1/13. 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 = handwriting (Clic here for more details about this article) |
2/13. When writing 0 (zero) is easier than writing O (o): a neuropsychological case study of agraphia.Though a few case studies reported a dissociation between intact writing of Arabic and impaired writing of alphabetical script, a detailed experimental analysis of such a dissociation is still lacking. We report a follow-up study of a patient with a parieto-occipital lesion who is affected by severe peripheral agraphia for letters, but not for Arabic digits. While letters in writing to dictation are frequently illegible, distorted, or consist in meaningless strokes, Arabic digits are well-formed and fluently produced. In a series of tasks, including copying of letters with tachistoscopic presentation and handwriting on a digitizing tablet, several processing levels are assessed in order to localize JS' functional writing impairment and to determine different processing routes for letters and for numbers. overall, the results of the experimental investigation suggest a notation specific deficit in the activation of graphomotor patterns for letters, but not for digits. The study thus adds evidence to the so far reported dissociations between Arabic and alphabetical scripts.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
3/13. Acquired epileptic dysgraphia: a longitudinal study.A male presenting with benign partial epilepsy with rolandic spikes from the age of 7 years was evaluated at age 11 years for worsening of his epilepsy associated with a specific regression of graphomotor skills. A longitudinal study over nearly 2 years showed an improvement in handwriting to an almost normal level under modified antiepileptic therapy. A detailed analysis with a computer-monitored graphics table showed at first a rapid improvement of skills followed by protracted slower progress. We argue that the initial rapid recovery of skills was directly linked to the improvement of his epilepsy. The slower late acquisition of motor programmes that had never been fully established was due to long-standing interference by his epilepsy. The specificity of the deficit within the graphomotor system and its possible neurobiological basis are also discussed. The analytical method and approach used in a single patient might provide an example for other patients in whom epilepsy can interfere in the acquisition, progress, and maintenance of new skills and can be responsible for selective deficits.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
4/13. Influence of motor disorders on the visual perception of human movements in a case of peripheral dysgraphia.We report the case of a 71 year-old female patient (DC) with a left parietal lesion resulting in a peripheral dysgraphia essentially characterized by difficulties in letter sequences writing. The aim of our experiments was to analyze the influence of motor difficulties on the visual perception of both writing and reaching movements. Results showed a strong link between motor and perceptual performance. For reaching movements, performances in both production and perception tasks conform to the motor principles identified in healthy subjects (Fitts' law and motor anticipation).By contrast, for handwriting movements, DC's productions do not follow the motor principles usually observed in normal subjects (isochrony principle, motor anticipation) and in perception the same results were observed. The motor references used by DC in the visual perception of writing movement were not the laws of movement but rather her own way of writing. Taken together these data strongly suggest that motor competences is involved in the visual perception of human movements. They are discussed in the general framework of the simulation theory.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
5/13. Prism adaptation improves spatial dysgraphia following right brain damage.Visuo-manual adaptation to prisms produces a long-lasting improvement of visuo-spatial neglect. Improvement is also observed in tasks that do not involve visuo-manual component and that can all be consider to rely on a rightward (ipsilesional) orienting bias. Here, we report positive effects of prism adaptation on spatial dysgraphia, in a neglect patient following right brain damage. A long-lasting improvement concerned the right-page preference reflecting the ipsilesional bias but also the sloping lines and the broken lines reflecting visuo-constructive disorders in handwriting. Moreover, a transient improvement was also evidenced for the graphic errors. These results reinforce the idea that the process of prism adaptation may activate brain functions related to multisensory integration and higher spatial representations and show a generalization at a functional level. Prism adaptation therefore appears as useful tool in the theoretical attempt to identify the underlying 'core' mechanisms of the neglect syndrome.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
6/13. Hand motor patterns after the correction of left-nondominant-hand mirror writing.In a previous report, the author studied a left-nondominant-hand mirror writer, postulating that her mirror writing resulted from the failure to reverse the right-hand writing motor patterns when transmitted from the left to the right cerebral hemisphere. In this study, the patient was asked to write in normal fashion with the left hand; the result was a mixture of handwriting motor patterns which included normal letters, letters with reversed direction tracings, letters with one or more than one loop-tracings and illegible letters. The author considers this result to be a further support for the above-proposed hypothesis.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
7/13. Multiple component agraphia in a patient with atypical cerebral dominance: an error analysis.A 52-year-old man with atypical cerebral dominance (left-handed for writing but mixed handedness for other tasks) suffered an extensive right hemisphere stroke, resulting in a combination of deficits that has not been previously reported. There were profound visual constructive and visual perceptual disturbances and a spatial agraphia, which were consistent with a nondominant hemisphere lesion. There was also a severe apraxic agraphia, which is typically associated with a dominant hemisphere lesion, but no other signs of dominant hemisphere dysfunction such as linguistic disturbance or limb-motor apraxia were present. This case serves to highlight the functional and anatomical relationship between handwriting and other forms of praxis; the various sources of error in letter formation; the need to be specific in labeling and describing agraphias ; and the role of a detailed analysis of writing errors in delineating the neuropsychological processes involved in handwriting.- - - - - - - - - - ranking = 1keywords = handwriting (Clic here for more details about this article) |
8/13. Pure dysgraphia with relative sparing of lower-case writing.We describe the cognitive analysis of a patient with acquired pure dysgraphia. She presented a peculiar dissociation between lower- and upper-case handwriting: lower-case writing was relatively spared and showed a significant superiority of words versus nonwords. Upper-case writing and oral spelling did not show lexical effects, but were affected by item length. In all modalities errors consisted mainly of single graphemic substitutions, deletions, insertions and transpositions, resulting in legal or illegal nonwords, and showed a similar distribution across letter positions. These findings were suggestive of an impairment of the graphemic output buffer, which however revealed itself to different degrees in the two handwriting styles.- - - - - - - - - - ranking = 1keywords = handwriting (Clic here for more details about this article) |
9/13. Perseverative dysgraphia: a selective disorder in writing double letters.Models of writing processes postulate that abstract graphemic representations contain information about letter doubling independent of letter identity. We describe a patient, R.T., who made perseverative errors only in handwriting geminate letters, [e.g.: "CORTECCIA" (cortex)-->"CORTECCCIA"]. Perseveration was specific to orthography. To explain R.T.'s errors, we argue that after the selection of the correct graphic motor programs, the geminate feature induced a perseverative graphic behaviour. This form of dysgraphia supports the notion that graphemic representations contain specific information about letter doubling.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
10/13. Right unilateral agraphia following callosal infarction in a left-hander.A left-handed Japanese man is reported who presented right-hand agraphia and tactile anomia following callosal infarction. magnetic resonance imaging revealed an ischemic lesion extending from the posterior half of the trunk to the splenium of the corpus callosum. In his right handwriting, the 'Kana' (phonogram) was more severely impaired than the 'Kanji' (ideogram), and the most frequent typewriting error was morphological followed by neographism. His visuoconstructional ability was also more impaired in the right hand than in the left. Right-hand agraphia in our case is readily explained by the right hemisphere dominance both for language and visuoconstructional ability.- - - - - - - - - - ranking = 0.5keywords = handwriting (Clic here for more details about this article) |
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