1/19. Selective uppercase dysgraphia with loss of visual imagery of letter forms: a window on the organization of graphomotor patterns.We report a patient who, after a left parieto-occipital lesion, showed alexia and selective dysgraphia for uppercase letters. He showed preserved oral spelling, associated with handwriting impairment in all written production; spontaneous writing, writing to dictation, real words, pseudowords, and single letters were affected. The great majority of errors were well-formed letter substitutions: most of them were located on the first position of each word, which the patient always wrote in uppercase (as he used to do before his illness). The patient also showed a complete inability to access the visual representation of letters. As demonstrated by a stroke segmentation analysis, letter substitutions followed a rule of graphomotor similarity. We propose that the patient's impairment was at the stage where selection of the specific graphomotor pattern for each letter is made and that the apparent selective disruption of capital case was due to a greater stroke similarity among letters belonging to the same case. We conclude that a visual format is necessary neither for spelling nor for handwriting.- - - - - - - - - - ranking = 1keywords = dysgraphia (Clic here for more details about this article) |
2/19. Visuographemic alexia: a new form of a peripheral acquired dyslexia.We report a single-case study of peripherally acquired dyslexia that meets the clinical criteria of "alexia without agraphia." The patient, AA, has a large infarct involving the left posterior cerebral artery. The most striking feature is a severe impairment in recognizing single visually presented letters that precludes explicit or implicit access to reading, even in a letter-by-letter fashion. AA can, however, differentiate letters from similar nonsense characters and digits, and he is also able to identify alphanumeric signs when the visual channel is bypassed (through somesthesic or kinesthesic presentation). Spelling tasks are also well performed. Since there is a breakdown in mapping a visually presented letter to its abstract graphemic representation, we propose the term "visuographemic alexia" for this kind of reading disorder. The pattern of deficits is interpreted following theoretical models previously developed in cognitive neuropsychology. An alexia for arabic numerals with preserved comprehension lends additional support for the crucial processing of different notational systems (e.g., phonographic vs logographic). More general perceptive disorders do not seem to account for these patterns; they are material-specific. Finally, we attempt to specify functional correlations with the implied neural networks.- - - - - - - - - - ranking = 0.065019471013346keywords = agraphia (Clic here for more details about this article) |
3/19. Alexia without agraphia: a century later.A case of alexia without agraphia is presented. It is a rare but classic disconnection syndrome, first described by Dejerine in 1892. Recent advances in modern neuroimaging techniques such as FLAIR MRI can now localise in vivo the site of origin of the syndrome, especially when computerised axial tomogram of the brain is normal.- - - - - - - - - - ranking = 0.32509735506673keywords = agraphia (Clic here for more details about this article) |
4/19. Word-centred neglect dyslexia: evidence from a new case.Neglect dyslexia resulting from damage to word-centred representations is extremely rare. We report on a new case. A left-handed subject, SVE, presented with aphasia and neglect dyslexia/dysgraphia following a right hemisphere stroke. In tachistoscopic reading tasks, some of his errors resulted from retina-centred neglect, as he responded more accurately to words flashed in the left visual field than to words flashed in the right visual field. However, the critical aspects of his reading performance indicated word-centred neglect. SVE incorrectly produced the initial elements of four-letter words, regardless of stimulus location (to the left and to the right of fixation, or at fixation), and orientation (horizontal and vertical presentation). A similar distribution of errors was demonstrated in writing (very inaccurate performance on initial letters). This pattern of performance suggests damage to an abstract letter string representation defined by spatial coordinates, rather than to an ordering mechanism. It is most naturally accommodated by models of word recognition which assume a word-centred level of representation, and cannot be explained by models which do not include such a representational level. Consideration of our subject in the light of other similar reports prompts hypotheses on the neural mechanisms involved in computing word-centred representations.- - - - - - - - - - ranking = 0.2keywords = dysgraphia (Clic here for more details about this article) |
5/19. Hanja alexia with agraphia after left posterior inferior temporal lobe infarction: a case study.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.- - - - - - - - - - ranking = 0.39011682608008keywords = agraphia (Clic here for more details about this article) |
6/19. Cognitive presentation of multiple sclerosis: evidence for a cortical variant.BACKGROUND: Although neuropsychiatric complications are well recognised, the presentation of multiple sclerosis with cognitive or neuropsychiatric symptoms has generally been considered a rare occurrence and to reflect subcortical pathology. OBJECTIVES: To document the clinical, neuropsychological, and radiological features of six cases of cognitive presentation of multiple sclerosis, to review the relevant literature, and to propose a possible cortical basis for this clinical presentation. SUBJECTS: Six patients (five women; age range 38 to 60 years) presented to the memory and cognitive disorders clinic in Cambridge with an initially undiagnosed cognitive/neuropsychiatric syndrome. All underwent neuropsychological evaluation, brain imaging, and ancillary investigations to establish a diagnosis of multiple sclerosis. RESULTS: The six cases all had a progressive dementia syndrome with prominent amnesia, often accompanied by classic cortical features including dysphasia, dysgraphia, or dyslexia. Mood disturbance was ubiquitous and in three patients there was a long history of preceding severe depression. All six developed characteristic physical signs on follow up, with marked disabilities. A review of 17 previously reported cases highlighted the prominence of memory impairment and depression in the early stages. CONCLUSIONS: On clinical, pathological, and radiological grounds, the neuropsychiatric presentation of multiple sclerosis may represent a clinicopathological entity of "cortical multiple sclerosis." Failure to recognise this will delay diagnosis and may expose patients to potentially dangerous and invasive investigation. Because the neuropsychiatric features of cortical multiple sclerosis are a major cause of handicap, their early recognition may be particularly important in view of emerging treatments.- - - - - - - - - - ranking = 0.2keywords = dysgraphia (Clic here for more details about this article) |
7/19. Musical alexia for rhythm notation: a discrepancy between pitch and rhythm.In the process of reading music, the reading of rhythm and pitch might be differentiated, although there is no evidence of this to date. There have been cases of disorders restricted to the reading of pitch, but none in which the disorder has been restricted to the reading of rhythm. We present a case of musical alexia and agraphia with Wernicke's aphasia. An in-depth assessment of the subject's musical reading ability showed that her musical alexia was restricted to unfamiliar melodies. When a melody was divided into rhythm elements and pitch elements, pitch reading was preserved, but rhythm reading was severely disturbed. This is the first case reported of a disorder restricted to rhythm reading, and suggests the independence of rhythm reading and pitch reading.- - - - - - - - - - ranking = 0.065019471013346keywords = agraphia (Clic here for more details about this article) |
8/19. Developmental surface dyslexia and dysgraphia: an orthographic processing impairment.This study presents a detailed investigation of a young man in his early twenties who has suffered from a severe spelling impairment since childhood, and currently has a spelling age of only 9 years and 2 months. In contrast with the developmental phonological dyslexics reported by Campbell and Butterworth (1985) and Funnell and Davison (1989), his performance on tests of phonological awareness is good. In addition, he can read and spell non-words competently and, unlike normal 9-year-old children, virtually all of his spelling errors are phonologically appropriate. Further analysis of these errors reveals that he has knowledge of many of the different ways in which a given phoneme can be written, and that he uses phoneme-to-grapheme correspondences at the end of a word that are different from those he uses earlier in a word. However, he finds it difficult to spell words that contain uncommon phoneme-to-grapheme correspondences, which is compatible with the view that he has not developed an orthographic spelling lexicon. Although his oral reading of words is prompt and generally accurate, analysis of his lexical decision performance and the way that he defines homophones indicate that he does not have fully specified lexical entries available for reading either. We suggest that he suffers from a general orthographic processing deficit, and relies instead upon the combination of sub-lexical phonology and a lexicon that contains only partial information about the way in which words are spelt. This leads to reasonably competent reading, even of many irregular words, but produces very poor spelling. It is argued that qualitatively different types of developmental dyslexia do genuinely exist, but that reading impairments are likely to be much more pronounced in children who have a phonological rather than an orthographic processing deficit.- - - - - - - - - - ranking = 0.8keywords = dysgraphia (Clic here for more details about this article) |
9/19. Cognitive and neural mechanisms underlying reading and naming: evidence from letter-by-letter reading and optic aphasia.We report detailed analysis of language performance in a patient, RMI, a 55-year-old man who presented with a homonymous hemianopsia, optic aphasia, and alexia without agraphia (with letter-by-letter reading) acutely after stroke. MRI showed infarct in the left occipital and medial temporal lobe and hypoperfusion of the entire posterior cerebral artery territory, including the splenium. Extensive language testing revealed severely impaired picture naming and oral reading, with relatively spared tactile naming and recognition of orally spelled words, consistent with impaired access to lexical and semantic representations from vision. In addition, he had a milder deficit in accessing lexical representations for output from all input modalities. RMI's execution of various language tasks provided considerable insight into the mechanisms that underlie oral reading. His performance indicated that both semantic access and orthographic to phonologic conversion mechanisms were partially intact. When information from these two impoverished systems was coupled (the picture of an object presented with its written name), his ability to read/name improved significantly, consistent with the hypothesis that partially accessed semantic information from vision can combine with partially accessed sublexical orthographic to phonologic conversion mechanisms to access phonological representations for output. Furthermore, his written word and picture recognition improved to normal at a time when magnetic resonance perfusion imaging demonstrated reperfusion of the splenium. We interpret these results, as well as results from previous studies in the literature, within a model of the neural regions critical for various cognitive processes underlying reading.- - - - - - - - - - ranking = 0.065019471013346keywords = agraphia (Clic here for more details about this article) |
10/19. letter-by-letter reading: natural recovery and response to treatment.The present investigation provides a longitudinal study of an individual (RB) with acquired alexia following left posterior cerebral artery stroke. At initial testing, RB exhibited acquired alexia characterized by letter-by-letter (LBL) reading, mild anomic aphasia, and acquired agraphia. Repeated measures of reading accuracy and rate were collected for single words and text over the course of one year, along with probes of naming and spelling abilities. Improvements associated with natural recovery (i.e., without treatment) were documented up to the fourth month post onset, when text reading appeared to be relatively stable. Multiple oral reading (MOR) treatment was initiated at 22 weeks post-stroke, and additional improvements in reading rate and accuracy for text were documented that were greater than those expected on the basis of spontaneous recovery alone. Over the course of one year, reading reaction times for single words improved, and the word-length effect that is the hallmark of LBL reading diminished. RB's response to treatment supports the therapeutic value of MOR treatment to in LBL readers. His residual impairment of reading and spelling one-year post stroke raised the question as to whether further progress was impeded by degraded orthographic knowledge.- - - - - - - - - - ranking = 0.065019471013346keywords = agraphia (Clic here for more details about this article) |
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