Alexia without agraphia associated with right occipital lesion.

A 78 year old, right handed man developed the syndrome of alexia without agraphia due to a right occipital thrombotic stroke. The cerebral dominance test strongly suggests that his right hemisphere is dominant. This is believed to be the first case of alexia without agraphia secondary to a right occipital lesion in a right handed person.     

Alexia without agraphia or hemianopia

The case of a right-handed man with pure alexia without hemianopia due to intraparenchymal haematoma is reported. Ct scan and nuclear magnetic resonance showed a lesion in the lateral temporo-occipital area confirming the assumption that the anatomic pathways responsible for reading run close to the lateral temporo-occipital or inferior temporal gyrus.     

Alexia with agraphia

The authors presented a case of relatively pure syndrome of alexia with agraphia in a patient speaking Serbo-Croatian language. Reading disturbances showed some characteristics of a deep dyslexia. Besides severely impaired reading and writing abilities, some components of Gerstamnn's syndrome were also present. Infarction in the posterior half of the left supramarginal and in the anterior half of the left angular gyrus was accurately located by the graphic reconstruction of CT scans.     

Alexia without agraphia in Creutzfeldt-Jakob disease

Progressive dementia uncommonly presents with focal deficits referable to posterior cortical dysfunction. We describe a 62 year-old man who presented with progressive visual disturbance in whom detailed cognitive testing documented alexia without agraphia. The only finding from diagnostic investigations was hypoperfusion of the posterior left temporoparietal region on brain SPECT scan. He rapidly progressed and Creutzfeldt-Jakob disease (CJD) was confirmed at autopsy. Although reading disorders may develop in association with posterior cortical atrophy due to CJD, this is the first reported autopsy-confirmed case presenting as alexia without agraphia.     

Alexia without agraphia and the inferior splenium

A patient who had alexia without agraphia, right homonymous hemianopia, and intact color-naming was studied anatomically. Pathologic involvement of the splenium and related forceps was restricted to the inferior third, supporting published suggestions that inferior elements of this commissure and left peristriate cortex may be essential to the decoding to the written word, while color-naming may be functionally aligned to more dorsal elements.     

Alexia without agraphia: lateral and medial infarction of left occipital lobe

Four cases of alexia without agraphia were studied by 99m-technetium pertechnetate brain scan. Two types of increased uptake were seen. One was of the triangular type near the midline in the posterior view, said to characterize an infarction in the distribution area of the posterior cerebral artery. This was associated with the well-known clinical picture of alexia without agraphia accompanied by hemianopia and color-naming defect, and was confirmed by postmortem examination. The other type of pathologic isotope uptake, observed in three patients, was more laterally placed, in the basal part of the left occipital lobe, and did not reach the midline. In these cases the alexia was transient and not associated with color-naming defects.     

Alexia without agraphia: a clinico-tomographic study

The authors report the clinical findings and CT-scanning results in two cases of alexia without agraphia and review the literature on this subject. Both patients had extensive infarction in the territory supplied by the left posterior cerebral artery and developed severe alexia without agraphia, right hemianopia without color-anomia and one of them presented with transient verbal memory difficulties. In both cases the evolution was very good, with total regression of the alexia after 17 months in the first patient and almost complete recovery after there months in the second one. The authors comment on the causes and possible mechanisms of the alexias, especially of the alexia without agraphia, and suggest that every patient with right hemianopic disturbances due to occlusion of the left posterior cerebral artery be thoroughly studied from a neurological point of view, so that this syndrome can be detected since, notwithstanding its recognized rarity, it seems highly probable that many cases have been overlooked as a result of incomplete examination of the patients.     

Alexia without agraphia in a left-handed patient with prosopagnosia

A left-handed patient was studied who had the acute onset of alexia without agraphia, a left homonymous hemianopia, and prosopagnosia. Neurodiagnostic tests including computerized axial tomography and angiography disclosed bilateral lesions in the posterior cerebral hemispheres involving the splenium of the corpus callosum. Neuropsychologic examination indicated marked impairment of facial discrimination, deficient naming and memory of presented visual material, and mild visual agnosia with relative preservation of other cognitive functions. These findings are consistent with a double disconnection syndrome involving disconnection of the dominant angular gyrus and right inferotemporal cortex from their bilateral visual inputs.     

Alexia without agraphia following cerebral venous thrombosis associated with protein C and protein S deficiency

A 26-year-old right handed female was admitted to hospital with right homonymous hemianopia associated with alexia without agraphia. Her cranial magnetic resonance imaging and magnetic resonance angiography revealed a left occipital venous infarction due to thrombosis of the left transverse, sigmoid sinuses and the left internal jugulary vein. The underlying conditions were protein C and protein S deficiency associated with the use of oral contraceptives. To our knowledge, alexia without agraphia has never been described due to a venous infarction associated with hereditary thrombophilia in the literature.     

Alexia without agraphia following cerebral venous thrombosis associated with protein C and protein S deficiency

A 26-year-old right handed female was admitted to hospital with right homonymous hemianopia associated with alexia without agraphia. Her cranial magnetic resonance imaging and magnetic resonance angiography revealed a left occipital venous infarction due to thrombosis of the left transverse, sigmoid sinuses and the left internal jugulary vein. The underlying conditions were protein C and protein S deficiency associated with the use of oral contraceptives. To our knowledge, alexia without agraphia has never been described due to a venous infarction associated with hereditary thrombophilia in the literature.     

Alexia without agraphia. Anatomical basis and physiopathological mechanisms

Clinical, neuropsychological and radiological signs were studied in a patient suffering from pure alexia associated with right superior quadrantanopia. The lesion responsible for the defects was located in the periventricular white substance at the level of the left inferior occipitotemporal convolutions. These structures seem to constitute the pathway of the visual information channelled from the two hemispheres towards the language centres. The lesion therefore disconnects the angular gyrus from its visual information and gives rise to alexia without agraphia.     

Alexia with agraphia in multiple sclerosis

Alexia with agraphia has not been reported in multiple sclerosis (MS), while aphasia is rare. This report documents these findings in a woman with relapsing MS. Associated features included dysmnesia, achromatopsia and elements of Gerstmann's syndrome. Cranial CT showed a large contrast-enhancing area of demyelination in the left temporo-parietal region.     

Alexia without agraphia in a left-handed patient with a right occipital lesion

A left-handed patient who had suffered an ischemic vascular accident in the territory of the right posterior cerebral artery displayed alexia without agraphia. Clinical examination of this alexia revealed semiological characteristics comparable with those observed in cases of left temporo-occipital lesions in right-handed patients. Analysis of these disturbances indicated that they were agnosic in nature. The associated disturbances included problems of visual representation and topographic memory together with an amnesic syndrome.