1/127. Cerebral polyopia with extrastriate quadrantanopia: report of a case with magnetic resonance documentation of V2/V3 cortical infarction.This is a case report of the occurrence of cerebral diplopia with right-side superior homonymous quadrantanopia in a young woman after chiropractic neck manipulation. magnetic resonance imaging confirmed an infarct in the left inferior V2/V3 (extrastriate) cortex. The characteristics of the diplopia are illustrated with the patient's drawings, and persisting abnormalities in perception are described in the area of the initial field defect after static (computed) visual field testing yielded normal results.- - - - - - - - - - ranking = 1keywords = perception (Clic here for more details about this article) |
2/127. association of high-dose intravenous methylprednisolone with reversal of blindness from lightning in two patients.OBJECTIVE: To report possibly beneficial effects of treatment with high-dose corticosteroids given intravenously to two patients with loss of vision after lightning strikes. DESIGN: case reports. PARTICIPANTS: Two patients who suffered the effects of a lightning strike. INTERVENTION: High-dose intravenous methylprednisolone (NASCIS-2 Protocol). MAIN OUTCOME MEASURES: Vision recovery, pupil responses, and optic nerve appearance. RESULTS: One patient had unilateral ophthalmoscopically visible abnormality with light perception vision and a relative afferent defect in that eye; vision recovered to 20/25. The other patient had no light perception, nonreactive pupils, and normal fundus examinations in both eyes; vision recovered bilaterally to normal (20/20). CONCLUSIONS: High-dose intravenous corticosteroid treatment in these patients may have had a role in their visual recovery.- - - - - - - - - - ranking = 2keywords = perception (Clic here for more details about this article) |
3/127. Visual recovery after a year of craniopharyngioma-related amaurosis: report of a nine-year-old child and a review of pathophysiologic mechanisms.BACKGROUND: The probability of visual recovery in tumor-related optic neuropathy usually correlates with the severity and duration of optic pathway compromise. Recovery of visual acuity to normal levels is unexpected after profound loss of vision extending for a period of weeks and months. methods: A 9-year-old girl who had neurosurgical resection of a craniopharyngioma compressing the optic chiasm and optic tract was followed up serially with neuroimaging and clinical examinations over a 6-year period. RESULTS: Within 3 months of the diagnosis of craniopharyngioma, the girl's vision was reduced to no-light-perception blindness when she viewed with the more involved eye. The blindness correlated with an amaurotic (i.e., >3.6 log unit) relative afferent pupillary defect and an absence of any response when tested with visual field perimetry. After more than a year of total blindness and cessation of all neurosurgical and radiation therapy, visual acuity recovered to a normal level (20/25), the afferent pupillary defect improved, and sensitivity in a portion of the temporal hemivisual field was restored. In the follow-up that has extended for 5 years from the time of recovery, stability of the restored vision has been documented. CONCLUSION: Children who have tumor-related loss of vision due to damage to the anterior visual pathways may be capable of recovery after intervals of blindness that would be considered irreversible in adults. The mechanism of the recovery in our patient may have been decompression-related restoration of axoplasmic flow, followed by gradual remyelination of visual fibers, which allowed reorganization of connections to the lateral geniculate nucleus to optimize synaptic transmission.- - - - - - - - - - ranking = 1keywords = perception (Clic here for more details about this article) |
4/127. Alexia for Braille following bilateral occipital stroke in an early blind woman.Recent functional imaging and neurophysiologic studies indicate that the occipital cortex may play a role in Braille reading in congenitally and early blind subjects. We report on a woman blind from birth who sustained bilateral occipital damage following an ischemic stroke. Prior to the stroke, the patient was a proficient Braille reader. Following the stroke, she was no longer able to read Braille yet her somatosensory perception appeared otherwise to be unchanged. This case supports the emerging evidence for the recruitment of striate and prestriate cortex for Braille reading in early blind subjects.- - - - - - - - - - ranking = 1keywords = perception (Clic here for more details about this article) |
5/127. Bilateral blindness as the initial presentation of lymphoma of the sphenoid sinus.PURPOSE: To report a patient with large-cell lymphoma of the sphenoid sinus presenting with bilateral blindness and no other signs or symptoms. METHOD: Case report. A previously healthy 5-year-old boy complained of sudden vision loss without other systemic complaints. RESULTS: Ophthalmologic examination revealed no light perception bilaterally. The pupils of the patient were fixed at 8 mm without reaction to the brightest light stimulus. Systemic examination was unremarkable, and neuroimaging revealed a large sphenoid tumor extending intracranially. biopsy of the tumor proved to be large-cell lymphoma. CONCLUSION: Large-cell lymphoma affecting children may present initially with blindness, without other systemic symptoms.- - - - - - - - - - ranking = 1keywords = perception (Clic here for more details about this article) |
6/127. mucormycosis manifesting as proptosis and unilateral blindness.A 51-year-old woman presented to the emergency department (ED) of another institution with sudden onset of blindness in the left eye. The patient was found to have no light perception in the left eye and a marked chemosis occurring several days after a fall. She was transferred to the hospital for ophthalmologic evaluation. Upon careful history and physical examination, the diagnosis of rhinocerebral mucormycosis was considered and urgent ophthalmology and otolaryngology consults were obtained. The patient underwent extensive surgical debridement and pharmacologic treatment. The diagnosis was confirmed by pathological specimens. In this case report, the clinical presentation, pathogenesis, diagnostic workup, and ED management of mucormycosis are discussed, highlighting the possible diagnostic and therapeutic pitfalls that are most pertinent to the emergency physician.- - - - - - - - - - ranking = 1keywords = perception (Clic here for more details about this article) |
7/127. Bilateral angle closure glaucoma and visual loss precipitated by antidepressant and antianxiety agents in a patient with depression.A 71-year-old woman with depression had been treated with an antidepressant (maprotiline) and antianxiety agents (clotiazepam and alprazolam). She had previously complained of ocular pain and blurred vision. However, thorough ocular examination was not performed at those times. On examination, visual acuity was no light perception OD and hand motion OS. Intraocular pressures were 33 mm Hg OU. Moderately dilated pupils, atrophic irises, shallow anterior chambers and closed angles were seen in both eyes. Despite treatment, her visual acuity decreased to no light perception bilaterally. Psychiatrists and ophthalmologists should be aware that antidepressants and antianxiety agents can precipitate angle closure glaucoma in susceptible eyes.- - - - - - - - - - ranking = 2keywords = perception (Clic here for more details about this article) |
8/127. Can a motion-blind patient reach for moving objects?It has been claimed that the visual brain is organized in two separate processing streams for spatial vision: one for perception and one for action. To determine whether motion vision is also divided into vision for action and for perception we examined the interceptive behaviour of the motion-blind patient LM. The task for LM and three age-matched control subjects was to reach-and-grasp for an object that moved away. Three experiments were conducted to examine the effects on perfomance of target speed (Expt 1), observation time (Expt 2) and visual feedback (Expt 3). As LM is only able to reach for objects which move at 0.5 m/s or less, her performance is inferior to that of controls who can reach for objects moving at 1.0 m/s, but it is better than would be expected from her performance in psychophysical experiments on her motion vision. Kinematic analysis of LM's reaching movements showed that she adapted the speed of her moving hand to the speed of the target but only when full vision was available. In contrast to normal subjects, LM required long observation times and vision of her moving hand to produce successful reaching responses. Thus, the impairment of both perception and action in LM suggests that the motion area MT/V5 is located at an early stage of the extrastriate hierarchy and provides input to both the perception and the action processing streams.- - - - - - - - - - ranking = 4keywords = perception (Clic here for more details about this article) |
9/127. Enhanced responsiveness of human extravisual areas to photic stimulation in patients with severely reduced vision.Lesions in the primary visual cortex induce severe loss of visual perception. Depending on the size of the lesion, the visual field might be affected by small scotomas, hemianopia, or complete loss of vision (cortical blindness). In many cases, the whole visual field of the patient is affected by the lesion, but diffuse light-dark discrimination remains (residual rudimentary vision, RRV). In other cases, a sparing of a few degrees can be found (severely reduced vision, SRV).In a follow-up study, we mapped visually induced cerebral activation of three subjects with SRV using functional magnetic resonance imaging. We were especially interested in the visual areas that would be activated if subjects could perceive the stimulus consciously although information flow from V1 to higher visual areas was strongly reduced or virtually absent. Because subjects were only able to discriminate strong light from darkness, we used goggles flashing intense red light at a frequency of 3 Hz for full visual field stimulation. Besides reduced activation in V1, we found activation in the parietal cortex, the frontal eye fields (FEF), and the supplementary eye fields (SEF). In all patients, FEF activation was pronounced in the right hemisphere. These patterns were never seen in healthy volunteers. In a patient who recovered completely, we observed that extrastriate activation disappeared in parallel with the visual field restitution. This result suggests that damage to the primary visual cortex changes the responsiveness of parietal and extravisual frontal areas in patients with SRV. This unexpected result might be explained by increased stimulus-related activation of attention-related networks.- - - - - - - - - - ranking = 1.136096286079keywords = perception, discrimination (Clic here for more details about this article) |
10/127. Prolonged epileptic blindness in an infant associated with cortical dysplasia.We report a female infant with status epilepticus amauroticus and intractable focal motor seizures associated with congenital cortical dysplasia. EEG demonstrated persistent epileptiform discharges over the right parieto-temporal regions extending to occipital areas. She required cortical resection of the epileptic zone at age 8 months given failure of very high dose antiepileptic combinations. Histological analysis of a sample of cortex resected from the right central parieto-temporal region, identified by electrocorticography as the focus of epileptic activity, showed cortical dysplasia. The seizures ceased and the infant gained full vision after 48 hours. During an 8-year follow-up period she has had a few short-lived seizures, currently controlled with carbamazepine and vigabatrin. Her cognition and speech are intact. This case demonstrates that: (1) resection of a central temporo-parietal focus, which may have spread to the occipital regions, may result in complete visual recovery and cessation of seizures; and (2) EEG should be considered in every infant with alleged delayed visual maturation, to rule out concealed epileptic activity.- - - - - - - - - - ranking = 0.003638984414495keywords = speech (Clic here for more details about this article) |
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