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At least 919 records · Page 51Linked to original sources
PubMed1986

The cerebral ocular pursuit pathways. A clinicoradiological study of small-field optokinetic nystagmus.

Optokinetic nystagmus was tested in patients with intracerebral tumors restricted to one hemisphere, by using a simple, hand-held drum and visual evaluation of symmetry of horizontal response. Computed tomographic mapping revealed that lesions associated with asymmetric optokinetic nystagmus involved the posterior hemisphere. The critical region appeared to extend from the posterior splenium and the anteromedial occipital lobe to the posterior internal capsule. It seemed to course below the posterior horn of the ventricular system, then turn anteriorly, and finally medially, above the temporal horn. It is argued that the posterior extremity of this C-shaped region contains the ipsilateral and contralateral visual inputs to a parietal cortex control over ipsilateral smooth eye movements, and that the anterior extremity contains the efferent motor command pathways destined to the brain stem.

Adolescent↗
PubMed1988

Evidence of orbital deformation in indirect optic nerve injury. Weight lifter's optic neuropathy.

A 16-year-old boy developed monocular visual loss due to optic neuropathy following frontal head trauma. His trauma was unique in that it consisted of a static loading force to the brow, rather than the dynamic impact more commonly associated with blunt orbital injuries. This case demonstrates the role of isolated deformation of orbital bones in the pathogenesis of indirect optic nerve injury.

Adolescent↗
PubMed1991

Rapid change in visual fields associated with suprasellar lymphocytic hypophysitis.

A young woman presented in the third trimester of pregnancy with a rapid onset of bitemporal hemianopia and reduced visual acuity caused by an unusual steroid responsive suprasellar tumor. A computerized tomography scan revealed a 2-cm suprasellar mass which was thought to be a tuberculum sellae meningioma. Surgery was delayed because of pregnancy. A short course of high-dose steroids was given to promote fetal lung maturity. This produced an unexpected and dramatic resolution of the field loss. As the steroid dose was reduced, the visual fields deteriorated, necessitating a craniotomy. The histology revealed lymphocytic hypophysitis, a rare but distinct clinicopathological entity affecting the anterior pituitary lobe. The significance of the suprasellar site and a possible role for the use of steroids in the preoperative management of this condition is discussed.

Adrenal Cortex Hormones↗
PubMed1989

Acidophil stem-cell pituitary adenoma in a prepubescent female. Case report.

Acidophil stem-cell pituitary adenomas account for less than 5% of pituitary tumors. Only 15 cases have previously been reported, with a mean age of occurrence of 38.7 years. A case of this unusual tumor is reported in a prepubertal girl. Clinical symptoms included prominent behavioral disturbance with associated headache and visual disturbance. There was marked elevation of serum growth hormone concentration without clinical features of growth hormone excess, suggesting that this tumor has the capacity to excrete biologically inactive hormones. The clinical and pathological features of this unusual invasive pituitary tumor are reviewed; the age spectrum for this neoplasm must be expanded to include prepubertal children.

Adenoma, Acidophil↗
PubMed1995

Papillary craniopharyngioma: a clinicopathological study of 48 cases.

Two distinct clinicopathological variants of craniopharyngioma exist: the classic adamantinomatous type and a recently described papillary form that predominates in adults and reportedly behaves in a less aggressive manner. The present study describes the clinicopathological features of 48 patients with papillary craniopharyngioma treated at the Mayo Clinic between 1910 and 1994. An additional four tumors were found to have histological features of both adamantinomatous and papillary craniopharyngioma. Whereas adamantinomatous tumors typically occur in adolescent patients, the mean age of the 48 patients (23 males and 25 females) with papillary craniopharyngioma was 44.7 years (range 10 to 74 years). Presenting clinical features included visual impairment (84%), headache (68%), and pituitary insufficiency (anterior 42%; posterior 27%). Preoperative computerized tomography (CT) and magnetic resonance (MR) imaging in 17 patients typically revealed a noncalcified, partially cystic mass that enhanced peripherally and contained mural nodules (67%). Many (41%) of the lesions involved or extended into the third ventricle on imaging. At first surgery, gross total tumor removal was achieved in 17 patients (36%) and subtotal resection in 30 patients (64%) in whom tumor resection was attempted. Tumor recurrence was noted in two patients who underwent gross total removal. Tumor-free survival rates of 100% and 78% were obtained in patients who underwent gross total and subtotal resection at initial surgery, respectively. Postoperative radiation therapy was beneficial to patients having undergone a subtotal resection, with an increase in tumor-free survival from 26% to 86%. Aside from well-documented morphological distinctions, papillary craniopharyngiomas differ from adamantinomatous tumors in several important respects. These include the almost exclusive occurrence of papillary tumors in adulthood and their more uniform appearance on both CT and MR imaging. However, a preliminary analysis of our data suggests there are no significant differences between the two lesions with respect to resectability, efficacy of radiation therapy, and overall survival.

Adolescent↗
PubMedDate not supplied

Pituitary tumors: diagnosis and therapy.

The newer diagnostic methods for identifying pituitary tumors have been presented, along with a discussion of therapy. Not all the issues are clear, particularly those for prolactin-secreting tumors. Drug therapy may play an increasing role, especially dopamine agonists, which control either hGH or prolactin secretion and can cause shrinkage of tumor tissue.

Adolescent↗
PubMed2005

Acquired simulated brown syndrome following surgical repair of medial orbital wall fracture.

Simulated Brown syndrome is a term applied to a myriad of disorders that cause a Brown syndrome-like motility. We encountered a case of acquired simulated Brown syndrome in a 41-year-old man following surgical repair of fractures of both medial orbital walls. He suffered from diplopia in primary gaze, associated with hypotropia of the affected eye. We performed an ipsilateral recession of the left inferior rectus muscle as a single-stage intraoperative adjustment procedure under topical anesthesia, rather than the direct approach to the superior oblique tendon. Postoperatively, the patient was asymptomatic in all diagnostic gaze positions.

Adult↗
PubMed2005

Optic nerve injury secondary to endoscopic sinus surgery: an analysis of three cases.

Major orbital complications after the endoscopic sinus surgeries are rare and of these, optic nerve injury is one of the most serious. This study was to undertaken to analyze 3 cases of optic nerve injury after endoscopic sinus surgery. The three cases included one patient with a loss of visual acuity and visual field defect, and two patients with total blindness. In all cases, no improvement of visual acuity was observed despite treatment. It is important to frequently check the location and direction of the endoscope during surgery to avoid optic nerve injury. In addition, surgeons must have a precise knowledge of the detailed anatomy through cadaver dissections, an ability to interpret the PNS CT scan and experienced procedural surgical skills.

Adult↗
PubMedDate not supplied

Bilateral optic nerve hypoplasia associated with cerebral atrophy.

We present a series of 12 consecutive cases of optic nerve hypoplasia. Eight of these were unassociated with significant CNS malformations; of these, two had tomographic evidence of cerebral atrophy. This represents the first adequately documented cases of isolated cerebral atrophy associated with optic nerve hypoplasia. We discuss the increasing prevalence and marked variability of optic nerve hypoplasia, note the lack of clear distinction between primary failure of differentiation and secondary degeneration of optic pathways, and mention the inadequacy of the classic explanation of primary failure of ganglion cell development as the cause of hypoplastic nerves. The cause of cerebral atrophy are mentioned, and we hypothesize that the wide range of CNS insults resulting in atrophy may be responsible for a correspondingly wide range of abnormalities of the optic nerves. We speculate that cerebral atrophy may result in an inadequate cortical mass for induction of normal optic nerve growth, possibly by decreased retrograde axoplasmic flow and insufficient nerve growth factor. We encourage a complete neurologic evaluation, including CAT scan of the brain, in children with optic nerve hypoplasia.

Adolescent↗
PubMedDate not supplied

Visual loss in infantile osteopetrosis.

Osteopetrosis should be considered in an infant with unexplained visual loss. In particular, the possibility of this diagnosis must be intimated to the radiologist involved in the investigation of the child.

Blindness↗
PubMedDate not supplied

Association of Duane retraction syndrome and Brown syndrome.

Brown syndrome and esotropic Duane syndrome are common forms of noncomitant strabismus. We report the unusual coexistence of these two eye movement abnormalities in a 5-year-old boy. Strabismus surgery for both conditions was required to improve the head posture.

Child, Preschool↗
PubMed1994

Visual loss in pregnant women with pituitary adenomas.

OBJECTIVE: To investigate the potential risk for developing visual loss during single or multiple pregnancies in women with pituitary adenomas. DESIGN: Cohort study. SETTING: Referral center of a neuro-ophthalmology service. PATIENTS: 65 consecutive women with pituitary adenomas who had not been previously treated with surgery or radiation were monitored during 111 pregnancies. Sixty had increased levels of serum prolactin or growth hormone and 5 did not. MAIN OUTCOME MEASURES: Visual field or acuity loss was compared with the baseline size of the adenoma measured on the coronal view of the computed tomographic or magnetic resonance image. RESULTS: Computed tomography or magnetic resonance imaging showed a definitive tumor (> 0.3 cm, vertical height) in 57 patients, 8 of whom had macroadenomas (> or = 1.1 cm). Visual field loss occurred in 6 of 8 primiparous patients, all with adenomas greater than 1.1 cm (range, 1.2 to 2.5 cm). None of the 57 patients (95% CI, 0% to 6.3%) with a microadenoma or presumed microadenoma of 1 cm or smaller developed visual loss after as many as four full-term pregnancies. CONCLUSIONS: The risk for developing visual loss during single or multiple pregnancies in patients with microadenomas was small. Six of eight pregnant women with macroadenomas, however, developed visual field loss during pregnancy.

Acromegaly↗
PubMed1999

Examination of shape complementarity in docking of unbound proteins.

Here we carry out an examination of shape complementarity as a criterion in protein-protein docking and binding. Specifically, we examine the quality of shape complementarity as a critical determinant not only in the docking of 26 protein-protein "bound" complexed cases, but in particular, of 19 "unbound" protein-protein cases, where the structures have been determined separately. In all cases, entire molecular surfaces are utilized in the docking, with no consideration of the location of the active site, or of particular residues/atoms in either the receptor or the ligand that participate in the binding. To evaluate the goodness of the strictly geometry-based shape complementarity in the docking process as compared to the main favorable and unfavorable energy components, we study systematically a potential correlation between each of these components and the root mean square deviation (RMSD) of the "unbound" protein-protein cases. Specifically, we examine the non-polar buried surface area, polar buried surface area, buried surface area relating to groups bearing unsatisfied buried charges, and the number of hydrogen bonds in all docked protein-protein interfaces. For these cases, where the two proteins have been crystallized separately, and where entire molecular surfaces are considered without a predefinition of the binding site, no correlation is observed. None of these parameters appears to consistently improve on shape complementarity in the docking of unbound molecules. These findings argue that simplicity in the docking process, utilizing geometrical shape criteria may capture many of the essential features in protein-protein docking. In particular, they further reinforce the long held notion of the importance of molecular surface shape complementarity in the binding, and hence in docking. This is particularly interesting in light of the fact that the structures of the docked pairs have been determined separately, allowing side chains on the surface of the proteins to move relatively freely. This study has been enabled by our efficient, computer vision-based docking algorithms. The fast CPU matching times, on the order of minutes on a PC, allow such large-scale docking experiments of large molecules, which may not be feasible by other techniques. Proteins 1999;36:307-317.

Algorithms↗