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At least 541 records · Page 30Linked to original sources

PubMed2003

Stereoscopic processing in the human brain as a function of binocular luminance rivalry.

We investigated the neural substrates of a recent model of human stereodepth perception by obtaining measurements of regional cerebral blood flow (rCBF) using PET. Subjects experienced the perceptual properties of stereopsis by viewing rival-luminance stereograms displaying an identical random-dot pattern in their central portion while the backgrounds exhibited correspondent dots contrasting in black/white luminance. The stereoscopic vision induced by retinal luminance rivalry coincided with a significant elevation of rCBF in the dorsal visual pathway. Area V5 (MT) was activated bilaterally by the experimental condition while the remaining active loci were restricted to the right hemisphere. The neural sites that responded to this novel stereoscopic stimulus are similar to those activated by traditional stereograms containing horizontal disparities.

Adult↗

PubMed1988

Pseudo-pseudo-Foster Kennedy syndrome.

An 80-year-old woman presented with a classic story and findings of an anterior ischemic optic neuropathy in her left eye. Her right eye had slow and progressive decreased vision, ostensibly secondary to a cataract. However, the right eye showed slight temporal pallor of the optic disc and a superior temporal field defect was found. Her radiologic exam showed a tuberculum sella meningioma extending into the right optic canal compressing the right optic nerve. Two diseases, ischemic optic neuropathy and meningioma, in one patient may be termed a pseudo-pseudo-Foster Kennedy syndrome.

Aged↗

PubMedDate not supplied

Fractures of the sphenoid bone.

Fractures of the sphenoid bone occur following injury to the orbit and base of the skull. Such fractures are important since they can cause loss of vision and damage to various neural and muscular tissues. Ocular injury is also commonly associated. This paper reviews the hospital records of 112 consecutive patients with fractures of the base of the skull for the cause, frequency of signs and symptoms, and treatment of the sphenoid bone injury. Various deformities and dysfunctions are correlated with imaging data and classified to describe specific clinical syndromes. Several cases of sphenoid bone fracture serve as examples of diagnostic and treatment techniques.

Eye Injuries↗

PubMed1990

Extrageniculate vision in hemianopic humans: saccade inhibition by signals in the blind field.

The functional competence of extrageniculate visual pathways in hemianopic humans was demonstrated by showing that distractor signals in the blind half of the visual field could inhibit saccades toward targets in the intact visual field. This inhibitory effect of unseen distractors in patients occurred only when distractors were presented in the temporal half of the visual field, was specific to oculomotor responses, and did not occur in normal subjects. These results show that a peripheral visual signal activates retinotectal pathways to prime the oculomotor system and that these pathways can mediate orienting behavior in hemianopic humans.

Analysis of Variance↗

PubMed1992

Visual evoked potentials during the early phase of optic nerve compression in the orbital cavity.

We obtained case histories and electrophysiologic recordings from four patients with transient vision impairment due to acute orbital compression. The visual evoked potentials (VEPs) displayed alterations that depended on the size and consistency of the compressing pathology and also on the duration of the compression. This study provides evidence of the utility of the VEP in the assessment of the severity and reversibility of optic nerve lesions. The case histories also emphasized the necessity to elucidate the pathologic process of compressive lesions of the optic nerve.

Acute Disease↗

PubMed1997

Metastatic liposarcoma to the orbit.

PURPOSE: To report a woman with blurred vision and proptosis who harbored an orbital liposarcoma that had metastasized from her abdomen. METHODS: The patient underwent an orbital biopsy, followed by postoperative intravenous corticosteroids and radiation. RESULTS: Pathology showed a dedifferentiated liposarcoma. The patient's visual acuity improved from 20/200 to 20/50 after treatment. CONCLUSIONS: Physicians should suspect the presence of this rare orbital tumor in a person with a history of liposarcoma who has proptosis. Liposarcomas usually exhibit a higher grade of malignancy with recurrence, as shown in this patient.

Abdominal Neoplasms↗

PubMed2004

Spontaneous otogenic intracerebral pneumocephalus: case report and review of the literature.

Pneumocephalus is commonly associated with head and facial trauma, ear infection or surgical interventions. We describe the rare case of a spontaneous pneumocephalus arising from lateral mastoid air cells. A 48-year-old man presented with a 10-day history of sudden, repetitive, 'hammering-like' acoustic sensations in his left ear that were followed by word-finding difficulties and loss of vision in the right visual field. Imaging revealed a large, left temporal pneumatocele associated with a small acute intracerebral hemorrhage. Left temporal and subtemporal craniotomy and decompression were performed. Further exploration confirmed a dural and osseous defect in the anterolateral surface of the mastoid that was consecutively closed watertight. Although extremely rare, a spontaneous pneumocephalus with mastoidal origin should be considered as a possible diagnosis in patients with suggestive acoustic phenomena and other non-specific neurological symptoms.

Aphasia↗

PubMed2002

Coexistence of a cerebellopontine epidermoid cyst with a pituitary adenoma.

We report on an 18-year-old girl with the coexistence of an epidermoid cyst in the cerebellopontine angle (CPA) with a pituitary adenoma. The clinical course and histopathological characteristics were reviewed. The patient presented with headache, vision loss and amenorea. Computerised tomographic (CT) scan and magnetic resonance imaging (MRI) examinations demonstrated a solid sellar lesion with supra-sellar extension. There was another mass lesion in the CPA with prepontine extension. The tumours were removed surgically. Histopathological examination revealed an epidermoid cyst in the prepontine area and a pituitary adenoma in the sellar region. This has been the second case to be reported in the literature with the coexistence of an epidermoid cyst and a pituitary adenoma.

Adenoma↗

PubMed1987

Recovery of vision after presumed direct optic nerve injury.

Immediate loss of light perception after direct optic nerve injury is usually irreversible. Our patient sustained presumed direct optic nerve injury because of a shotgun injury with loss of light perception, absent pupillary response, and absent visual-evoked potential. A small pupillary response was noted 12 days after injury, light perception returned by 15 days, and visual acuity was 20/100 at 4 months. A variety of pathophysiologic mechanisms may lead to visual loss after direct optic nerve injury. It is important to recognize that blindness is not always permanent in these cases despite the results of initial clinical and electrophysiologic testing.

Adolescent↗

PubMed2005

Concomitant optic nerve transection and chorioretinitis sclopetaria.

BACKGROUND: Optic nerve transection and chorioretinitis sclopetaria may occur following blunt ocular trauma. However, simultaneous occurrence has not yet been reported. We report the first case of concomitant optic nerve transection and chorioretinitis sclopetaria. CASE PRESENTATION: A 12-year-old boy with history of BB gun injury to his right eye was referred for loss of vision. His visual acuity was counting fingers at one meter in the right eye and with 3+ relative afferent pupillary defect (RAPD). On slit lamp examination, the right eye appeared normal except for 1+ vitreous reaction. Fundus examination of the right eye revealed a pale disc with superior retinal scar and diffuse submacular fibrosis compatible with chorioretinitis sclopetaria. Orbital CT-scans showed transection of the optic nerve by the BB gun pellet, which was lodged at the orbital apex. CONCLUSION: BB gun injury may cause concomitant optic nerve transection and chorioretinitis sclopetaria.

Child↗

PubMed1978

[Impaired visual perception in progressive multifocal leukoencephalopathy; a clinical diagnosis based on sequential computerized axial tomography (author's transl)].

Progressive multifocal leukoencephalopathy (PML) is a viral illness affecting principally cerebral white matter of patients, who have diminished immunologic resistance. A patient is presented, whose initial complaint was blurred vision. Relentless progression over a period of seven months to left hemianopsia, prosopagnosia, alexia with agraphia and eventually cortical blindness was observed. Accompanying the visual impairment was a steady deterioration of mental function. Sequential computerized axial tomography defined low density lesions in the occipital white matter with sparing of the cortical ribbon. As hemianopsia progressed to cortical blindness, the scans confirmed the evolution of bilaterial occipital lesions. The diagnosis was made clinically and established on histological and cultural grounds. Computerized tomography seems to be valuable in diagnosis and monitoring progress of PML.

Aged↗

PubMed1997

Neglect in vision and visual imagery: a double dissociation.

We report two patients with right hemisphere lesions who demonstrate a double dissociation on visual imagery and visual perceptual tasks. One (M.N.) performed normally on a variety of standard tests for neglects as well as on measures of visual attention known to be sensitive to the presence of neglect, yet failed to report items from the left side of an imagined scene. In contrast, the other (C.I.) performed normally on tests of visual imagery but demonstrated substantial neglect on visual perceptual and visual attentional tasks. These data are not readily accommodated by accounts which attribute neglect to a single processing deficit, but suggest that the disorder is a heterogeneous syndrome attributable to disruptions of different aspects of spatial cognition.

Adult↗

PubMed1999

[Epidemiology of orbital processes in children. 54 cases].

PURPOSE: The aim of this work was to study epidemiological aspect of orbital processes occurring in childhood. PATIENTS AND METHODS: Fifty-four cases of orbital processes treated between January 1990 and January 1997 were retrospectively reviewed. RESULTS: Mean patient age was 4.2 years (range 1 to 15), 36 were males and 18 were females. Proptosis was the first manifestation in 34 cases, other manifestations were low vision (8 cases), ocular pain (14 cases), inflammatory signs (11 cases), ocular palsy (14 cases). The first cause of these processes was secondary tumors, especially retinoblastoma (13 cases). Other causes were rhabdomyosarcoma (9 cases), orbital hydatic cyst (8 cases), inflammatory pseudotumors (7 cases), capillary hemanigoma (4 cases) chloroma (3 cases), glioma (1 case), lymphangioma (8 cases), and mucocele (1 case). DISCUSSION: We emphasize the particular epidemiological aspect of orbital processes in Moroccan children where retinoblastoma predominates and compare our findings with data in the literature.

Adolescent↗

PubMed2005

Bilateral subretinal haemorrhage with Terson's syndrome.

PURPOSE: To present a case of Terson's syndrome with bilateral subretinal haemorrhage emanated from peripapilla, resulting in Mariotte blind spot enlargement. METHODS: Preoperative CT scan and postoperative eye examinations, including funduscopy, fluorescein angiography, optical coherence tomography (OCT), and Goldmann perimetry. RESULTS: A 41-year-old Japanese man had suffered a subarachnoid haemorrhage. Three months later, he recovered from disturbance of consciousness and was referred for decreased vision in both eyes. A CT scan, obtained on the day after the event, had revealed bilateral vitreous hemorrhage. The patient underwent a standard pars plana vitrectomy to clear vitreous haemorrhage. Surprisingly we found bilateral subretinal haemorrhage around peripapilla during surgery. Although subretinal haemorrhage was almost absorbed at six months after the operation, Mariotte blind spot enlargement corresponding to the area of subretinal haemorrhage was detected in both eyes. CONCLUSIONS: In some population of the patients with Terson's syndrome, it was demonstrated that the disturbance of peripapillary structure, presumably due to intracranial hypertension, causes subretinal haemorrhage, resulting in irreversible visual field defect.

Adult↗

PubMed2003

Transient, idiopathic nystagmus in infants.

The aim of this study was to characterize children with transient nystagmus. Eleven children (six males, five females) developed nystagmus in infancy and then experienced regression of the problem, usually within a few months. Mean age at onset was 2.7 months, and mean age at regression was 8.5 months. No etiology could be ascertained in any of the patients, although four children had other eye or vision abnormalities (regressed retinopathy of prematurity, n=1; asymmetric fundus colobomata, n=1; delayed visual maturation, n=2). Results of this study suggest that mechanisms which allow ocular motor stability undergo a period of postnatal maturation, during which nystagmus can occur, but also during which nystagmus may disappear. Not every case of transient nystagmus should be categorized as spasmus nutans. There is a subset of infants and young children who develop transient nystagmus with no other findings and in whom the nystagmus disappears.

Age of Onset↗

PubMed1985

Rapid fading of visual sensations in a subject with a parietal-occipital tumour.

We present psychophysical data measured for a single subject, who had a tumour in the left parieto-occipital region, located by CT scan and post-mortem study. Her vision was characterised by rapid fading during voluntary fixation of images located in the right hemifield. We describe a number of simple tests which we developed in order to study this phenomenon. The results of these tests established that significant loss of function occurs within 1 s of fixation and that the effects associated with fixation are spatially localised. We compare our subject's response characteristics with those observed in other cases of visual disturbance and we examine the possible underlying mechanisms which give rise to the rapid fading of her visual images.

Adult↗

PubMedDate not supplied

Lung cancer, proptosis, and decreased vision.

A 48-year-old man presented to the emergency department with a 3-day history of decreased vision in a painful proptotic right eye. The patient was being treated with chemotherapy and radiation for non-small cell lung carcinoma. Examination showed visual acuity of hand motions, decreased motility, and an afferent pupillary defect on the right, consistent with an orbital apex syndrome. Neuroimaging revealed "dirty" orbital fat and no paranasal sinus disease. Orbital biopsy initially showed only fibrosis; however, on subsequent biopsies, nonseptate hyphae later identified as mucormycosis was recovered. The patient survived with exenteration and systemic amphotericin B.

Amphotericin B↗

PubMed2006

Invasive fungal sinusitis of isolated sphenoid sinus in immunocompetent subjects.

Invasive fungal sinusitis of the paranasal sinuses in a healthy immunocompetent person is uncommon. Isolated involvement of any paranasal sinus, particularly sphenoid sinus is rare. In this study, five immunocompetent patients who had no nasal complaints but obscure symptoms of headache and orbital symptoms such as diplopia, retro-orbital pain and loss of vision were diagnosed to be having fulminant fungal sinusitis of the sphenoid sinus. Three patients had aspergillosis and two patients had mucormycosis. These patients initially presented to neurologists and ophthalmologists because they had no ENT complaints. The diagnosis was made on endoscopy, radiology and histopathology. They were treated aggressively according to the standard protocols. The purpose of this paper is to bring to light the changing clinical spectrum of invasive fungal sinusitis. It can occur in immunocompetent patients and in the form of isolated sphenoid sinus involvement.

Adolescent↗