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PubMed2006

[A case of alexia with agraphia caused by the re-infarct in left lateral occipital gyrus].

The angular gyrus has been proposed as the key area of reading and writing function. In recent PET (positron emission topography) activation studies, role of angular gyrus in the reading and writing has been reestimated. Whether the angular gyrus is necessary for reading and writing or not is now under discussion and should be clinically revised. We experienced a case that presented classical alexia with agraphia of kana (Japanese syllabogram) caused by the re-infarct in left lateral occipital gyrus. This case showed the alexia with agraphia more apparent in Japanese kana than in kanji characters. Interestingly, no higher cortical dysfunction was revealed at the first cerebral infarction in left angular gyrus which was assumed as the key area for alexia with agraphia. This case supported the opinion which pointed out the importance of left occipital gyrus on Japanese kana reading.

Aged↗
PubMed1977

[Alexia without agraphia (clinicotomographic correlation)].

Two cases of alexia without agraphia, one due to a cerebrovascular accident which improved spontaneously and the other in a cerebral abscess partially recovered after surgical treatment are presented. Both were anatomically verified by computed tomography. The second was also verified at surgery. A small well localized lesion of the fusiform and lingual gyri in the dominant hemisphere can lead to alexia without agraphia. The lack of involvement of the optic radiation and calcarine fissure explain the abscence of visual field defects and hence the purest type of this syndrome as shown in our first case. The involvement of the splenium of the corpus calosus and related forceps majors seems essential for a long lasting reading defect. The integrity of the dorsal or superior splenium is responsible for the abscence of the color warning defect found on about 30% of the cases of pure word blindness. The severity and ultimate progression of the alexia will depend not only upon the extension of the dominant occipital lesion but of its association with the damage of other possible pathways. A slowly growing and potentially treatable expanding lesion, as in our second case, can also produce an almost pure form of the syndrome. It appears to us that the wider use of CT will allow on the near future will lead to a better knowledge of the anatomical lesions and a better understanding of this fascinating syndrome.

Adult↗
PubMed1995

[A case of pure alexia whose writing ability with eyes closed was superior to that with eyes open].

We compared the writing ability between eyes open (looking at one's writing) and eyes closed (without looking) in a case of pure alexia. The patient is a 84-year-old right handed man who developed pure alexia following an infarction in the distribution of the left posterior cerebral artery. He showed right homonymous hemianopsia, slight memory disorder and slight anomia. He could not read any kinds of letters and words at all though he could categorize letters: Kana (phonograms), Kanji (morphograms) and Arabic numbers, and he could distinguish the real letters from false ones. He could achieve almost 60-70% of Kana and Kanji dictation, though it was not perfect. He was often confused and could not continue writing correct letters once interrupted. He wrote poorly when looking at what he was writing. So we compared the ability of dictation with his eyes closed, and that with his eyes open. We found the former way never caused confusion and got better results, which was statistically significant (Fisher's exact test (p < 0.05)). It seemed that his visual feedback of his own writing rather caused trouble in his writing. Thus we concluded that input (reading) process and output (writing) process work simultaneously and bi-directionally. Slight impairment of writing in pure alexia patients might be caused by the effect of impairment of input (reading) process, which is simultaneously connected with the output (writing) process.

Aged↗
PubMedDate not supplied

[Reading numbers in pure alexia: effects of the task and hemispheric specialization].

Selective conservation of the ability to read Arabic numbers in patients unable to read words or even letters is a classical characteristic of pure alexia described by Dejerine (1982). We report our work on the capacity of two patients with pure typical alexia to process numbers. Our main finding was that these patients could count pairs of Arabic numbers correctly when the reading task was simple (example 2 4-->"two four") or when the task involved comparing sizes (example 2 4-->"four is bigger than two"). Inversely, these patients often made mistakes when asked to perform arithmetic operations (example 2 4-->"two plus four equals six"). Using these two numbers, there was a similar dissociation between excellent performance on comparison tests and severe deficiency in reading out loud. We interpret these findings with the hypothesis that both of the hemispheres can identify Arabic numbers, but that the visual systems on the right and left play a different role during different tasks. In pure alexia, a lesion in the left identification system leads to selective deficiency in linguistic tasks such as reading numbers out loud, recognizing numbers with several figures or mental arithmetic. The right identification system in intact and is sufficient for comparison or reading isolated Arabic numbers.

Aged↗
PubMed2004

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.

Adult↗
PubMed2004

Alexia without agraphia in multiple sclerosis: case report with magnetic resonance imaging localization.

The syndrome of alexia without agraphia occurs rarely in multiple sclerosis (MS). We report a patient with right homonymous hemianopsia and alexia without agraphia as his initial manifestations of relapsing-remitting MS. Magnetic resonance imaging (MRI) demonstrated a hyperintense lesion in the left occipital subcortical white matter (WM) and an enhancing lesion in the splenium of the corpus callosum. The clinical presentation and MRI findings were consistent with disconnection of the functional right occipital visual cortex from structures responsible for language comprehension in the left hemisphere. The diagnosis of MS was confirmed by subsequent development of additional periventricular WM lesions.

Alexia, Pure↗
PubMed1982

Word and letter reading and the mechanism of the third alexia.

Four patients, two with global aphasia and two with Broca's aphasia, demonstrated the seemingly paradoxical ability to read words but not their component letters. Picture naming was only moderately impaired, and repetition of word and letter names was intact, excluding both a generalized dysnomia and an articulatory disturbance as the cause of the literal alexia. Matching tests revealed processing deficits in three of the patients, more severe for letters than for words. Oral reading of word lists showed that short, high-frequency, and picturable words were read best, whereas nonsense trigrams, which require phonetic processing, were the most difficult. The residual reading of patients with severe Broca's or global aphasia and the "third alexia" appears to involve purely visual, nonphonetic mechanisms for word recognition, using posterior left hemisphere or even minor hemisphere centers. Letter reading, by contrast, along with phonetic reading of syllables, appears to be a more specialized, anterior left hemisphere process.

Aphasia↗
PubMed1987

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.

Aged↗
PubMed1998

Pure alexia and word-meaning deafness in a patient with multiple sclerosis.

OBJECTIVE: To describe pure alexia and auditory comprehension problems in a young woman with multiple sclerosis (MS). PATIENT: A 33-year-old woman with MS who complained of difficulties in reading and comprehending spoken language was referred for a neuropsychological examination. Reading difficulties were confirmed and most of the reading errors were additions, omissions, and substitutions of single letters. While the patient reported that the letters seemed to disappear before her eyes, no general problems with visual attention, visual discrimination, or scanning were detected. No difficulties with spelling were reported. The auditory comprehension deficit is interpreted as a form of a semantic access disorder and is not due to generalized slowing in information processing or conceptual disintegration. CONCLUSIONS: Pure alexia is unusual in MS and to our knowledge only 1 other case has been reported (in Japanese). Memory impairments and slowed information processing are probably the most frequent cognitive sequelae of the disease and, consequently, the literature is biased toward the study of those cognitive domains. However, given the wide distribution of sclerotic plaques in MS, it could be argued that we should expect some variability of cognitive changes in MS. Striking deficits as seen in this patient should make us more sensitive to this possibility.

Adult↗
PubMed1978

Alexia and left homonymous hemianopia in a non-right-hander.

A non-right-handed patient developed alexia without agraphia from a right occipital lobe infarction. An intracarotid amobarbital test showed left hemispheric dominance for speech. The cause of alexia in this patient could not be explained simply by the accepted disconnection hypothesis, which proposes that speech, handedness, and reading functions reside in the same hemisphere. The findings in this patient suggest that his speech function is located on the left, whereas his functions for reading and writing are located in the right hemisphere.

Dominance, Cerebral↗
PubMed1993

Jules Dejerine and his interpretation of pure alexia.

Dejerine's interpretation of pure alexia is routinely mentioned in all neuropsychological textbooks, yet the details of his account and the evidence on which it is based have never been subjected to a critical analysis. We provide such an evaluation in this paper, summarizing the behavioral data that Dejerine presented in his now famous case report and the theoretical framework he adopted to explain the phenomenon of alexia without agraphia. We also provide a link between Dejerine's work and current hypotheses on the nature of the syndrome.

Brain↗
PubMed1995

Visual word activation in pure alexia.

A patient with pure alexia (DM) is shown to perform rapid and accurate lexical decisions for common words without the ability to recover their complete identity. We provide evidence using a speeded decision task that DM is not forced to rely on a laborious analysis of individual letter forms when judging the lexical status of orthographic patterns varying in length, though he clearly must use this approach to fully identify a word for explicit report. By contrast, the ability to rapidly classify a word apparently does not extend to judgements of its superordinate category. DM makes semantic decisions for visual words by adopting the same inefficient procedure he uses for verbal report of their identity. The results provide further constraints on the functional deficit responsible for pure alexia. We argue that DM is able to monitor the overall activation of word units without achieving full identification and that such a process may be a characteristic of the normal reading mechanism.

Adult↗
PubMed1996

Preserved semantic priming effect in alexia.

BH, a left-handed patient with alexia and nonfluent aphasia, was presented with a lexical-decision task in which words and pronounceable pseudowords were preceded by semantically related or unrelated picture primes (Experiment 1). In Experiment 2, BH was given an explicit reading task using the word lists from Experiment 1. Performance on Experiment 2 disclosed severe reading deficits in both oral reading and semantic matching of the words to pictures. However, in Experiment 1, BH demonstrated a significant semantic priming effect, responding more accurately and more quickly to words preceded by related primes than by unrelated primes. The present results suggest that even in a patient with severe alexia, implicit access to semantic information can be preserved in the absence of explicit identification. The possibility of categorical gradient in implicit activation (living vs. nonliving) in BH was also discussed, which, however, needs to be clarified in the further investigation.

Brain↗
PubMed1982

Mechanisms of reading and spelling in a case of alexia without agraphia.

In the clinical syndrome of alexia without agraphia, reading is greatly disturbed while writing and spelling remain relatively intact. The most commonly accepted explanation of this pattern of findings is that the center for written language interpretation remains intact, but has become inaccessible to visual input. This paper examines the nature of the intact written language center with respect to specific mechanisms of reading and spelling in a patient presenting with the major components of alexia without agraphia. It is concluded that the dissociation between reading and writing performance found in this patient reflects the existence of separate and distinct mechanisms for reading and spelling.

Adult↗
PubMed1984

Alexia in recent and late Broca's aphasia.

The hypothesis was tested that alexia associated with Broca's aphasia may often be a residual receptive disorder of a broader picture of global aphasia. It was found that alexia does tend to be associated, as expected, to the long-standing Broca's aphasias more often than to the recent ones. However, the CT scan failed to disclose larger and more posterior lesions in Broca's alexic than in Broca's non-alexic patients.

Adult↗
PubMed1995

The efficacy of kinesthetic reading treatment for pure alexia.

This paper presents an effective treatment for pure alexia by a type of single-case design, which we termed a "material-control single-case design" [Sugishita et al., Neuropsychologia, Vol. 31, 559-569, 1993]. Two patients with pure alexia were treated using kinesthetic reading (reading by tracing or copying the outline of each letter with the patient's finger). The results clearly demonstrated that both patients significantly improved their reading and copying performances. Their recovery of reading performance arose from improvement in copying. The results of tachistoscopic reading tests suggested that the patient obtained the ability to read without kinesthetic movements.

Adult↗
PubMed2006

Alexia and quadrant-amblyopia: reading disability after a minor visual field deficit.

Reading difficulties caused by hemianopia are well described. We present a study of alexia in a patient (NT) with a milder visual field deficit. The patient had suffered a cerebral haemorrhage causing damage to the left occipital cortex and underlying white matter. NT's text reading was slow and prone to error, but recognition of single letters was preserved. Single word reading was accurate, but slower than normal. On perimetric testing NT initially showed an upper right quadrantanopia, but by attending covertly to this quadrant he could achieve luminance detection except in a small scotoma above the reading line. A whole report experiment showed that letter perception was severely compromised in the quadrant, consistent with cerebral amblyopia. On follow-up testing one and a half year post stroke, a clear spontaneous recovery had occurred, reflected in improved text reading with close to normal eye movements. Still, subtle reading difficulties and oculo-motor abnormalities remained. Overall, the study shows how amblyopia in one quadrant can lead to a characteristic form of alexia.

Adult↗
PubMed1979

Rehabilitation of alexia: a case study.

This case study described the success of a technique labeled Multiple Oral Rereading (MOR) in the remediation of a case of acquired alexia in an adult male. Unusually slow visual-verbal processing characteristic of this patient is sometimes noted in dyslexic children. The possibility that MOR might prove effective for other selected cases of acquired alexia and "developmental" dyslexia is considered.

Adult↗