[The difference in writing disorders in primary agraphia and congenital dyslexia and their clinical relevance].
If after a brain injury reading and writing disturbances persist, the question is: primary agraphia or writing disorders due to dyslexia? If the anamnesis cannot answer this question, a decision is possible by means of four essential differences between writing disorders on the background of primary agraphia and those associated with dyslexia: 1. Agraphic persons correct their mistakes, dyslectics do not. 2. The word formations (paragraphias) due to primary agraphia do not bear close phonetical resemblances, whereas word formations by dyslectic persons are plainly phonetical. 3. Agraphics persevere, dyslectics do not. 4. In primary agraphia, the patient will also show difficulties in writing numbers; in a dyslectic disorder, he/she will not.