Abstract
We reported a case with typing impairment and agraphia without aphasia, alexia, apraxia or construction impairment. The patient was a 69-year-old, right-handed male. Prior to cerebral infarction, the patient was skilled at typing and used the blind-touch typing technique, and his speed of typing was faster than writing.Almost all of his writing errors were errors in direction, length or location of pen-stroke lines, and there were no errors evidential of phonological or meaning disturbance. Such features suggest that his agraphia involved a disturbance in “kinesthetic image of writing.” Similarly, all of his typing errors were due to spatial errors in keying, i.e. miss-touching keys adjacent to the target. There were no errors evidential of phonological disturbances. These features suggest that his typing impairment involved a disturbance in “kinesthetic image of typing.” Two lesions were located: one in the left precentral gyrus, and the other in the left angular expanding to the superior and inferior parietal lobule, not including the posterior portion of the left second frontal gyrus, which is indicated as involved in the phonological process of writing. We consider that highly skilled typing and writing share common neural substrates, and in this case the damage to the region localized for writing simultaneously developed typing impairment.
