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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.
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.
This typical case of alexia without agraphia, caused by an astrocytoma, is the first recorded case in the literature of alexia without agraphia with a right homonymous hemianopia caused by a tumor. This case differs from previously reported cases of the syndrome by its fluctuating clinical course and its slow progression. All but one of previously reported cases had been of vascular or surgical etiology. This course and the associated radiographic findings should differentiate the neoplastic from the vascular etiology of this most fascinating syndrome.
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.
Korean written language is composed of ideogram (Hanja) and phonogram (Hangul), as Japanese consists of Kanji (ideogram) and Kana (phonogram). Dissociation between ideogram and phonogram impairment after brain injury has been reported in Japanese, but few in Korean. We report a 64-yr-old right-handed man who showed alexia with agraphia in Hanja but preserved Hangul reading and writing after a left posterior inferior temporal lobe infarction. Interestingly, the patient was an expert in Hanja; he had been a Hanja calligrapher over 40 yr. However, when presented with 65 basic Chinese letters that are taught in elementary school, his responses were slow both in reading (6.3 sec/letter) and writing (8.8 sec/letter). The rate of correct response was 81.5% (53 out of 65 letters) both in reading and writing. The patient's performances were beyond mean-2SD of those of six age-, sex-, and education-matched controls who correctly read 64.7 out of 65 and wrote 62.5 out of 65 letters with a much shorter reaction time (1.3 sec/letter for reading and 4.0 sec/letter for writing). These findings support the notion that ideogram and phonogram can be mediated in different brain regions and Hanja alexia with agraphia in Korean patients can be associated with a left posterior inferior temporal 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.
Impairment of writing ability was studied in 20 patients with mild to moderate dementia caused by early-onset Alzheimer's disease. A multicomponent analysis was made of a brief narrative writing sample obtained from each patient, and this writing proficiency score was compared with results of standard tests of cognitive function as well as ratings of the degree of dementia. In these patients, significant correlations were observed between this brief test of narrative writing ability and the severity of dementia. An analysis of writing proficiency appears to be a simple means of assessing the severity of dementia caused by Alzheimer's disease. Further studies are needed to show the potential usefulness of such measures of agraphia in subtyping this disease.
A 60-year-old right-handed Japanese man with infarction of the left occipital lobe and inferior temporal gyrus initially showed pure alexia in kana and kanji. Later, though pure alexia in kana persisted, his kanji reading improved markedly, but with little improvement of kanji writing. We speculate that different pathways are involved in kanji reading and writing. Wernicke's area and its surrounding left middle temporal lobe might play the most important role for kanji reading when visual information is transmitted by any pathway. The pathway from Wernicke's area to the left occipital lobe via the middle and inferior temporal pathway may be indispensable for kanji writing. We postulate "agraphia without alexia in kanji" due to left inferior temporal subcortical damage.
We present an original case of Marchiafava-Bignami disease in a 47-year-old left-handed alcoholic man. Computed tomography and magnetic resonance imaging demonstrated the typical lesion, a necrosis of the middle portion of the corpus callosum. Diagnosis may thus be established in the living. In our case, the course was not fatal, which, to our knowledge, has only been described in four other cases in the literature. Clinically, our patient demonstrated an interhemispheric disconnection syndrome. The striking feature is that some of the symptoms were on the side opposite of the one that has previously been described in the literature, eg, right-handed agraphia, while others were on the usual side, eg, left-handed anomia. We discuss cerebral dominance for speech and handedness in left-handers and come to the conclusion that our patient's clinical features can only be explained by right hemispheric dominance for handedness and bilateral hemispheric representation of speech.
We describe a patient with left unilateral ideomotor apraxia without left-sided agraphia caused by a callosal lesion that was demonstrated by magnetic resonance imaging. The clinical features, together with data in the literature, suggest that the callosal fibers for writing are concentrated in the posterior corpus callosum, while those for praxis cross in the more rostral part of the posterior half of the callosum.
Twenty-one patients with right hemisphere damage were studied (11 men, 10 women; average age = 41.33; age range 19-65). Subjects were divided into two groups: pre-Rolandic (6) and retro-Rolandic (15) right hemisphere damaged patients. A special writing test was given to each patient. The writing errors observed included literal substitutions, feature omissions and additions, letter omissions and additions, inability to maintain horizontal writing, inappropriate grouping and fragmentation of elements, and changes in handwriting style. Associated disorders included left-hemiparesis, visual field defects, spatial hemi-neglect, constructional apraxia, spatial alexia, and spatial acalculia. It is proposed that spatial agraphia is related to: (1) left hemi-neglect, (2) constructional deficits, (3) general spatial defects, and (4) some motor disautomatization and tendency to perseverate. In cases of right frontal damage, motor-associated deficits (iterations of features and letters) predominated, whereas in cases of posterior right hemisphere damage, spatial defects (inappropriate distribution of written material in the space, grouping of letters belonging to different words, and splitting of words) were more evident. Writing impairments are in general more noticeable in cases of retro-Rolandic damage.
Two cases, one with probable Pick's disease and one with herpes simplex encephalitis, are presented, focusing on Gogi (word-meaning) aphasia-like syndrome as their salient clinical feature. Their aphasic symptoms were characterized by impaired kanji processing and preserved kana processing in writing and oral reading known as a defining feature of Gogi aphasia, but little evidence of so-called "phonetic use of kanji in writing" and "confusion between on- and kun-readings of kanji in oral reading" often observed in Gogi aphasia. Systematic neuropsychological test batteries administered to them showed that the selective impairment of kanji processing did not always arise from a disturbance of a specific ability known to be essential to Gogi aphasia (i.e., failure in comprehending the semantic content of spoken and written language), but rather from an amnestic disruption in the ability to access the correct orthographic and phonological forms of kanji words. This selective impairment of kanji processing may be compatible with "alexia with agraphia of kanji," recently known to be attributable to left posterotemporal lesions. These results suggest that Gogi aphasia (or similar syndromes) is not necessarily a real syndrome but a polytypic constellation of symptoms.
This study was conducted to delineate the pattern of the writing impairments in 12 patients with Alzheimer type dementia. The patients performed writing tasks involving regular and irregular words and nonwords given by dictation as well as a decision test composed of printed words and pictures requiring phonologic, lexical, and semantic processing. Writing from dictation demonstrated a predominant, but nonisolated, lexical deficit. In order to better evaluate this lexical disorder, the correlation between the dictation writing scores and the decision task scores was analyzed. No significant correlation was found among scores for irregular words, phonologically plausible errors, and scores of the lexical or semantic decision tasks, but there was a significant correlation among scores for the nonwords, nonphonological spelling errors, and scores of the phonologic decision task using printed words. These results would suggest that the "lexical" deficit in agraphia, i.e., difficulty in retrieval or loss of the spelling representations of words, is independent of the lexical or semantic capacities involved in other modalities.
Four patients with alexia without agraphia had CT lesions which correlated with the clinical findings. All lesions were vascular; two were spontaneous intracerebral hematomas and two were ischemic infarctions in the posterior cerebral artery distribution. The lesions were located in the posterior portion of the dominant hemisphere. The location of the lesion correlated with the presence or absence of visual field abnormalities.
Two new cases of alexia without agraphia are presented. Pertinent clinical findings, anatomy, pathophysiology and differential diagnoses are reviewed. The importance of carefully examining the inferior portion of the left side of the splenium of the corpus callosum on CT and/or MR scans in patients who present with this clinical syndrome is stressed.
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.
Most right-handed crossed aphasics are not apractic. They usually have agraphia characterized by misspellings but retain the ability to write well-formed graphemes. We describe a right-handed patient with a right parietal lesion who was aphasic and not apractic. He was unable to write any formed graphemes despite a relatively preserved ability to spell aloud. We postulate that praxis and writing are dissociated in this patient because the motor engrams for praxis were located in his left hemisphere and the engrams for writing were in his right hemisphere. In addition, he comprehended commands for limb motor activities (praxis) far better than he comprehended other speech. This suggests that in this patient the areas used to comprehend limb motor commands may be anatomically distinct from areas important in comprehending other aspects of speech.
We report the case of a left-handed man (MCR), who presented with a peripheral agraphia as an early sign of multiple sclerosis. His left-handed writing was neologistic, whilst oral spelling, typing and spelling with the right hand were intact. Structural MRI scanning revealed a lesion of the body of the corpus callosum. Dichotic listening tests indicated that MCR displayed left hemisphere dominance for language. It is proposed that MCR represents a case of a disconnection syndrome in which right hemisphere systems that provide the basis for movement templates during left-handed writing are isolated from left hemisphere language systems. Analysis of left-handed writing indicated that peripheral movement control was highly structured with both individual letter frequency and sequential dependencies between letters represented within these motor control units. This case represents an opportunity to explore the mechanisms of movement control for writing and to examine the characteristics of isolated letter templates.