronic camera systems permit easy quantification of the motor performance during natural acts in freely moving humans. We used a simple test movement (PLM test) to quantify the disturbance in the postural (P), locomotor (L) and manual (M) part of the body movement and the coordination of the different movement phases into a smooth motor act. The test movement time was used to quantify the overall performance. With this technique we have measured the effects of selegiline on the degree of parkinsonism in a double-blind, placebo-controlled pilot study of 5 de novo patients with Parkinson's disease. There was a clear trend that selegiline was superior to placebo in reducing the test movement time.

Aged

Serial quantitative electroencephalography.

Repeated EEG examinations are often used in diagnostically difficult cases to assess whether an EEG abnormality is progressive, regressive, or stationary. The conventional visual method is, however, poorly adapted to consider the variability when consecutive EEG recordings are compared. Using computer analysis of EEGs, the feature of the recordings as well as their variances can be measured, and the differences between the recordings can be tested statistically. The aim of the present study was to develop a practicable method for quantitative serial EEG examinations. Twenty EEGs from 5 volunteers were recorded to obtain reference data. The data acquisition was automated to obtain data without visual bias. The previously developed method using age ratios was employed for the primary analysis. The changes of the EEG activity during the observation period were evaluated statistically. Differences between consecutive EEGs could be observed even in normal subjects but the number of 'false positive' findings was reduced by the automatic data selection, by the choice of proper measures, and by adequate statistical treatment. The diagnostic value of the method was tested in 59 EEGs from 13 patients with well-defined brain disorders. Most EEG changes which could be attributed to the development of the disease were discovered and labelled as statistically significant.

Adult

Automatic measurement of the vigilance level and its possible application in psychopharmacology.

The main object of the study was to separate the specific EEG effects of psychopharmaca from changes caused by drowsiness. The study was based on quantitative evaluation of the vigilance level during five minutes of EEG recording under standardized conditions. The equation for computing the vigilance level from EEG spectra was obtained by using a training material. The segments were classified visually either as alert EEG, or as EEG marked by drowsiness. As confirmed by independent test material, the coefficients derived by means of multiple linear regression were applicable to other EEGs for estimating the vigilance level. The procedure was used in the evaluation of the psychopharmacological treatment. It was concluded that the specific EEG drug profiles were certainly influenced by the accompanying drowsiness, but the main information was still preserved. In contrast to the specific drug effect, the drug-induced sleep activity could be isolated from other events and studied separately. It was also found that after a standard stimulation, both the general trend and periodicity of the vigilance fluctuations were closely related to the psychic state of the patient.

Arousal

Central nervous system effects of local anaesthetic agents.

A review is given of an experimental study on cats where the influence of acid-base changes on central nervous system toxicity of local anaesthetic agents was studied. The conclusion of this study was that a respiratory acidosis increased the central nervous system toxicity of local anaesthetics and that the underlying metabolic conditions modified this increase. Thus a respiratory acidosis increased this toxicity more if it was based on a metabolic acidosis than on a metabolic alkalosis (Englesson, 1974; Englesson and Grevsten, 1974). An extended analysis is presented where automatic frequency analysis was performed on the e.e.g. recordings performed during the i.v. infusion of lignocaine, bupivacaine, L 134, HS 37 and its optical isomers. The preliminary results show that the electrical changes appearing in the e.e.g. from the start of the i.v. infusion until seizure activity were the same if this time interval was as short as 1 min or as long as 8 min. It also revealed remarkable individual differences between agents, for instance lignocaine displaying marked electrical changes already in the first third of this time period where bupivacaine showed no changes until shortly before seizures.

Acid-Base Equilibrium