[Spelling impairments. Neuropsychological study in two adolescents with developmental dysgraphia]

Two adolescents 14 and 16 years of age presented with isolated developmental agraphia. The spelling errors were correlated with the degree of orthographic ambiguity and with the word frequency as in acquired agraphia. Patients used to simplify the words spelling and to follow the phoneme-grapheme conversion. The deficit is interpreted as a failure of a selective visual memory for irregular words, representing a developmental graphemic logogene impairment. The better performance of reading is interpreted in relation to phonological system integrity which could better supply the grapheme phoneme conversion of reading even for irregular words. The ambiguous and irregular words recognition during reading appeared easier than their spelling during writing. Short term and working memory for irregular words appeared normal; the deficit occurred only for the long term recall after 20 minutes. Learning of 20 irregular words was made possible in one case by selective reminding of the errors. In spite of normal MRI, a developmental disorder involving the angular gyrus is proposed as for acquired lexical agraphia in adults.