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Biomedical subjects

J C Hache

Publications and source records attributed to J C Hache.

At least 73 records · Page 4Linked to original sources
PubMed1986

Fully automated screening procedure for early detection of visual field defects.

A major problem in mass screening for glaucoma is the substantial time required to detect areas of depressed visual sensitivity, scotoma. We have developed a novel instrument for testing rapidly and automatically the sensitivity of the visual field. The patient views a large CRT screen on which up to four luminous points are presented in a prearranged pattern. The patient's vocal response is a number from zero to four, the number of stimulus points that he has observed, which is recognized by the controller and recorded. A series of 90 such patterns is presented sequentially, giving a 288 points visual field test, at the conclusion of which a hard copy probabilistic map of the retinal location of scotoma is drawn. The examination procedure is much faster than that using conventional 'automatic' tests and its results are almost identical with those from two commercial instruments with which our experimental 'perimeter' has been compared. Initial clinical trials are very encouraging.

Glaucoma↗
PubMed1986

[Refsum's disease. Epidemiologic, clinical and biological correlation. 6 cases].

Nine patients with symptoms and signs of Refsum's disease are reported. In 6 a systemic accumulation of phytanic acid was demonstrated, together with low phytanic acid oxidase activity in skin fibroblasts in 5 of them. In 3, no disorder of phytanic acid metabolism was demonstrated. In 3, the diagnosis was made during the pre-clinical period. The disease seems more frequent in Northern France, which agrees with the hypothesis of a genetic mutation which would have taken place in Scandinavia some centuries ago and was subsequently spread by the Vikings. The effects of a dietary treatment on serum phytanic acid levels and clinical disorders are reported. The general condition of the patients improved remarkably but only partially. The diet is unpalatable and in some patients the level of serum phytanic acid increased, due to the mobilization of body fat. Patients with very high levels of phytanic acid might be initially treated by plasmapheresis. For the same reason, the diet should supply enough calories to keep body weight unchanged, and body weight loss whatever its cause should be avoided.

Adolescent↗
PubMed1986

[11 cases of neuropathy induced by almitrine, of which one had optic neuropathy].

The only etiologic factor retained in 11 patients with sensory or sensory-motor neuropathy was almitrine therapy. In one patient there was in addition an optic neuropathy. The reduction in visual acuity in this patient coincided with the onset of the sensory-motor neuropathy of lower limbs after treatment with 100 mg/day of almitrine over a 2-year period. No other metabolic, inflammatory, toxic, vascular or immunologic cause was found. There was a moderate chronic respiratory insufficiency. Visual recuperation started one month after the arrest of almitrine treatment and was satisfactory 7 months later. The other 10 patients had neuropathy of limbs without visual disorders. Neuromuscular biopsy in one case showed lesions to be of the axonal type.

Aged↗
PubMed1985

[Ocular and head movements in infarctions of the thalamic region].

Oculomotor disorders in 22 infarctions in the thalamic region are recorded. Clinical examination and electro-oculography (17 cases) showed that paramedian thalamo-subthalamic lesions were responsible for clear deficits: upgaze paralysis and in some cases downgaze paralysis, partial paresis of the oculomotor nerve, deficits of lateral eye movements, myosis, paralysis of head flexion combined with downgaze paralysis. Postero-median choroid artery infarction was associated with upgaze paresis, slight deficit of lateral eye movements and myosis. Postero-lateral choroid artery infarction resulted in a partial visual field defect and in some cases, a contralateral hypometria; myosis was slight and inconstant. Infarctions of the internal capsule (anterior choroid artery, deep branches of the middle cerebral artery) were associated with a deficit of contralateral saccades. Ocular pursuit, when possible, was often saccadic, whatever the site of the infarction. This prevailed with gaze towards the lesion side.

Adult↗
PubMed1984

[Influence of low concentrations of halogenated anesthetics on the electroretinogram and visual evoked potentials in children].

During anaesthesia for neurophysiological investigations, halogen anaesthetics delivered at high concentrations altered visually evoked potentials. Low concentrations of volatile anaesthetics were proposed to avoid these alterations. Thirty young children, with visual or neurological abnormalities, were divided in two groups: the first group (n = 16), mean age of 20 months, was anaesthetized with halothane 0.5%, and the second (n = 14), mean age of 14 months, with enflurane 1.5%. Retinal action potentials (RAP) and visually evoked potentials (VEP) were obtained by computerized methods. The morphology of graphs before anaesthesia and after increasing concentrations of anaesthetics were compared. Height and latencies of the principal waves were measured. Low concentrations of halothane as well as enflurane avoided RAP and VEP disturbances. Nevertheless, no statistically significant data was obtained because of individual variations due to age, pathology and technical conditions.

Anesthetics↗
PubMed1984

[Alternating oblique deviation of the gaze. 3 cases].

Three cases of alternating skew deviation of gaze are reported. In two patients, it was associated with oculomotor disorders suggestive of a medial mesencephalic lesion. CT scan showed 3rd ventricule abnormalities accounting for the mesencephalic involvement. The third patient had a tuberculous meningo-encephalitis with basal symptoms. The pathophysiological mechanisms of the vertical interocular divergence is discussed. It was probably related to a bilateral disorder of the superior recti and an overaction of the inferior obliques. It suggested a medial supranuclear dysfunction.

Adult↗