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Biomedical subjects

Y Grall

Publications and source records attributed to Y Grall.

15 recordsLinked to original sources
PubMed1990

[Visual electrophysiology in 101 children with encephalopathy].

The electrophysiological recordings (E.R.G. associated with C.V.E.P.) performed on 101 children suffering from encephalopathy of different origins demonstrate a trend towards retinal integrity for subjects with encephalopathy and no suspicion of acid-base disorders. However a functional macular deficiency is frequently observed in encephalopathy with suspicion of acid-base disorders (encephalopathy due to intracranial hypertension or cardio-vascular disorders or metabolic deficiencies with acid-base disturbance). In these cases, a common pathophysiological substratum with disturbance of the acute or chronic acid-base equilibrium has been assumed. Over a period of time, in fixed encephalopathy, the electrophysiological results reflect a real but slow maturation of the visual pathways.

Brain Diseases↗
PubMed1989

Data processing software for electrophysiological visual exploration.

The software we have developed originated after careful study of a routine functional visual processing session. It has three objectives: (i) to have available a large library of data processing programs; (ii) to add to these electrophysiological results, automatically transferred into a file, a clinical record card, creating a personalized file for study of visual characteristics of each patient; (iii) to allow programs providing statistical studies, creation of groups based on the same clinical features and various comparisons between files or groups. The database now contains 5000 different files and the results of its use are very encouraging. Some results are presented, especially those of a study on multiple sclerosis. The goal of the operation is the creation, in the future, of an expert system.

Clinical Laboratory Information Systems↗
PubMed1985

Correlation functions in the analysis of visual evoked potentials.

Our "vision" laboratory has been working for several years on stimulation methods and data processing. We present here the results of an analysis of correlation functions between VEPs obtained by flashes and patterned stimulations. This study provides additional information about possible interpretations.

Evoked Potentials, Visual↗
PubMed1985

[Methods of stimulation in visual electrophysiology].

After introducing physical and physiological stimulation parameters, the authors present different techniques and discuss their clinical usefulness for the investigation of the visual system: flashes: chiefly 'ganzfeld' stimulators (whole field or local stimulation). A solution using optic fibres incorporated in a sclero-corneal electrode built in our laboratory is presented; patterns: bars or chekerboards, especially on TV screens. Advantages and inconveniences of video images are discussed; other techniques: essentially endocular laser interference fringes, electrical stimulations, high level flashes for ERP and binocular studies, particularly dynamic random dot pattern EVP. In conclusion, the necessity for the careful control of stimulation characteristics and for a strategy suitable for clinical examination is discussed.

Brain↗
PubMed1975

Effect of pentazocine on the evoked potentials recorded in the primary somesthetic cortical areas of guinea pigs.

The influence of pentazocine on the evoked potentials registered in the primary somesthetic cortical area in guinea pigs under pentobarbital anesthesia was studied. The stimulation was applied in the contralateral lip and the evoked cortical responses from different zones on the cortex stereotaxically localized were registered. Pentazocine (5-10 mg/kg i.v.) induced a significant increase in the latency of the evoked potentials as compared with controls. Since morphine does not modify these potentials, the effect of pentazocine is interpreted as being a direct one on the primary pain pathway.

Animals↗
PubMedDate not supplied

[Statistical results of 700 electrophysiologic tests (ERG) in patients without ophthalmologic manifestations treated with synthetic antimalarials for rheumatologic or dermatologic disease].

737 adapto-electroretinograms are registered on patients treated by chloroquine for a rheumatoid arthritis (RA) or for a lupus. Their ophthalmological examinations are completely normal. In term of the cumulative doses, the statistical results of the electrological characteristics of the different waves of the ERG issued from white, red and blue stimulations show: a great stability of the latencies of the "a" and "b" waves; a gradual decrease of the "b" wave amplitudes for the RA; a gradual increase of the "b" wave amplitudes till a level dose reached between 800 and 900 g and then a decrease of the "b" wave amplitudes, for the lupus. We discuss the electrophysiological criterions for a beginning intoxication. As a standard, for the R.A., it seems that a certain amount of "b" wave amplitude decrease could be admitted but the "a" and "b" wave latencies must be very constant. For the lupus, the hyper normality or at least stability of the "b" wave amplitude can be admitted till a dose around 800 g, associated to a good stability of the "a" and "b" wave latencies. Beyond these statistically established limits a beginning intoxication should be suspected.

Adolescent↗
PubMedDate not supplied

[Effect of fundus vagotomy on the gastric emptying of the solids and liquids of a meal in patients with and without postoperative duodenal ulcer recurrence].

The effects of fundic vagotomy (FV) on gastric emptying in the solid and liquid phases of a meal were studied by an isotopic technique in 12 patients with duodenal ulcer. Postoperative results were compared with those obtained in the same subjects before FV and with control values obtained in an identical group of healthy subjects. Early gastric emptying (perprandial) of the two phases of the meal was enhanced by FV but the results failed to reach statistical significance. Gastric emptying of liquids, measured during the 3 h following the end of the meal, was not significantly modified by FV (half-emptying times: 62 +/- 5 min before FV, 75 +/- 8 min after and 65 +/- 7 min for controls). That of solids was significantly delayed by FV (per cent emptied by min: 0.50 +/- 0.02 p. 100 before FV, 0.40 +/- 0.03 p. 100 after, and 0.49 +/- 0.02 p. 100 for controls); this delay was found in all but one patient, but the difference was very slight. Eleven of the 12 investigated patients cured by the operation, were compared with 6 subjects presenting with post FV recurrence: gastric emptying rates of solids (0.41 +/- 0.02 p. 100/min and 0.47 +/- 0.07 p. 100/min) and half emptying times of liquids (72 +/- 10 min and 61 +/- 10 min) were not significantly different. Thus, the gastric emptying rate of an ordinary meal remains practically unchanged by FV and postoperative recurrences of duodenal ulcer cannot be explained by alteration of gastric evacuation.

Adult↗