Navegando por Palavras-chave "vision"

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    Lorazepam induces an atypical dissociation of visual and auditory event-related potentials
    (Sage Publications Ltd, 2003-03-01) Pompeia, S.; Manzano, G. M.; Galduroz, JCF; Tufik, S.; Bueno, OFA; Universidade Federal de São Paulo (UNIFESP)
    Lorazepam has been reported to atypically disrupt visual processing compared to other benzodiazepines (BZs), but it is not known to what extent this effect extends to impairment in other modalities. Our objective was to compare the effects of lorazepam with those of flunitrazepam, a BZ with standard effects, on visual and auditory event-related potentials (ERPs) using the same paradigm. the study followed a placebo-controlled, double-blind, parallel group-design and involved single oral doses of lorazepam (2.0 mg), flunitrazepam (1.2 mg) and placebo. Thirty-six young, healthy subjects completed a test battery before and after treatment including classic behavioural tests, visual and auditory ERPs. Both drugs led to comparable alterations on behavioural tests and double-dissociations were found, indicating that the doses used were equipotent: lorazepam was more deleterious than flunitrazepam and placebo in fragmented shape identification, while simple reaction times were prolonged for flunitrazepam in comparison to lorazepam and placebo. Effects on P3 latencies were also distinct: alterations in both modalities for flunitrazepam were equivalent and greater than placebo's. in contrast, lorazepam at the frontal and central electrode sites led to greater changes in visual than in auditory latency, and also to longer visual latencies than flunitrazepam and placebo, but lorazepam's auditory latency effects were only different to placebo's at the parietal electrode site. Peripheral visual changes were not responsible for these effects. Differences in the impairment profile between equipotent doses of lorazepam and flunitrazepam suggests that lorazepam induces atypical central visual processing changes.
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    Standard full-field electroretinography in healthy preterm infants
    (Kluwer Academic Publ, 2003-11-01) Berezovsky, Adriana [UNIFESP]; Moraes, NSB; Nusinowitz, S.; Salomão, Solange Rios [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Jules Stein Eye Inst
    The purpose of this study was to determine electroretinographic parameters according to the standard protocol from the International Society for Clinical Electrophysiology of Vision (ISCEV) in healthy preterm infants with normal fundus. Seventeen healthy preterm infants with normal fundus were recruited and divided in two age groups: 3-week group, nine infants with mean adjusted age at test = 2.67 +/- 0.92 weeks and 8-week group, eight infants with mean adjusted age at test = 7.92 +/- 1.72 weeks. Full-field ERGs were obtained with a Burian-Allen bipolar contact lens electrode from the anesthetized cornea in one eye, through a fully dilated pupil after 30 min of dark adaptation. the standard ISCEV protocol was used and the following responses were recorded: rod, maximal, oscillatory potentials, cone and 30 Hz flicker. Median values and 1st, 5th, 95th and 99th percentiles for amplitude and implicit time are described for both age groups. There was statistically larger amplitude for 30 Hz flicker (t = 2.191; p = 0.046) and for cone response (t = 2.307; p = 0.044) in the 8-week-old group. Statistically shorter implicit times were found in 8-week group for rod response (t = 3.219; p = 0.015), cone response (t = 2.839; p = 0.016) and flicker response (t = 3.326; p = 0.005). Shortening of implicit time was evident in the older group of preterms and this finding is consistent with other maturational studies confirming the anatomical and functional development of the photoreceptors. Medians and ranges between the 1st and 99th and the 5th and 95th percentiles can be used as a baseline for future comparisons with infants with ROP.