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 alex ia 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 s ingle letters were affected. The great majority of errors were well-formed letter substitutions: most of them were located on the first position of ea ch word, which the patient always wrote in uppercase las he used to do befo re 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 o f the specific graphomotor pattern for each letter is made and that the app arent selective disruption of capital case was due to a greater stroke simi larity among letters belonging to the same case. We conclude that a visual format is necessary neither for spelling nor for handwriting. (C) 2000 Acad emic Press.