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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a case with a sequential appearance and disappearance of homonymous hemianopsia, palinopsia and metamorphopsia in the defective visual field within two days. She had a stroke nine months ago and recovered completely. During that episode, dizziness and unsteadiness happened suddenly and was followed by above-mentioned visual symptoms. Brain image and blood perfusion studies showed an old right occipital lesion with hemodynamic changes. Electroencephalograms performed immediately just after the disappearance of all the above-mentioned symptoms subsided and four months later showed similar findings, some isolated independent sharp waves over bilateral temporal areas, with right posterior extension. These were independent of her visual symptoms. The pathophysiologies of our case could be a sequential hemodynamic change in the right occipital area, from hypoperfusion to transient hyperperfusion and finally to normal perfusion. Potential mechanisms are discussed with literature review.
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PMID:Sequential appearance and disappearance of hemianopia, palinopsia and metamorphopsia: a case report and literature review. 1547 79

Patients with metamorphopsia perceive objects or faces as being distorted and/or different in size. In most cases, recognition is not impaired. The stimulus specificity, particularly in the case of face perception, has led to the suggestion that metamorphopsia is a deficit at the entry level of category-specific recognition systems; in this case, the face processing system. An explanation in terms of a visuosensory deficit (i.e., Funktionswandel) that affects the perception of specific stimulus categories has not been systematically evaluated. In this study, we report two patients (MZ and CM) who experienced hemi-metamorphopsia for faces after a stroke in the posterior part of the brain. Despite the distortions, they could still match and recognize faces. We carried out a detailed evaluation of their visual-sensory status and found that both MZ and CM had specific problems with discriminating and estimating sizes and shapes, especially in the contralesional visual field. It was concluded that these cases, metamorphopsia was not due to a higher-order perception impairment specific for faces, but rather of a specific impairment in shape perception in the contralesional visual field that proportionally affects the perception of faces.
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PMID:The role of Funktionswandel in metamorphopsia. 1933 15