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Biomedical subjects

F Rigaudiere

Publications and source records attributed to F Rigaudiere.

9 recordsLinked to original sources
PubMed2000

[Functional visual explorations of Bardet-Biedl syndrome. A study of three cases].

Laurence-Moon syndrome, which is very rare, and Bardet-Biedl syndrome, which is more frequent are now well-recognized as two distinct entities in pediatric neurology. Bardet-Biedl syndrome includes a number of common clinical signs it shares with Laurence-Moon syndrome but also with other syndromes, particularly Alströme syndrome. These signs are retinitis pigmentosa, mental retardation, obesity, and hypogonadism. Ophthalmological and electrophysiological examinations are essential for confirmation and correct diagnosis of Bardet-Biedl syndrome. We present three case histories. Our third case illustrates the possibility of below normal yet discernable electroretinogram amplitudes which do not infirm the diagnosis of Bardet-Biedl syndrome.

Bardet-Biedl Syndrome↗
PubMed1999

Recording the photopic electroretinogram from conscious adult Yucatan micropigs.

The micropig is viewed by many as one of the best animal models of human system physiology. The purpose of this study was to develop a simple, rapid and reliable method to record clinical electroretinograms from conscious adult Yucatan micropigs. Photopic ERGs were recorded from 18 conscious animals following a 3-h period of preadaptation to a moderate photopic environment. Rectal temperature and blood pressure were monitored throughout the experiment. In order to test the reproducibility of our procedure, the same protocol was repeated (n=6 micropigs) on three different recording sessions each separated by a 48-h period. Our results indicate that the recording of reproducible ERGs, in the conscious Yucatan micropig, is feasible provided that an adequate experimental approach is used. We believe that our method will enable investigators to perform retinal physiology experiments using an approach which is compatible with that used in a human clinical setup thus facilitating the transposition of experimental data from animal to human.

Adaptation, Ocular↗
PubMed1994

Contribution of scanning laser ophthalmoscopy to the functional investigation of subjects with macular holes.

A study was designed to validate a functional investigation performed with the scanning laser ophthalmoscope before surgery for macular holes in 12 eyes: The assessment included fundus examination, a functional examination resulting in evaluation of the preferred retinal lows, visual acuity and recording of visual evoked potentials. The preferred retinal locus was evaluated by presenting a small square area, and visual acuity was determined by means of calibrated figures. The visual evoked potentials were evoked by three alternating checkerboards (check size, 30', 2 Hz) centered over the hole and seen at an angle of 6.5 x 6.5 degrees, 2.5 x 2.5 degrees and 6.5 x 6.5 degrees with central exclusion of 2.5 x 2.5 degrees. The appearance of the fundus visualized by scanning laser ophthalmoscopy consisted of a clear central disk corresponding to the hole, surrounded by a very dark ring, associated with a second, less dark ring with unclear margins. Fixation was unstable in one case with a visual acuity of 20/70. In 11 cases, fixation was localized to the superior retina with a visual acuity superior to 20/70. The visual evoked potentials evoked by 6.5 x 6.5 degrees were discernible in all 12 eyes; visual evoked potential by annular stimuli were discernible in 11 cases. The 2.5 x 2.5 degrees stimulus evoked no response in eight cases, proving the area of the hole was nonfunctional. A response was recorded in the four other cases, where the dimension of the holes was less than 2 degrees. The results of this scanning laser ophthalmoscopic assessment demonstrated a precise evaluation of the residual macular function in the cases of full-thickness macular holes.

Aged↗
PubMed1993

Is there a systematic location for the pseudo-fovea in patients with central scotoma?

The retinal location of preferential fixations of twenty-four patients with central scotoma were studied when reading digits projected onto their retina with a scanning laser ophthalmoscope. In the majority of cases the fixation was located on the left part, or the inferior part of the visual field relative to the central scotoma. The fact that the inferior visual field is used is coherent with the notion that the lower visual field is important for locomotion. However the preferential use of the left field appears contradictory with data showing superiority of visual faculties in the right visual field. This result may possibly be explained in relation to the need for left-to-right readers to monitor where their eyes have landed relative to the word previously fixated on the left.

Adult↗
PubMed1991

A hereditary syndrome with retinopathy and ataxia or deafness in two consanguineous brothers.

Of two brothers born of Sephardic first cousin parents one presented with congenital neural deafness, nyctalopia, visual field loss, flat ERG, unintelligible speech and a shuffling gait, and the other with severe ataxia, severe decreased visual acuity, mild field loss, decreased ERG, dysarthric speech and high grade myopia. The diagnosis of Usher syndrome type 1 or 2 is discussed as well as the possibility that both brothers have different genetic disorders.

Adolescent↗
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↗
PubMed1978

An apparatus for studying electroretinographic responses under conditions of space flight.

This project has developed so as to include the total range of electroretinographic responses under conditions of space flight. We built two special containers which made stratospheric balloon flights. The second prototype carries the following specifications: Immobilisation of two frogs; Light stimulation by flashes; Special corneal electrodes; Amplification and recording system. There is almost no tissue damage after prolonged observation (several days) of the animals and the electroretinographic responses do not show any significant changes. Such an apparatus could be used as the basis for an assembly to be incorporated into Spacelab.

Animals↗