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At least 1,603 records · Page 89Linked to original sources
PubMed2000

The use of titanium mesh in the management of orbital trauma--a retrospective study.

This study examines the use of titanium mesh in the reconstruction of internal orbital defects. The goals of reconstruction when treating orbital fractures include restoration of internal wall continuity and provision of support to the orbital contents. In this way the untoward sequelae of post-traumatic enophthalmos and disturbance of visual acuity are avoided. Autogenous grafts have been the material of choice for most surgeons involved with treatment of these injuries. The major disadvantages of using autologous tissue are the need for a graft donor site, with attendant increases in operative time, prolonged hospitalization, increased postoperative discomfort and problems intrinsic to the donor site wound. The purpose of this report is to present the author's experience with the use of titanium alloplasts in the early repair of traumatic orbital wall fractures. Patients treated at the Townsville General Hospital from July 1, 1997-March 1, 2000 with injuries involving the orbit repaired with titanium mesh or micro-mesh were included in the study.

Adult↗
PubMed2002

[Microvzor-2: a system for automated dry blood smear analysis].

Upgraded system Microvzor-2 for investigation of blood morphology in space flight is composed of soft- and hardware for dry smear image analysis. Ground-based testing showed that it could be utilized to investigate a broad spectrum of blood parameters in space flight, including erythrocytes, hemoglobin content in erythrocytes, volumetric erythrocyte distribution, diagnostics of anisocytosis, and poikilocytosis, leukocytes and leukocyte count. Analyzed are smears prepared from a fixed volume of finger blood. The process consists of smear scanning, input of the vision field images in the spacecraft computer and ensuing automated identification and counting. Information is stored in a dedicated database. Results of analysis are displayed as forms and cell galleries.

Adaptation, Physiological↗
PubMed2003

[A case of solitary and unilateral trochlear nerve palsy due to a blunt head impact].

A case of solitary and unilateral trochlear nerve palsy following a minor, blunt head impact is reported. A 72-year-old man fell down backwards from the top of a staircase having 13 steps and hit his right parietal head and shoulder. Routine neurological examination revealed no remarkable findings, however, the subject complained of double vision when he focused downwards. The computed tomography four hours after the initial impact showed a localized small high-density lesion on the left quadrigminal cistern. The magnetic resonance imaging also indicated subarachnoid bleeding expressed by the low-intensity area in T2 weighted images in the same place. There was no evidence of any contusion within the midbrain. Hess chart test clearly showed solitary left superior oblique muscle palsy. The manner of the injury was thought to be quite typical, since he had hit his right parietal area up-side-down when falling, that is, the accelerated force acted as an impact against the firm floor. This impact caused the midbrain concussion against the cerebellar tentorial notch resulting in a localized subarachnoid hemorrhage which caused the unilateral trochlear nerve palsy.

Aged↗
PubMed2005

[Posterior cerebral encephalopathy].

Posterior reversible encephalopathy (PRE) is a recent syndrome characterized by headache, vomiting, seizures, visual loss, altered mental status with or without motor or sensitive deficit. Neuroimaging demonstrates symmetrical posterior cortical and subcortical lesions. The aetiology remains uncertain but vascular hypotheses is the most retained. We report a case of a 21 year old man with posterior cerebral encephalopathy, the toxic hypo these remains the most probable.

Adult↗
PubMed1992

Psychophysical experiments and a neural network model of binocular rivalry.

The alternation process in binocular rivalry was examined by psychophysical experiments. The stimulus strength to the central part of the visual field in one eye was varied while the stimulus strength in the other eye remained constant. The data obtained by the experiments indicate that the variations in stimulus strength alter the mean dominance duration, variance and predominance, and the frequency histogram of the dominance duration almost fits to the gamma distribution. To explain these results, a model which consists of neural elements receiving impulse trains with stochastic fluctuations is proposed and the experimental results are simulated on a computer using the model. Although the present model is restricted to explain only the rivalry between two lines which have different orientations, we could obtain agreement between the simulation results and the experimental results by giving appropriate values for some parameters of the model.

Humans↗
PubMed2006

[Hyperpneumatization of sphenoid sinus--a possible etiology of posterior optic neuropathy].

We take in debate a rare cause of compressive retrobulbar optic neuropathy. We present three patients with bilateral retrobulbar optic neuropathy in which these could not be found any other cause, but the hyperpneumatization of sphenoid sinus. We emphasize the role of cranial computer tomography in the diagnosis of this disease and the necessity to keep in mind this possible etiology of posterior optic neuropathy.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Visual functional changes in patients with pituitary adenoma: results of transnasal-transsphenoidal tumor removal].

The study was based on the analysis of case histories of 371 patients with pituitary adenoma who were examined and treated at the Acad. N. N. Burdenko Institute of Neurosurgery in 1999 to 2004. The patients' age was 13 to 75 years; the peak of the disease fell on the age of 40-50 years. Females were 61% and males 39%. The symmetrical and asymmetric chiasmal syndrome was detected in 42 and 58% of patients, respectively. Early chismal syndrome was identified in 32% of patients; insignificant and significant one being in 27 and 41%, respectively. According to the stage of visual disorders, the patients were divided as follows: those with an early stage (62.9%) and those with a late stage (37.1%). An analysis has indicated that the pattern of visual disorders correlates with the site, predominant growth, and sizes of a tumor. Early postoperative visual functions restore mainly in patients with early-stage visual disorders, which is accounted for by timely decompression of visual fibers and their better blood supply. Functional block cessation, axonal transport recovery, and, probably, visual fiber remyelination result in positive changes in the late postoperative period.

Adenoma↗
PubMed2006

[Bilateral optic nerve sheath meningioma (ONSM) --diagnostic and therapeutic problems].

The authors describe the case of bilateral optic nerve sheath meningioma /ONSM/ in 14 years old girl. When being hospitalized at the Neurology Clinic with paresis n.VII, the patient was examined by ophthalmologist. The diagnosis was made on the basis of clinical and characteristic changes revealed by USG, CT and MRI. The very first ophthalmologic examination confirmed a visual acuity 5/5 OD and hand movements OS, associated with papilloedema OD and edematous optic atrophy OS. The use of USG, CT and MRI revealed bilateral tubular thickening of the optic nerves (8mm), with calcification. After the period of one year, clinical progression was observed. The intracranial tumor extended. It was shown in diagnostic imaging. The patient was operated on by neurosurgeons with histopathology verification. In the later stage she underwent radiotherapy. The case has been described because of its diagnostic and therapeutic difficulties.

Adolescent↗
PubMed1991

Neurologic complications in allogeneic bone marrow transplant patients receiving cyclosporin.

Regimens using cyclosporin (CSP) and either methylprednisolone (MP) or methotrexate (MTX) have been useful in the prophylaxis of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). However, CSP produces a number of side effects, including neurologic toxicity. A retrospective review of recipients of 239 BMTs given CSP-based prophylactic regimens revealed that 10 patients (4.2%, 95% confidence interval 0% to 10.4%) experienced a syndrome characterized by hypertension, severe visual disturbances, seizures and occipital lobe density changes on brain computed tomography (nine patients) or nuclear magnetic resonance imaging (one patient). Neurologic findings were reversible in all cases, usually after temporary discontinuation of CSP. Univariate analysis identified the following risk factors for neurotoxicity: use of unrelated or HLA-mismatched related donors, administration of etoposide (VP-16) or total body irradiation as part of conditioning, use of corticosteroids for prophylaxis or treatment of acute GVHD, or development of either acute GVHD or clinically significant microangiopathic hemolytic anemia (MAHA) post-BMT. In multivariate analysis, the most important predictors were the use of VP-16 (p = 0.008), the use of a continuous infusion CSP plus MP prophylactic regimen for GVHD (p = 0.003) and the development of MAHA after BMT (p less than 0.001). The strong association with MAHA suggests that endothelial damage is related to the development of this complication.

Adolescent↗
PubMed1986

Central nervous system toxicity of fludarabine phosphate.

Fourteen patients developed severe central nervous system (CNS) toxicity after receiving an investigational antitumor agent, fludarabine phosphate (FAMP). The CNS toxicity has the distinctive features of delayed onset and progressive clinical course. Visual deficits were the most common presenting symptom and developed eventually in most cases. Deterioration of mental status and progressive encephalopathy were also observed. The development of clinical CNS toxicity appears dose-related; thirteen of 36 patients (36.1%) who received FAMP at high doses (greater than or equal to 96 mg/m2/day for 5-7 days per course) developed neurotoxicity, while only one of 443 patients (0.2%) who received the drug at low doses (less than or equal to 125 mg/m2 per course) developed similar toxicity. Although the precise mechanism responsible for this toxicity is yet unknown, progressive demyelination appears to be the responsible process. Extensive review of the clinical data failed to identify factors which might contribute to the development of CNS toxicity. Patients on trials of FAMP should be meticulously monitored for the possible development of neurotoxicity.

Acute Disease↗
PubMed1988

[Binocular functional exploration: fundamental aspects and analysis by the Fusio-Test].

After reviewing psychophysical and neurophysiological data concerning disparity processing and stereoscopic depth perception, as well as the limits of variation in perceived depth and fusion in function of binocular disparity, a new computer controlled apparatus named Fusio-Test is presented for functional binocular exploration. A battery of stereograms available in the test library made it possible to study in particular depth perception or stereoacuity, aniseikonia and fixation disparity, using the most suitable preprogrammed psychophysical procedure such as the limit method, constant stimuli, Cornsweet's psychophysical staircase, and one alternative forced choice method or multiple choice method. The test selected for each phase of the binocular examination was presented in polarized light on two Video Units. The required measurements were displayed on a small terminal and occasionally the data variations were recorded in real time. For the control of depth perception and the evaluation of stereoscopic acuity, two types of tests were programmed: line stereograms made of series of vertical lines varying in number and relative spacing or stylized shapes, random dot stereograms with different cyclopean shapes (circle, square, triangle or scaled pyramid), some of them with reduced binocular correlation according to Julesz. The originality of this apparatus for aniseikonia lies in its use of a battery of Ogle's spatial test stereograms, having incorporated vertical and horizontal magnifications ranging from 0 to 15% by 1% increments. The measurements were obtained by trying to find the pair of stereograms that must be presented to the right and the left eyes in order to eliminate the perceived distorsions (geometric or induced effect) and to recover the normal classical configuration of the spatial test. The test for fixation disparity was comprised of the Ogle arrangement with two polarized vertical lines forming a binocular nonius in the middle of a field surrounded with letters to stimulate fusion. Data for a sample of observers wearing glasses, contact lenses or implants, are presented and analyzed, bringing to light certain anomalies in binocular disparity processing. Differences in stereoacuity are noted: partial or total stereoblindness depending on the test selected (line stereograms or random dot stereograms, crossed or uncrossed disparities), on the spacing of the test elements; variations of threshold in time.(ABSTRACT TRUNCATED AT 400 WORDS)

Aniseikonia↗
PubMed1994

Computational principles in Purkinje I and IV reflection pattern evaluation for the assessment of ocular alignment.

PURPOSE: To develop a standardized reasoning for the evaluation of Purkinje I and IV Reflection Pattern data in primary, secondary, and tertiary positions of gaze in the diagnosis of strabismus with a mathematical approach. To demonstrate the applicability of certain mathematical relations and the appropriate graphic representation of computed ocular alignment data. METHODS: Starting from the known Reflection Pattern Evaluation formulae, equations were derived that allowed for the computation of the relative and absolute positions of the optical and visual axes of both eyes from original data in binocular and monocular fixation. These equations were simplified for clinical use. RESULTS: The authors obtained a set of equations that could be applied to the objective, quantitative analysis of eye alignment in screening for microtropia, in concomitant and incomitant diagnoses of strabismus in primary and nonprimary positions. CONCLUSIONS: Purkinje I and IV Reflection Pattern Evaluation can be extended to the diagnosis of strabismus in nonprimary positions with sufficient clinical accuracy. The newly presented principles and equations serve as a basis for a convenient graphic representation of Purkinje I and IV Reflection Pattern data. These principles of evaluation may be applied to any data dealing with ocular alignment, independently of the method.

Afterimage↗
PubMed1977

[The influence of dopamine on the regional blood volume in liver, abdomen, chest and extremities (author's transl)].

The influence was studied of 3 and 6 gamma/kg/min. dopamine on the blood volume in the liver, abdomen, chest, arms and legs in ten volunteers with healthy livers, and a comparison was made between the effect of dopamine and the blood volume changes caused in these body regions by inflatable whole-leg boots at a pressure of 40 mm Hg. Regional blood volumes and any induced changes were studied by means of 99 m Tc labelled autologous erythrocytes. A gamma camera with a pinhole collimator and a small computer was used, the field of vision of the camera being 148 cm in diameter. Changes in regional activity reflect changes in the regional blood volume. 1. Whole-leg compression at 40 mm Hg led to an increase in the blood volume of the liver, abdomen and chest, but to a reduction in the legs, while no significant change was observed in the arm blood volume. 2. On infusion of 3 gamma/kg/min. dopamine for 15 minutes no significant change occurred in the blood volume of the liver and abdomen. The chest blood volume increased, while the blood volume of the upper and the lower extremities showed a statistically significant decrease. 3. On infusion of 6 gamma/kg/min. dopamine for 10 minutes no significant change occurred in the blood volume of the liver, while the chest blood volume continued to rise and that of the upper and lower limbs continued to fall. 4. Ten minutes after the end of the infusion there was no significant change in liver and abdominal blood volume as compared with the last value measured during infusion of 6 gamma/kg/min. dopamine. By that time the chest blood volume had already fallen and the blood volume of the arms and legs increased. The possible action mechanisms via dopamine-specific and other catecholamine receptors are discussed in this paper.

Abdomen↗