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Biomedical subjects

J C Hache

Publications and source records attributed to J C Hache.

At least 19 recordsLinked to original sources
PubMed1991

Upbeat and downbeat nystagmus occurring successively in a patient with posterior medullary haemorrhage.

In a patient with posterior medullary haemorrhage, first upbeat and later downbeat nystagmus occurred in the primary position. The lesion was limited to the posterior and medial part of the medulla. Clinical and electro-oculographic examination first showed upbeat nystagmus in the primary position and upgaze, with downbeat nystagmus in downgaze. Two and a half months later, there was downbeat nystagmus in the primary position and downgaze and upbeat nystagmus in upgaze.

Adult↗
PubMed1991

[Normal perceptual latencies during visual field measurement].

The perceptual latency (PL) to detect stimuli during visual field measurement is not a usual routine test. An automated perimeter ('moniteur ophtalmologique') was used to measure the central 30 degrees of vision with static targets in 50 normal subjects. The visual field was divided into four areas. The purpose of this study was to compare the PL in each area. An increase in the PL was observed, the nasal superior area being longer than the inferior temporal area. It seems that this psychophysical test is transmitted by a specific class of retinal ganglion cells: Y cells. We believe that PL could be a tool for detecting retinal ganglion cell damage.

Adult↗
PubMed1991

[Epidemiology and prevalence of hereditary retinal dystrophies in the Northern France].

The authors present part of a study concerning inherited retinal dystrophies as recorded among the inhabitants of the Nord-Pas-de-Calais region of France. This retrospective study, covering eighteen years (from 1972 to 1989) and covering a population of nearly 4 millions inhabitants, has enabled us to assess the prevalence of each disease. 1,660 cases have been detected and 650 pedigrees have been established. The spatial distribution of the patients in reference to their places of origin in relation to the spatial division of area into "communes" or districts roughly corresponded to the population density and revealed a few centres of dominant retinal dystrophies in rural areas. The analysis of the distribution and inheritance of the various forms of retinitis pigmentosa confirmed the results obtained in other recent and similar studies carried out in other countries. The age pyramid of the detected cases followed that of the population under surveillance. Detection of all dystrophies increased up to the age of 35, then followed the normal decreasing pattern for older generations. As for retinoschisis, detection usually took place in the first fifteen years after birth; for Stargardt's disease, it has occurred up to the age of 20 and for Best's dystrophy, the process was the most extensive and the slowest to appear. The global number of dystrophies studied, corresponded to a prevalence of 1:1,490, which allowed us to estimate that the number of cases in France was 33,800. If we apply the phenomenon to all the populations of the European Community, we must consider that more than 300,000 patients are now affected by disabling hereditary retinal dystrophies.

Cohort Studies↗
PubMed1990

[Progressive cone dystrophy: electrophysiological changes in female carriers].

The authors evaluated a family with X-linked progressive cone dystrophy and special attention was paid to female carriers. Twenty-four members of the family were examined. One generation II--male and five generation III--males were affected. Two generation II--females who, in each case had affected children, but who were asymptomatic, underwent electrophysiological evaluations. The electroretinograms were found to be subnormal in both patients with alterations of cone-mediated responses and color vision. The discovery of abnormalities in female carriers emphasized the necessity of systematically performing electroretinography, together with color vision testing and pedigree examination, when assessing so called sporadic cone dystrophy or in cases where the modes of inheritance are not clear.

Adolescent↗
PubMed1990

[Opticochiasmatic apoplexy].

A 26-year-old patient presented with acute chiasmal syndrome. Computerized Tomography and Magnetic Resonance Imaging demonstrated an intrachiasmal hematoma which was evacuated via a right subfrontal approach. Histological examination revealed an arteriovenous malformation. In 21 similar cases in the literature, surgery generally resulted in the improvement of ophthalmological signs. In 3/4 of the cases, histology identified a subjacent lesion (arteriovenous malformation, cavernoma, venous angioma, glioma).

Adult↗
PubMed1989

X-shaped macular dystrophy with flavimaculatus flecks.

Two families showed a retinal pigment epithelial dystrophy characterized by an X-shaped yellowish macular lesion and numerous flavimaculatus retinal flecks. Nine members were variously affected. The condition was bilateral, had a dominant inheritance and started in middle age with a slow-developing macular lesion. Visual functions were often minimally disturbed for 2 or 3 decades. The flavimaculatus flecks which differed in number appeared only as secondary phenomena yet increased in number and size. At the onset of the disease, the ERG and EOG as well as colour vision were normal and became altered only in the course of a very slow process.

Adult↗
PubMed1989

[Blindness following orbital reconstruction].

A 20 year old patient who suffered from contusion of the optic nerve due to a complex craniofacial fracture, developed, after orbital reconstruction for sequelae of the fracture, loss of light perception which was transiently improved by drug treatment. The clinical and electrophysiological course suggest the presence of ischaemic optic neuropathy.

Adult↗
PubMed1989

[Jaffe's syndrome and anomalies of capillary permeability].

The parallelism between ophthalmoscopy and angiography in the different grade classifications of idiopathic epiretinal membranes is not compulsory: spotty and irregular fluorescein leakage is apparent in many cases, even early. This leakage, who might bring biochemical factors stimulating cellular migration and proliferation could therefore be usually associated with more progression of the membrane.

Adult↗
PubMed1989

[Asymmetry of visual perceptive activity of faces and emotional facial expressions].

Eye movements were studied in 40 right-handed subjects during perception of symmetrical chimerical faces. These movements were recorded using an original system based on a differential optical method for the detection of corneal reflection and of the pupil made shiny. Under basal conditions, the first fixation was usually located in the left visual hemifield. The subjects spent more time gazing at the right hemiface (P less than 0.04). This visuo-spatial asymmetry in favour of the left hemispace was increased when the subject was requested to determine the emotional expressions of a new series of faces (P less than 0.002). Compared with basal conditions, the increase in the percentage of time spent in the left area was significant (P less than 0.035). An analysis performed on the first 3 seconds confirmed and amplified the differences observed. These results can partly be explained by reading habits and exploratory activity for symmetrical shapes. However, activation of the right hemisphere, specialized in the perception of faces and facial expressions, probably influenced visual exploration by drawing attention to the left area and favouring the left visual hemifield.

Adult↗