989 resultados para Visual stimuli
Resumo:
Purpose: To evaluate rates of visual field progression in eyes with optic disc hemorrhages and the effect of intraocular pressure (IOP) reduction on these rates. Design: Observational cohort study. Participants: The study included 510 eyes of 348 patients with glaucoma who were recruited from the Diagnostic Innovations in Glaucoma Study (DIGS) and followed for an average of 8.2 years. Methods: Eyes were followed annually with clinical examination, standard automated perimetry visual fields, and optic disc stereophotographs. The presence of optic disc hemorrhages was determined on the basis of masked evaluation of optic disc stereophotographs. Evaluation of rates of visual field change during follow-up was performed using the visual field index (VFI). Main Outcome Measures: The evaluation of the effect of optic disc hemorrhages on rates of visual field progression was performed using random coefficient models. Estimates of rates of change for individual eyes were obtained by best linear unbiased prediction (BLUP). Results: During follow-up, 97 (19%) of the eyes had at least 1 episode of disc hemorrhage. The overall rate of VFI change in eyes with hemorrhages was significantly faster than in eyes without hemorrhages (-0.88%/year vs. -0.38%/year, respectively, P < 0.001). The difference in rates of visual field loss pre- and post-hemorrhage was significantly related to the reduction of IOP in the post-hemorrhage period compared with the pre-hemorrhage period (r = -0.61; P < 0.001). Each 1 mmHg of IOP reduction was associated with a difference of 0.31%/year in the rate of VFI change. Conclusions: There was a beneficial effect of treatment in slowing rates of progressive visual field loss in eyes with optic disc hemorrhage. Further research should elucidate the reasons why some patients with hemorrhages respond well to IOP reduction and others seem to continue to progress despite a significant reduction in IOP levels. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2010; 117: 2061-2066 (C) 2010 by the American Academy of Ophthalmology.
Resumo:
Objective: To investigate clinical and MRI findings that are predictive of both visual loss in patients with pituitary adenomas and visual recovery after treatment. Design: Cohort study. Participants: Thirty patients (60 eyes) with pituitary adenoma. Methods: Patients underwent neuro-ophthalmic examination and MRI before and after optic chiasm decompression. Visual field (VF) was assessed using the mean deviation in standard automated perimetry (SAP) and temporal mean defect, the average of 22 temporal values of the total deviation plot. Tumour size was measured on sagittal and coronal cuts. Results: Visual loss was found in 47 eyes; 35 had optic atrophy (subtle in 9, moderate in 14, and severe in 12). Before treatment, the average SAP mean deviation and temporal mean defect were -11.78 (SD 8.56) dB and -18.66 (SD 11.20) dB, respectively. The chiasm was 17.3 (SD 6.2, range 10-34) mm above the reference line on the sagittal and 21.8 (SD 8.3, range 12-39) mm on the coronal images. Tumour size correlated with the severity of VF defect. VF improvement occurred in 80% of eyes after treatment. The degree of optic atrophy, visual loss, and tumour size were significantly associated with improvement after treatment. Conclusions: The best predictive factor for visual loss was tumour size, and factors related to visual recovery were the degree of optic atrophy, the severity of VF defect, and the tumour size. Diagnosing pituitary adenomas before optic atrophy becomes severe may be related to a better prognosis in such patients.
Resumo:
The aim was to investigate inter-tester and intra-tester reliability and parallel reliability between a visual assessment method and a method using a pachymeter for locating the mid-point of the patella in determining the medial/lateral patella orientation. Fifteen asymptomatic subjects were assessed and the mid-point of the patella was determined by both methods on two separate occasions two weeks apart. Inter-tester reliability was obtained by ANOVA and by intraclass correlation coefficient (ICC); intra-tester reliability was obtained by a paired t-test and ICC; and parallel reliability was obtained by Pearson`s Correlation and ICC, for the measurement on the first and second evaluations. There was acceptable inter-tester agreement (p = 0.490) and reliability for the visual inspection (ICC = 0.747) and for the pachymeter (ICC = 0.716) at the second evaluation. The inter-tester reliability in the first evaluation was unacceptable (visual ICC = 0.604; pachymeter ICC = 0.612). Although there was statistical similarity between measurements for the first and second evaluations for all testers, intra-tester reliability was not acceptable for both methods: visual (examiner 1 ICC = 0.175; examiner 2 ICC = 0.189; examiner 3 ICC = 0.155) and pachymeter (examiner 1 ICC = 0.214; examiner 2 ICC = 0.246; examiner 3 ICC = 0.069). Parallel reliability gave a perfect correlation at the first evaluation (r=0.828; p<0.001) and at the second (r=0.756; p<0.001) and reliability was between acceptable and very good (ICC = [0.748-0.813]). Both visual and pachymeter methods provide reliable and similar medial/lateral patella orientation and are reliable between different examiners, but the results between the two assessments at 2 weeks` interval demonstrated an unacceptable reliability. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Background: Selective serotonin reuptake inhibitors (SSRIs) are first-line treatments for posttraumatic stress disorder (PTSD). Serotonergic (5HT) attenuation of stress sensitivity is postulated from SSRIs` effects in other anxiety disorders, and we studied this in PTSD. Methods: Ten patients with PTSD fully recovered on SSRIs (Clinical Global Impression Scale-I 1 and 2) were enrolled in the study. Patients were tested on two occasions I week apart; in each session, they received a drink containing large neutral amino acids (LNAAs) either with (sham tryptophan depletion [STD], control) or without (acute tryptophan depletion [ATD]) tryptophan. At 5.5 hours after the drink, subjects were exposed to a trauma-related exposure challenge. Self-reports of PTSD (visual analogue scales [VAS] and the Davidson Trauma Scale [DTSI), anxiety (Spielberger State Inventory [STAI] Form Y-1), and mood (Profile of Mood States [POMS]) were obtained. Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure were also measured. Results: The trauma-related exposure challenge induced anxiety on both days, with more marked responses on the ATD day according to VAS, DTS, POMS, and DBP (p < .05). A trend of significance (.1 > p >.05) was observed for STAI Form Y-1, HR, and SBP. Conclusions: These data demonstrate that ATD accentuates responses to trauma-related stimuli in SSRI-recovered PTSD. They also suggest that SSRI-induced increases in serotonin function restrain PTSD symptoms, especially under provocation, supporting a role for serotonin in mediating stress resilience.
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To examine abnormal patterns of frontal cortical-subcortical activity in response to emotional stimuli in euthymic individuals with bipolar disorder type I in order to identify trait-like, pathophysiologic mechanisms of the disorder. We examined potential confounding effects of total psychotropic medication load and illness variables upon neural abnormalities. We analyzed neural activity in 19 euthymic bipolar and 24 healthy individuals to mild and intense happy, fearful and neutral faces. Relative to healthy individuals, bipolar subjects had significantly increased left striatal activity in response to mild happy faces (p < 0.05, corrected), decreased right dorsolateral prefrontal cortical (DLPFC) activity in response to neutral, mild and intense happy faces, and decreased left DLPFC activity in response to neutral, mild and intense fearful faces (p < 0.05, corrected). Bipolar and healthy individuals did not differ in amygdala activity in response to either emotion. In bipolar individuals, there was no significant association between medication load and abnormal activity in these regions, but a negative relationship between age of illness onset and amygdala activity in response to mild fearful faces (p = 0.007). Relative to those without comorbidities, bipolar individuals with comorbidities showed a trend increase in left striatal activity in response to mild happy faces. Abnormally increased striatal activity in response to potentially rewarding stimuli and decreased DLPFC activity in response to other emotionally salient stimuli may underlie mood instabilities in euthymic bipolar individuals, and are more apparent in those with comorbid diagnoses. No relationship between medication load and abnormal neural activity in bipolar individuals suggests that our findings may reflect pathophysiologic mechanisms of the illness rather than medication confounds. Future studies should examine whether this pattern of abnormal neural activity could distinguish bipolar from unipolar depression.
Resumo:
Objective: The objective of this study is to evaluate the visual feedback influence on pelvic floor muscle contraction. Study design: Seventeen nulliparous, urinary-continent women participated in this study. Pelvic floor muscle strength with and without the use of visual feedback was measured with a dynamometric speculum in two directions (anteroposterior and left-right). To compare the mean strength values with and without the use of visual feedback, the t test was applied. Results: There was no significant difference between the pelvic floor muscle anteroposterior strength values with and without the use of visual feedback (p = 0.30), and no significant difference for the left-right strength (p = 0.37). Conclusion: There was no difference between the pelvic floor muscle strength values with and without the use of visual feedback. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
Resumo:
In this study, morphological changes in the optic nerve were determined by light microscopy in Wistar rats on an iron-deficient diet for 32 days or for 21 days followed by 10 days on an iron-recovery diet. The morphometric findings showed significantly fewer blood vessels and oligodendrocytes in the iron-deficient rats and iron-recovery rats than in the control group, as well as more astrocytes in the iron-recovery rats. Serum iron levels of the iron-deficient rats were significantly lower than those of the controls. On the other hand, iron-recovery rats had normal serum iron levels, but no change in the abnormal morphology of the myelinated axons and morphometric parameters. Our data indicate that iron is necessary for maintenance of the optic nerve cell structure, and morphological damage from iron-deficiency is not easily reverted by iron reposition.
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In the present study, the participation of the Na(v)1.8 sodium channel was investigated in the development of the peripheral pro-nociceptive state induced by daily intraplantar injections of PGE(2) in rats and its regulation in vivo by protein kinase A (PKA) and protein kinase C epsilon (PKC epsilon) as well. In the prostaglandin E(2) (PGE(2))-induced persistent hypernociception, the Na(v)1.8 mRNA in the dorsal root ganglia (DRG) was up-regulated. The local treatment with dipyrone abolished this persistent hypernociception but did not alter the Na(v)1.8 mRNA level in the DRG. Daily intrathecal administrations of antisense Na(v)1.8 decreased the Na(v)1.8 mRNA in the DRG and reduced ongoing persistent hypernociception. once the persistent hypernociception had been abolished by dipyrone, but not by Na(v)1.8 antisense treatment, a small dose of PGE(2) restored the hypernociceptive plateau. These data show that, after a period of recurring inflammatory stimuli, an intense and prolonged nociceptive response is elicited by a minimum inflammatory stimulus and that this pro-nociceptive state depends on Na(v)1.8 mRNA up-regulation in the DRG. in addition, during the persistent hypernociceptive state, the PKA and PKC epsilon expression and activity in the DRG are up-regulated and the administration of the PKA and PKC epsilon inhibitors reduce the hypernociception as well as the Na(v)1.8 mRNA level. In the present study, we demonstrated that the functional regulation of the Na(v)1.8 mRNA by PKA and PKC epsilon in the primary sensory neuron is important for the development of the peripheral pro-nociceptive state induced by repetitive inflammatory stimuli and for the maintenance of the behavioral persistent hypernociception. (C) 2008 Elsevier Inc. All rights reserved.