Search PubMed⌕ Search

Biomedical subjects

J Corvera

Publications and source records attributed to J Corvera.

33 records · Page 2Linked to original sources
PubMedDate not supplied

Evaluation of the vestibular autorotation test (VAT) for measuring vestibular oculomotor reflex in clinical research.

BACKGROUND: A method is needed to measure parameters of vertigo and disequilibrium. Our objective was to ascertain whether the vestibular autorotation test (VAT) gives numerical data on the vestibular oculomotor reflex (VOR) that are useful for clinical research. METHODS: A VAT was carried out on 17 healthy young volunteers twice, with an interval of 7 days (group A), and on a single occasion on another 17 volunteers of similar age and health (group B). The parameters studied were vertical and horizontal gains and phases and horizontal eye velocity symmetry. The resulting values were paired inter-session in the same individuals of group A, and between the first test of group A with the test in group B, chosen at random. Variances for the sets of numbers in each parameter as a whole and for each frequency of stimulation were calculated and statistical validity was determined. RESULTS: No significant differences were found between the inter-session and inter-individual results. Variances of gain (horizontal and vertical) were small, but variances of phase and symmetry were large. An analysis of frequencies of stimulation revealed that variances increased with the elevation of frequency. CONCLUSIONS: For clinical research and evaluation, the VAT affords sufficiently consistent figures for vertical and horizontal gain in the entire spectrum of frequencies tested (2-5.9 Hz) and for horizontal phases between 2-3.9 Hz. Vertical phases and horizontal asymmetry vary too greatly for our stated purpose.

Adult↗
PubMedDate not supplied

Vestibular and oculomotor abnormalities in vertebrobasilar insufficiency.

The early diagnosis of vertebrobasilar insufficiency in patients with vertigo as their only symptom was attempted using a battery of vestibulo-oculomotor tests. With this testing procedure, we were able to find abnormal vestibulo-oculomotor mechanisms that could account for the vertigo in 41 of 42 patients. These abnormalities, however, did not fall into an easily recognizable pattern that could be considered characteristic of vertebrobasilar insufficiency. The large intersubject variability probably arises from the very different and widespread lesions that occur at the vestibular and neurological levels as a consequence of vertebrobasilar insufficiency.

Acoustic Stimulation↗
PubMedDate not supplied

[The psychodynamics of deafness].

OBJECTIVE: Deafness generates psychological conflicts for the deaf as well as for others in their environment. Our purpose is to obtain a panorama of the topic based on the available bibliography. INFORMATION: Relevant articles were located in Medline and in unlisted journals, accessible at the National Institute of the Human Communication and at the Juan N. Navarro Hospital of Mexico City. The books were located at the National Institute of the Human Communication. SELECTION OF THE MATERIAL: The articles were selected by the authors, based in their apparent internal consistency and relation to our purpose. Two different concepts became apparent: one which recognizes a "personality of the deaf" that would predispose to emotional damage, and the other that denies that concept, explaining the distinctive features of deaf people as due to basically environmental factors. CONCLUSION: We think that this review sustains the premise that the psychological damages of deafness are real, not inherent to it, but caused by the social, occupational, pedagogical and familiar conflicts that are generated. Those damages vary with the age at the presentation of deafness the personal adjustment to the deficiency and acceptance by the community. The mitigation of deafness, damage depends on educated parents, adequate instruction programs (scholastic as well as occupational), and when needed, appropriate supportive psychotherapy based on the specific needs of each deaf person and this/her environment. We consider highly desirable to promote the elaboration and publication of interdisciplinary studies related to this topic.

Adolescent↗
PubMedDate not supplied

[Vestibular and oculomotor disorders in patients with congenital strabismus].

A group of patients with congenital endotropia or exotropia was investigated in their capacity to perform reflex eye movements. Some patients had a successful surgical correction of their eye defect. The functions measured were the vestibulo-oculomotor reflex, the feedback control loop for searching and following eye movements and the optomotor reflex. A loss in the functional capacity was displayed in all the tests done. The average value of the losses found for the whole group, according to the test used, were from 8 to 27% for the vestibulo-oculomotor reflex; 22 to 42% for the eye tracking feedback loop, and 48% for the optomotor reflex. The deficit was not due to the incorrect eye position, because the successfully operated subjects had the same magnitude of the motor defect than the non-operated patients.

Adolescent↗