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Jules Dejerine and the third alexia.

Modern concepts of pure alexia and alexia with agraphia are derived from Dejerine's eloquent clinicopathologic studies of the late 19th century. More recently, a third variety of alexia has been described in association with left frontal lesions causing Broca's aphasia. Dejerine also recognized this "third alexia." For Dejerine, alexia with Broca's aphasia was indispensible to his view of a left-hemisphere language zone in which cortical lesions disrupt all language modalities (speech, reading, and writing). Viewed in light of modern neurolinguistic advances, Dejerine's descriptions of the third alexia are surprisingly prescient.

Agraphia↗

The continuum of deep/phonological alexia.

Two patients exhibited all the characteristics of deep alexia shortly following brain injury. Both subsequently recovered some reading abilities and evolved to show a pattern of oral reading consistent with phonological alexia. These findings suggest that deep alexia and phonological alexia share common underlying deficits that are mediated by common neurological systems. A two-deficit psycholinguistic model is presented to account for the apparent continuity between deep alexia and phonological alexia.

Adult↗

Reversal of alexia in multiple sclerosis by weak electromagnetic fields.

The occurrence of cognitive deficits in patients with multiple sclerosis (MS) has been recognized since 1877 when Charcot first observed "enfeeblement of memory" in his patients. Cognitive deficits have been reported in almost 50% of patients with a relapsing-remitting course and in a significantly higher percentage of patients with a chronic progressive course leading to intellectual disability which is often severe enough to preclude employment. MS is considered a form of subcortical dementia and the occurrence of classical cortical disorders such as aphasia, agnosia and apraxia is reported to be rare in the disease. However, in my experience alexia, a reading impairment unrelated to visual acuity or visual field defects, is common in patients with MS. Recently, I reported that treatment with picotesla range electromagnetic fields (EMFs) is an efficacious modality in the management of both the motor and cognitive symptoms of MS. Three patients with MS who developed alexia as a manifestation of the disease are presented. In all patients the alexia was reversed several months after they began treatment with EMFs. Since alexia usually reflects a disconnection syndrome whereby lesions involving the left visual cortex and the splenium of the corpus callosum disconnect language association areas from visual association areas, it is suggested that reversal of the alexia in these patients by EMFs was related to improved interhemispheric transcallosal transmission of visual information. In addition, it is conceivable that changes in the metabolism of monoamines, which are involved in visual information processing and reading comprehension, may have been important in causing reversal of the alexia. This report further supports the unique efficacy of this treatment modality in reversing specific cognitive deficits in MS.

Adult↗

[Pure alexia due to a fusiform gyrus lesion].

We present a patient with pure alexia following a hemorrhagic infarction in the left fusiform gyrus. The symptom began with alexia preferentially disturbed for kana, but during the course of recovery slight agraphia for kanji became pronounced. In the earlier phase, alexia was more severe than agraphia and he could write kanji that he could not read. Furthermore, kinesthetic reading was effective. These findings are consistent with the symptoms of pure alexia, although the fact that a writing disturbance for kanji persisted resembles the profile of alexia with agraphia for kanji due to a posterior inferior temporal lesion. Based on the fact that the posterior inferior temporal lesion showed more severe agraphic symptom and more frequent nonresponse writing errors of kanji, and that our patient's lesion was mainly located in the fusiform gyrus that is medial to the inferior temporal gyrus, we believe that alexia occurred when the inferior temporal gyrus was disconnected from the fusiform gyrus, as a result, visual information could not reach the inferior temporal gyrus in which the visual images of individual kanji are stored.

Aged↗

The third alexia.

A variety of alexia has been demonstrated that can be distinguished from the two classically recognized types of alexia. This reading disorder is seen in patients with a dominant frontal lobe pathologic condition that has produced a motor language disturbance (Broca aphasia) and is sufficiently disabling to deserve consideration as a variety of alexia. Functionally, the frontal reading disturbance differs from the other two types in that the patient comprehends meaningful content words better than relational or syntactic structures. Four factors that may underly frontal alexia have been noted: (1) gaze paresis, (2) inability to maintain verbal sequences; (3) inability to comprehend syntactic structure, and (4) literal alexia.

Agraphia↗

Alexia with agraphia due to the left posterior inferior temporal lobe lesion--neuropsychological analysis and its pathogenetic mechanisms.

We report three cases of alexia with agraphia due to the left posterior inferior temporal lesions. In Case 1, the reading disability was more prominent in the use of Kana than in the use of Kanji, which is similar to previously reported cases of alexia with agraphia due to angular gyrus lesion. In Cases 2 and 3, by contrast, the reading disability was more prominent in the use of Kanji than in the use of Kana. In spontaneous writing and dictation, the disability was more pronounced in the use of Kanji compared with the use of Kana. In each of the three cases, the CT scan and positron emission tomography showed a localized lesion in the lower part of the left posterior temporal lobe. A typical form of an alexia with agraphia could be caused not only by the left angular lesion but also by the left posterior inferior temporal lesion. We discuss the neuropsychological analysis and pathogenetic mechanisms of alexia with agraphia due to the left posterior inferior temporal lesion in the comparison of alexia with agraphia caused by the left angular lesion.

Aged↗

Music and language: musical alexia and agraphia.

Two aphasic right-handed professional musicians with left hemispheric lesions had disturbed musical function, especially musical alexia and agraphia. In Case 1 aphasia was of transcortical sensory type, with severe agraphia and decreased comprehension of written words, although she could match them with pictures. Except for reading and writing, musical ability was normal; she could sing in five languages. Musical alexia and agraphia affected pitch symbols more than rhythm. Case 2 had conduction aphasia and severe expressive amusia, especially for rhythm. Although his language alexia and agraphia were milder than Case 1's, his musical alexia and agraphia were more severe, affecting rhythm as much as pitch. In neither patient were those aspects of musical notation either closest to verbal language or most dependent upon temporal (sequential) processing maximally impaired. These cases are consistent with the literature in suggesting that the presence or absence of aphasia or of right or left hemispheric damage fails to predict the presence, type, or severity of amusia, including musical alexia and agraphia. The popular notion that receptive amusia follows lesions of the language-dominant temporal lobe, whereas expressive amusia follows non-dominant frontal lobe damage, is an over-simplification, as is the view that increasing musical sophistication causes a shift of musical processing from the right hemisphere to the left.

Adult↗

Aphasia, alexia, and oral reading.

Alexia is an acquired disturbance in reading. Alexias that occur after left hemisphere damage typically result from linguistic deficits and may occur as isolated symptoms or as part of an aphasia syndrome. This article presents an overview of the classification of the alexias, including both the traditional neuroanatomical perspective and the more recent psycholinguistic approach. Then, assessment procedures are reviewed, followed by a summary of treatment approaches for alexia. Finally, two case studies illustrate how oral reading of connected language (sentences and paragraphs rather than single words) has been used as a technique for treating alexia in patients with aphasia.

Aphasia↗

[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.

Adult↗

[Kanji-predominant alexia with agraphia in opticospinal multiple sclerosis].

Alexia with agraphia is very rare symptom in multiple sclerosis. We present a patient of opticospinal multiple sclerosis with kanji-predominant alexia with agraphia. A 55-year-old, right-handed man was admitted to our hospital because of difficulty in reading and writing in August 2001. The patient had been diagnosed as having relapsing-remitting opticospinal multiple sclerosis eight years prior to admission. Language examination showed alexia with agraphia predominantly affecting kanji and also mild naming difficulties, but a good comprehension and a normal repetition. T2-weighted MRI demonstrated hyperintensity area in the left temporo-parietal lobe, involving the white matter beneath the postero-inferior temporal lobe and inferior parietal lobule. On brain SPECT, low blood perfusion was observed in the left temporo-parietal regions. Although agraphia for kana and alexia for both kana and kanji improved after steroid therapy, agraphia for kanji did not improve. After the treatment, high intensity area of inferior parietal lobule was disappeared on MRI, and the hypoperfusion of inferior parietal lobule on brain SPECT was also improved, but the lesion of left postero-inferior temporal lobe did not show any remarkable changes. We considered that the kanji-predominant alexia with agraphia was due to the lesions of left inferior parietal lobule and postero-inferior temporal lobe, and agraphia for kanji was due to the lesion of left postero-inferior temporal lobe.

Agraphia↗

[Alexia without agraphia, colour "agnosia" and right visual field defect: a syndrome of the posterior cerebral artery (author's transl)].

Two cases of alexia without agraphia are reported, with differences in the characters of the alexia and in the accompanying signs. The visual field defect was limited to quadranopia in both cases which was upper quadrantic and mild in one, lower quadrantic and severe in the other. These differences make it unlikely that a similar anatomical location of the lesion and a unique mechanism are responsible of all cases of alexia without agraphia. Persistance of visual inputs in the right visual field is partial in our cases, but alexia without hemianopsia does exist. These facts are against the mechanism of "splenio-cortical" disconnection proposed by Geschwind as the only explanation. A "cortical", or agnosic mechanism has been also claimed, with lesions of the lingual and fusiform gyri on the dominant side, as well as "subangular", mechanism, with intrahemispheric disconnection by a lesion located between the visual associative areas and the angular gyrus: in these last two situations an hemianopsia is not necessarily associated to the alexia without agraphia.

Agnosia↗

[Alexia with agraphia produced by localized infarction in the inferior posterior region of the left temporal lobe].

There have been several reports on alexia with agraphia due to hemorrhage or trauma in the inferior posterior region of the left temporal lobe since Yamadori (1982) first reported a case of cerebral hemorrhage. We presented the first case of alexia with agraphia due to a circumscribed infarct in the inferior posterior region of the left temporal lobe. A 65-year-old right-handed man had an acute onset of inability to read Japanese "kana" letters and to write any letters. He had no difficulty in speaking or understanding. Neurological examination on admission was normal except for homonymous quadrantanopia in the right upper field. Neuropsychological findings: Spontaneous speech was fluent without dysprosody. There were no disturbances in auditory understanding or in repetition. He could read Japanese "kanji" characters correctly, however, he could not read any "kana" letters. Writing was also disturbed severely even as to his address, name or telephone number. Calculation was also difficult. There were no disturbances in naming colors, no ideomotor or constructional apraxia nor visual agnosia. X-ray computed tomography (CT) scan showed a faint low density area with ring enhancement suggesting a cerebral infarct in the inferior posterior region of the left temporal lobe. Patient's hospital course was characterized by a marked improvement of alexia, especially of "kana" letters as compared with that of "kanji" characters. Dissociative improvement of alexia compared with agraphia in this case could be explained by the fact that the lesion was in close contact with the occipital lobe and that he also had pure alexia in the early stage.

Agraphia↗

[Alexia-agraphia of kanji (Japanese morphogram) after left posterior-inferior temporal lesion].

Several cases of selective alexia with agraphia of kanji have been reported in Japan in this decade. It is well known that the lesion in the posterior inferior temporal lobe of the dominant hemisphere is responsible for this cognitive syndrome. Neuropsychological data in our patient suggest that the postero-inferior region of the temporal lobe of the dominant hemisphere may be the visuo-verbal association area for the analysis of the complex visuo-verbal information. The symptoms caused by the same lesion in western patients might be subangular alexia (alexia without agraphia). Alexia with agraphia of kanji and subangular alexia would appear to be distinct entities, but a dual processing hypothesis of visuo-verbal information and the concept of the visuo-verbal association area might well explain both syndromes.

Agraphia↗

Alexia without agraphia following biopsy of a left thalamic tumor.

Alexia without agraphia is a rare disconnection syndrome characterized by the loss of reading ability with retention of writing and verbal comprehension. We report a patient who developed alexia without agraphia after undergoing a biopsy for a malignant glioma involving the left thalamus. A 15-year-old right-handed male presented with 3 days of severe headache, and vomiting, and 1 month of blurry vision in his right visual field. Magnetic resonance imaging of the brain disclosed a large exophytic mass originating in the left thalamus, with mass effect and hydrocephalus. The patient underwent biopsy of the left thalamic mass via a transcallosal approach. Postoperatively, the patient complained of inability to read or identify letters. Examination revealed alexia without agraphia. The syndrome of alexia without agraphia can be rarely caused after surgery. A transcallosal procedure through the splenium of the corpus callosum may disrupt the visual association fibers traveling from the right occipital cortex to the left angular gyrus. In our case the syndrome occurred because of a preexisting right homonymous hemianopia resulting from a left thalamic tumor.

Adolescent↗

[Pure alexia secondary to progressive multifocal leukoencephalopathy as first manifestation of HIV infection].

INTRODUCTION: Pure alexia, or alexia without agraphia, is usually caused by disconnection between the gyrus angularis and visual areas of both hemispheres. Cerebrovascular disease is the most frequent cause of this syndrome. CLINICAL CASE: We report the first case of a patient with pure alexia secondary to progressive multifocal leukoencephalopathy (PML) as the first manifestation of Human Immunodeficiency Virus (HIV) infection. Polymerase chain reaction in cerebrospinal fluid was positive for JC virus. Despite favorable immunological and virological response to highly active antiretroviral therapy, neurological symptoms and demyelinating lesions progressed during the first months, and right homonyous hemianopsia, acalculia, and color anomia were noted. In magnetic resonance imaging (MRI) demyelinating lesions involved white matter of both occipital lobes, with left predominance, forceps major and splenium of the corpus callosum, together with white matter of the left temporal lobe and both hippocampal regions. During the following months, coinciding cidofovir treatment, the patient had partial clinical improvement, but neurological deficits persisted. The size of MRI lesions significantly improved. CONCLUSIONS: PML is frequently the first manifestation of AIDS (acquired immunodeficiency syndrome). It should be considered as a possible diagnosis of pure alexia.

Alexia, Pure↗

Transcortical alexia with agraphia following a right temporo-occipital hematoma in a right-handed patient.

We describe the case of a 51-year-old right-handed man who was affected by a transcortical alexia with agraphia and aphasia. Transcortical alexia produces errors in both reading and writing while copying is preserved. The patient had a severe alexia and was unable to read letters, words or sentences. Language examination showed mild aphasia with reduced fluency, intermittent paraphasia but a good comprehension and a normal repetition. Spontaneously and from dictation, writing was impaired by an agraphic jargon, but copying was excellent even though the patient was unable to read his own written production. There was no visual agnosia nor hemianopia. CT scan and MRI of the brain showed that there was a single right temporo-occipital hemorrhage but no lesion in the left hemisphere. Following surgical evacuation of the hematoma, the patient improved. One month after onset, his language was quite intact and reading was possible. We hypothesize that this particular syndrome was the result of a double disconnection: alexia would result from a disconnection of the right angular gyrus and the occipital associative areas by a subangular lesion; agraphia would result from a disconnection of the right angular gyrus and the semantic store, probably located in the right hemisphere.

Agraphia↗

Anomic alexia of kanji in a patient with anomic aphasia.

The ability to read aloud kanji (logogram) words and to comprehend their meaning was systematically examined to clarify the underlying mechanism of kanji alexia in a patient with anomic aphasia. Confrontation naming, reading aloud and reading comprehension tasks were performed using 110 words from 11 semantic categories written in kanji or kana. Performance in oral reading of kanji words was significantly worse than oral reading of the same words transcribed into kana words. In addition, for kanji words reading aloud was much worse than reading comprehension. Oral reading of kanji words had a significant correlation with naming pictures corresponding to the words, but no correlation with comprehension of kanji words. Qualitative analyses demonstrated that errors in oral reading and naming tasks had many features in common. Our results indicated that some common mechanisms underlie both naming and oral reading of kanji words. We propose calling this type of alexia "anomic alexia of kanji", which should be distinguished from kanji alexia with difficulty in both reading aloud and comprehension. Lesions in our patient were located in the middle part of the left middle temporal gyrus and its subcortical area, which could be important for access to the phonological lexicon from semantics.

Aged↗

Two types of phonological alexia.

It is hypothesized, on the basis of a lexical model of reading, that there are two different underlying causes of phonological alexia. It is predicted that these two types of phonological alexia will be accompanied by different sets of symptoms. Published cases of phonological alexia are examined for evidence in support of these predictions. Two distinct groups of phonological alexic patients are observed. These results support the notion of two types of phonological alexia. The failure to find any phonological alexic patients who do not fall into one of these two categories provides evidence against non-lexical reading models.

Dyslexia, Acquired↗